California's Proposition 65Identifying Chemical Hazards for Regulation
California's Proposition 65Identifying Chemical Hazards for Regulation:The Scientific Basis and Regulatory Scope of California's Proposition 65 List of
Carcinogens and Reproductive Toxicants
William S. Pease*
Introduction
California's Proposition 65, the Safe Drinking Water and Toxic Enforcement Act
of 1986,1 has attracted considerable attention as an expression of "toxics
populism" and as a model for innovative reform of chemical regulation.
Reflecting widespread public concern that "current toxic laws aren't tough
enough,"2 the initiative statute established a new incentive structure for
toxics regulation in an attempt to end the regulatory paralysis affecting
conventional approaches to hazard identification, risk assessment and
enforcement.3
Proposition 65 shifts the burden of proof in the regulatory process from
government to industry. Use of chemicals known to cause cancer or reproductive
toxicity is no longer considered "innocent" until proven "guilty" of harming
public health by governmental agencies. Identified hazards are placed on a list
and automatically become subject to the Act's warning requirements (12 months
after listing) and discharge prohibition (20 months after listing). Exemptions
from these requirements are allowed only if the business responsible for an
exposure or discharge can demonstrate that the amount of chemical in question
poses "no significant risk." Consequently, businesses have an economic incentive
to avoid using listed chemicals or to keep exposures and discharges below levels
that would pose any significant health risk. Both businesses and government also
have a legal incentive to reach agreement quickly on the regulatory levels
governing exemption from the law.
This paper focuses on Proposition 65's approach to reforming the hazard
identification component of traditional toxic chemical regulation. The
environmental organizations promoting the initiative were concerned that no
federal regulatory agency had taken action on more than one-third of the
chemicals which had tested positive for carcinogenicity in National Toxicology
Program bioassays.4 Even less regulatory attention had been given to
reproductive toxicants.5 In an effort to forestall prolonged procedural debates
over whether specific substances deserved regulation, Proposition 65 applies
automatically to all substances that have been identified as carcinogens or
reproductive toxicants by certain authoritative scientific or regulatory
organizations. By requiring regulation once scientists reach consensus that a
substance is a hazard, this approach immediately extends the scope of existing
controls and ensures that the regulatory process does not lag behind scientific
awareness of chemical hazards.
The "regulate upon identification" approach represents an effective means for
increasing and accelerating the regulatory coverage of known hazards, but it
also involves three major unforeseen consequences that deserve analysis before
similar reforms of other environmental statutes are considered:
First, the approach shifts the focus of political debate from establishing
standards to identifying substances for regulation. Because only listed
chemicals are affected by Proposition 65, hazard identification has become a
principal arena of controversy between competing interest groups. Political
concerns about regulatory impact have shaped the listing process and been
interjected into scientific deliberations about a substance's toxicological
characteristics, demonstrating how policy can influence science at even the
hazard identification level of risk regulation.
Second, the approach requires that various regulatory and scientific
organizations share a consensus about what constitutes sufficient evidence of
hazard if a list that combines their identification efforts is to be consistent.
Criteria for identification, however, can vary substantially across
organizations. Substances will be evaluated differently depending on whether an
organization is more concerned about preventing potential public health problems
or minimizing the economic impact of false positive identifications. If a
combined list reflects inconsistent criteria, regulatory resources may be
misallocated as substances posing substantially different degrees of hazard are
treated identically.
Third, the approach encourages judging regulatory performance by examining the
extent of regulatory coverage rather than the effectiveness of regulatory
controls. Proposition 65 emphasizes expanding its list of regulatory targets
whenever there is scientific consensus that a substance is a carcinogen or
reproductive toxicant. However, scientific considerations are not the only
relevant criteria for selecting regulatory targets. An effective program must
also consider whether there is significant human exposures to a substance and
whether application of regulatory requirements is likely to reduce health risks.
Extending regulatory coverage to more chemicals is attractive political
symbolism, but there are no public health benefits and potentially significant
administrative costs when targeted chemicals are neither in use nor susceptible
to regulatory control.
This paper explores these issues by examining the origin, scientific basis and
regulatory scope of the Proposition 65 list. As of January 1, 1992, the list
included 376 carcinogens and 127 reproductive toxicants.6 It represents the most
extensive compilation of potential human carcinogens available from any state,
national or international organization. Its list of reproductive toxicants is
unique; no other organization has undertaken a generic hazard identification
process for agents associated with male or female reproductive toxicity or
developmental toxicity. The Proposition 65 list is becoming an authoritative
source of hazard identification for a number of state and federal regulatory
programs.7
Part II reviews the history of the list's expansion to reveal how the political
context of Proposition 65 has influenced the use of scientific information in
the regulatory process. Part III analyzes the selection criteria and evidence
underlying the listing of chemicals to illustrate what tradeoffs are made
between increasing the number of regulatory targets and ensuring that regulation
is based on consistent evaluations of hazard. Part IV compares the uses of
listed chemicals and their coverage under existing federal environmental
statutes to provide a quantitative assessment of the regulatory scope of
Proposition 65. The conclusion assesses the costs and benefits of Proposition
65's approach to reforming conventional hazard identification and identifies
opportunities for improving the process of selecting targets for regulation.
The Origin and Expansion of the Proposition 65 List
Confronted with the poor record of federal regulatory action on potential human
carcinogens and reproductive toxicants, the proponents of Proposition 65 wanted
to guarantee that scientifically identified hazards were automatically
regulated. The law would apply to a list of agents "known to the State to cause
cancer or reproductive toxicity" established by California's Governor.8 To
redress the historical delays between hazard identification and regulation, this
list was to include at a minimum substances already identified as carcinogens by
the National Toxicology Program (NTP) and the International Agency for Research
on Cancer (IARC) and as reproductive toxicants by the Occupational Safety and
Health Administration (OSHA).9
To provide a scientific basis for additional listing decisions, California's
Governor is authorized to consult with the "State's qualified experts," who
determine if "it has been clearly shown through scientifically valid testing
according to generally accepted principles" that a chemical is a carcinogen or
reproductive toxicant. To ensure that hazard identifications conducted by other
groups were incorporated into the list, the State's experts are authorized to
designate regulatory agencies or scientific organizations they consider
"authoritative" on carcinogenesis or reproductive toxicity. Chemicals identified
by these bodies are automatically listed as known to the State to cause cancer
or reproductive toxicity. In addition, substances that are "formally required...
to be labeled or identified as causing cancer or reproductive toxicity" by other
state or federal agencies are also automatically added to the Governor's
Proposition 65 list.10
With these four methods of listing (the minimum list, nomination by the State's
experts, identification by an authoritative body or by regulatory labeling
requirements), proponents of Proposition 65 believed they had established an
approach to hazard identification that would quickly increase the universe of
chemicals affected by regulation. By emphasizing the role of scientific
consensus in listing decisions ("authoritative" experts using "generally
accepted principles"), environmentalists also hoped to preclude political
considerations from this phase of the regulatory process. Listing decisions were
exempted from the procedural constraints (like notice and comment requirements)
typically applied to regulatory action.11 Hazard identification was to take
place separately from working out the regulatory implications of listing.
Since Proposition 65's requirements apply automatically if a substance is
listed, however, opponents of regulation are lead by the law's structure to
express their economic and political concerns during the hazard identification
phase. Specific industries and businesses have attempted to prevent the listing
of commercially important compounds and the regulated community in general has
sought to restrict the scope of the law by slowing down the listing process.
Delaying the initial date of listing is attractive because it postpones
potentially costly compliance obligations.
During the first four years of Proposition 65 implementation, the regulated
community possessed a strong ally in California's Republican Governor, George
Deukmejian, who had vigorously opposed the initiative statute.12 Ignoring
California voters' determination that government agencies "have failed to
provide them with adequate protection" against toxic chemicals,13 the Deukmejian
Administration pursued an implementation strategy based on the premise that
existing environmental regulations are generally adequate.14 Believing that
Proposition 65 "should not break new ground,"15 the Administration sought to
minimize the impact of the law in a variety of ways. In the area of hazard
identification, the Administration attempted to restrict the number of chemicals
affected by the law and to limit efforts to identify new carcinogens or
reproductive toxicants that were not covered by existing regulations.
The creation of an administrative procedure for selecting, evaluating and
ultimately listing chemicals as carcinogens or reproductive toxicants occurred
within this political context. Proposition 65 includes several methods for
identifying chemical hazards, but it was left to the Administration to define
critical features of the listing process by regulation. A Scientific Advisory
Panel (SAP) of the "State's qualified experts" was created to advise the
Governor on listing decisions16 and to provide a forum for hazard identification
debates. Announcing its formation, Governor Deukmejian maintained that hazard
identification would not be politicized: "What we are doing is turning this
decision over to the scientists, to the experts.... It won't be politicians
making the decision. It won't be lobbyists for the business interest or
lobbyists for environmental interests."17
The Deukmejian Administration, however, retained the ultimate authority to make
listing decisions. It controlled both the membership and agenda of the SAP,18
selecting which chemicals the Panel would evaluate. Through regulations, it
specified the conditions under which hazard identifications made by
authoritative bodies are automatically added to the Proposition 65 list.19
Regulations also define how chemicals "formally required" to be labeled as
carcinogens or reproductive toxicants by other agencies are identified.20 The
final say on listing decisions was delegated to the California Health and
Welfare Agency (CHWA), the Governor's lead agency for implementing Proposition
65.21 By shaping the listing process, the Administration could influence both
the number and type of chemicals affected by Proposition 65's regulatory
requirements.
Delaying the Inevitable: How Identified Carcinogens
Were not Initially Incorporated into the Proposition 65 List
The first setback for environmentalist efforts to extend regulation to
unaddressed hazards occurred February 27, 1987, when Governor Deukmejian
announced that Proposition 65 applied to a short list of only 29 chemicals. This
list included 26 substances with sufficient evidence of carcinogenicity in
humans according to IARC or NTP and 3 chemicals identified by OSHA as
reproductive toxicants. Ignoring the "minimum" list of more than 250 chemicals
that was specifically referenced in the statute,22 the CHWA maintained that the
State was required to list only those chemicals known to cause cancer in humans,
and not all chemicals known to cause cancer in experimental animals and hence
suspected of being human carcinogens.
