Commiphora myrrha, ext.

Endpoint summary

Description of key information

Valid acute studies based on international guidelines are available for the two required aquatic trophic levels (aquatic invertebrates and algae). Water Accommodated Fractions (WAFs) were used to test this resin, whereby the concentrations of dissolved organic material were checked by analysis of the Chemical Oxygen Demand (ST-COD) at the start and every day thereafter until the end of each test. Although every effort were made in a first time to extract and solubilise the soluble fraction of the substance in test water (heating, sonication, mixing without headspace) and secondly to maintain the concentrations of the WAFs (semi-static for the acute Daphnia study and closed conditions without headspace for both tests), COD analyses indicate that significant losses of test material occurred in the WAF preparations but concentrations were overall stable throughout the exposure period although this is not unusual as non-soluble fractions are excluded from WAFs. For the aquatic invertebrate Daphnia magna, no immobilisation of the test animals was observed after 48 hours of exposure in the control and the loading rate of 100 mg/L. For the green algae species Pseudokirchneriella subcapitata, a very slight inhibition of algae growth after 72 hours relative to control values was observed at 100 mg/L (loading), but lower than 10%. Therefore, under the experimental conditions and based on nominal concentrations, the 48h-EL50 and 72h-ErL50 values were determined to be higher than 100 mg/L (loading).