This DNEL was derived using the NOAEL of 450 mg/kg/day from a 90-day oral toxicity study in rats conducted according to OECD test guideline 408 by oral route (Fabreguettes, 1999a), after a route to route extrapolation (oral-to-inhalation) and after correction for difference in exposure conditions and between respiratory rates under standard conditions and under conditions of light activity (1/0.38 m3/kg x 7d/5d x 6.7 m3/10 m3).
This DNEL was derived using the NOAEL of 450 mg/kg/day from a 90-day oral toxicity study in rats conducted according to OECD test guideline 408 by oral route (Fabreguettes, 1999a), after a route to route extrapolation (oral-to-dermal) and after correction for difference in absorption and in exposure conditions (50%/5% x 7d/5d). The oral and dermal absorptions are estimated to be 50 and 5% respectively.
Occupational exposure limits (8-h time weighted average) of 10 ppm (49 mg/m3) have been adopted in Austria and Germany (DFG) or of 25 ppm (125 mg/m3) in Belgium, Denmark and Great Britain. Short-term OEL of 10 ppm is in force in Austria, of 20 ppm in Germany (DFG) and of 25 ppm in Denmark, France, Spain, Sweden and UK.
“Carcinogenicity studies with hexylene glycol are not available. However, the genotoxicity studies provide no evidence of a carcinogenic potential. In animal studies of limited validity, 40 mg/kg body weight and day was found to be the NOEL for systemic toxicity after oral administration of the substance. The critical effect of hexylene glycol, however, is the eye irritation, which was observed in animals treated with the undiluted substance. Hexylene glycol does not seem to be a very powerful eye irritant as 25 % solutions were not irritating. In an early study, eye irritation developed in most of the 12 male and female test persons exposed for 15 minutes to hexylene glycol vapour in a concentration of 50 ppm (approximately equivalent to the saturation concentration at 25°C). No NOEL was determined in this study. The eye irritation seems not to have been very severe, a fact which is also suggested by the steepness of the dose-response curve seen in the Draize test data. The MAK value was established provisionally at 10 ml/m3. Because the eye irritation was not severe, for the restriction of exposure peaks hexylene glycol was classified in Peak limitation category I with an excursion factor of 2. Then, even during the permissible peak concentrations up to 20 ml/m3, no marked irritation is expected. Because of the lack of adequate data for the irritant potential of hexylene glycol, the MAK value must be considered provisional and requires confirmation in further studies. Assuming that 100 % of the inhaled substance is absorbed, exposure to concentrations in the range of the MAK value could result in a daily dose of 7.5 mg/kg body weight which is still below the NOEL determined in animal studies with oral administration, assuming 100 % absorption here too. As there are no reproductive toxicity studies, hexylene glycol is listed in Section II of the List of MAK and BAT Values. The sensitizing potential is low and so the substance is not designated with an "Sh". The solubility of the substance suggests that it would be readily absorbed through the skin, but as the toxicity after repeated dermal application to experimental animals is low, the substance is not designated with an "H"”.
This DNEL was derived using the NOAEL of 450 mg/kg/day from a 90-day oral toxicity study in rats conducted according to OECD test guideline 408 by oral route (Fabreguettes, 1999a), after a route to route extrapolation (oral-to-inhalation x 1/1.15 m3/kg). The absorption by inhalation is expected to be of the same order than the absorption by oral route.
This DNEL was derived using the NOAEL of 450 mg/kg/day from a 90-day oral toxicity study in rats conducted according to OECD test guideline 408 by oral route (Fabreguettes, 1999a), after a route to route extrapolation (oral-to-dermal, x 50%/5%). The oral and dermal absorptions are estimated to be 50 and 5% respectively.
This DNEL was derived using the NOAEL of 450 mg/kg/day from a 90-day oral toxicity study in rats conducted according to OECD test guideline 408 by oral route (Fabreguettes, 1999a).