The Administration attempted to provide a scientific justification for its
political decision to restrict the list, but it quickly became known that the
CHWA had ignored the advice of its public health experts in the California
Department of Health Services23 (CDHS). Those experts argued unsuccessfully that
the Governor was "scientifically and ethically" required to apply Proposition 65
to the larger list of animal carcinogens and emphasized that "from its
perspective, the Department of Health Services does not believe human exposures
to known animal carcinogens to be in the best interest of public health."24
Environmentalists maintained that the Deukmejian Administration was placing
special interests above human health. Al Meyerhoff, an attorney for the Natural
Resources Defense Council, charged that chemical companies had influenced the
Governor to shorten the list and accomplished "through the back door what they
couldn't do at the polls."25 Joining with labor unions, proponents of
Proposition 65 promptly filed suit to expand the list and won the first round in
court. In April 1987, the Sacramento County Superior Court ordered the Governor
to add more than 200 chemicals to his initial list.26
The Deukmejian Administration continued to resist the automatic extension of
Proposition 65's requirements to all the substances identified as potential
human carcinogens by IARC and NTP. Pursuing a very effective strategy of delay,
the CHWA appealed the Court's decision and directed the Governor's SAP to
evaluate all the disputed compounds from the "minimum" list
substance-by-substance. The SAP obliged, reviewing the CHWA's "candidate" list
of carcinogens alphabetically and slowly recommending that they be added to the
Proposition 65 list.27 Through its control over the SAP's agenda, the
Administration ensured that the Panel spent its initial two years reviewing data
on chemicals that were already legally covered by Proposition 65 rather than
conducting de novo hazard identifications.
Throughout the political struggle over the size of the Proposition 65 list, the
Governor's expert advisors on the SAP approached their tasks from a
predominantly scientific perspective, questioning neither the Administration's
control of their agenda nor the legal ramifications of their review of the
"minimum" list. As scientists representing the different disciplines involved in
cancer and reproductive risk assessment, SAP members clearly preferred
conducting their own evaluations of toxicological data to simply accepting
hazard identifications by other organizations. The SAP's predisposition to
independent review facilitated the Administration's efforts to minimize the
impact of Proposition 65 listing methods that had been designed to accelerate
hazard identification.
By the time the Deukmejian Administration's position on the "short" list was
finally repudiated by the courts, the environmentalist's legal victory actually
had only a limited impact on the size of the Proposition 65 list. California's
Court of Appeal upheld the lower court's order to expand the Proposition 65 list
in July 1989, but by then about 90% of the chemicals at issue had already been
nominated by the SAP and placed on the list. The Administration's strategy of
delay had granted temporary regulatory reprieves of from 1 to 30 months for many
chemicals, as well as monopolized the agenda of the SAP. While the Court
emphasized that Proposition 65 directs the State and the SAP "to engage in a
diligent, thorough, and continuing search for additional chemicals which
evolving scientific knowledge demonstrates are subject to the Act,"28 the
Deukmejian Administration successfully frustrated new hazard identification
efforts through its control over the listing process.
Environmentalists believed chemical-by-chemical reviews were unnecessary if
substances had already been identified as carcinogens. One goal of Proposition
65 was to establish a listing process that automatically incorporated hazard
identifications by other scientific and regulatory organizations. To initiate
this process, the proponents of Proposition 65 petitioned the SAP to designate
EPA and other agencies as "authoritative" bodies; chemicals identified by these
agencies could then be added to the Governor's list without further review.
Concerned about losing their prerogative to make listing decisions, the SAP
decided not to recognize any authoritative bodies.29
To environmentalists, the SAP's refusal to designate authoritative bodies was
just another manifestation of the Administration's strategy of delaying full
implementation of Proposition 65.30 They challenged the policy in court,
charging the SAP with "arbitrarily failing to act" and "abuse of discretion,"
and won a summary judgment in April 1989.31 Confronted with the Court's order to
evaluate various organizations for designation as authoritative bodies, the SAP
subsequently agreed to accept hazard identification decisions made by EPA,32
IARC and NTP33 and the Food and Drug Administration (FDA) and the National
Institute of Occupational Safety and Health (NIOSH).34
Policy concerns about the potential regulatory impact of Proposition 65 have
clearly shaped the role of independent scientific review in the listing process.
In order to prevent Proposition 65 from applying immediately to hundreds of
chemicals that had been identified as carcinogens by 1987, the Deukmejian
Administration initially insisted that the SAP reevaluate each chemical
individually. After the adverse court decisions of 1989, this policy shifted as
the Administration sought to ensure its control over the listing process. Once
it became inevitable that the Proposition 65 list would include virtually all
the chemicals that have been identified as carcinogens by other authoritative
agencies, further Administration efforts to restrain growth of the list focused
on discouraging de novo hazard identification by the Panel.
CHWA informed the SAP in late 1989 that evaluating data on chemicals that were
identified as carcinogens by other authoritative bodies was unnecessary.35 Using
its control over the SAP agenda, the Administration effectively eliminated
further carcinogen identification efforts by the Panel. No resources were
allocated to identifying chemicals that had bioassay data but remained
unevaluated by other groups; panel discussions were redirected to risk
assessment issues. While the Proposition 65 list has slowly grown to include the
results of most existing carcinogen identification efforts, the listing method
that environmentalists expected to make new contributions to hazard
identification has proven to be a disappointment: The SAP has been responsible
for identifying only one of 117 carcinogens listed between October 1989 and
January 1992.36
Searching for Authority:
Bases for Identifying Reproductive Toxicants
Proposition 65's mandate to regulate reproductive toxicants presents a
significant challenge to conventional approaches to hazard identification.
Reproductive endpoints like developmental toxicity and male or female
reproductive toxicity have not been the focus of chemical testing programs and
have rarely served as the basis for regulation.37 In contrast to the situation
with carcinogens, no scientific or regulatory agencies have compiled lists of
known reproductive toxicants. With reproductive toxicants, the reform sought by
the proponents of Proposition 65 transcended establishing legal mechanisms for
extending regulatory coverage automatically to hazards identified by other
authorities. Success would require the creation of both a scientific consensus
on how to define reproductive hazards and a review process that could
systematically evaluate data and identify substances for listing.
Listing reproductive toxicants was initially a major focus of the SAP. With CDHS
staff support, the SAP added ten chemicals to the Governor's initial list of
three reproductive toxicants by July 1987, formed a Subpanel on Reproductive
Toxicity and developed a priority list for future nominations.38 The first
compounds to be identified were either drugs (like diethylstilbestrol and
thalidomide) or environmental contaminants (like methyl mercury) with extensive
human evidence of reproductive harm.
The SAP's ability to reach agreement quickly on hazard identification decisions
eroded once it finished reviewing data on textbook reproductive toxicants. To
guide their assessment of substances with limited human evidence or just animal
evidence, Panel members decided to "develop guidelines criteria used for
identifying teratogens or reproductive toxicants."39 The SAP had confronted a
similar need for carcinogen identification guidelines, but it had decided to
"recognize the work that's already been done in the field without reinventing
it"40 and use existing EPA guidelines. Apparently unaware that there were
comparable EPA guidelines for reproductive hazard identification,41 the SAP
suspended listing activities and began developing its own guidelines.
Shaping the criteria for listing became a major focus of all parties interested
in the regulatory impact of Proposition 65.42 The effort to initiate a generic
process for identifying reproductive toxicants occurred in an even more
politically charged context than carcinogen identification. While many listed
carcinogens are already regulated under other environmental laws, identifying
reproductive toxicants under Proposition 65 promised to subject a previously
unaddressed class of toxic compounds to stringent new requirements. The law's
proponents encouraged the SAP to adopt guidelines that were consistent with
EPA's approach and quickly return to evaluating chemicals for listing.
Concerned that thousands of chemicals have at least some evidence of
reproductive toxicity, opponents of Proposition 65 sought to delay reproductive
hazard identification. They argued that the consequences of listing a substance
under Proposition 65 would be so severe (e.g., costly restrictions on chemical
use, inappropriate public response to warnings) that novel constraints needed to
be placed on established approaches to hazard identification. Represented by the
International Life Sciences Institute-Nutrition Foundation (ILSI), a group which
receives its support from food industry corporations, opponents maintained that
current federal guidelines on reproductive toxicity needed to be significantly
modified. ILSI's own "expert committees" proposed hazard identification
criteria43 which narrowly defined reproductive toxicity, restricted the types of
evidence considered sufficient for listing and generally limited the number of
chemicals likely to be affected by Proposition 65.44
In such a contested debate, the Reproductive Subpanel's effort to develop its
own approach to reproductive hazard identification collapsed as it sought to
base its policy decisions on existing scientific consensus. It ultimately
proposed criteria for identifying developmental toxicants45 that were
substantially equivalent to existing EPA guidelines.46 Plans to develop
independent criteria for identifying male and female reproductive toxicants
never materialized; the SAP criteria incorporate EPA female and male
reproductive toxicity guidelines by reference.47
Completion of the developmental toxicity guidelines in late 1988 appeared to
provide the SAP with the evaluation criteria it needed to address more difficult
listing decisions. Only two substances had been listed during the period of
guidelines development; both had substantial human evidence of reproductive
toxicity (ethyl alcohol in alcoholic beverages and tobacco smoke). During 1989,
the SAP identified 16 reproductive toxicants, including several industrial
chemicals with strong animal evidence but only limited human data (e.g., glycol
ethers).
This renewed listing activity was short-lived, however. As with carcinogens, the
Deukmejian Administration used its administrative control over the listing
process to discourage de novo hazard identification by the SAP and ensure that
new listings did not extend regulatory controls to unaddressed chemicals. The
Reproductive Subpanel that had been screening reproductive toxicants for the
full SAP was allowed to disintegrate by the CHWA.48 With no members who
participated in creating the consensus on hazard identification guidelines and
only one expert in reproductive toxicity, the full SAP now has only a limited
institutional capacity to identify reproductive hazards. The SAP has been
responsible for identifying only four of the 99 reproductive toxicants listed
between October 1989 and January 1992.49
The CHWA has largely taken over the listing process, acting to restrict listing
to those substances already regulated by other federal regulatory agencies as
reproductive toxicants. Unwilling to allow the SAP to make major new
contributions to reproductive hazard identification, the Administration has
sought out other "authoritative" sources for listing. It has relied most heavily
on labeling requirements established by FDA for prescription drugs, almost
doubling the Proposition 65 list of reproductive toxicants during 1990.50 As
with recently identified carcinogens, these listings have occurred
automatically, without any review by the SAP or reference to the SAP guidelines.
