Trifluoro(tetrahydrofuran)boron

Carcinogenicity

Justification for classification or non-classification

Severe toxicity is expected to be observed after exposure to boron trifluoride as the leading toxophor well before effects related to tetrahydrofuran can be induced. For this reason, no classification is proposed.

Additional information

No data are available for this endpoint.

NTP (1998) reported about toxicity and carcinogenicity effects via the inhalation route using F344/N rats and B6C3F1 mice.

Male and female rats were exposed to 0, 200, 600 or 1800 ppm of tetrahydrofuran vapours (CAS: 109-99-9) for 6 hours/day, 5 days/week for 105 weeks. No clinical findings related to tetrahydrofuran exposures were reported. Survival rates and mean body weights of male and female rats exposed to tetrahydrofuran were similar to chamber controls. There were neither significant gross pathological changes nor significant non-neoplastic changes noted in exposed rats. The incidence of renal tubule epithelial adenoma or carcinoma (combined) in exposed males occurred with a positive trend, and the incidence in 600 and 1800 ppm males exceeded the historical range for chamber controls in 2-year NTP inhalation studies. Based on the criteria of the NTP, there was some evidence for carcinogenicity in male F344/N rats. There was no evidence for carcinogenicity in female F344/N rats.

Male and female mice were exposed to 0, 200, 600 or 1800 ppm of tetrahydrofuran vapours (CAS: 109-99-9) for 6 hours/day, 5 days/week for 105 weeks. No clinical findings related to tetrahydrofuran exposures were reported for female mice. Male mice exposed at the highest test concentration were observed to be in a state of narcosis during and up to 1 hour after exposure. After week 36, the survival of male mice exposed at the highest exposure concentration (1800 ppm) was significantly less than that of the chamber controls. The highest level selected in the 2-year studies (1800 ppm) exceeded the maximum tolerated dose in male mice. Survival rates of female mice and mean body weights of male and female mice exposed to tetrahydrofuran were similar to chamber controls. The incidences and multiplicity of hepatocellular neoplasms were significantly greater in female mice exposed to 1800 ppm than in the chamber controls. The incidence of nephropathy in 200 ppm male mice was significantly greater than in chamber controls. Male mice exposed to 1800 ppm had significantly greater incidences of non-neoplastic lesions of the urogenital tract than did chamber controls. The incidences of inflammation of the penis and urethra and necrosis of the urethra in the 1800 ppm male mice were greater than those in the chamber controls. These may have been secondary effects of ascending urinary tract infection. Based on the criteria of the NTP, there was clear evidence for carcinogenicity in female B6C3F1 mice. There was no evidence for carcinogenicity in male B6C3F1 mice.