Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Patchouli, ext. and its underlying constituents are regarded as readily biodegradable based on the level of degradation achieved over 28-days in a ready biodegradablity screening test (OECD 301F). In addition, at the concentration used in the test (100 mg/L), it is not inhibitory to micro-organisms.

Further biotic degradation testing and the assessment of hydrolytic stability have not been conducted. Since Patchouli, ext. is readily biodegradable simulation tests and a hydrolysis test will provide little additional information as rapid mineralisation in the environment is already assumed.

Information on phototransformation in air, water and soil is not available. It is not a standard information requirement under REACH.

For complex mixtures (such as Patchouli, ext.) a single value of Koc and BCF will not be definitive. Thus for environmental exposure assessment, the Koc of the three peaks in the HPLC method (OECD 121) were assigned to the three major constituents representing blocks of related constituents in Patchouli, ext. These are alpha-guaiene, alpha-bulnesene and patchouli alcohol. The Koc values are 42658, 38019 and 4265 respectively. For the purposes of the environmental risk assessment, the BCF of these three constituents has been estimated using log Kow based QSARs. The values used in the CSA are 19700, 15670 and 482 respectively. The range of Kow values determined from a HPLC method for Patchouli ext. have been used to screen for bioaccumulation potential for the purposes of classification and PBT assessment. Since a significant fraction of Patchouli, ext. has partition coefficients greater than 5.7, the substance is considered to bioconcentration for classification purposes and to meet the screening bioaccumulation criterion for PBT/vPvB assessment purposes.