Summary of Proposition 65 Activities

Dear Interested Parties:

It has been some time since I last provided you with an update on the Office of Environmental Health Hazard Assessment's (OEHHA) Proposition 65 activities.

This letter highlights OEHHA's major Proposition 65 activities since July 1999.

Safe Harbor Number Development

"Safe harbor numbers" provide assurance to the regulated community that exposures or discharges below these numbers are considered not to pose a significant risk of cancer, birth defects or other reproductive harm as defined by Proposition 65. These safe harbor numbers consist of no significant risk levels (NSRLs) for chemicals listed as causing cancer and maximum allowable daily levels (MADLs) for chemicals listed as causing reproductive toxicity. Exposures that do not constitute a significant risk are not subject to the warning requirement in Proposition 65.

OEHHA last established safe harbor numbers in the early 1990's for slightly over 200 chemicals. Due to a series of budget cuts in the mid-1990's, OEHHA had insufficient resources to continue this activity. A recent budget increase has provided OEHHA with the necessary funds to resume developing safe harbor numbers. OEHHA anticipates developing between 20 - 35 safe harbor numbers per year for chemicals which currently do not have numbers. OEHHA held a public hearing on July 23, 2001, concerning the first round of new safe harbor numbers.

Adoption of these additional safe harbor numbers in regulation will bring greater clarity and certainty to regulated businesses, the Attorney General, environmental groups, and private citizens that make determinations of compliance with Proposition 65. These safe harbor numbers will help businesses determine whether they need to provide the warning required for exposures to Proposition 65 chemicals above specified risk levels and whether certain discharges of Proposition 65 chemicals into sources of drinking water are prohibited.

Following a public workshop held last fall, OEHHA released one document that explains how safe harbor numbers would be developed and another document that provides a priority list of chemicals for which dose response assessments have not been completed. These documents are available from the OEHHA Web site at: Documents Related to the November 15, 2000 Public Workshop on Developing Safe Harbor Numbers.

Clarifying Regulations

OEHHA is initiating the development of clarifying regulations. The purpose of these regulations will be to clarify ambiguous and vague provisions of the Proposition 65 regulations. I have met with various representatives of the regulated community, environmental groups, and the Attorney General's Office to gather input as to which areas of the Proposition 65 regulations could benefit from regulatory clarification. I received input suggesting both major and minor regulatory changes.

Instead of proceeding with a single voluminous regulatory package, I envision this will be an ongoing process in which OEHHA will propose a series of regulatory amendments during the next several years. We will begin with minor changes of a less complex nature and progress to more significant regulatory amendments. This will help ensure an orderly process that will allow for complete public review and discussion of each specific regulatory proposal.

OEHHA hopes to develop the first set of proposed clarifying regulations during the second half of 2001. The OEHHA Web site will carry announcements of future developments in this area.

Petition to Amend Clear and Reasonable Warning Regulations

On February 22, 2000, OEHHA received a petition from the Advanced Medical Technology Association (formerly the Health Industry Manufacturers Association). The petition sought amendments in several areas of the clear and reasonable warning regulations. In particular, the petition sought to have OEHHA adopt a regulation requiring passage of the warning from the manufacturer through the distribution chain to the health care provider to the patient, amendments that differentiate between the various categories of medical devices (i.e., prescription, over-the-counter and in-vitro diagnostic devices), and specific warning language for medical devices.

OEHHA believed that the petition was overly broad in its requests and did not provide an adequate basis for creating unique warning regulations for all medical device products. However, OEHHA also believed there was merit to a limited regulation that addresses giving Proposition 65 warnings to an unconscious patient, a patient undergoing an emergency medical procedure, or a person legally incapable of giving consent. These were all situations discussed by the petitioner as problematic and requiring a specific provision in the warning regulations. OEHHA has developed a regulation pursuant to the Administrative Procedure Act for these situations. All interested parties will have an opportunity to comment on the proposed regulations prior to any final regulatory action by OEHHA. A public hearing will be held on September 10, 2001 to receive public comments.


Dr. Andrew G. Hendrickx, chair of the Developmental and Reproductive Toxicant (DART) Identification Committee, and Dr. John R. Froines, a longtime member of the Carcinogen Identification Committee (CIC), recently announced their resignations. Dr. Hendrickx has been a part of Proposition 65 since the beginning and was a founding member of the Scientific Advisory Panel, which was the original body of "state's qualified experts" formed in 1987. Dr. Hendrickx and Dr. Froines had served in their positions on the DART Identification Committee and CIC, respectively, since the committees were established in 1994.

