Isononyl alcohol

Endpoint summary

Description of key information

Low  acute oral, dermal and inhalation toxicity, based on test data for the material.

Additional information

Acute toxicity studies have been undertaken on Isononanol by all three major routes of human exposure. Although none of the studies were conducted to GLP, they were reasonable well documented and generally conformed to recognised standards for acute toxicity testing.

Oral

Three acute oral toxicity studies have been undertaken.

In the key study, Isononanol was administered via oral gavage to 5 male and 5 female rats at dosages of 3160, 3980 and 5010 mg/kg. Deaths occurred at all dosages in a treatment-related manner. Clinical signs comprised ruffled fur, crouched posture, light tremor, temporary light sedation and ataxia with face-down position, followed by decelerated and uncontrolled action, breathing difficulties, semi-closed eyes, diarrhoea, hypothermia and lateral position. The estimated combined LD50 is 3950 (confidence interval 3527-4424) mg/kg. In a second acute oral toxicity study with Isononanol, an approximate LD50 of 3160 mg/kg was obtained.

In a third, supporting study, single administrations of Isononanol were given via oral gavage to 5 male rats at doses of 34.6, 120, 417, 1450, 5000, and 10000 mg/kg to assess the acute oral toxicity.  All animals died within 24 hours post exposure in the 10000 mg/kg dose group.  Three of 5 animals in the 5000 mg/kg dose group died within 48 hours of exposure.  Based on the results of this study, the estimated LD50 is 2979 mg/kg.

 

Inhalation

Two acute inhalation toxicity studies have been undertaken.

A saturated atmosphere of Isononanol was generated by directing a high pressure air current (200l/h) through a temperature controlled substance-containing bottle. This saturated air/product mixture was charged through six glass tubes to expose 3 male and 3 female rats for 7 hours. The Isononanol consumption was determined by weighing the bottle after exposure. There were no deaths or clinical signs during 14 -day observation period and necropsy findings were unremarkable. The mean concentration calculated during the 7 -hour exposure period was 0.21 mg/l (LC0 >0.21mg/l).

In a second study, Isononanol was administered via a vapor inhalation, generated by positive pressure spray, to 10 each of mice, rats, and guinea pigs at the nominal concentration of 21.7 mg/l for 6 hours.   During the exposure, signs of irritation observed included transient restlessness followed by extreme inactivity, eye irritation, and shallow respiration.  Swelling of the rims of the eyes, hyperemia of the ears, and a red-brown encrustation around the nose were noted when the animals were returned to group housing.  In addition, three rats and two mice were in a state of collapse.  Two rats and one mouse succumbed within 14 hours of the termination of the study.  Gross necropsy findings included discolored lungs and livers in the animals.   At the end of the study, the LC50 was >21.7 mg/l for each species.

 

Dermal

Two acute dermal toxicity sutdies have been undertaken.

Isononanol was administered via an occluded dermal patch to 4 male and female rabbits at doses of 50, 200, 794, and 3160 mg/kg for 24 hours to assess acute dermal toxicity.  Clinical observations were made once daily for 14 days following the 24 exposure.  All animals survived until study termination.  The only adverse clinical signs noted were slight irritation 24 hours after exposure.  This finding was resolved by day 6.  Based on the results in this study, the LD50 is greater than 3160 mg/kg. In a second acute dermal toxicity study in rats, the LD50 was >4000 mg/kg.

Justification for classification or non-classification

No classification for acute toxicity is indicated according to the general classification and labeling requirements for dangerous substances and preparations (Directive 67-548-EEC) or the classification, labeling and packaging (CLP) regulation (EC) No 1272/2008.