Because federal drug regulation is generally more stringent than Proposition 65
(and preempts state regulation as well), listed prescription drugs are generally
unaffected by Proposition 65's regulatory requirements. By focusing on listing
drugs, the Deukmejian Administration was able to appear as if it was extending
Proposition 65's coverage of reproductive toxicants without actually imposing
any new regulatory burdens on commercial interests.
Controlling Hazard Identification:
The Administrative Implementation of Environmental Reform
Proposition 65's "regulate upon identification" approach has not eliminated the
concerns about economic and political impact that have traditionally paralyzed
toxic chemical regulation. The State's approach to listing substances under
Proposition 65 has been primarily determined by concerns about regulatory impact
rather than by commitment to improving the hazard identification process. During
the Deukmejian Administration's implementation of the law, one principal
Proposition 65 reform (automatic extension of regulatory coverage to known
toxicants) was successfully delayed and another (establishment of an independent
chemical review process) was completely frustrated. The law's explicit mandate
to list carcinogens already identified by authoritative organizations was
ignored by the Deukmejian Administration. Over two years were required to extend
Proposition 65's regulatory requirements to the chemicals on its initial
"minimum" list.
While political opposition to accelerating regulatory coverage of known hazards
was eventually overcome, it has proven more difficult to create an
institutionalized source of de novo hazard identification. No independent
process for reviewing toxicological data and identifying new hazards has been
established. Using its control of the SAP's agenda and resources, the Deukmejian
Administration virtually eliminated the Panel's role in the Proposition 65
listing process.51 The SAP has considered listing only two carcinogens and five
reproductive toxicants since October 1989. Figure 1 shows the number of
chemicals evaluated for carcinogenicity and reproductive toxicity at each SAP
meeting since June 1987, revealing the dramatic decline over time of the Panel's
hazard identification efforts.
The State's administrative control over the Proposition 65 listing process has
had a much more substantial impact on the law's effort to extend regulatory
controls to reproductive toxicants than carcinogens. While the listing of many
carcinogens may have been delayed, it could not be completely prevented. For
reproductive toxicants, the absence of other authoritative hazard identification
programs allowed the State considerably more opportunity to limit Proposition
65's impact. By preventing the creation of an independent chemical review
process, the State ensured that the law's goal of instituting the first generic
regulatory program focused on reproductive toxicants would remain unfulfilled.
Figure 1
Number of Chemicals Evaluated at SAP Meetings [Omitted]
Scientific Consistency of the Proposition 65 List
The listing methods established by Proposition 65 intentionally combine hazard
identification efforts by various regulatory and scientific organizations, but
the law establishes no mechanism for ensuring that listing decisions are
supported by consistent evidence. Proposition 65 requires that SAP nominated
chemicals be "clearly shown through scientifically valid testing according to
generally accepted principles to cause cancer or reproductive toxicity,"52 but
provides no additional guidance on how strong evidence needs to be for listing.
The statute establishes no explicit requirements for chemicals listed as a
result of identification by authoritative bodies or regulatory labeling.53
Aiming to compile a list of regulatory targets quickly, proponents of the law
avoided attempting to define the amount of scientific evidence required to
justify preventive regulation.
The absence of guidance about what constitutes sufficient evidence for listing
has two potentially adverse consequences for the Proposition 65 hazard
identification process. First, to the extent that the combined list reflects
inconsistent criteria, regulatory resources may be misallocated as substances
posing substantially different degrees of hazard are treated identically.
Second, opportunities to introduce a double standard into listing decisions have
increased. The evidentiary threshold for listing commercially significant
substances can be higher than for unimportant substances. This section assesses
the consistency of evidence used to suppor listing by examining how substances
were identified as hazards. Methods of listing and sources for identification54
of carcinogens and reproductive toxicants are reviewed.
Carcinogens
Table 1 classifies listed Proposition 65 carcinogens by their method of listing
and by the agency responsible for their identification as carcinogens. As a
result of independent efforts, the SAP has identified 54 chemicals as
carcinogens.55 If one accepts the legal decision that a "minimum" list of 235
carcinogens was established by Proposition 65, it is clear that the vast
majority (85%) of carcinogens have been listed on the basis of hazard
identifications made by two authoritative scientific organizations, NTP and
IARC. Several regulatory agencies have also made contributions as authoritative
bodies: EPA, for example, is responsible for identifying most pesticides listed
as carcinogens. Very few chemicals have been listed as carcinogens on the basis
of regulatory labeling requirements.56
Table 1 Method of Hazard Identification: Carcinogens [Omitted]
Concerns about creating a list of carcinogens without consistent hazard
identification criteria were taken into account early in the listing process.
The SAP decided to rely on existing EPA carcinogen identification guidelines in
its evaluations.61 To address SAP concerns about the adequacy of chemical
evaluations conducted by authoritative bodies like NTP and IARC, the CHWA issued
regulations requiring that their hazard identifications meet defined criteria
for "sufficient evidence" in order for a chemical to be automatically listed.62
While there are differences between NTP's approach, IARC's strength of evidence
approach and EPA's weight of evidence approach,63 these authoritative bodies
share common definitions of what constitutes sufficient evidence for identifying
a chemical as a potential human carcinogen.64
Application of uniform identification criteria has created a list of chemicals
supported by relatively consistent evidence of carcinogenicity. Chemicals
identified by authoritative bodies using substantially different criteria than
EPA have been subjected to more intensive review by the CHWA before automatic
listing. FDA, for example, relies on expert committees working without uniform
guidelines to identify carcinogens. It has accepted single positive bioassays as
evidence of carcinogenicity and rarely publishes its identification decisions.
After CHWA review, only a portion of chemicals considered carcinogens by FDA
have been listed.65 Similarly, a number of commercially important agents
considered potential occupational carcinogens by NIOSH (e.g., asphalt fumes)
have not been listed automatically because of problems with formal documentation
or evidence.66
The State's effort to ensure that listed carcinogens meet its criteria for
sufficient scientific evidence has involved a significant tradeoff between
scientific consistency and extent of regulatory coverage. Because Proposition 65
establishes no evidentiary test for substances identified as a result of
labeling requirements, a large number of chemicals regulated in the workplace
have potential for listing. OSHA's Hazard Communication Standard requires that
industry provide workers with warnings on material safety data sheets about all
substances which have exhibited carcinogenic potential in one valid, positive
animal bioassay.67 Although these substances satisfy Proposition 65's procedural
criteria for automatic listing, many do not meet the State's sufficiency of
evidence test. Consistent with its policy of restricting the extent of
Proposition 65's coverage, CHWA has used its administrative discretion to avoid
listing so many potential occupational carcinogens.
Reproductive Toxicants68
Table 2 classifies listed Proposition 65 reproductive toxicants by their method
of listing and by the agency responsible for their identification as hazards.
Independent review by the SAP has identified 27% of listed reproductive
toxicants, double the Panel's de novo contribution to carcinogen identification.
The Panel has played a more important role because no scientific or regulatory
agencies have organized programs to identify reproductive toxicants. Just two
reproductive toxicants have been listed as a result of identification by
authoritative bodies: TCDD (by EPA) and nitrofurantoin (by NTP).
In contrast with carcinogens, most reproductive toxicants (72%) have been listed
automatically on the basis of regulatory labeling requirements. FDA prescription
drug labels account for 65% of the list; EPA and CDFA pesticide labels account
for 7% of the list.69 Among scientific and regulatory agencies, FDA has played
the predominant role in reproductive hazard identification because it has the
statutory authority to require that pharmaceutical manufacturers report adverse
effects from use of their products. The strongest evidence of reproductive
toxicity generally involves epidemiological studies of human high dose
exposures, but such exposures are regularly monitored only in therapeutic
settings. Since there is no mandatory surveillance of high dose exposures
occurring in the workplace, there is usually less human evidence of reproductive
toxicity for commercial chemicals.
Table 2
Method of Hazard Identification: Reproductive Toxicants [Omitted]
Listing decisions made by the SAP or on the basis of EPA labeling have generally
been supported by consistent evidence because of the similarity between SAP and
EPA guidelines for evaluating developmental, male and female reproductive
toxicants.70 Listing decisions based on FDA labeling, however, are frequently
not supported by similar types of evidence.71 Compared with the SAP or EPA, FDA
conducts hazard identification using a lower evidentiary threshold and a
different process. No uniform criteria guide FDA efforts to identify
reproductive toxicants.72 Suggestive case reports or chemical similarity may be
sufficient to justify providing patients and physicians with a warning about
potential adverse reproductive effects. The agency also considers tradeoffs
which are unique to therapeutic agents, placing drugs in pregnancy categories
based on the degree of risk to the fetus balanced against the drug's potential
benefits to a patient.73
By emphasizing hazard identification based on FDA drug labeling,74 the
Deukmejian Administration introduced a clear double standard into the
Proposition 65 list of reproductive toxicants. Therapeutic drugs (which are
unlikely to be affected by the law's regulatory requirements) have been listed
on the basis of limited animal studies or even membership in a chemical class.
Commercially significant substances, however, have only been listed if SAP or
EPA sufficiency of evidence criteria are met. Ironically, the lower threshold of
evidence for drugs originates in the FDA's health-conservative approach to
identifying potential reproductive toxicants. If the State were to consistently
apply such a preventive bias to the implementation of Proposition 65, a
significant number of industrial substances would be suitable for listing. Many
commercially significant substances that have been reviewed possess evidence of
reproductive toxicity that is comparable to that supporting the listing of many
therapeutic drugs.75
Regulatory Scope of the Proposition 65 List
Proposition 65's proponents accepted that the law could "not cover all
potentially harmful chemicals. It concentrates only on the known worst
offenders."76 The law's principal criterion for selecting regulatory targets is
whether there is a scientific consensus that a substance is a carcinogen or
reproductive toxicant. By creating a science-based list, environmentalists hoped
to eliminate political considerations about regulatory impact from hazard
identification debates. However, many substances with sufficient scientific
evidence of carcinogenicity or reproductive toxicity may not be suitable targets
for a regulatory program. Targeting substances which are not in commercial use
or which are not amenable to applicable controls may waste regulatory resources.
In addition to the strength of toxicological evidence, at least two criteria are
relevant to the identification of "known worst offenders" for a regulatory
program: a substance's potential for human exposure and its susceptibility to
regulatory control.
