Notice of Modifications to the Risk Assessment Document for Naphthalene

Jun 21, 2005

Notice of Modifications to the Risk Assessment Document for Naphthalene Which Serves as the Basis For the Proposed Regulations Title 22, California Code of Regulations Section 12705 OAL Rulemaking Files 04-1110-06s, 05-0318-04sr and 05-0602-03sr

As required by Government Code Sections 11346.8(c) and 11347.1, and Title 1, Cal. Code of Regs., section 44, the Office of Environmental Health Hazard Assessment (OEHHA) is providing notice of changes made to the technical support document which serves as the basis for the proposed regulation, Title 22, California Code of Regulations, Section 12705, which was the subject of a regulatory hearing on August 23, 2004. OEHHA is including in the administrative record copies of documents cited in the risk assessment document attached to this notice. OEHHA received two written comments on the proposed adoption of a “safe harbor” level for naphthalene and these changes are in response to those comments. The changes are not substantive in that they do not alter the NSRL value proposed for naphthalene, however, they are additions to the administrative record for this rulemaking, therefore OEHHA is providing this notice.

The technical support document “No Significant Risk Level (NSRL) for the Proposition 65 Carcinogen Naphthalene,” included with this notice as Attachment 1, has been slightly modified based upon the two comments received. One sentence stating that the National Toxicology Program (NTP) has listed naphthalene as “reasonably anticipated to be a human carcinogen” was added on page two. An editorial change was made on page two to abbreviate “National Toxicology Program” to NTP. One sentence was added on page five to explain the choice of the default linear model for cancer potency derivation. Four sentences were added on page seven to explain why the NSRL is considered applicable to multiple routes of exposure. The date of the document was updated to June 2005. Three references were added in support of the above described changes to the technical supporting document (Buckpitt A, Boland B, Isbell M, Morin D, Shultz M, Baldwin R, Chan K, Karlsson A, Lin C, Taff A, West J, Fanucchi M, Van Winkle L and Plopper C, 2002. Naphthalene-induced respiratory tract toxicity: metabolic mechanisms of toxicity. Drug Metab Rev 34:791-820; NTP, 2004. Report on Carcinogens, Eleventh Edition. Carcinogen Profiles. U.S. Department of Health and Human Services, Public Health Service. National Institute of Environmental Health Sciences, Research Triangle Park, NC; OEHHA, 2004. Memorandum from Joan E. Denton, OEHHA Director, to Terry Tamminen, California Environmental Protection Agency Secretary. Subject: Adoption of a Unit Risk Value for Naphthalene, dated August 2, 2004. Memorandum and attachments are available in the downloads section below. All changes are noted in underline/strikeout in Attachment 1.

The technical support document “No Significant Risk Level (NSRL) for the Proposition 65 Carcinogen Naphthalene” (Attachment 1) cites certain key supporting documents (NTP, 2000. Toxicology and Carcinogenesis Studies of Naphthalene [CAS No. 91-20-3] in F344/N Rats [Inhalation Studies]. Technical Report Series No. 500. NIH Publication No. 00-4434. U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health. NTP, Research Triangle Park, NC; NTP, 1992. Toxicology and Carcinogenesis Studies of Naphthalene [CAS No. 91-20-3] in B6C3F1 Mice [Inhalation Studies]. Technical Report Series No. 410. NIH Publication No. 92-3141. U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health. NTP, Research Triangle Park, NC.; OEHHA, 2004). Copies of these key supporting documents are included as Attachment 2 in this notice and are thereby included as part of the administrative record of this rulemaking action.

If you have any comments regarding the noted changes to the risk assessment document for naphthalene, OEHHA will accept written comments between June 21, 2005 and July 6, 2005. All written comments must be submitted to OEHHA by mail, fax, courier or hand-delivery, no later than 5:00 p.m. on July 6, 2005, and addressed to:

Office of Environmental Health Hazard Assessment
Mailing Address: P. O. Box 4010
Sacramento, California 95812-4010

Street Address: 1001 I Street, 19th Floor
Sacramento, California 95814

Fax No.: (916) 323-8803
Telephone: (916) 445-6900

Comments may also be transmitted via email addressed to: P65Public.Comments@oehha.ca.gov. It is requested but not required that written statements or arguments be submitted in triplicate. A copy of the revised document is attached. Amendments to the text of the original document which was introduced during the 45-day comment period which closed on August 23, 2004 are shown in the following manner: deletions from the original text of the document are shown in strikeout and underline, and additions to the text of the original document are shown in double underline. Inquiries concerning the action described in this notice may be directed in writing at the address given above, or by telephone at (916) 445-6900.