Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Effect on neurotoxicity: via oral route

Endpoint conclusion
Dose descriptor:
NOAEL
200 mg/kg bw/day

Additional information

The neurological consequences of repeated oral exposure to DCP have been investigated in F344 rats (n = 15/sex/group) given 0 (corn oil), 20, 65 or 200 mg/kg bw/day for 13 weeks by gavage. The study followed U.S. E.P.A. guidelines and was conducted to the standards of GLP. Prior to treatment, and at monthly intervals during the study, all animals were assessed for a number of endpoints including functional observational battery, hindlimb grip strength, and motor activity. After a 13-week treatment, 4 rats/sex/dose were randomly selected for terminal examination (including histopathological examination of brain, spinal cord and nerve) while the remainder were retained (no further treatment) for a 9 week recovery period. Transient clinical signs (lacrimation, blinking, and decreased spontaneous motor activity) were reported on days 3-4 of treatment, and body weight was slightly decreased at week 13 in both sexes. There were no effects attributable to DCP in the functional observational battery, grip strength, or motor activity. Results from the gross and microscopic examination of the brain and nervous system revealed no treatment-related lesions. Overall, apart from a minor effect on body weight (NOAEL males = 20 mg/kg bw/day; NOAEL females 65 mg/kg bw/day), no adverse structural or functional neurological consequences were apparent in rats following 13 weeks gavage administration of DCP at doses up to 200 mg/kg bw/day.

Justification for classification or non-classification

No effectrs in a 13 week study up to the highest dose level.