Registration Dossier

Administrative data

Description of key information

The weight of evidence based on a category approach indicates that isoheptane is unlikely to present a hazard as neurotoxicant.

Key value for chemical safety assessment

Additional information

No data are available on neurotoxic effects of isoheptane. However, several members of the category have been tested, namely n-heptane; n-octane; hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, < 5% n-hexane; hydrocarbons, C7-C9, isoalkanes; naphtha (petroleum), light alkylate (analogue substance for hydrocarbons, C7-C9, isoalkanes) and alkanes, C7-10-iso- (analogue substance for iso-octane). Studies on neurotoxic effects were performed in rodents upon single and/or repeated dose inhalation exposure to the test substances at maximum concentrations ranging from 12000 up to 24300 mg/m³. In the majority of cases, measurement of various parameters of neurobehavioral response showed minimal to no adverse effects. In some cases, however, reversible neurobehavioural effects occurred at the higher dose levels. NOAEC values for neurobehavioural effects were ≥ 1000 ppm (ca. 3500-5200 mg/m³ depending on composition), mice being much more sensitive than rats (Frantik et al., 1994; CEFIC, 2000, 2001; Lammers, 2001; Balster et al., 1997; Bowen and Balster, 1997; Schreiner et al. 1998).

Therefore, the substances in this category are unlikely to present a hazard as neurotoxicants.

 

 

References:

 

Frantik, E. et al. (1994). Relative Acute Neurotoxicity of Solvents: Isoeffective Air Concentrations of 48 Compounds Evaluated in Rats and Mice. Environmental Research 66: 173-185.

 

CEFIC,(2000). The Effects of Short-term Inhalatory Exposure to n-octane on Behaviour in the Rat. Unpublished. Testing laboratory: TNO Nutrition and Food Research Institute. Report no.: V99.429 Final. Owner company: CEFIC,. Study number: 40.144/01.04. Report date: 2000-01-12.

 

Lammers, J. H. C. M. (2001). The Effects of Short-term Inhalatory Exposure to Cypar 7 on Behaviour in the Rat. Unpublished. Testing laboratory: TNO Nutrition and Food Research Institute. Report no.: V99.1115 Final. Owner company: CEFIC,. Study number: 40.144/01.10. Report date: 2001-02-15.

 

Balster, R. L. et al. (1997). Evaluation of the acute behavioral effects and abuse potential of a C8-C9 isoparaffin solvent. Drug and Alcohol Dependence 46: 125-135.

 

Bowen, S. E. and Balster, R. L. (1998). The Effects of Inhaled Isoparaffins on Locomotor Activity and Operant Performance in Mice. Pharmacology Biochemistry and Behavior, 61(3): 271-280.

 

Schreiner, C. et al. (1998). Toxicity evaluation of petroleum blending streams: inhalation subchronic toxicity/neurotoxicity study of a light alkylate naphtha distillate in rats. Journal of Toxicology and Environmental Health (Part A) 55:277-296.

 

CEFIC,(2001). The Effects of Short-term Inhalatory Exposure to Iso-octane on Behaviour in the Rat. Unpublished. Testing laboratory: TNO Nutrition and Food Research Institute. Report no.: V99.430 Final. Owner company: CEFIC,. Study number: 40.144/01.09. Report date: 2001-02-15.

Justification for classification or non-classification