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Toxicological information

Carcinogenicity

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Description of key information

Terphenyl, hydrogenated was studied for dermal carcinogenicity in mice for 37 weeks under different conditions (once or more times a week; followed by croton oil administration) and in different strains (Balb/c and PLA). All studies were negative, demonstrating that there were no indications for dermal carcinogenicity.

Key value for chemical safety assessment

Carcinogenicity: via dermal route

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

Additional information

Literature studies were available as weight of evidence for carcinogenicity testing for the skin. Terphenyl, hydrogenated was dermally administered from tail to neck over a 2 cm swathe on the back, at a dose of 50mg/week for 37 weeks to male and female Balb/c mice, followed by 22 weeks with croton oil administration (Henderson & Weeks, 1973a). The mice were examined weekly. Each one of the early tumors was drawn as soon as it appeared. The late tumors were drawn during surveys in which whole experiments were depicted at monthly intervals. An autopsy was done on every mouse dying during the experiments and on every survivor at the end. Tissues, excised post mortem or, in a few -instances, during life tinder anaesthesia, were fixed by buffered formalin and stained with hematoxylin and phloxine. There were no abnormal clinical observations, gross pathological observations and histopathological findings. The NOAEL for carcinogenicity was therefore 50 mg/week, corresponding with 280 mg/kg bw/day (50 mg/week = 7 mg/day/25g = 280 mg/kg bw day).

In a second part of the study, Terphenyl, hydrogenated was dermally administered from tail to neck over a 2 cm swathe on the back at 50 mg/week for 37 weeks to male and female Balb/c mice (Henderson & Weeks, 1973b). The mice of one group were painted five times a week, those of another group four times, of another group three times, of another group twice and of the fifth group one once per week. After 14 weeks applications of Terphenyl, hydrogenated were stopped and all were painted thereafter twice weekly with croton oil. The mice were examined weekly. Each one of the early tumors was drawn as soon as it appeared. The late tumors were drawn during surveys in which whole experiments were depicted at monthly intervals. An autopsy was done on every mouse dying during the experiments and on every survivor at the end. Tissues, excised post mortem or, in a few -instances, during life tinder anaesthesia, were fixed by buffered formalin and stained with hematoxylin and phloxine. There were no abnormal gross pathological observations and histopathological findings. All the Terphenyl, hydrogenated painted mice continued to grow hair; the dorsal fur of those most painted was difficult to clip and it formed a matted shield for the skin beneath. No skin tumor resulted.The NOAEL for carcinogenicity was 50 mg/week, corresponding with 280 mg/kg bw/day.

Finally, Terphenyl, hydrogenated was dermally administered from tail to neck over a 2 cm swathe on the back, at a dose of once a week 50 mg for 37 weeks to male and female PLA mice (Henderson & Weeks, 1973c). The mice were examined weekly. Each one of the early tumors was drawn as soon as it appeared. The late tumors were drawn during surveys in which whole experiments were depicted at monthly intervals. An autopsy was done on every mouse dying during the experiments and on every survivor at the end. Tissues, excised post mortem or, in a few -instances, during life under anaesthesia, were fixed by buffered formalin and stained with hematoxylin and phloxine. There were no abnormal clinical observations, gross pathological observations and histopathological findings. The NOAEL for carcinogenicity was therefore 50 mg/week, corresponding with 280 mg/kg bw/day.

Justification for classification or non-classification

The endpoint does not meet classification criteria according to EU and/or CLPcriteria.