To examine whether Proposition 65's science-based approach has generated a
suitable list of regulatory targets, this section categorizes carcinogens and
reproductive toxicants by their type of use77 and by the extent to which they
are covered by existing federal pollution control regulation.78 In the absence
of data on the volume of use or on the extent of public exposure for the
majority of listed substances,79 the type of chemical use serves as the best
available indicator of potential exposure. Federal regulatory coverage of
classes of listed substances is then examined to assess whether Proposition 65
has extended controls to previously unaddressed but commercially significant
compounds.
Carcinogens
Three hundred and seventy-six agents are listed as carcinogens under Proposition
65. Table 3 classifies these into broad categories of chemical use. The
Proposition 65 list of carcinogens represents a reasonably broad sample from the
universe of chemicals. Two-fifths (43%) of listed carcinogens are industrial
substances; most are chemical intermediates used in manufacturing although some
are present in final consumer products. Therapeutic drugs and food constituents
each comprise an additional fifth of the list. Twenty-two percent of listed
agents are prescription drugs, particularly anti-neoplastic agents. Eighteen
percent are compounds that occur in food; about half of these are naturally
occurring or the result of preparation and half are synthetic additives or
environmental contaminants. Fifteen percent of listed chemicals are agricultural
chemicals, primarily pesticides. Ten percent are energy-related substances,
primarily combustion by-products, and 10% are laboratory research compounds. An
additional 10% are chemicals associated with various life style choices,
particularly smoking tobacco, drinking alcohol or using cosmetics. Two percent
of listed compounds are associated with the use of chlorine as a disinfectant in
water supplies or bleaching agent in industry.
Table 3
Types of Use of Listed Proposition 65 Compounds [Omitted]
Figure 2 indicates the percentage of listed carcinogens that are covered by
federal programs focused on controlling the quality of air, water, land or the
workplace. In general, identified carcinogens appear to be underregulated: the
vast majority of listed carcinogens are not covered under existing statutes
(Figure 2(a)).80 The extent of coverage increases if one examines the chemical
use classes which are targeted by conventional regulatory programs. Coverage
under most statutes increases for carcinogenic industrial substances (Figure
2(b)), agricultural chemicals (Figure 2(c)), energy-related substances (Figure
2(d)) and chlorination by-products (Figure 2(e)). Carcinogens that are outside
the traditional purview of environmental agencies, like laboratory research
compounds (Figure 2(f)), medicines (Figure 2(h)) and substances associated with
life style choices (Figure 2(i)) are less frequently addressed.81
Figure 2
Percentages of Listed Chemicals Covered by Federal Programs [Omitted]
Approximately half of listed Proposition 65 carcinogens may not be suitable
regulatory targets. At least 15% of listed carcinogens are no longer
commercially used in the U.S.; this includes about half of the listed
agricultural chemicals. An additional 30% of listed carcinogens have extremely
limited potential for widespread human exposure because their used is restricted
to medical or research settings. Listed drugs in particular are unlikely to be
discharged to drinking water and are exempt from Proposition 65 warning
requirements.
In spite of the inclusion of substantial proportions of irrelevant compounds,
Proposition 65 has clearly extended regulatory controls to a larger absolute
number of chemicals with the potential for widespread human exposure than any
federal statute. Its discharge ban, for example, affects four times more
carcinogenic industrial substances than are regulated under the Clean Water Act.
In additional, although significant proportions of listed industrial chemicals
are covered by major federal environmental statutes, these programs rarely
address exposures through consumer products, which are a principal focus of
Proposition 65's warning requirements.83
Reproductive Toxicants
One hundred and twenty-seven compounds are listed as developmental or
reproductive toxicants under Proposition 65. Table 3 also classifies these
compounds into broad categories of chemical use. In contrast to carcinogens, the
Proposition 65 list of reproductive toxicants is dominated by one type of
chemical use. The overwhelming majority (80%) of listed reproductive toxicants
are therapeutic drugs.84 All other chemical use classes represent about 10% or
less of the total list. Twelve percent are agricultural chemicals, 9% are
industrial substances, 6% are food constituents (all chlorinated hydrocarbon
environmental contaminants), 6% are associated with tobacco, alcohol or other
drugs, and 3% are energy-related substances.
Figure 2 illustrates the percentage of listed reproductive toxicants that are
covered by federal programs focused on controlling the quality of air, water,
land or the workplace. Reproductive toxicants appear to be addressed even less
frequently than carcinogens (Figure 2(a)), but this reflects the predominance of
listed drugs, which are rarely covered by major environmental statutes (Figure
2(h)). Focusing on the chemical use classes that have been the target of
conventional regulatory programs (Figure 2(b-e)), reproductive toxicants are
generally addressed as frequently or more frequently than listed carcinogens. It
is important to note that federal regulatory coverage rarely address exposures
through consumer products, a principal focus of Proposition 65's warning
requirements.85
The apparently extensive regulatory coverage is largely attributable to the
small number of substances in widespread commercial use that have been
identified as reproductive toxicants under Proposition 65. Just 12 chemicals
with industrial uses have been listed. Several ubiquitous environmental
contaminants (lead, mercury, PCBs, TCDD) have been historically important
regulatory targets. Four other commercially significant chemicals (carbon
disulfide, ethylene glycol monoethyl and monomethyl ether and toluene) have been
addressed by most environmental statutes. Just 15 agricultural chemicals have
been listed. Use of many of these pesticides has been virtually eliminated
(e.g., aminopterin, cyhexatin, DBCP, dinoseb, hexachlorobenzene, kepone,
warfarin).86 Only a few are widely used (e.g., benomyl, bromoxynil, cyanazine,
carbon disulfide, ethylene oxide).87
Most listed reproductive toxicants are not suitable regulatory targets for
Proposition 65. The drugs which dominate the list are already subject to more
stringent FDA regulation. While there is widespread exposure to a number of
drugs,88 usage is unlikely to be affected by Proposition 65's regulatory
requirements.89 Less than one-quarter of listed reproductive toxicants are
appropriate targets for regulatory provisions aimed at eliminating drinking
water contamination and reducing public exposure generally.
Conclusions
The Tradeoffs of List-Based Regulation
The size of the Proposition 65 list is itself an indication of the Act's
capacity to reform the status quo of toxics regulation. By ensuring that all
identified carcinogens and reproductive toxicants become subject to its
provisions almost automatically, Proposition 65 has precluded the
time-consuming, case-by-case debates which have plagued efforts to extend the
regulatory coverage of most federal laws. No other regulatory program is based
on such a large list of potential targets or has established as many regulatory
levels as quickly.90 Virtually the entire spectrum of political participants in
the Proposition 65 debate seem to agree that the Act has resulted in a far more
rapid assessment of carcinogens and reproductive toxicants than has occurred
under other state and federal legislation.91
The politically charged effort to create a list of regulatory targets inevitably
involves significant tradeoffs between extending regulatory coverage,
facilitating efficient regulation and ensuring scientific consistency.
Proposition 65's approach to hazard identification was designed to correct the
poor performance of traditional regulatory programs. Lists of Clean Water Act
(CWA) priority pollutants and Clean Air Act (CAA) hazardous air pollutants, for
example, are substantially shorter than the Proposition 65 list and clearly do
not address all commercially significant identified hazards. While these federal
lists exemplify substantial flaws in the existing hazard identification
process,92 they also reflect an effort to focus monitoring and control
requirements on just those chemicals which are likely to be discharged into an
environmental medium.
Compared with most environmental legislation, Proposition 65 strikes a different
balance between extent of coverage and applicability of regulatory requirements.
Rather than restrict its coverage to chemicals likely to be affected by its
provisions, it adopts an inclusive approach to hazard identification. To avoid
the political debates likely to accompany considerations of regulatory
relevance, the law specifies that sufficient scientific evidence is the only
appropriate criterion for selecting targets. As a consequence, about 45% of
listed carcinogens and 75% of listed reproductive toxicants are not
substantially affected by Proposition 65's warning requirements or discharge
ban. This regulatory irrelevance can occur because a substance has already been
banned (e.g., most listed pesticides), because it has no important commercial
use (e.g., laboratory research chemicals), because its use is controlled by more
stringent requirements (e.g., therapeutic drugs) or because its use cannot be
affected by Proposition 65 requirements (e.g., illegal drugs).
The extent of administrative inefficiency introduced by this inclusive approach
to hazard identification varies with the specific regulatory requirements of
Proposition 65. Restricting the application of its discharge ban to chemicals
likely to be released to drinking water would reduce monitoring requirements,
facilitate permitting activity and simplify enforcement.93 For Proposition 65's
warning requirements, there is less of a need to focus on a short list of
regulatory targets. The burden of providing warnings about exposures to listed
chemicals is not assigned to an administrative agency but is instead spread
among businesses which have better access to information about chemical use.
While compliance with Proposition 65's warning requirements could be better
assured if a regulatory agency monitored chemical exposures, the law provides
significant incentives for businesses to police themselves.
Important tradeoffs between coverage, efficiency and consistency have been
obscured throughout the Proposition 65 listing debate as parties have appealed
to science to justify their policy preferences. Environmentalists sought to
increase the number of substances subject to preventive regulation by
restricting listing decisions to scientific considerations: is there sufficient
evidence of hazard? is there a scientific consensus that a substance is a
hazard? The actual goal of this emphasis on science was not, however, to
guarantee that listed substances shared consistent evidence, but rather to
eliminate considerations of regulatory impact from the hazard identification
phase of risk regulation. By combining hazard identifications conducted by
different organizations without specifying a uniform threshold of sufficient
evidence, Proposition 65 values extending regulatory coverage over ensuring
scientific consistency. While this tradeoff has not had a major impact on listed
carcinogens, it allowed the State to introduce a double standard for identifying
developmental and reproductive toxicants. Substantial evidence of reproductive
toxicity (including both human and animal data) has been required to list
industrial substances, but much less evidence (including chemical similarity
alone) has been accepted as sufficient for listing drugs.
Opponents of Proposition 65 have also maintained that "science [should] be given
the preeminent role" in the implementation process.94 The regulated community
and the Deukmejian Administration sought to minimize the law's regulatory impact
by appealing to scientific considerations in order to delay hazard
identification. "Sound science" justified shortening the list to cover only
toxicants with human evidence and adopting substance-by-substance review
procedures. As with environmentalists, the Administration's emphasis on science
obscured the political balance it wanted to strike between regulatory coverage,
efficiency and consistency. To prevent the development of an extensive list of
new regulatory targets, listing was focused on substances unlikely to be
affected by Proposition 65's requirements and scientific concerns were
emphasized at the expense of accelerated hazard identification.
Recommendations to Improve the Proposition 65 Listing Process
Although the Proposition 65 list of carcinogens and reproductive toxicants has
now grown to include virtually all hazard identifications made by national and
international organizations, the Act's mandate "to engage in a diligent,
thorough, and continuing search for additional chemicals"95 remains unfulfilled.
Throughout the implementation of Proposition 65, the listing process has
exhibited only a limited capacity to select chemicals for evaluation based on
potential health risks or to evaluate chemicals not already identified as
hazards by other organizations.
The failure to establish an effective system for assessing unaddressed toxic
chemicals can be attributed to limitations in the Act's original statutory
scheme as well as to the State's administrative implementation of the law.
Proposition 65 itself does not mandate any procedure for selecting candidate
toxicants for listing.96 Its emphasis on scientific consensus helped shape a
listing process that selects candidate chemicals based on sufficiency of
evidence rather than on public health concerns.97 To prevent the law from
imposing new regulatory burdens on the business community, the Deukmejian
Administration limited the listing agenda to known hazards and continually
postponed prioritizing unassessed chemicals for evaluation by the SAP.98
Several recommendations can be made to improve future hazard identification
efforts:
* The State should support the creation of an independent chemical review
process that can make unique contributions to hazard identification. While the
Proposition 65 listing methods which ensure that the law automatically covers
hazards identified by other organizations have been implemented, the State has
not fulfilled Proposition 65's mandate to conduct de novo hazard identification.
There are two major sources of toxicological data on compounds that have not
been assessed by other authoritative organizations which could be evaluated:
public databases compiling bioassay results99 and regulatory agency files
containing premarket test results.100
* De novo hazard identification efforts should principally focus on evaluating
reproductive toxicants for listing under Proposition 65. While existing federal
programs have established a process to screen and test commercially significant
compounds and to identify potential carcinogens, no such effort is currently
focused on reproductive toxicants. Since new carcinogen identifications
conducted by authoritative bodies are automatically incorporated into the
Proposition 65 list, there are only a few remaining sources of carcinogenicity
data requiring evaluation (e.g., pesticide test results). In contrast, there are
significant opportunities to contribute to reproductive hazard identification
since these toxicants are generally unaddressed by existing state and federal
regulatory systems.101
* Chemicals selected as candidates for listing under Proposition 65 should be
prioritized for evaluation on the basis of potential for significant human
exposure and relevance of the regulatory control requirements of Proposition
65.102 It is imperative to develop more effective selection methods than
alphabetic order (previously used by the SAP with most IARC and NTP carcinogens)
or anecdotal scientific judgment (used by the SAP with its initial list of
reproductive toxicants). There are a number of sources of data on chemical use
and exposure which have not generally been used to guide the selection of
candidate chemicals.103 Early assessment of whether a chemical is likely to be
affected by Proposition 65's requirements can avoid wasting resources on listing
irrelevant substances (e.g., illegal drugs).
* The SAP's institutional capacity to conduct independent hazard identification
should be substantially strengthened. The SAP should be allowed control over its
own agenda and provided with sufficient resources to carry on de novo chemical
evaluations. Quarterly SAP meetings should be reinstituted to provide adequate
time for data reviews. To facilitate Proposition 65's unique mandate to identify
reproductive toxicants, the Subpanel on Reproductive Toxicity should be
reestablished.
* The SAP should address science policy questions associated with the
Proposition 65 listing process, but limit its consideration of risk assessment
or regulatory policy issues. Listing decisions are the only statutorily mandated
function of the Governor's "qualified experts" under Proposition 65. In the
past, the Panel's attention has been diverted to other issues in order to delay
the hazard identification process.104
One major outstanding hazard identification issue involves whether listing
decisions should emphasize scientific or regulatory consistency. Is it more
important to ensure that all listed substances are supported by consistent
scientific evidence or to ensure that all substances covered by a Proposition 65
listing method are listed? With carcinogens, the State has subjected substances
which could be identified on the basis of authoritative bodies or regulatory
labeling requirements to a sufficiency of evidence test and refused to list many
commercially significant compounds. With reproductive toxicants, the State has
avoided evaluating supporting evidence and listed many irrelevant therapeutic
compounds automatically because of FDA labeling requirements.
To encourage a more consistent approach to listing decisions, the SAP must
explicitly address the issue of what constitutes sufficient evidence to justify
preventive regulation under Proposition 65. The Panel can (a) reassert the
relatively high standard of evidence represented by current SAP hazard
identification criteria and insist that all procedurally-based listing decisions
be subjected to a sufficiency of evidence test; or (b) revise its standards to
accept that lesser amounts of evidence are sufficient to identify a substance as
"known to the State" to cause cancer or reproductive toxicity. Substances with
relatively limited evidence have been listed as a result of Proposition 65's
procedural requirements.105 The Panel must consider whether these listings have
established a new minimum threshold of evidence that should be applied in future
chemical evaluations. Given the preventive goals of Proposition 65, it may be
appropriate to extend its scope beyond traditional "known" toxicants to suspect
compounds with more limited evidence of hazard.106
Proposition 65 provides an interesting model for reforming hazard identification
in environmental regulation. It has successfully increased the number of
carcinogens and reproductive toxicants affected by regulatory requirements. Its
dramatic extension of regulatory coverage has occurred at the expense of both
regulatory relevance and scientific consistency. Moreover, political concerns
about automatically expanding the scope of regulation have prevented a major
effort to evaluate unassessed compounds. The State's failure to contribute many
new hazard identifications does not reflect a scientific determination that all
potential chemical carcinogens and reproductive hazards have been discovered,
but is rather a consequence of the political importance of listing under
Proposition 65. In the future, the challenge in implementing Proposition 65 will
involve establishing an effective process for selecting and evaluating new
compounds.
---
Notes
* Dr. Pease received his Ph.D. in Environmental Health Sciences from the
University of California at Berkeley. He is an environmental planner with the
San Francisco Bay Regional Water Quality Control Board, CalEPA.
1 CAL. HEALTH & SAFETY CODE (CH&SC) ch. 6.6, Secs. 25249.5 et seq. (West 1986).
2 I. REINER, BALLOT ARGUMENT IN FAVOR OF PROPOSITION 65 (1986).
3 Roe, Incentive-Conscious Approach to Toxic Chemical Control, 3 ECON. DEVEL. Q.
179-187 (1989).
4 OFFICE OF TECHNOLOGY ASSESSMENT (OTA), IDENTIFYING AND REGULATING CARCINOGENS
(1987).
5 GENERAL ACCOUNTING OFFICE (GAO), REPRODUCTIVE AND DEVELOPMENTAL TOXICANTS:
REGULATORY ACTIONS PROVIDE UNCERTAIN PROTECTION (1991).
6 Cal. Code of Regulations (CCR) tit. 22, Sec. 12000 (1992).
7 Pollution control laws which target chemicals identified as carcinogens or
reproductive toxicants under Proposition 65 have been introduced in a variety of
states. See e.g., H. 4618, Massachusetts Act to Provide Warnings of Significant
Health Risks from Toxic Chemicals (1990). Pending federal legislation to expand
the universe of chemicals covered by emissions reporting requirements also
incorporate the Proposition 65 list. See e.g., H.R. 2880, The Community
Right-to-Know More Act (1991).
8 CH&SC Sec. 25249.8.
9 CH&SC Sec. 25249.8(a).
10 CH&SC Sec. 25249.8(b).
11 CH&SC Sec. 25249.8(e).
12 The election of Republican Pete Wilson as Governor in 1990 may result in a
new approach to implementing Proposition 65. The law's incentive-based approach
is compatible with the Wilson Administration's interest in using market forces
rather than conventional command and control regulation to achieve environmental
goals. In addition, Proposition 65's focus on reducing unnecessary exposures to
toxic chemicals is consistent with the new Administration's emphasis on
preventing environmental and public health problems. P. WILSON, GOVERNOR'S
REORGANIZATION PLAN NUMBER ONE: CREATING THE CALIFORNIA ENVIRONMENTAL PROTECTION
AGENCY (1991).
13 CH&SC Sec. 25249.5 (preamble).
14 See W. Pease, Environmental Pollution and Cancer in California: Evaluating
the Significance of Risks under Proposition 65 (1988) (Masters Thesis, Energy
and Resources Group, University of California at Berkeley), a detailed
discussion of how State regulations issued to implement Proposition 65 generally
maintain compliance with applicable federal laws (e.g., governing pesticide
application, hazardous waste disposal or occupational hazard communication)
constitutes compliance with Proposition 65.
15 Statement by Thomas Warriner, Deputy Secretary of the California Health and
Welfare Agency, reported in The Sacremento Bee, Oct. 23, 1988. Warriner was the
Deukmejian Administration official responsible for implementing Proposition 65.
16 While Proposition 65 authorizes the Governor to consult with "qualified
experts" on listing decisions, CH&SC Sec. 25249.8(d), it does not require
formation of an advisory panel. The SAP was created by regulations, CCR Secs.
12302-12305, which specified its composition and basic duties. The Governor
retained complete control over the appointment and removal of Panel members and
asserted his "discretion to accept or reject [Panel] advice in implementing the
Act." CALIFORNIA HEALTH AND WELFARE AGENCY (CHWA), FINAL STATEMENT OF REASONS,
22 CODE OF CALIFORNIA REGULATIONS DIVISION 2, SAFE DRINKING WATER AND TOXIC
ENFORCEMENT ACT OF 1986 (1987).
The creation of scientific panels to advise regulatory agencies on controversial
issues is a common practice, although the independence, representativeness and
authority of such panels vary widely. S. JASANOFF, THE FIFTH BRANCH: SCIENCE
ADVISERS AS POLICYMAKERS (1990). For one legal analyst's perspective on whether
"Governor Deukmejian... actually stacked the Panel to promote his own political
outlook," see Shaffer, Improving California's Safe Drinking Water and Toxic
Enforcement Act Scientific Advisory Panel Through Regulatory Reform, 77 CAL. LAW
REV. 1211-1258 (1989).
