Abstract
Pentanols
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of 20 ml/m3 for pentanols, considering local and systemic toxicity as well as developmental toxicity. Pentanols are irritating to skin and eyes. In rats, the most sensitive effect due to irritation from 2‐methyl‐2‐butanol is lacrimation at 225 ml/m3 with a NOAEC of 50 ml/m3. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. However, the NOAEC for lacrimation in the absence of histopathological effects cannot be extrapolated to humans and the MAK value of 20 ml/m3 is confirmed. Peak Limitation Category I is retained due to local effects. The former excursion factor of 4 seems too high and is reduced to 2 as for linear alcohols, whose chain length is inversely associated with their eye irritating capacity, which is assumed to be similar for branched alcohols. Compared with butanols with a peak limit concentration of 100 ml/m3 and 4‐methyl‐2‐pentanol with a peak limit concentration of 10 ml/m3, the irritating potency of pentanols is supposed to be in between. Previous developmental toxicity studies showed no risk for the foetus if the MAK value is observed; as there are no new studies available, Pregnancy Risk Group C is retained.
Hartwig, A