Subchronic inhalation toxicity study of 2-ethylhexanol vapour in rats

A 90-day subchronic inhalation toxicity study was performed on Wistar rats in accordance to OECD testing guidelines to evaluate the toxicological profile of 2-ethylhexanol, potential target organs, and a no-observable-adverse-effect-level (NOAEL). 10 males and 10 females per group were exposed to 2-ethylhexanol vapours at concentrations of 15, 40 and 120 ppm (the latter corresponding to the vapour saturation at 20 degrees C) 6 hours/day for 90 days. The respective controls inhaled clean air under the same conditions. No substance-related adverse effects were observed for body weight, body weight gain, mortality, organ weights, clinical biochemistry and haematological parameters including clotting time. Cyanide-insensitive palmitoyl-CoA oxidation, a marker for peroxisome proliferation, was found elevated in a subchronic study in Fischer 344 rats after gavage application of 500 mg/kg but not under the conditions of this 90-day subchronic inhalation study. There were no findings related to the treatment with 2-ethylhexanol either at necropsy or at histological examination. The highest concentration tested under these conditions (120 ppm) was found to be the NOAEL for male and female rats.