Reaction Mass of 1,4-dimethyl-7-(prop-1-en-2-yl)-1,2,3,4,5,6,7,8-octahydroazulene and 3,8-dimethyl-5-(prop-1-en-2-yl)-1,2,3,3a,4,5,6,7-octahydroazulene and 4,8a,9,9-tetramethyldecahydro-1,6-methanonaphthalen-1-ol

Endpoint summary

Additional information

Patchouli ext. is a multi-constituent substance consisting of sesquiterpene hydrocarbons and sesquiterpene alcohols. The acute lethal loading E(L)L 50 values for a mixture may be used directly for classification. The lowest short-term L(E)L50 was for fish with a 96-hour LL50 value of 5.7 mg/L. Since all E(L)L50 values are > 1mg/L, the substance is not classified for short-term hazards to the aquatic environment.

The algal inhibition test also yields chronic effect concentrations. The 72h No Observed Effect Loading Rate (NOEL) value for specific growth rate was 12.5mg/L. Since this is > 1mg/L it does not trigger any long term hazard classification. However, based on the fish 96h LL50 value of 5.7 mg/L and the fact that many constituents have a log Kow of greater than 4.0,  Patchouli ext. is classified as Aquatic Chronic 2 (H411) according to Regulation 1272/2008/EC & adaptation 286/2011/EC (CLP).  

Lethal loading E(L)L 50 values for a mixture cannot be used to derive PNECs since partitioning in the environment will make the comparison with PEC meaningless. To assess environmental exposure and risks of Patchouli oil, three major constituents were chosen to represent blocks of related constituents: alpha-guaiene (represents lower boiling sesquiterpene hydrocarbons), alpha-bulnesene (represents higher boiling sesquiterpene hydrocarbons) and Patchouli alcohol (represents sesquiterpene alcohols).

Chromatographic profiles show that the majority of peak area in the aqueous samples from the acute daphnia, acute fish and algal inhibition studies conducted on Patchouli Oil is from a single peak, which can be assigned to Patchouli alcohol. Given that any low levels of hydrocarbon components present are unlikely to exhibit acute aquatic toxicity at levels up to their limit of water solubility, the patchouli alcohol component is considered the lead substance responsible for the aquatic toxicity of Patchouli Oil. Toxicity data for Patchouli Oil based on loading rates shows that fish is the most sensitive species. Therefore, the 96-hour LC50 value of 1.0mg/L based on the alcohol component of the test item has been used to derive PNECaquatic for the sesquiterpene alcohol block. PNECaquatic for the hydrocarbon blocks has been derived from water solubility data.