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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Description of key information

The EC50 daphnia is 468 µg/L based on test material, derived from a 21d-daphnia test according to OECD TG 211. The EC50 is 465 µg/L converted to active ingredient content.

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
465 µg/L

Additional information

For Quaternary ammonium compounds, C12-18-alkylbis(hydroxyethyl)methyl as registered, no studies on the acute toxicity to aquatic invertebrates are available. The 21d-EC50 determined in a long term OECD 211 test (reliability 1) is used as a worst case key value for the short term toxicity to aquatic invertebrates. Furthermore, read-across is used as supporting information for this endpoint. The two supporting studies (OECD 202) are performed with quaternary ammonium compound C12 and quaternary ammonium compound C14 (both reliability 4, because no GLP, no certificates of analysis of the technical products were available, nominal concentrations based on test material).

The two read-across studies were conducted in a period when no reliable specific method of analyses was available. The concentrations were therefore not analytically verified. The substance is known for its poor water solubility and the strong tendency to adsorb onto the walls of test vessels. Therefore it was decided to perform a number of higher tier chronic invertebrate studies with analytical monitoring of the test concentrations. These higher tier tests were performed in river water to allow a PECaquatic,bulk/PNECaquatic,bulk approach for the environmental risk assessment. The long term 21d-EC50 for parental mortality determined in the OECD211 test with river water (reliability 1) was used as the key value for acute toxicity for daphnia in the chemical safety assessment. 

The 21d-EC50 of 468 ug/l was determined according to OECD TG 211.The study was assigned reliability 1 as all validation criteria were fulfilled (GLP,complete identification of test substance, including chemical analyses). The effects are expressed as nominal values because the tests were performed with river water as they are intended to be used in an evaluation of the environmental risks based on the bulk approach. Further experimental details of the key study are described in the section on long term toxicity to aquatic invertebrates.