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Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

A number of studies have been carried out using multiple species of fish, both fresh and salt water. One study in two species is sufficiently well reported to judge it as reliable and this is used to derive the key parameters. All the other available experimental studies, whilst not individually robust, report data that is consistent with the key study and provide strong evidence that 2 -(2 -butoxyethoxy)ethanol is practically non-toxic to fish over the acute timeframe. The acute LC50 value is 1300mg/l.

A number of studies have been carried however there is no single 48hr study that determines an actual EC50 value for invertebrates. The most reliable is a GLP protocol limit test which clearly establishes an EC50 value of 100mg/l. Other experimental studies are only for 24hr exposure periods. In conjunction with the results from QSAR models it can be concluded that the EC50 is likely to be in excess of 1100mg/l.

There sufficient data available on the toxicity of 2 -(2 -butoxyethoxy)ethanol to algae. There is a guideline and GLP limit test study available which confirms that the substance is of low toxicity and a guideline value from another study indicating an EC50 value of 1100mg/l.

QSAR models predict that algae is likely to be the most sensitive species, with LD/EC50 values of 3978, 1742 and 394mg/l in fish, invertebrates and algae respectively. There is no chronic data available, but the same model predicts the chronic NOEC values would be in the same order of sensitivity at 369, 154 and 113mg/l respectively. This information is taken into account in setting appropriate assessment factors to derive the PNEC.

A number of studies have been carried out to assess the toxicity of 2 -(2 -butoxyethoxy)ethanol to micro-organism using multiple species in fresh water. These studies that are reliable indicate that the substance is practically non-toxic to micro-organisms. One study reported lower toxicity threshold to one particular species than the value chosen as the key parameter. Since this study was performed over a longer period than is usual, its use is likely to over-estimate the toxicity of the substance. The key parameter also comes from a study using a 'standard' bacteria which are relevant to the degradation of substances in waste water treatment plants. The EC0 value is 1995mg/l