NICARBAZIN

Comments:

The ADI for nicarbazin was established based on toxicological effects. The Committee concluded that it was not necessary to establish an ARfD.

MRL Comment:

Chicken: 4000μg/kg for muscle, 15 000μg/kg for liver, 8000μg/kg for kidney, and 4000μg/kg for skin with fat.

Intake:

For a nicarbazin inclusion rate of 125mg/kg feed, the global estimate of chronic dietary exposure (GECDE) was 120, 160 and 210μg/kg bw per day (13%, 18% and 23% of the upper bound of the ADI of 900μg/kg bw) for adults and the elderly, children and adolescents, and toddlers and infants, respectively. For a nicarbazin inclusion rate of 50mg/kg feed, the global estimate of chronic dietary exposure (GECDE) was 95, 120 and 160μg/kg bw per day (11%, 14% and 18% of the upper bound of the ADI of 900μg/kg bw) for adults and the elderly, children and adolescents, and toddlers and infants respectively

Meeting:

94

Report: 

ADI:

0-0.4 mg/kg bw

Comments:

The Committee noted the absence of certain toxicological studies in support of nicarbazin; however, the other data available provided sufficient information to overcome most of these deficiencies. It was noted that nicarbazin has been used in veterinary medicine in many countries for over 40 years. On the basis of this long history of use and the fact that use is restricted to starter rations in broiler chickens, the Committee considered that an ADI could be supported. The Committee established an ADI of 0-400 µg/kg bw on the basis of the NOEL of 200 mg/kg bw/d in the study of developmental toxicity in rats and a safety factor of 500, chosen to account for the limitations in the database.

MRL Comment:

MRLs (expressed as N,N'-bis-(4-nitrophenyl)urea, in mg/kg): Muscle (chickens): 0.2; Liver (chickens): 0. 2; Kidney (chickens): 0.2; Fat (chickens): 0.2 (fat/skin in normal proportions)

Intake:

0.214 mg/p/d TMDI nicarbazin equivalents

Meeting:

50

Report: 

Tox Monograph: 

Residues: