Oxolinic Acid (Pesticides/Veterinary Medicinal Products)

Food Safety Commission of Japan (FSCJ) conducted a risk assessment of oxolinic acid (CAS No. 14698-29-4), an antimicrobial agent with a quinoline structure, based on results from submitted documents. For the fifth edition, additional residue data for crops (including taro and broccoli) were submitted by the Consumer Affairs Agency. The data used in the assessment include fate in animals (including rats) and humans, fate in plants (including paddy rice and napa cabbage), residues in crops, residues in livestock products (including cattle and pigs), subacute toxicity (rats, mice, and dogs), chronic toxicity (dogs), combined chronic toxicity/carcinogenicity (rats), carcinogenicity (mice), two-generation reproductive toxicity (rats), developmental toxicity (rats and rabbits), and genotoxicity. Major adverse effects of oxolinic acid were observed in the body weight (suppressed weight gain), the testes (interstitial cell hyperplasia in rats), the ovaries (organ weight increase in rats), excitatory neurological symptoms, and behavioral changes (Table 1). No adverse effects were observed on either fertility, teratogenicity, or biologically significant genotoxicity. The lowest NOAEL for potential adverse effects after a single oral administration of oxolinic acid was 6 mg/kg bw from the results of the acute neurotoxicity study in rats (Table 2). FSCJ established an acute reference dose (ARfD) of 0.06 mg/kg bw by applying a safety factor of 100 to this NOAEL.