高卧东山
第1楼2007/10/07
呵呵,这个AOAC方法是不是你需要的
AOAC Method 974.02
核桃
第4楼2007/10/07
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