17 Los Angeles Times, Mar. 13, 1987, at 30.
18 K. Shaffer, supra note 16.
19 CCR Sec. 12306.
20 CCR Sec. 12902.
21 Cal. Exec. Order D-61-87 (1987) (Gov. George Deukmejian). As a result of an
administrative reorganization of environmental agencies in California,
responsibility for Proposition 65 was shifted from the CHWA to a newly formed
California Environmental Protection Agency in July 1991. Cal. Exec. Order
W-15-91 (1991) (Gov. Pete Wilson).
22 CH&SC Sec. 25249.8(a).
23 Los Angeles Times, Mar. 17, 1987, at 3.
24 Memo from S. Book to Alex Kelter, Cal. Dept. of Health Services (Jan. 22,
1987) (discussing the use of animal carcinogens for the Proposition 65 list of
cancer causing chemicals).
25 Los Angeles Times, Feb. 28, 1987, at 1.
26 AFL-CIO v. Deukmejian, No. 348195 (Sacramento County Superior Court April 24,
1987).
27 Safe Drinking Water and Toxic Enforcement Act Scientific Advisory Panel (SAP)
members invited efforts to prioritize their evaluations on the basis of a
chemical's "inherently controversial nature, high public visibility.... [or
potential for] widespread human exposure in California." SAP, TRANSCRIPT OF
PUBLIC MEETING ON OCT. 30, 1987, at 11, 156 (Capitol Reporters 1987) (subsequent
references to SAP transcripts are cited only as SAP -- with date and page
number). When no schemes to rank chemicals by opportunity for exposure or
regulatory control were subsequently proposed, the SAP proceeded alphabetically
except for its consideration of alcohol and tobacco.
28 AFL-CIO v. Deukmejian, 212 Cal. App. 3d 425, 440 (1989).
29 SAP, Oct. 30, 1987, at 158.
30 San Francisco Chronicle, April 4, 1989, at 1.
31 AFL-CIO v. Deukmejian, No. 359223 (Sacramento County Superior Court June 22,
1988).
32 SAP, April 14, 1989.
33 SAP, Oct. 20, 1989.
34 SAP, April 6, 1990. The SAP declined to designate the American Council of
Governmental Industrial Hygienists as authoritative because the Panel was
unfamiliar with the ACGIH identification process. California regulatory agencies
were not designated as authoritative to avoid the appearance of conflict of
interest; both CDHS and the California Department of Food and Agriculture (CDFA)
are active in the regulatory implementation of Proposition 65.
35 The CHWA informed SAP members that "if the Panel identifies EPA, IARC, and
NTP as authoritative bodies for purposes of Proposition 65, there will be no
need to discuss the chemicals" identified by these organizations as carcinogens.
Letter from S. Book, CHWA, to SAP Members on Aug. 9, 1989.
36 The SAP has reviewed data on only two potential carcinogens since mid-1989.
It evaluated two pesticides at its April 1991 meeting, listing oxadiazon and
refusing to list tetrachlorvinphos. Neither substance was considered as a result
of de novo hazard identification efforts by the Panel. Oxadiazon had been
deferred from an earlier meeting, where it was brought to the Panel's attention
because it was on an EPA list of potential carcinogens. Tetrachlorvinphos had
also been deferred from an earlier meeting, where it was brought to the Panel's
attention because of National Cancer Institute test results.
37 GENERAL ACCOUNTING OFFICE (GAO), REPRODUCTIVE AND DEVELOPMENTAL TOXICANTS:
REGULATORY ACTIONS PROVIDE UNCERTAIN PROTECTION (1991).
38 SAP, April 14, 1988.
39 SAP, Mar. 31, 1987, at 30.
40 Id., at 110.
41 At the first SAP meeting, Chairman Kilgore reported that he was advised by
the reproductive scientists on the Panel that "we do not have the guidelines
that we have available for carcinogens." The full Panel's subsequent discussion
makes no mention of the existence of EPA criteria for identifying developmental
toxicants (published in 1986) or draft EPA criteria for identifying male and
female reproductive toxicants. SAP, Mar. 31, 1987, at 118 et seq. EPA
developmental criteria were briefly cited at the first Subpanel meeting devoted
to guidelines development, SAP Subpanel, April 14, 1988, at 62, but there
appears to have been no discussion of simply adopting these criteria.
42 Pease, When Scientists Become Policy Makers: Shaping Hazard Identification
under Proposition 65, 5 REPROD. TOXICOL. 169-173 (1991).
43 Mattison et al., Criteria for Identifying and Listing Substances Known to
Cause Developmental Toxicity under California's Proposition 65, 4 REPROD.
TOXICOL. 163-175 (1990).
44 Pease, supra note 42.
45 SAP, CRITERIA FOR RECOMMENDING CHEMICALS FOR LISTING AS "KNOWN TO THE STATE
TO CAUSE REPRODUCTIVE TOXICITY" (1988).
46 Environmental Protection Agency (EPA), Proposed Amendments to the Guidelines
for the Health Assessment of Suspect Developmental Toxicants, 53 Fed. Reg.
9386-9403 (1989).
47 EPA, Proposed Guidelines for Assessing Female Reproductive Risk, 53 Fed. Reg.
24834-24847 (1988); EPA, Proposed Guidelines for Assessing Male Reproductive
Risk, 53 Fed. Reg. 24850-24868 (1988).
48 After the Subpanel's February 1989 meeting, its initial four members resigned
because of other professional commitments or frustration with the Proposition 65
process and were never replaced by the CHWA.
49 The SAP has reviewed data on five reproductive toxicants since mid-1989 and
decided to list aspirin, PCBs, toluene and benomyl.
50 After the CHWA began placing therapeutic drugs on the SAP agenda in 1989,
Panel member Diana Petitti recommended designating FDA as an authoritative body
in order to preclude time-consuming, case-by-case reviews and to devote
resources to evaluating chemicals other than drugs. Letter to S. Book, CHWA
(Nov. 30, 1989). While the SAP subsequently designated FDA as authoritative in
April 1990, CHWA chose not to list FDA-rated drugs as reproductive toxicants
under the authoritative bodies rule, relying instead on the regulatory labeling
rule that did not require any sufficiency of evidence test. See note 97 infra
for a complete discussion of the CHWA focus on listing drugs.
51 In 1989, the CHWA reduced the SAP schedule to two meetings per year instead
of four and directed the SAP to review quantitative risk assessments of listed
Proposition 65 chemicals. As a result of political changes at the gubernatorial
level in California, the SAP has not met for any purpose since April 1991.
52 CH&SC Sec. 25249.8(b).
53 Interpreting the ambiguous language of Proposition 65, CHWA regulations have
further confused this issue by imposing a sufficiency of evidence test on
identifications by authoritative bodies, CCR Sec. 12306, but not on
identifications by regulatory labeling requirements. In the case of listing as a
result of labeling, substances are known to cause cancer or reproductive
toxicity if a formally required message is "intended to communicate a risk" of
cancer or reproductive toxicity, no matter what strength of evidence supports
the warning. CCR Sec. 12902.
54 CHWA, CHEMICALS KNOWN TO THE STATE TO CAUSE CANCER OR REPRODUCTIVE TOXICITY:
BASIS FOR LISTING (1991).
55 Crediting the SAP for their review of agents on the "minimum" list increases
their hazard identification contribution from 15% to almost 60% of the list.
Assuming that 43 of the 54 agents listed as a result of SAP de novo review would
have eventually been listed automatically because they had been classified by an
authoritative body reduces the SAP's contribution to less than 5% of the list.
56 Warning requirements for occupational carcinogens have been used
inconsistently as a source of listing by the CHWA. Five chemicals labeled
"cancer hazard" or "regulated carcinogen" by California OSHA were automatically
listed in July 1987, SAP, June 18, 1987, at 6 et seq. & 162 et seq., while eight
chemicals labeled "cancer suspect agent" (a term applied by OSHA to several
known human carcinogens) and one labeled "potential cancer hazard" were not
listed on the basis of warning requirements. CCR tit. 8, Secs. 5209-5220.
57 In all tables, the sums exceed subtotals because of overlaps in
subcategories. Here, for example, several organizations have identified the same
listed agent as a carcinogen.
58 The case in which environmentalists challenged the State's initial short list
of Proposition 65 compounds is known as "Duke I." After the California Court of
Appeals ruled against the State, 28 substances on the minimum list that had not
yet been reviewed by the SAP were automatically listed.
59 OSHA is not an "authoritative body."
60 The SAP evaluated a number of agents that were classified as carcinogens by
various agencies before it designated those agencies as authoritative bodies.
Agents classified by an authoritative body (e.g., EPA B2 carcinogens) and
possessing sufficient evidence of carcinogenicity (according to CCR Sec. 12306)
would have eventually been listed automatically.
61 SAP, Mar. 31, 1987, at 109; SAP, June 18, 1987, at 64.
62 CCR Sec. 12306.
63 Ashby et al., A Scheme for Classifying Carcinogens, 12 REGUL. TOXICOL.
PHARMACOL. 270-295 (1990).
64 Matula & Somers, The Classification of Chemical Carcinogens, 10 REGUL.
TOXICOL. PHARMACOL. 174-182 (1989). The few disagreements over hazard
identification between the SAP, EPA, NTP and IARC have been limited to chemicals
with marginal carcinogen rankings. While the SAP generally considers EPA
Category C or IARC Group 3 compounds to have insufficient evidence of
carcinogenicity, its independent review of the data has led to the listing of
several such chemicals. Two chemicals that elicited extensive discussions before
listing were para-dichlorobenzene, SAP, Dec. 16, 1988, at 100 et seq., and
oxadiazon, SAP, April 26, 1991, at 5 et seq.
65 In 1990, CDHS identified a set of 38 chemicals considered carcinogens by FDA,
but the lack of public documentation and/or the failure to meet criteria for
sufficiency of evidence, CCR Sec. 12306, resulted in only 7 compounds being
listed authoritatively.
66 In 1990, CDHS identified a set of 28 agents considered potential occupational
carcinogens by NIOSH, but the lack of public documentation and/or the failure to
meet criteria for sufficiency of evidence, CCR Sec. 12306, resulted in only 5
compounds being listed authoritatively. NIOSH also identifies several classes of
compounds (monohalomethanes and vinyl halides) as potential occupational
carcinogens, National Institute for Occupational Safety and Health (NIOSH),
NIOSH Recommendations for Occupational Safety and Health Standards, 37(S-7) MMWR
SUPPLEMENT 1-29 (1988), but CHWA has not listed specific chemicals like methyl
bromide, methyl chloride or vinyl fluoride because they do not individually meet
sufficiency of evidence criteria.
