Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Three studies are available in three different fish species. Of these, two tested for the required period of 96hrs and both gave consistent results. The key study indicated an LC50 somewhere between 20mg/l (the LC100) and 40mg/l (the LC0). The estimated LC50 of 28mg/l is used as the key value. There are no chronic fish studies available but these are not required to establish a suitable PNEC.

A number of studies in invertebrates have been carried out using multiple species, both fresh and salt water. These indicate that 2 -butoxyethyl acetate is somewhat toxic to invertebrates. A number of studies are available in the preferred species daphnia magna. One of these was not performed for the normally required 48hrs (only 24hr studies) however 3 studies were carried out for the requisite period. Of these studies, two of the study reports are available (Devillers and BASF) and the average of these two results is used as the value for the key parameter for fresh water. One reliable chronic study is available in invertebrates. There is no chronic data available in saltwater species.

There is limited data available on the toxicity of 2 -butoxyethyl acetate to algae, but sufficient to meet the requirements of the end point. Two experimentally derived results are available, both showing relatively low toxicity to the species. The study used to derive the key parameter shows the lower of the two results and is to a modern protocol. It is deemed reliable, although the available publication is not particularly detailed. Overall, the data is sufficient to judge with confidence that the substance is of low toxicity to algae and is sufficient to provide a NOEC for use in deriving the PNEC for the aquatic compartment.

Three valid studies in micro-organisms are available. One of these was effectively a limit test and showed no significant effects on sewage derived micro-organisms up to the top dose tested of 500mg/l. The second test showed an EC20 value of around 900 -1000mg/l. The third test was a toxicity test using the bacteria Pseudomonas putida. Both EC10 and EC50 values were determined. The results from this were consistent with the sewage sludge results and since they are absolute values for the effects are therefore used to derive the key parameters. Clearly the substance has relatively low toxicity to bacteria.

Two long term test results from two species representing two trophic levels (primary consumers and primary producers) will be used to derive the PNECaqua for this substance.