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Carcinogenicity

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Description of key information

Two key read across carcinogencity studies were identified for n-hexane (API, 1995a,b; Klimisch score = 1).  

Key value for chemical safety assessment

Carcinogenicity: via inhalation route

Endpoint conclusion
Dose descriptor:
NOAEC
31 680 mg/m³

Additional information

In a key read across carcinogenic study the oncogenic effect of inhalation exposure of commercial hexane was determined (API, 1995; Klimisch score = 1). Groups of 50 male and 50 female mice were exposed to 0, 900, 3000, or 9018 ppm (0, 3168, 10560, 31680 mg/m3) of test substance for 6 hrs/day, 5 days/week, for 2 yrs. Histopathology revealed increased liver masses and nodules in female mice at the 9018 ppm exposure group. Liver tumors in B6C3F1 mice are known to be sensitive to body weight changes, especially in female B6C3F1 mice, as referenced in NTP 2004. Therefore, the increased incidence of liver masses and nodules in female mice should be interpreted with care. The NOAEC level for oncogenic effects in female mice is 3000 ppm (10560 mg/m3). The LOAEC for female mice was 9018 ppm (31680 mg/m3). No oncogenic effects were seen in male mice. The NOAEC level for oncogenic effects in male mice is 9018 ppm (31680 mg/m3).

 

 

A key read across study examined the carcinogenic oncogenic effect of inhalation exposure from commercial hexane (API, 1995; Klimisch score = 1). Groups of 50 male and 50 female rats were exposed to 0, 900, 3000, or 9016 ppm of test substance for 6 hrs/day, 5 days/week, for 2 yrs. Mortalities of exposure groups were consistant with control groups. Body weight gain was significantly reduced in exposure groups. Histopathology revealed dose-related effects in the nasoturbinal tissue in all exposure groups. Therefore, there was no NOAEC level for local irritation effects. The LOAEC level for both sexes was 900 ppm. No oncogenic effects were seen in the exposure groups. The NOAEC for systemic effects was 9016 ppm in rats of both sexes.

Justification for classification or non-classification

n-Hexane is not classified for carcinogenicity.