Notice of Intent to List Methyl Isopropyl Ketone by the Labor Code Mechanism

The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) intends to list the chemical identified in the table below as known to the State to cause reproductive toxicity under the Safe Drinking Water and Toxic Enforcement Act of 1986.  The Act, commonly known as Proposition 65, is codified in Health and Safety Code section 25249.5 et seq.  This action is being taken by the Labor Code mechanism pursuant to Health and Safety Code section 25249.8(a).

Chemical

CAS No.

Reproductive Toxicity Endpoint

Reference

Methyl isopropyl ketone

563-80-4

Developmental toxicity

ACGIH (2011)

Background on listing by the Labor Code mechanism: Health and Safety Code section 25249.8(a) requires that substances identified in Labor Code section 6382(d) as causing reproductive toxicity be included on the Proposition 65 list.  Labor Code section 6382(d) captures any chemicals within the scope of the federal Hazard Communication Standard that are identified as reproductive toxicants.  Chemicals fall within the scope of the Hazard Communication Standard if they are listed as hazardous in the latest edition of the American Conference of Governmental Industrial Hygienists (ACGIH) “Threshold Limit Values (TLVs).”  The TLV for methyl isopropyl ketone was assigned on the basis of ACGIH’s findings of reproductive effects (developmental toxicity endpoint).

Opportunity for comment:  OEHHA is committed to public participation in its implementation of Proposition 65.  OEHHA is providing this opportunity to comment as to whether the chemical identified above meets the requirements for listing as causing reproductive toxicity, specified in Health and Safety Code section 25249.8(a).  Because this is a ministerial listing, comments should be limited to the question whether the ACGIH has assigned a TLV based in whole or in part on an endpoint of reproductive toxicity.  Under this listing mechanism, OEHHA cannot consider scientific arguments concerning the weight or quality of the evidence considered by the ACGIH when it established the TLV, and will not respond to such comments if they are submitted.

OEHHA must receive comments by 5:00 p.m. on Monday, January 30, 2012.  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 the chemical name in the subject line.  Comments submitted in paper form may be mailed, faxed, or delivered in person to the address below.  A public workshop will be held only upon request.  Such request must be made in writing to the address below or to sam.delson@oehha.ca.gov within 10 days from the publication of this notice:

Mailing Address:
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-19B
Sacramento, California 95812-4010
Fax: (916) 323-8803
Street Address: 1001 I Street
Sacramento, California 95814

If you have any questions, please contact Sam Delson at (916) 445-6900.

Link to Public Comments

The comment period closed on January 30, 2012. No comments were received.

Footnotes and References

American Conference of Governmental Industrial Hygienists (ACGIH).  2011 TLVs and BELs Based on Documentation of the Threshold Limit Values for Chemical Substances and Physical Agents & Biological Exposure Indices, ACGIH, Cincinnati, OH, page 41.