UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

Date: 5/7/ 1 3 MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREV ENTION

SUBJECT: Hexythiazox. Amended Registration to Allow Use on Cotton in Arizona. PC Code: 128849 DP Barcode: D4¢72.6.) Decision No.: 

### 4'-YV'.?O Registration No.: 1016 3-277 Petition No . : 2F807 3 Regulatory Action: Registration Review Risk Assessment Type: Si ngle Chemical Case No.: 7404-1 Aggregate TXRNo.: NA CAS No.: 78587-05-0 MRIDNo.: NA 40 CFR: 40 CFR 180.448 FROM: DonnaS

. Davis, Risk Assessor

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# I Health Effects Division (7509 ) TO: Olga Odiott, Risk Manger Mark Suarez, Product Manager Meredith Laws, Chief Insecticide Branch Registration Division (7505 P)
Recommendations HED has no objection to the amendment of th e Onager ® Miticide labe l to permit use of hexythiazox on cotton in the state of Arizona. This amendment will expand the current regional registration from Cali fornia only to both Cali fornia and Arizona

. Tolerances are estab li s hed under 40 CFR 180.448 (c) for residues ofhexythiazox on undelinted cotton seed and cotton g in byproducts. The tolerance expression and tolerance level established therein are adequate; however, the geographic limitation specified should be revised to include Arizo na.
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### Background Gowan Company has petitioned (2F8073) the Agency to amend the hexythiazox registration to allow the use of the end u se product, Onager® Miticide (EPA Reg No. 1 0 16 3

-277) on cotton in the State of Arizona. Hexythiazox is currently registered for use on cotton only in California. The proposed us e pattern in Arizona is identical to the current use pattern in Ca lifornia. Regionally restricted tolerances are established under 40 CFR 180.448 (c) for residues of hexythiazox on undelinted cotton seed at 0.2 ppm and cotton gin byproducts at 3 ppm for use in California only. No change in tolerance definition or tolerance level is proposed ; the only change requested to the tolerance is to expand the regional registration from California only to California and Arizona.


### Residue Chemistry Considerations No new residue chemistry data were submitted with this petition. The registrant wishes to rely on previously submitted residue data which were reviewed and supported the regional registration of hexythiazox on cotton in California. The registrant notes that the only reason they did not seek regional registration in Arizona at the time that the California registration was requested was because hexythiazox was not registered in the State of Arizona at the time (personal communication via email from Kyla Smith, Gowan Company to Olga Odiott, EPA , 7/5112). HED concurs that the residue data submitted to support the regional registration of hexythiazox on cotton in California is also adequate in terms of number and geographic representation to support the requested use in Arizona. No additional residue chemistry data are required to support the requested use expansion

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### Risk Assessment Considerations The risk assessment conducted to support the use of hexyt hiazox on cotton in California did not include consideration of the regional nature of the registration for cotton, but used to lerance level re sidues and assumed I00% crop treated for cotton seed oil, the only human feed item associat ed with use on cotton. The assessment effectively assumed a national use ; therefore this expansion to Arizona has no impact on the dietary risk assessment.

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