Bis(2-ethylhexyl) hydrogen phosphate

Short-term toxicity to aquatic invertebrates

Description of key information

For bis(2-ethylhexyl) hydrogen phosphate the most reliable and sensitive toxicity value on Daphnia magna is 48h-LC50 of 60.7 mg/l.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

60.7 mg/L

Additional information

For bis(2-ethylhexyl) hydrogen phosphate two tests assessing the toxicity towards aquatic invertebrates are available.

The most reliable and sensitive toxicity value is obtained in a static test, where Daphnia magna was exposed to bis(2-ethylhexyl) hydrogen phosphate for 96 hours. The experiment was designed to reveal possible influence of two alternate procedures for preparation of test solutions. Acetone was used as co-solvent and also added to the control. There was no guideline stated but the test was performed in Standard Reference Water as recommended by ISO (1977) under generally accepted scientific principles and is widely in accordance with OECD guideline 202. The deviation was that the neonates were less than 66 h old instead less than 24 h. The test was conducted with 9 - 14 animals in duplicate or triplicate at a temperature of 20 +/-0.5°C. The pH was in the range of 8.0 - 8.4. Dead and life animals were recorded after 3, 24, 48, 72 and 96 h. The animals were classified as dead when their second antenna did not move within 15s after irrigation. Other reactions of the animals like swimming at the surface and general activity (swimming or resting) were also recorded. Analytical monitoring was not carried out. LC50 values and 95 % confidence limits were calculated using probit analysis. The values at 72h and 96h are not taken into account for assessment as for daphnids a test duration of 48 hour is standard (Guidance R.7b, ECHA, 2012). Using acetone, a 48h-LC50 of 60.7 mg/l was obtained. A 48h-LC50 of 80.3 mg/l is obtained without the use of acetone. Thus, addition of acetone to a final concentration of 0.5 mL/L (0.025% v/v) was not found to have an influence to results. ). Despite no details on amount of test concentrations were reported and the age of daphnids is > 24 h, the study was considered as sufficiently reliable to serve as key study.

In the second test, with a static test system a 48h-LC50 of > 42 mg/L related to nominal concentrations was observed on Daphnia magna. The LC50 was above the highest concentration tested. There was no guideline stated but the test was performed in Standard Reference Water as recommended by ISO (1977) under generally accepted scientific principles. Neonates (< 24h old) were exposed to bis(2-ethylhexyl) hydrogen phosphate. The test was performed with 9 - 12 concentrations and a control with 12 - 15 animals. The pH was in the range of 7.8 - 8.2 and the temperature was 20 - 23°C. Acetone was used as co-solvent and also added to the control (0.025% v/v). No analytical monitoring was carried out. Despite no details on amount of test concentrations were reported the study was considered as reliable and useful for assessment as a supporting study.