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Diflubenzuron - Application for Registration of a Major Change in Label 8/99

New York State Department of Environmental Conservation
Division of Solid & Hazardous Materials
50 Wolf Road, Albany, New York 12233-7250
Phone 518-457-6934 FAX 518-457-0629

August 1999


Mr. Ken Kendall, MBA;
BCE Technical Director;
Urban Entomologist Ensystex, Inc.
P.O. Box 2587 Fayetteville, NC 28302

Dear Mr. Kendall:

Re: Application for Registration of a Major Change in Label for the Active Ingredient - Diflubenzuron Contained in the Pesticide Product Labyrinth Termite Bait (EPA Reg. No. 68850-2)

The New York State Department of Environmental Conservation (NYSDEC) has reviewed your application, received on March 25, 1999, to register the pesticide product Labyrinth Termite Bait (EPA Reg. No. 68850-2) for use as a termite bait placed in bait stations or fabric mesh bags around and under foundations of structures. Diflubenzuron is currently registered in New York State for agricultural use (including greenhouse) as an insect growth regulator. Use as a termiticide was determined to be a major change in label because use on termites in and around structures could cause public health concerns.

The application was determined complete on May 21, 1999 with the registration decision date set at October 18, 1999.

The formulated product was not very acutely toxic to laboratory animals via the oral, dermal or inhalation routes of exposure. It was also neither very irritating to animal eyes or skin, nor was ita skin sensitizer.

The United States Environmental Protection Agency (USEPA) in its recently issued Reregistration Eligibility Decision (RED) for diflubenzuron, presented toxicological information that indicated that this compound does not cause oncogenic, teratogenic or reproductive effects and was negative in several genotoxicity studies. However, in subchronic and chronic toxicity studies, diflubenzuron caused increased methemoglobin and sulfhemoglobin formation. The USEPA established a reference dose of 0.02 milligrams per kilogram body weight per day (mg/kg/day) based on a no-observed-effect level of 2.0 mg/kg/day in a one-year dog feeding study (increased methemoglobin and sulfhemoglobin formation at 10 mg/kg/day) and an uncertainty factor of 100.

There are no chemical specific federal or State drinking water/groundwater standards for diflubenzuron. Based on its chemical structure, diflubenzuron falls under the 50 micrograms per liter general New York State drinking water standard for "unspecified organic contaminants" (10 NYCRR Part 5, Public Water Systems).

For the treatment of structures, the formulated product is placed either in a rigid box or in a bait bag made of flexible mesh fabric. The bags are intended for placement in voids or under concrete slabs which are not accessible to children. These bags have openings that allow termites free access to the bait placed within. For aboveground installation, the bait is placed in tamper-resistant stations (rigid boxes) which are held shut with four tamper-resistant screws. Ensystex, Inc. submitted a copy of the training manual which contains pictures of these containers and instructions for their placement and maintenance.

The Labyrinth Termite Bait system does not appear to pose any significant exposure potential or risks to public health. However, proper use of Labyrinth Termite Bait requires professional training and expertise. The directions for use indicate that specialized tools and equipment will be needed to successfully install and monitor these bait stations as well as an understanding of the effect of temperature on the feeding habits of termites. Additionally, improper storage of the fabric mesh bags in a home could make this product accessible to children.

Therefore, the Departments accepts Labyrinth Termite Bait (EPA Reg. No. 68850-2) for registration in New York State as a "restricted use" product. As such this product is restricted in its purchase, distribution, sale, use and possession in New York State. Furthermore, this product may only be purchased and used by a certified applicator in New York State.

According to New York State Environmental Conservation Regulations 6NYCRR 326.3(a): "It shall be unlawful for any person to distribute, sell, offer for sale, purchase for the purpose of resale, or possess for the purpose of resale, any restricted pesticide unless said person shall have applied for, and been issued a commercial permit." Should you require information to obtain a commercial permit, please contact the Pesticide Management Section at (518) 457-7482.

Enclosed for your records are the Certificate of Registration and the stamped accepted product label.

If you have any questions on this matter, please contact Maureen Serafini, Chief of our Pesticide Product Registration Section, at (518) 457-7446.


Stephen Hammond,
P.E. Director
Division of Solid & Hazardous Materials

cc: w/enc. - N. Kim/D. Luttinger - NYS Dept. of Health
E. Biel/ R. Mungari - NYS Dept. of Ag. & Markets
G. Good/W. Smith - Cornell University, PMEP