Table 22.
Incidence of tumours in male mice administered long‐chain chlorinated paraffin (C23, 43% chlorination) (NTP, 1986b)
| Dose (mg/kg bw per day) | Males | Females | ||||
|---|---|---|---|---|---|---|
| Control | 2,500 | 5,000 | Control | 2,500 | 5,000 | |
| Malignant lymphomas |
6/50 (12%)c |
12/50 (24%) | 16/50 (32%)a , b |
15/50 (30%) |
12/49 (24%) |
20/50 (40%) |
| Hepatocellular carcinomas |
9/50 (18%) |
12/50 (24%) | 12/50 (24%) |
1/50 (2%) |
1/49 (2%) |
6/50 (12%) |
| Hepatocellular adenomas and/or carcinomas | 18/50 (36%) | 21/50 (42%) | 23/50 (46%) |
4/50 (8%)d |
3/49 (6%) |
10/50 (20%) |
bw: body weight.
a
Life table analysis, p < 0.05, increase relative to control.
b
Incidental tumour test for trend, p < 0.05, increase relative to control.
c
Historical incidence at the study laboratory (mean ± SD): 35/299 (12% ± 5%); historical incidence in NTP studies: 132/1,097 (12% ± 4%).
d
Historical incidence at the study laboratory (mean ± SD): 18/300 (6% ± 3%); historical incidence in NTP studies: 74/1,092 (7% ± 4%).