1-nitropropane

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

P/vP: Based on screening level criteria, persistence of 1-nitropropane cannot be ruled out. Thus, the test substance is assumed to meet the criteria for persistence since data is not available to conclude otherwise.

B/vB: The test substance does not meet the criteria of B and vB. The substance has a low potential to bioaccumulate because of its low log Pow value (0.79 at 22°C) and its high water solubility (15 g/L at 25°C).

T: Since the acute aquatic toxicity endpoints are more than 2000-fold higher than the 0.1 mg/L threshold for toxicity (T), the test substance is not T.

One key study and two supporting studies indicated that 1 -nitropropane did not induce reverse mutations in the Ames test with or without metabolic activation. It was negative in a chromosomal aberration test using Chinese hamster lung cells with or without metabolic activation. 1 -Nitropropane was negative in DNA repair tests using rat hepatic or rat, mouse, hamster or human extrahepatic cell lines. Conversely, one in vitro test indicated that 1-NP enhanced the formation of micronuclei in Chinese Hamster lung cells V79. Another in vitro mammalian cell gene mutation test (HPRT) did show an increase in the number of 6-thioguanine resistant mutations. However, both of these positive results should be interpreted in light of conflicting in vitro testing and the higher tiered in vivo testing, specifically, where the bone marrow micronucleus test and the in vivo rat UDS test were negative.

In a chronic inhalation study, male and female Long-Evans rats were exposed to 100 ppm (364 mg/m3) 1 -nitropropane vapor for 7 hours a day 5 days a weeks for up to 21.5 months. Upon histologic examination no hepatocarcinomas were found in the exposed group. In a chronic oral study, male Spraque Dawley rats were exposed to 1 mmole//kg (89.1 mg/kg) of 1 -nitropropane 3 x a week for 16 weeks then once per week for an additional 10 weeks. No treatment related tumours occurred in the rats.

An OECD 422 Guideline study, Combined Repeated Dose Toxicity Study with the Reproductive/Developmental Toxicity Screen Test, was conducted on Sprague Dawley rats at doses of 0, 25, 50, 100 ppm. There was only a slightly reduced litter size in animals exposed to 100 ppm 1-nitropropane and was likely secondary to maternal toxicity

Thus, based on the available data, 1-nitropropane is neither classified as carcinogen, nor as mutagen, repro toxicant, T-R48, nor Xn-R48.