Turpentine Oil
MAK Value Documentation, addendum – Translation of the German version from 2017
Andrea Hartwig1 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)MAK Commission2
1 Department of Food Chemistry and Toxicology, Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
2 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany
Abstract
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated turpentine oil, considering all toxicity endpoints.
Turpentine oil [8006‐64‐2] is a mixture of different terpenes, terpenoids and terpene hydrocarbons, mostly mono and bicyclic monoterpenes like pinene, camphene, dihydropinene, carene or dipentene (limonene) with the main component being alpha‐pinene with 60 to 86%. In 14‐week studies with alpha‐pinene in rats and mice, the critical effect was hyperplasia of the epithelium of the urinary bladder in mice at 100 ml/m3 with a no observed adverse effect concentration (NOAEC) of 50 ml/m3. No irritation was observed up to the highest concentration of 400 ml/m3 in rats and mice. Taking into account that the systemic NOAEC might be lower after chronic exposure and with the increased breathing volume of workers, a maximum concentration at the workplace (MAK value) of 5 ml/m3 was derived for turpentine oil. This concentration is far below 80 ml/m3, at which changes in bronchoalveolar lavage fluid were observed in volunteers after short‐term exposure to a mixture of alpha and beta‐pinene and delta‐carene and which is below the NOAEC for alpha‐pinene of 40 ml/m3 for sensory irritation in humans.
The MAK value was derived from a systemic effect; therefore, turpentine oil is classified in Peak Limitation Category II with an excursion factor of 2.
Turpentine oil and its major constituents do not have genotoxic potential. There are no carcinogenicity studies available with turpentine oil or its major components. Results of a dermal initiation‐promotion study with turpentine oil alone were negative; promoting activity was seen only after application of an initiator. Turpentine oil is no longer classified as carcinogenic to humans, based on the Commission's evaluation of this type of study.
A significant contribution to systemic toxicity was demonstrated in a model calculation of dermal absorption and turpentine oil is designated with an “H”. Due to the data described in the evaluation of 1996, turpentine oil continues to be designated with an “Sh”.
Valid developmental toxicity studies are lacking; therefore, turpentine oil is assigned to Pregnancy Risk Group D.