As a result of their leadership and insightful guidance, both Dr. Hendrickx and Dr. Froines furthered California's efforts to protect public health by identifying chemicals that cause cancer, birth defects and other reproductive harm.

In informing OEHHA of his resignation, Dr. Hendrickx said he wishes "to give greater priority to interests other than scientific research and service," and that he will miss working with the DART Committee and OEHHA staff. He is a Professor of Cell Biology and Human Anatomy at the University of California, Davis (UC Davis). He also served as Director of the California Regional Primate Research Center at UC Davis from 1987 to 2000, and as the center's Associate Director from 1978 to 1987. He is a past president of both the Teratology Society and the American Society of Primatologists and was an advisor to the World Health Organization from 1977 to 1999. His research focuses on birth defects.

In announcing his resignation, Dr. Froines stated a desire to focus on his other duties. He is a Professor at the University of California, Los Angeles (UCLA) School of Public Health, with expertise in toxicology and industrial hygiene. He is also the director of the school's Center for Occupational and Environmental Health and the co-director of the UCLA Pollution Prevention Education and Research Center. His research focuses on exposure assessment, toxicokinetic factors of chemical toxicity, and risk assessment. Dr. Froines currently serves as the Chairman of the Air Resources Board's Scientific Review Panel and is a member of the National Toxicology Program's Board of Scientific Counselors' Report on Carcinogens Subcommittee.

Progress Report on Listing Activities Under Proposition 65

Since July 1999, 53 chemicals have been added to the Proposition 65 list. Of these, 25 occurred via the authoritative bodies mechanism, 23 occurred via the formally required mechanism, and 5 occurred via the State's qualified experts mechanism. Collectively, there were 22 listings of chemicals known to the state to cause cancer and 31 listings of chemicals known to the state to cause reproductive toxicity. The current list is available on the OEHHA Web site at /proposition-65/proposition-65-list.
Administrative listing mechanisms, those listing mechanisms other than by the State's qualified experts mechanism, continue to be the primary method by which chemicals are added to the Proposition 65 list. Of the 737 listings under the Proposition to date, over half (401) of these have been made through an administrative listing mechanism, as noted in the table below.

Listing Procedure


Labor Code


Authoritative Bodies


Formally Required


State's Qualified Experts


OEHHA is continuing to evaluate the remaining Toxic Release Inventory (TRI) chemicals under consideration for administrative listing. Of the 65 TRI chemicals, 38 have been administratively listed under Proposition 65, one has been listed by the State's qualified experts (DART) mechanism, 21 have been determined not to meet the regulatory criteria, and 5 are still under consideration for possible listing.

Delisting of Chemicals From the Proposition 65 List

For the first time, the CIC met in October 1999 to reconsider the listing of five previously listed chemicals (allyl chloride, chlorodibromomethane, 1,1-dichloroethane, p-toluidine, and zineb). The CIC determined that based upon new scientific information, allyl chloride, chlorodibromomethane, p-toluidine, and zineb (but not 1,1-dichloroethane) should be removed from the Proposition 65 list. These four chemicals are the first group to be removed from the Proposition 65 list.

More recently, saccharin was delisted. Saccharin was added to the Proposition 65 list on October 1, 1989, as a result of a judicial decision enforcing Labor Code Section 6382(b)(1) and (d), which are incorporated by reference as Proposition 65 listing mechanisms. The Labor Code provisions require inclusion of substances listed as human or animal carcinogens by the International Agency for Research on Cancer (IARC) or as carcinogens or potential carcinogens by the National Toxicology Program (NTP). At the time saccharin was added to the Proposition 65 list, IARC and NTP had identified it as causing cancer. In its most recent Report on Carcinogens, NTP removed saccharin from its list of substances "reasonably anticipated to be a human carcinogen." Also, in a recent monograph, IARC reclassified saccharin and its salts as "not classifiable as to their carcinogenicity to humans (Group 3)." In light of these recent re-designations by IARC and NTP, saccharin was removed from the Proposition 65 list in April 2001.

As you can see, OEHHA continues to be active in Proposition 65. If you have any questions or would like to receive a hard copy of a document referred to in this letter, you may call the Proposition 65 Implementation Office at (916) 445-6900.


Joan E. Denton, Ph.D.