Thiabendazole and its Hypophosphite Salt Under Consideration for Possible Listing Via the Authoritative Bodies Mechanism: Request for Relevant Information

The Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65 or the Act) which is codified at Health and Safety Code section 25249.5 et seq., requires the Governor to publish, and update at least annually, a list of chemicals known to the State to cause cancer or reproductive toxicity. The Act describes the mechanisms for administratively listing chemicals as known to the State to cause cancer or reproductive toxicity (Health and Safety Code section 25249.8.)

One mechanism by which a chemical is listed is if a body considered to be authoritative by the state’s qualified experts has formally identified it as causing cancer or reproductive toxicity. The U.S. Environmental Protection Agency (U.S. EPA), the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP ), the U.S. Food and Drug Administration (FDA), and the National Institute for Occupational Safety and Health (NIOSH) have been identified as authoritative bodies for purposes of the Act. For reproductive toxicity the designation of NTP holds solely for the 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 is investigating the possible listing of thiabendazole and thiabendazole hypophosphite salt based upon information in the references cited in the table below. Documentation summarizing the rationale for considering the evaluation of these chemicals for possible administrative listing is available from OEHHA’s Proposition 65 Implementation Office at the address and telephone number indicated below, or from the Internet at the following address: /proposition-65.html.

Chemicals which may meet the criteria set forth in Section 12306 for listing under Proposition 65 via the “authoritative bodies” mechanism:

Chemical CAS No. Chemical Use Toxicological Endpoints Reference
Thiabendazole 148-79-8 pre-planting dust treatment to potato seed-pieces, sweet potato seed pieces, soybean, and wheat; post-harvest as a dip or spray on citrus fruits, apples, pears, bananas, mangos, papaya, plantain, carrots, avocados, peas, and potatoes; on mushrooms Developmental toxicity U.S. EPA (1999a, 1999b, 2002)
Thiabendazole hypophosphite salt 28558-32-9 Uses include as a preservative in paints, carpets, adhesives and textiles, and in ready-to-use formulation on ornamental bulbs and elm and sycamore trees Developmental toxicity U.S. EPA (2002)

Thiabendazole has previously been the subject of a request for relevant information pertaining to consideration for listing as known to cause reproductive toxicity under Proposition 65 (California Regulatory Notice Register; October 9, 1998, Register 98, No. 41-Z). This chemical was under consideration for listing based on possible formal identification as causing reproductive toxicity by the U.S. EPA. OEHHA did not proceed with listing this chemical on the basis of the documents identified in the prior notices. More recent documents identified below appear to provide the basis for listing thiabendazole and thiabendazole hypophosphite salt under Proposition 65.

OEHHA is committed to public participation and external scientific peer review in its implementation of Proposition 65, and welcomes public input on this listing process. As part of its efforts to ensure that regulatory decisions are based upon a thorough consideration of all relevant information, OEHHA is soliciting information concerning whether the criteria set out in Section 12306 have been met for these chemicals.

This announcement initiates a 60-day public comment period on these chemicals. The comment period closes on Tuesday, August 26, 2008. A public forum to present oral comments and to discuss the scientific data and other information concerning whether these chemicals meet the criteria for listing set forth in Section 12306 will be scheduled only upon request. Such request must be submitted in writing by July 28, 2008. This date is approximately 30 days before the close of the comment period on August 26, 2008. The written request to hold a public forum must be sent to OEHHA at the address listed below. A notice for the public forum, if one is requested, will be posted on the OEHHA Web site at least ten days in advance of the forum date. The notice will provide the date, time, location and subject matter to be heard. Notices will also be sent to those individuals requesting such notification. Interested parties or members of the public wishing to provide information relevant to these chemicals should send it to the address given below.

Office of Environmental Health Hazard Assessment
Proposition 65 Implementation
P.O. Box 4010, MS-12B
1001 I Street
Sacramento, California 95812-4010
FAX: (916) 323-2265
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 Tuesday, August 26, 2008.

Following the review of all comments received, OEHHA will announce its intention to proceed with the listing of the candidate chemicals if they meet the regulatory criteria for administrative listing in a Notice of Intent to List Chemicals.

Footnotes and References

REFERENCES

U.S. EPA (U.S. Environmental Protection Agency) 1999a. Thiabendazole - Report of the Hazard Identification Assessment Review Committee. HED DOC. No. 013601. Office of Pesticide Programs, U.S. EPA, Washington DC.

U.S. EPA (U.S. Environmental Protection Agency) 1999b. Thiabendazole; P.C.Code 060101. The HED toxicology chapter for the Reregistration Eligibility Decision document (RED). DP Barcode: D251076. Office of Pesticide Programs, U.S. EPA, Washington DC.

U.S. EPA (U.S. Environmental Protection Agency) 2002. Reregistration Eligibility Decision for Thiabendazole and Salts. Case No. 2670. Office of Prevention, Pesticides and Toxic Substances, U.S. EPA, Washington DC.