Reconsideration of Listing of Methyl-n-butyl Ketone and Consideration of Listing of 2,5-Hexanedione

Announcement of the November 9, 2015 Meeting of the Developmental and Reproductive Toxicant Identification Committee

The Office of Environmental Health Hazard Assessment (OEHHA) announces the availability for public review of a hazard identification document to support the reconsideration of methyl-n-butyl ketone and the consideration of 2,5 hexanedione as known to cause reproductive toxicity. OEHHA, a department of the California Environmental Protection Agency, is the lead agency for the implementation of Proposition 651. The Developmental and Reproductive Toxicant Identification Committee (DARTIC) advises and assists OEHHA in compiling the list of chemicals known to the state to cause reproductive toxicity, as required by Proposition 65. The DARTIC serves as the state’s qualified experts for determining whether a chemical has been clearly shown through scientifically valid testing according to generally accepted principles to cause reproductive toxicity.

Background

Methyl-n-butyl ketone was originally added to the Proposition 65 list in 2009 on the basis of reproductive toxicity via the Labor Code mechanism2. In 2014, OEHHA initiated reconsideration by the DARTIC of several chemicals, including methyl‑n‑butyl ketone, based on changes to the federal regulations that affected the basis for the original listing via the Labor Code mechanism. Specifically, in March 2012, the federal Occupational Safety and Health Administration (OSHA) amended the regulations contained in the Code of Federal Regulations, Title 29, section 1910.1200. These changes affected the use of this section as a definitive source for identifying chemicals as known to cause reproductive toxicity by the Labor Code mechanism. During its reconsideration of methyl-n-butyl ketone on March 19, 2014, the Committee deferred making a decision and requested additional information both on this chemical and its active metabolite, 2,5-hexanedione. In response to that request, OEHHA has revised the hazard identification document for methyl-n-butyl ketone and added information on the reproductive toxicity of 2,5-hexanedione.

Public Comment

This notice marks the beginning of a 45-day public comment period on this document. The public comment period will close on Monday, October 12, 2015. Copies of the document are available from OEHHA’s web site. The document may also be requested from OEHHA’s Proposition 65 Implementation Office by calling (916) 445-6900.

DART IC Meeting

On Monday, November 9, 2015, the DARTIC will consider whether methyl-n-butyl ketone should remain listed under Proposition 65 as known to cause reproductive toxicity, and will also consider whether 2,5-hexanedione should be listed as known to cause reproductive toxicity. The meeting will be held in the Sierra Hearing Room at the CalEPA Headquarters building, 1001 I Street, Sacramento, California. The meeting will begin at 10:00 a.m. and will last until all business is conducted or until 5:00 p.m. The agenda for the meeting will be provided in a future public notice published in advance of the meeting. OEHHA will send all comments received on the hazard identification document for these chemicals to DARTIC members prior to the meeting. Comments received during the public comment period will be posted on the OEHHA web site after the close of the comment period. Electronic files submitted should not have any form of encryption.
OEHHA must receive comments and any supporting documentation on the hazard identification document by 5:00 p.m. on Monday, October 12, 2015.

We encourage you to submit comments in electronic form, rather than in paper form. Comments transmitted by e-mail should be addressed to P65Public.comments@oehha.ca.gov. Please include “Methyl n-Butyl Ketone and 2,5‑Hexanedione” in the subject line. Comments submitted in paper form may be mailed, faxed, or delivered in person to the addresses below:

Mailing Address: Michelle Robinson
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-12B
Sacramento, California 95812-4010
Fax: (916) 323-2265
Street Address: 1001 I Street
Sacramento, California 95814

Link to Public Comments

Tuesday, September 22, 2015

Footnotes and References

1 The Safe Drinking Water and Toxic Enforcement Act of 1986, codified at Health and Safety Code section 25249.5 et seq.

2 Health and Safety Code section 25249.8(a)