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EC number: 202-075-7 | CAS number: 91-53-2
The Chronic toxicity value (ChV) for daphnids of the substance ethoxyquin was determined by the QSAR program ECOSAR Version 1.11 (EPIWIN software) by US-EPA.The ECOSAR Class Program is a computerized version of the ECOSAR analysis procedures as currently practiced by the Office of Pollution Prevention and Toxics (OPPT), and estimates log Kow values using the US EPA's KOWWIN Program.The ChV, or Chronic Value, is defined as the geometric mean of the no observed effect concentration (NOEC) and the lowest observed effect concentration (LOEC).
When collecting studies for inclusion in the training sets, standard test species were preferred as identified in OPPTS guidelines for aquatic toxicity testing. Species frequently include Daphnia magna or Daphnia pulex.
The Chronic values were determined to be 0.907 mg/l for daphnids.
Adequacy of the QSAR:
- QSAR model is scientifically valid.
- The substance falls within the applicability domain of the QSAR model.
- The prediction is fit for regulatory purpose.
ChV = 0.907 mg/L for daphnids (ECOSAR estimation)
The Chronic values was determined to be 0.907 mg/l for daphnids.The ChV, or Chronic Value, is defined as the geometric mean of the no observed effect concentration (NOEC) and the lowest observed effect concentration (LOEC). This can be mathematically represented as: ChV = 10^([log (LOEC x NOEC)]/2). As a result, the NOEC cannot be adequately determined to select the required key value for safety assessment.
According to REACH Annex IX column 2, Long-term toxicity testing shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the effects on aquatic organisms. The choice of the appropriate test(s) depends on the results of the chemical safety assessment.
Based on the available short-term information on daphnids, the EC50 (48 h) = 2.0 mg/L for daphnia magna (OECD II A 8.3.1, flow-through)
does not trigger classification as acute toxic to the environment. Taking however into account the fact that ethoxyquin is not readily biodegradable, and the BCF is not available, the logPow however was determined to be 3.39 at pH 7 (i.e. < 4), this value would trigger classification as hazardous to the aquatic environment Category Chronic 2. In consequence, QSAR estimation was performed to determine the absolute necessity for classification. The ChV was determined as 0.907 mg/l for daphnids, but a NOEC could not be determined by the ECOSAR program. According to Regulation 1272/2008 as amended, non-rapidly degradable substances must be classified as chronic 2 if the NOEC is <= 1 mg/l. As, based on the equation given above, the NOEC is expected to be >0.1 and <1 mg/l, also QSAR estimation would trigger the same classification. Hence, the necessity for further testing is not given, as both available values consistently trigger classification as hazardous to the aquatic environment Category Chronic 2.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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