2,2'-[6-(4-methoxyphenyl)-1,3,5-triazine-2,4-diyl]bis{5-[(2-ethylhexyl)oxy]phenol}

Carcinogenicity

Description of key information

2 year Dermal NOAEL: >= 1000 mg/kg bw/day

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

chronic

Species:

rat

Justification for classification or non-classification

The present data on carcinogenicity do not fulfill the criteria laid down in regulation (EU) 1272/2008 and therefore, a non-classification is warranted.

Additional information

In the chosen key study for carcinogenicity, i.e. a dermal carcinogenicity study in Wistar rats (acc. to OECD TG 451), three test-treated groups of 100 Wistar Han rats (50 males and 50 females) received Bemotrizinol at 100, 500 or 1000 mg/kg/day by daily cutaneous application for 104 weeks (CIT 25382; 2006). Another group of 50 males and 50 females received no treatment and acted as an untreated control group. An additional group of 50 males and 50 females received the vehicle alone (polyethylene glycol 400) under the same experimental conditions and acted as vehicle control group. The animals were checked daily for mortality, clinical signs and possible signs of skin irritation. The animals were palpated every 2 weeks after 6 months of treatment in order to monitor the onset and progression of any masses. Body weight and food consumption were recorded at designated intervals (weekly during the first 3 months of treatment and then monthly). Ophthalmological examinations were performed on all the animals before the beginning of the treatment period and on 10 animals/sex in the vehicle control and high-dose groups in weeks 26, 52, 78 and 103. The differential white cell count was determined in weeks 52 and 78 for the animals in the vehicle control and high-dose groups. Blood samples for the determination of plasma levels of the test item were taken in weeks 13, 26, 52, 78 and 104. On completion of the treatment period, blood samples were taken from 10 animals/sex and group for hematology and blood biochemistry investigations. All surviving animals were euthanized and submitted to a macroscopic post-mortem examination. Designated organs and any masses or lesions were sampled from each animal and retained for microscopic examination.

The survival rate was not affected by treatment with Bemotrizinol. There were no clinical signs and no effects on body weight or food consumption at any dose-level. At laboratory investigations, no differences among hematological and blood biochemical parameters were attributed to treatment with Bemotrizinol. The systemic exposure seemed similar among the test item treated groups whatever the dose-level applied. Bemotrizinol induced dose-related non-neoplastic skin lesions at the treated skin from 100 mg/kg/day. The pattern of changes was indicative of chronic moderate skin irritation. No other non-neoplastic or neoplastic organ changes were attributed to treatment with Bemotrizinol. Overall, the daily treatment with Bemotrizinol for 104 weeks induced only non-neoplastic findings at the treated skin area indicative of a chronic and moderate local skin irritation.

Consequently, under the experimental conditions of the study, Bemotrizinol, was not carcinogenic by cutaneous application at 100, 500 and 1000 mg/kg/day (CIT, 2006)