67 29 C.F.R. Secs. 1910 & 1200 (1990).
68 The CHWA officially lists reproductive toxicants as male, female or
developmental toxicants, although this classification is not based on
recommendations made by the SAP or any complete review of available
toxicological data. The SAP Reproductive Subpanel regularly recommended listing
chemicals as "reproductive toxicants," without specifying the type of toxicity.
The basis for the State's classification of reproductive endpoints was
questioned publicly during an SAP Subpanel meeting (using the example of
ethylene oxide), but CHWA never provided an adequate explanation of its
approach. SAP Subpanel, Oct. 31, 1988, at 79 et seq.
Classification generally indicates which reproductive endpoint possessed the
strongest evidence of toxicity, but it cannot be reliably used to distinguish
which populations are susceptible to listed compounds. Ethylene oxide, for
example, was listed as a female reproductive toxicant on the basis of OSHA
regulation. There is, however, both suggestive evidence in human males and clear
evidence in rats and monkeys that the chemical is a male reproductive toxicant
as well. AGENCY FOR TOXIC SUBSTANCES AND DISEASE REGISTRY (ATSDR), TOXICOLOGICAL
PROFILE FOR ETHYLENE OXIDE (1990). There are several examples where SAP members
stated compounds were "reviewed only for developmental toxicity" and agreed that
they also possessed evidence of male reproductive toxicity, but CHWA only listed
them as developmental toxicants (e.g., chlorambucil, SAP Subpanel, Oct. 31,
1988, at 123). Similar inconsistencies are apparent in the classification of
listed therapeutic drugs: label warnings for procarbazine hydrochloride, for
example, note case reports of developmental toxicity and clinical studies
indicating azoospermia and antifertility effects, PHYSICIAN'S DESK REFERENCE
(PDR) (1991), but the drug is only listed as a developmental toxicant.
69 As with carcinogens (see supra note 56), occupational warning requirements
have been used inconsistently by the CHWA to identify reproductive toxicants.
The California OSHA label for ethylene dibromide (EDB), for example, uses the
same words ("may cause sterility") as the label for the listed male reproductive
toxicant dibromochloropropane, CCR tit. 8, Secs. 5212 & 5219, but EDB has never
even been considered for listing as a reproductive toxicant.
70 The pesticide cyanazine may be an exception to this generalization. While
listed as a result of EPA labeling requirements, its supporting evidence may not
satisfy SAP criteria for identifying developmental toxicants. The birth defects
associated with cyanazine are present "at doses which cause serious maternal
illness in laboratory animals;" SAP criteria require special evaluations of this
type of adverse effect.
71 There is a wide range in the strength of evidence supporting FDA rating and
labeling requirements. PDR (1991). This evidence includes well-conducted
epidemiological studies (e.g., androgens and estrogens), case reports alone
(e.g., procarbazine hydrochloride), reports of experience with a class of drugs
(e.g., anti-convulsants and benzodiazepines), or very limited animal studies
(e.g., mitomycin and clomiphene citrate). Some labeled drugs do not even have
individual evidence of developmental toxicity. For example, there are no
positive clinical reports or animal evidence to support identifying most
aminoglycosides as developmental toxicants. FDA Category D ratings for these
drugs are based only on their chemical similarity to streptomycin, which is
associated with fetal deafness if used during pregnancy.
72 Frankos, FDA Perspectives on the Use of Teratology Data for Human Risk
Assessment, 5 FUND. APPL. TOXICOL. 615-625 (1985). FDA attempts to develop
criteria to support consistent interpretation and use of reproductive data,
Interagency Regulatory Liaison Group (IRLG), Interagency Regulatory Liaison
Group Workshop on Reproductive Toxicity Risk Assessment, 66 ENVIRON. HEALTH
PERSPECT. 193-221. (1986), were never completed.
73 21 C.F.R. Sec. 201.57 (1990). Current pregnancy category labeling for
therapeutic drugs can be found in the PDR (1991).
74 To obtain complete control over the listing of labeled reproductive
toxicants, CHWA eliminated any review of its decisions by the SAP or even CDHS
professional staff. Consequently, apparent agency errors in the use of FDA
pregnancy categories, PDR (1991), were not corrected. CHWA failed to
consistently list all drugs rated Category D ("positive evidence of human fetal
risk or... known teratogenic effect in some animal species") or Category X
("studies in animals or human beings have demonstrated fetal
abnormalities....contraindicated in women who are or may become pregnant"). For
example, quinine is rated Category X on the basis of reports of congenital
malformations in humans and strong evidence of teratogenicity in animals, but
has not been listed. Five aminoglycosides are rated Category D and have
identical supporting evidence, but only three have been identified as
reproductive toxicants under Proposition 65. (Amikacin sulfate, netilmycin
sulfate and tobramycin sulfate have been listed; kanomycin sulfate and neomycin
sulfate have not.)
75 J. SCHARDEIN, CHEMICALLY INDUCED BIRTH DEFECTS (1985).
76 YES ON 65, QUESTIONS AND ANSWERS ABOUT PROPOSITION 65 (1986).
77 Chemical uses for listed compounds were ascertained from a review of IARC and
NTP supporting documentation and the Merck Index (1989). Many listed compounds
have more than one use, so chemical class totals exceed 100%. A spreadsheet of
listed Proposition 65 carcinogens and reproductive toxicants specifying chemical
uses and regulatory coverage is available from the author on request.
78 Regulatory coverage was ascertained by cross-correlating the Proposition 65
list with the lists of chemicals affected by the following statutes: CAA: Clean
Air Act, Sec. 112 (list of hazardous air pollutants) CWA: Clean Water Act, Sec.
304 (list of priority pollutants) SDWA: Safe Drinking Water Act, Sec. 300 (list
of substances with current or proposed national primary drinking water
regulations) OSHA: Occupational Safety and Health Act, Sec. 6 (list of
substances with permissible exposure limits) RCRA: Resource Conservation and
Recovery Act, Subtitle C (list of hazardous waste constituents) SARA: Superfund
Amendments and Reauthorization Act, Sec. 313 (list of substances subject to
information disclosure requirements).
79 See Pease et al., Regulating Carcinogens under California's Proposition 65,
10 RISK ANAL. 255-271 (1990) for a presentation of available exposure data on
the most well-studied Proposition 65 carcinogens. The SARA Toxic Release
Inventory, which provides data on chemical emissions but not on exposure,
includes only 30% of the 500 carcinogens and reproductive toxicants listed under
Proposition 65. About 40% of listed carcinogens and 90% of listed reproductive
toxicants are not covered.
80 The distribution of coverage under different statutes illustrates that there
is an inverse relationship between the scope of regulatory coverage and the
stringency of regulatory requirements. Pease, The Role of Cancer Risk in the
Regulation of Industrial Pollution, RISK ANAL. (in press). The largest
percentages (35-100%) of identified carcinogens are affected by the least
stringent requirements, such as information disclosure or handling rules.
Smaller percentages (25% or less) are covered by standards limiting potential
human exposure in the workplace or through other environmental media.
81 Food constituents, which are not a principal target of the statutes examined
in this analysis, are covered extensively (Figure 2(g)) because of the large
proportion of n-nitroso compounds and synthetic environmental contaminants on
the Proposition 65 list (both are also regulated as industrial substances).
82 See legend for Figure 1, supra.
83 Excellent examples are provided by methylene chloride and
para-dichlorobenzene. While these chemicals are targeted by some federal
regulatory programs, important efforts to reduce consumer exposures through
paint strippers and air fresheners have been conducted using the warning
requirements of Proposition 65. ATTORNEY GENERAL, PROPOSITION 65 LITIGATION
SUMMARY (1991).
84 Listed drugs can be further categorized into anti-neoplastics (20),
antibiotics (16), hormones (13), benzodiazepine tranquilizers (7),
anti-convulsant drugs (4) and dermatologic agents (2).
85 An excellent example is provided by lead. While the compound is targeted by
all federal regulatory programs, important efforts to reduce consumer exposures
through food, wine and ceramics have been conducted using the warning provisions
of Proposition 65. ATTORNEY GENERAL, supra note 83.
86 EPA, SUSPENDED, CANCELLED AND RESTRICTED PESTICIDES (1990).
87 CALIFORNIA DEPARTMENT OF FOOD AND AGRICULTURE (CDFA), PESTICIDE USE REPORT
ANNUAL 1988 (1990).
88 A number of listed antibiotics (e.g., doxycycline and tetracycline),
anti-convulsants (e.g., phenytoin) and benzodiazepines (e.g., librium and
valium) are frequently prescribed, R. TALLARIDA, MPD 1985: MOST PRESCRIBED DRUGS
1985 (1985), perhaps at doses of reproductive concern. Friedman et al.,
Potential Human Teratogenicity of Frequently Prescribed Drugs, 75 OBSTET.
GYNECOL. 594-599 (1990). Two listed drugs (aspirin and retinols) are available
over the counter. Despite significant federal controls, there is widespread
abuse of a number of listed drugs, both illegal (anabolic steroids, cocaine) and
legal (alcohol, tobacco, toluene).
89 Proposition 65's discharge ban is generally irrelevant for listed drugs. As
currently implemented, Proposition 65's warning requirements for therapeutic
drugs are less stringent and less informative than required federal warnings
about reproductive toxicity. Pease, supra note 42. Proposition 65's most
significant impact in regard to drugs has involved requiring warnings about the
reproductive effects of alcohol and aspirin earlier than mandated federally. The
law may also result in occupational warnings in pharmaceutical manufacturing
that would not be required under existing federal laws.
90 Pease et al., supra note 79.
91 Corash and Shapiro, California's Proposition 65: An Isolated Experiment or a
Troubling Precedent? in CLEAN WATER AND TOXIC WASTE: AT WHAT COST FOR WHAT GAIN?
(1989); W. NORTH, RISK ASSESSMENT UNDER PROPOSITION 65: A PERSPECTIVE FROM THE
SCIENCE ADVISORY PANEL (1989) (proceedings of the 82nd Annual Meeting of the Air
and Waste Management Association, Anaheim, CA); Roe, Barking up the Right Tree:
Recent Progress in Focusing the Toxics Issue, 13 COL. J. ENVIRON. LAW 275-283
(1988).
