Chemical Characteristics

Diflubenzuron is a benzamine chitin inhibitor.
Chemical Family = substituted urea

CHEMICAL NAME:	N-[[(4-chlorophenyl) amino] carbonyl] -2, 6-difluoro-benzamide
Technical Name:	Diflubenzuron
CAS Number:	35367-38-5
Chemical Structure:
Empirical Formula:	C14H9Cl F2N202
Properties:	White crystalline solid Soluble in Organic Solvents No Odor

Environmental And Ecological Fate

Persistence and Movement in the Environment:
Diflubenzuron appears to be relatively non-persistent and immobile in the environment. It rapidly binds with soil particles and organic matter and is quickly broken down by soil biota. The half-life is approximately 2 days in aerobic soil. Diflubenzuron is stable to hydrolysis and photolysis. Available data indicate that it is unlikely that Diflubenzuron will contaminate ground or surface water.

Fate in Plants:
When foliarly applied at the rate registered or proposed for use on citrus, soybeans and cotton, Diflubenzuron undergoes very little, if any translocation from treated areas.

Acute, Subchronic and Chronic Toxicity of Diflubenzuron in Animals

Diflubenzuron is practically non-toxic to birds, small mammals, freshwater fish and marine/estuarine fish. It is non-toxic to honey bees. It is slightly toxic to birds on a subchronic dietary basis. It is very toxic to aquatic invertebrates.

Development/Reproductive Toxicity
Teratogenicity Mutagenicity

The EPA has determined that Diflubenzuron is not a carcinogen. The NOEL for maternal and fetal toxicity in rats and rabbits was >1000 mg/kg/day. The NOEL for reproductive effects in rats was 250 mg/kg/day. Diflubenzuron is not a mutagenic compound.

Safety Studies

Sufficient data has been reviewed to support EPA registrations of products containing Diflubenzuron and to establish acceptable tolerances. Established residue levels for Diflubenzuron in or on the following commodities: cottonseed, pasture, grass, soybeans, soybean hulls, milk, eggs and the meat, fat, and meat byproducts of cattle, goats, hogs, horses, sheep and poultry have been set.

Metabolism in Cattle

The metabolism of Diflubenzuron in cattle has been extensively studied in beef and dairy cattle. EPA has established tolerances for milk, animal fat, meat and meat by products at 0.05 ppm. Metabolism studies in dairy cows showed no detectable levels of Diflubenzuron residues in milk when dosed for up to 28 days. In studies in beef cattle and dairy cows, very low levels of residues were occasionally seen in liver, kidney, fat and muscle.

Effects on Horses

Accidental exposure of horses to ClariFly® via cattle feed would not be anticipated to pose any toxicological risk. While another formulation of Diflubenzuron is approved for equine use, ClariFly® is not labeled for feeding to horses and it is a violation of Federal law to use a product for a use that is not on the label.

Regulatory Status of Diflubenzuron

Diflubenzuron is a larvicide with activity against flies (house, stable, face, and horn) and many leaf eating larvae of insect feeding on agricultural, forest and ornamental plants (gypsy moths and rust mites), as well as mosquito larvae. The active ingredient, Diflubenzuron, was first registered by the EPA in 1976. Diflubenzuron has completed an extensive reregistration process, resulting in the publication by the EPA of the Reregistration Eligibility Document (RED) in 1997.

Regulatory Status of ClariFly®

ClariFly® was recently registered by the EPA in 2006 as the first Diflubenzuron† cattle product for use in feed. The following excerpt from the 2007 Feed Additive Compendium summarizes the regulatory status of the use of Diflubenzuron in cattle feed. “FDA Status: No feed mill license required. When used in medicated feeds, medicated feed application requirement is determined by regulatory status of the drug. EPA Status: Product is a pesticide when used in non-medicated feeds. EPA registration is required for feeds offered for sale except when custom-blended per the provisions of 40 CFR 167.3. In medicated feeds, the product is a food additive and no EPA registration is required when the source of Diflubenzuron is an EPA-registered product.”