2-aminobutan-1-ol

Endpoint summary

Description of key information

OECD 422 study, Oral (diet) in rats

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Dose descriptor:

NOAEL

7.1 mg/kg bw/day

Study duration:

subacute

Species:

rat

Additional information

Oral route:

Dietary exposure to 300 mg/kg/day or 50 mg/kg/day of 2-AB-HCl produced treatment-related systemic toxicity in parental animals. In the 300 mg/kg/day group, male and female adult toxicity included decreased body weight and feed consumption, dermal irritation (acanthosis, inflammation, erosions and/or ulcers) possibly induced by feed contact during grooming, and an increased incidence of very slight centrilobular/midzonal hepatocyte hypertrophy, a finding associated with increased relative liver weight in males but not females. In high-dose males there were treatment-related increases in serum urea nitrogen, alanine aminotransferase, aspartate aminotransferase, and cholesterol, with the increased urea nitrogen and cholesterol likely being secondary to the lower body weight and reflective of a marginal change in protein catabolism and fat mobilization. In the 50 mg/kg/day group, parental toxicity was limited to increases in relative liver weights in males and adrenal weights in females. There was no systemic toxicity in the animals given 10 mg/kg/day. There were no neurologic effects in any dose level tested.

The No Effect Level of 10 mg/kg bw 2 -AB / HCl salt corresponds to a dose of approximately 7.1 mg/kg bw/day 2 -aminobutanol after adjusting the dose to take into account the HCl content. As such this value of 7.1 mg/kg bw will be taken forward as the starting point for DNEL derivation.

Repeated dose toxicity: via oral route - systemic effects (target organ) digestive: liver

Justification for classification or non-classification

The criteria for classification for Specific target organ toxicity, Category 2 require that significant toxic effects are observed between 10 and 100 mg/kg bw/day (when a rat study of 90 days duration is conducted).

In this repeated dose study, the duration was less than 90 days in duration, but toxicity was observed at doses lower than 100 mg/kg bw/day. However the toxicity observed was not 'severe', involving an increase in relative liver weight (males only) and increase in adrenal weights (females). Neither of these effects was accompanied by histopathological observations or clinical chemistry observations, therefore it is possible these effects are more adaptive than adverse. As such it is not considered that these effects warrant assignment as severe and therefore classification for specific target organ toxicity is not considered appropriate.