Registration Dossier
Registration Dossier
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EC number: 203-905-0 | CAS number: 111-76-2
Sediment toxicity
Administrative data
Link to relevant study record(s)
Description of key information
The EC50 value as shown below is derived using the partitioning equation, starting with the EC50 value of 2910mg/L, a logKow of 0.81 and the substance type as 'alcohols', to derive and EC50 in units of mg/kgdw sediment.
Key value for chemical safety assessment
- EC50 or LC50 for freshwater sediment:
- 11 400 mg/kg sediment dw
Additional information
In a study designed to generate data to prepare a QSAR model, the acute (48hr) and chronic (96hr) toxicity of 2 -butoxyethanol to the soil/sediment dwelling species C. Elegans was assessed. Acute toxicity was measured in terms of mobility as a proxy for lethality with a derived LC50 values of 2910mg/L. Chronic toxicity was measured in terms of impact on reproduction and growth rate with EC50 values of 1710mg/L and 2750mg/L respectively for these two end points. It is notable that the chronic toxicity 50th percentile for chronic toxicity is <2x lower than that for acute toxicity which suggests that the default factor of 10 normally used in extrapolating from acute to chronic toxicity is excessive for this substance. This should be taken into account when assessing the PNEC for sediment. However, since the PNEC aquatic is derived from a full set of chronic data, it is preferable to derive the PNEC for sediment from this by the equilibrium partitioning method rather than from a single acute toxicity value for a sediment dwelling species. The latter data does support the hypothesis that there is no significant difference in sensitivity between species from different trophic levels.
A waiver for this end point is retained as there is no chronic EC10 or NOEC available.
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.
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