2-chloroethanol

Carcinogenicity

Description of key information

2-Chloroethanol is not carcinogenic.

Key value for chemical safety assessment

Carcinogenicity: via dermal route

Endpoint conclusion

Dose descriptor:

NOAEL

7.5 mg/kg bw/day

Justification for classification or non-classification

Based on the available data, the test item is not subject to C&L according to Directive 67/548/EEC or the Regulation 1272/2008/EC.

Additional information

In the first chronic key study (NTP, (1985)) 50 F344/n rats per dose per sex received 2 -chloroethanol at dose level of 0, 50, or 100 mg/kg bw/day via the dermal route 5 days per week for 103 weeks. No treatment related effects were detected concerning clinical signs, body weight gain and survival; histopathology of neoplastic and non-neoplastic effects was negative. The NOEL was 100 mg/kg bw.

It could be concluded that a 2 years dermal dose of up to 100 mg/kg bw/day 2 -chloroethanol has no adverse effects in rats.

In the second key study (NTP, (1985)) carcinogenicity of 2 -chloroethanol after dermal exposure was investigated in mice. 50 Swiss CD-1 mice per dose per sex received 0, 7.5, 15 mg/mouse once daily 5 days per week for 104 weeks (0, 253, or 630 mg/kg bw/day at week 1; 0, 180, or 411 mg/kg bw/day at week 100). Beside the vehicle control also untreated controls (50/sex) were available for evaluation. No treatment-related clinical signs were found in any group and only slight effects on body weight. Survival was significantly reduced in high dose males which died during the first week of application with local effects at the site of application and pathological alterations in the lung. No carcinogenic effects were detected. In summary, no adverse effects in female mice exposed for 2 years to dermal doses of up to 15 mg/mouse/day could be observed, but adverse effects in male mice at this dose level; the NOAEL in males was 7.5 mg/mouse/day. 2 -Chloroethanol provided no carcinogenic activity in male and female mice.

In a carcinogenicity study by Dunkelberg et al., (1983), twice weekly oral applications of dose levels up to 10 mg/kg bw via gavage for 150 weeks did not result in toxic or carcinogenic effects in female rats. In female NMRI mice, investigated as second species, no local or systemic carcinogenic effects were detected after weekly s.c. injection of doses up to 3 mg/mouse (50 -90 mg/kg bw/injection).

In an insufficiently reported study (Mason et al., (1971) no carcinogenic activity was detected in male and female F344 rats after s.c. injection (2 times per week for 1 year) of doses up to 10 mg/kg bw/injection.

In two studies with transgenic mice (Tennant et al., 1996; Spalding et al., 1999) after dermal application of 2 -chloroethanol no increased skin tumor incidence could be observed. In a furhter carcinogenicity study (Nin et al., 1969) single s.c. injection of newborn mice at dose levels up to 0.17 mg/animal did not induce carcinogenic effects.