92 Under both federal statutes, the development of lists which specify targets
for regulatory control has been incomplete and very time-consuming. The 126
priority pollutants which are the focus of CWA regulation represent only 25% of
the most frequently occurring chemicals in wastewater from industries and
publicly owned treatment works, but the list has not been modified since 1977.
Slow progress with identifying hazardous air pollutants under the original
Section 112 of the CAA recently stimulated Congress to legislatively expand its
list of regulatory targets from 7 to 189 compounds. Robinson & Pease, From
Health-Based to Technology-Based Standards for Hazardous Air Pollutants, 81 AM.
J. PUB. HEALTH 1518-1523 (1991).
93 As of January 1992, there had been no effort to enforce Proposition 65's
discharge ban. Citizen suits have been hampered by the absence of monitoring
data on most listed substances. A principal reason for this inaction is the
substantial administrative resources required to extend the State's water
quality permit system to so many new chemicals.
94 Kizer et al., Sound Science in the Implementation of Public Policy: A Case
Report on California's Proposition 65, 260 JAMA 951-955 (1988).
95 AFL-CIO v. Deukmejian, 212 Cal. App. 3d at 440.
96 Earlier environmental policy proposals to prioritize chemicals for testing
and toxicological evaluation by presence in drinking water or by volume of use
(embodied legislatively in Lloyd Connelly's Assembly Bill 2582: The Pure
Drinking Water and Safe Chemical Act of 1985) were not incorporated into the
Proposition 65 initiative.
97 Once the SAP completed its review of chemicals included on Proposition 65's
"minimum" list of carcinogens, additional compounds were considered on the basis
of extent of scientific evidence. Beginning with substances which had been
classified by the EPA Carcinogen Assessment Group (4/22/88) and IARC (9/16/88),
the SAP moved on to compounds identified by the NTP as having three or four
positive animal studies (4/14/89) and then to those having two positive studies
(4/6/90). The SAP's listing agenda for reproductive toxicants was initially
determined by an informal agreement among members of the Reproductive Subpanel
to focus on those substances with sufficient human evidence.
Efforts to address chemicals on the basis of public concern have been relatively
limited. The most extensive effort to bring new chemicals before the SAP for
consideration focused on pesticides. Concerned "about the shortness of the Prop
65 list in regard to carcinogenic and teratogenic pesticides," the National Farm
Workers Health Group recommended 121 possibly carcinogenic and 66 possibly
teratogenic pesticides for review to the CHWA. Letter from M. Moses to W.
Kilgore, SAP Chair (July 14, 1988). Less than one-sixth of the carcinogens were
subsequently evaluated by the SAP. Focusing on 18 pesticides and herbicides that
EPA had designated as having sufficient evidence of carcinogenicity in animals,
the SAP considered several pesticides (e.g., lactofen) that were neither
registered nor used in California. SAP, Dec. 16, 1988, at 42. Less than
one-third of the teratogens were subsequently evaluated by the SAP.
98 For carcinogens, no state resources have ever been devoted to prioritizing
candidate chemicals for listing under Proposition 65.
The history of attempts to develop a prioritization scheme for reproductive
toxicants is indicative of the state's efforts to control the listing process.
The absence of established authoritative lists stimulated early interest in
establishing priorities for SAP consideration, given the large universe of
chemicals with at least some evidence of reproductive toxicity. At a meeting in
April 1988, the SAP Reproductive Subpanel specified a list of 12 compounds as
priorities for future consideration based on the extent of scientific data and
the potential for human exposure. SAP Subpanel, April 14, 1988. To supplement
the SAP effort, CDHS prepared a paper which prioritized compounds on the basis
of available chemical emissions and use data. J. VANDENBERG et al., THE USE OF
AN EVALUATED TOXICITY DATA BASE IN SETTING PRIORITIES FOR ASSESSMENT OF
REPRODUCTIVE TOXICANTS (1989) (proceedings of the 82nd Annual Meeting of the Air
and Waste Management Association, Anaheim, CA). The CHWA, however, ignored these
schemes and insisted that other chemicals have a higher priority for listing
consideration.
Maintaining that the SAP should focus on chemicals "with sufficient evidence of
reproductive toxicity in people," memo from S. Book to H. Collins, CDHS (Jan.
11, 1990) (concerning prioritization of reproductive toxicants), the CHWA
proceeded to focus SAP evaluations on drugs (e.g., 4 prescription antibiotics on
the SAP's October 1989 agenda). When SAP member Diana Pettiti stated that "in
looking over the list of potential reproductive toxicants that we are to
consider here today, it doesn't sort of match with my notion of what are serious
potential teratogens," SAP Chair Dorothy Burk explained that the Reproductive
Subpanel "prioritized a number of chemicals which, in our opinion, needed to be
addressed. Some of the ones you see on here were not ones that we prioritized.
They were put on by others." SAP, Oct. 20, 1989, at 33-34.
The SAP never regained control of its agenda. Only half of the compounds
originally prioritized by the SAP have subsequently been evaluated and just 3
have been identified as reproductive toxicants. Consideration of the
Reproductive Subpanel's number one priority (environmental tobacco smoke) has
been continually postponed. (The other priority chemicals that have not yet been
evaluated include: cadmium, arsenic, caffeine, styrene, xylene, benzene,
thiouracils and anesthetic gases (nitrous oxide). SAP Subpanel, Feb. 22, 1989.)
After the SAP's sole expert on reproductive toxicity insisted that "the more
important task before the Panel is the order of consideration of non-drug
chemicals," CHWA essentially took over the listing process for reproductive
toxicants, automatically listing FDA-rated drugs and proposing virtually no
compounds for SAP review.
Recently, the CHWA has acknowledged that the current listing process for
reproductive toxicants could be considered "arbitrary" and initiated the
development of a "clear, predictable scheme to identify chemicals of concern."
Memo from S. Book to H. Collins, CDHS (Jan. 11, 1990) (concerning prioritization
of reproductive toxicants). CDHS developed an elaborate scheme for selecting
chemicals for consideration on the basis of several different approaches,
ranging from expert identification to cross-referencing available toxicity data
with human exposure databases. Donald et al., Prioritizing Candidate
Reproductive/Developmental Toxicants for Evaluation, REPROD. TOXICOL. (1992) (in
press). As of January 1992, however, the State has not used the CDHS priority
candidate list of 42 industrial and agricultural chemicals to revive the
Proposition 65 listing process. While two priorities (PCBs and toluene) have
been listed as a result of SAP evaluations that began before the scheme was
proposed and one (ribavirin) has been listed as a result of FDA labeling
requirements, none of the remaining chemicals have been placed on the SAP agenda
for consideration.
99 The Carcinogen Potency Database, Gold et al., Third Chronological Supplement
to the Carcinogen Potency Database: Standardized Results of Animal Bioassays
Published Through December 1986 and by the National Toxicology Program Through
June 1987, 84 ENVIRON. HEALTH PERSPECT. 215-285 (1990), compiles published
bioassay results on potential carcinogens. The Registry of Toxic Effects of
Chemical Substances and the Hazardous Substances Data Bank contain extensive
summaries of reproductive toxicity test results.
100 A considerable amount of unassessed data exists in the files of regulatory
agencies. CalEPA's Department of Pesticide Regulation, for example, has
assembled a large database which includes results from two-year carcinogenicity
bioassays and reproductive toxicity studies on a variety of agricultural
chemicals that have not been evaluated by authoritative organizations.
To date, California regulatory agencies have generally not sought to bring
chemicals into the Proposition 65 listing process. CHWA attempts to solicit
nominations of priority chemicals from agencies have identified only a few
chemicals for SAP evaluation. Since the passage of Proposition 65, for example,
CDFA nominated only one pesticide for listing as a carcinogen (captafol, SAP,
Sept. 16, 1988) and three for listing as reproductive toxicants (cycloheximide,
cyhexatin and dinoseb, SAP, Dec. 16, 1988).
101 GAO, supra note 5.
102 Consistent with the State's effort to focus hazard identification efforts on
substances already covered by regulation, the State's current fifteen top
priorities for evaluation as reproductive toxicants, Donald et al., supra note
98, have already been listed as carcinogens under Proposition 65. Listing them
as reproductive toxicants will have minimal regulatory impact, requiring only
supplemental warning language. The State's existing priority list of
reproductive toxicants should be modified to focus on substances that are not
already covered by Proposition 65, unless regulatory levels based on
reproductive effects are likely to be lower than those based on carcinogenicity.
103 These include the EPA's Chemicals on Reporting Rules Database and CalEPA's
pesticide use inventories. CDFA, supra note 87.
104 As part of its strategy to limit de novo hazard identification, the
Deukmejian Administration focused SAP meetings on reviewing Proposition 65 risk
assessments rather than chemical data. Cursory SAP reviews did not substantially
modify the scientific content of most risk assessments, but they did monopolize
the SAP agenda (on average, six 50 page documents were presented and discussed
at each meeting after the fall of 1988). Cancer policy issues are more
appropriately addressed within the process California has established to modify
its Guidelines for Chemical Carcinogen Risk Assessment, relying on expert
committees with substantially broader expertise than the Proposition 65 SAP.
105 Some FDA-labeled therapeutic compounds have been identified as reproductive
toxicants on the basis of membership in a chemical class, structure-activity
relationships, limited bioassay results or epidemiological case reports.
106 The SAP should consider how it will proceed with carcinogen identification
after all chemicals with lifetime bioassay data have been reviewed. In
particular, the SAP should decide whether it will adopt recent proposals to
identify carcinogens on the basis of short-term test results alone. Ashby &
Marrod, Detection of Human Carcinogens, 352 NATURE 185-186 (1991).
Top of page
Risk Articles Index 惭愧,英文不是很专业. thanks for your data, please can you put a PDF version of p65? what is the implementation date? About the california Proposition 65 law,you can load the netweb site:[url]WWW.CALPROP65.COM[/url] There is anything that you what [s:8] 能不能麻烦楼主转成PDF档然后再上传好吗。谢谢 有没有中文版本的啊＞？楼主！这个自己翻译的话估计要翻译一个月！偶的英文不是很强！ [s:6]
要是有中文版本就好了！
谁有中文版本麻烦发给我可以吗？谢谢！十分感谢！万分感激！我的邮箱[email]ssff3344@163.com[/email] [s:4] [s:4] Thanks so much for your data。can you provide pdf version? everyone want to need it 。 看不懂,鹰文不好!!!!! can someone post it up again
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