Registration Dossier

Toxicological information

Endpoint summary

Currently viewing:

Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information
no valid data
Effect on fertility: via oral route
Dose descriptor:
NOAEL
200 mg/kg bw/day
Additional information

The avaliable studies reveald no evidence of significant adverse effects on male reproductive organs (testis, epididymis, prostatate) and exerted no effects on reproductive parameters.


Short description of key information:
In a repeated dose study, 5 male and 5 female rats per group were fed 1000, 10000 ppm thymol in the diet (= ca. 67, 667 mg/kg bw/day) for 19 weeks. After termination of the study gross and histopathological examination revealed no adverse effects on the reproductive organs (testis).
In an OECD combined repeat dose and reproductive/developmental toxicity test in rats with oral doses of 0 (vehicle), 8, 40, 200 mg/kg day, the highest applied dose of 200 mg/kg bw/d had no significant adverse effects on the reproductive organs (testis, epididymis, prostatate).
Additional, thymol exerted no effects on reproductive parameters such as the estrous cycle, mating index, fertility index, gestation lenght, number of corpora lutea or implatations, the implantation index, gestation index, delivery index, parturition or maternal behaviour. Birth weight and body weight gain tended to be low in the 200 mg/kg group neonates. There were no significant differences in numbers of offspring or live offspring at birth, the sex ratio, live birth index or viability index.

Effects on developmental toxicity

Description of key information
Thymol was studied for oral toxicity in rats in an OECD combined repeat dose and reproductive/developmental toxicity screening test at doses of 0 (vehicle), 8, 40, 200 mg/kg day.
Effect on developmental toxicity: via oral route
Dose descriptor:
NOAEL
200 mg/kg bw/day
Additional information

Thymol was studied for oral toxicity in rats in an OECD combined repeat dose and reproductive/developmental toxicity screening test at doses of 0 (vehicle), 8, 40, 200 mg/kg bw/day.

Birth weight and body weight gain tended to be low in the 200 mg/kg bw/d group neonates - but the marginaly reduced birth weight at 200 mg/kg bw was related to higher litter size. There were no significant differences in numbers of offspring or live offspring at birth, the sex ratio, live birth index or viability index. No abnormal findings ascribable to the compound were found on external examination, or in terms of clinical signs or necropsy finding for the neonates.

Toxicity to reproduction: other studies

Additional information

no valid data

Justification for classification or non-classification

Based on the avalable data for fertility and developmental/terotogenicity a classification is not justified