Notice of Intent to List Chemical: Avermectin B1 (CAS NO 71751-41-2)

The Safe Drinking Water and Toxic Enforcement Act of 1986 establishes mechanisms for administratively listing chemicals that are known to the State to cause cancer or reproductive toxicity. A chemical may be listed under Proposition 65 when a body considered to be authoritative by the state’s qualified experts has formally identified the chemical as causing cancer or reproductive toxicity. The following entities are identified as authoritative bodies for purposes of Proposition 65, as it pertains to chemicals known to cause reproductive toxicity: the U.S. Environmental Protection Agency (U.S. EPA), the International Agency for Research on Cancer, solely as to transplacental carcinogenicity, the U.S. Food and Drug Administration, the National Institute for Occupational Safety and Health, and the National Toxicology Program (NTP), solely as to final reports of the NTP’s Center for Evaluation of Risks to Human Reproduction. The criteria for listing chemicals through the authoritative bodies mechanism are set forth in Title 22, California Code of Regulations, section 12306.

As the lead agency for the implementation of Proposition 65, the Office of Environmental Health Hazard Assessment (OEHHA), within the California Environmental Protection Agency, intends to list avermectin B1, as identified in the table below, as known to the State to cause reproductive toxicity, pursuant to the administrative mechanism. This chemical has been determined by OEHHA to meet the criteria set forth in Section 12306 for such listing under the authoritative bodies mechanism.

Intent to List the Following Chemical

Chemical CAS No. Reference
Avermectin B1
(abamectin)
71751-41-2 U.S. EPA (1994a,b; 2005)

Relevant information related to the possible listing of avermectin B1 was requested in a notice published in the California Regulatory Notice Register on October 9, 1998. A public forum was held on November 20, 1998. OEHHA reviewed and responded to the comments received and has determined that the criteria for listing under Section 12306 had been met for this chemical.

On April 23, 1999, OEHHA issued a notice of intent to list avermectin B1. Subsequent to publication of that notice the U.S. EPA determined that data derived from studies in the CF-1 strain of mice were not suitable for use in the human health risk assessment of avermectin B1. Since U.S. EPA is the authoritative body whose formal identification of avermectin B1 as causing reproductive toxicity supports listing under Proposition 65, OEHHA re-evaluated the data contained in the administrative record for the U.S. EPA’s identification of avermectin B1 that were derived from species and strains other than the CF-1 mouse. OEHHA determined that the criteria for listing in Section 12306 were still met for this chemical. In addition, the 2005 U.S. EPA document “Avermectin B1 and its delta-8,9-isomer; Pesticide Tolerance. Final Rule” formally identifies avermectin B1 as causing developmental toxicity in a final document. (U.S. EPA, 2005). Therefore, OEHHA is re-issuing the notice of intent to list avermectin B1 to clarify the record for the basis for listing this chemical and to invite comments relevant to the current body of data and documents providing the basis for listing.

A document providing more detail on the basis for the listing of this chemical can be obtained from OEHHA’s Proposition 65 Implementation Office at the address and telephone number indicated below, or from the downloads section below. Interested parties or members of the public wishing to provide comments as to whether the listing of this chemical meets the criteria for listing provided in Section 12306 should send it to the address given below.

the Proposition 65 Office
Office of Environmental Health Hazard Assessment
Proposition 65 Implementation
P.O. Box 4010
1001 I Street, 19th Floor
Sacramento, California 95812-4010
FAX: (916) 323-8803

Or via e-mail to P65Public.Comments@oehha.ca.gov. It is requested that all hard-copy materials be submitted in triplicate.

Submissions may also be delivered in person or by courier to the above address. In order to be considered, the relevant information must be received at OEHHA (if delivered in person or sent by FAX) by 5:00 p.m. on Monday, July 28, 2008.

Footnotes and References

REFERENCES

U.S. Environmental Protection Agency (U.S. EPA, 1994a). Proposed Rule: Addition of Certain Chemicals; Toxic Chemical Release Reporting; Community Right to Know. Federal Register 59: 1788.

U.S. Environmental Protection Agency (U.S. EPA, 1994b). Final Rule: Addition of Certain Chemicals; Toxic Chemical Release Reporting; Community Right to Know. Federal Register 59(229): 61432.

U.S. Environmental Protection Agency (U.S. EPA, 2005). Avermectin B1 and its delta-8,9-isomer; Pesticide Tolerance. Final Rule. Federal Register 70(31):7876-7886.