Diflubenzuron

Comments:

The Committee established an ADI based on a NOAEL of 2 mg/kg bw per day for increased methaemoglobin and sulfhaemoglobin levels in a 2-year study of toxicity and carcinogenicity in rats; and increased methaemoglobin and sulfhaemoglobin levels, platelet counts and hepatic pigmentation in a 1-year study of toxicity in dogs – applying a safety factor of 100 (10 for interspecies variability and 10 for intraspecies variability). The Committee reiterated the conclusion of the 81st meeting that it was not necessary to establish an ARfD, in view of the low acute oral toxicity and the absence of developmental toxicity, and any other toxicological effects likely to be elicited by a single dose.

MRL Comment:

The Committee recommended a maximum residue limit (MRL) in salmon of 10 μg/kg in muscle+skin in natural proportions.

Intake:

Estimated chronic dietary exposure: The GECDE for the general population is 0.84 μg/kg bw per day, which represents 4% of the upper bound of the ADI. The GECDE for children is 2.85 μg/kg bw per day, which represents 14% of the upper bound of the ADI. Estimated acute dietary exposure: Acute dietary exposure was not estimated because the Committee concluded that it was not necessary to establish an ARfD.

Meeting:

88

Report: 

Tox Monograph: 

Residues: 

ADI:

Not established

Comments:

In the absence of adequate information on exposure to PCA, a genotoxic and carcinogenic metabolite and/or degradate of diflubenzuron, and on whether diflubenzuron can be metabolized to PCA in humans, the Committee was unable to establish an ADI for diflubenzuron because it was not possible to assure itself that there would be an adequate margin of safety from its use as a veterinary drug.

MRL Comment:

MRLs for diflubenzuron could not be recommended by the Committee, as no ADI was established and there is a lack of data about the metabolite/degradation product PCA.

Report: 

Tox Monograph: 

Residues: