Reaction products of diphosphorus pentaoxide and alcohol C7-9-iso, C8 rich, salted with 2-ethylhexylamine

Short-term toxicity to aquatic invertebrates

Description of key information

Read-across substance_Phosphoric acid, mono- and di-(C8-C10) ester, compds. with C12 - 14 amine_Daphnia magna_OECD 202: EL50(48h): 16 mg/L loading rate WSF (95 % CL: 14 - 19 mg/L loading rate WSF); NOEC(48h): 10 mg/L loading rate WSF

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

16 mg/L

Additional information

The target substance (Reaction products of diphosphorus pentaoxide and alcohol C7-9-iso, C8 rich, salted with 2-ethylhexylamine) was not investigated for its acute toxicity effects towards freshwater invertebrates. In order to fulfil this endpoint, an experimental result conducted with the source substance "Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine" is reported. The basic structure of the target and source substance is the same: aliphatic ester of phosphoric acid and a primary aliphatic amine. Thus, both represent a mixture of mono- and di-alkyl phosphates salted with an alkyl amine. Therefore it can be assumed that also the same mode of action in organisms will take place. For further details, please refer to the separate read-across statement of Chemservice S.A. (2013d).

The read-across substance (Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine) was investigated according to OECD Guideline 202 using the freshwater invertebrate Daphnia magna as test organism (Wetton, 1999b). The test solutions were prepared as Water Soluble Fractions (WSFs) based on the poor water solubility. The test substance is thereby mixed with a prolonged period of time (24 - 48 h) with water with subsequent filtration to separate the test substance phase. Based on the results of a preliminary range-finding experiment, the definitive test was conducted with nominal loading rates of 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg/L WSF. Duplicate vessels were prepared for each test and control group using 10 daphnids per concentration. Evaporation was reduced by coverage of the vessels. A photoperiod of 16 h light and 8 h dark with 20 min dusk and dawn transition periods was employed. The test solutions were not renewed during the exposure period. Water temperature was recorded daily throughout the test. Dissolved Oxygen Concentration (DOC)and pH were recorded at the start and termination of the study. Water samples were taken from all groups at 0 and 48 hours for Total Organic Carbon (TOC) analysis. The moving average method of Thompson (1947) was used to calculate the EL50 values and associated confidence limits. During testing, all WSFs were observed to be clear, colourless solutions. The temperature was maintained at 21 °C. There was a general trend for increasing carbon concentration with increasing loading rate. As final results, the EL50(48h) was determined to be 16 mg/L loading rate WSF with 95 % confidence limits of 14 - 19 mg/L loading rate WSF. The No Observed Effect Loading Rate (NOELR) was 10 mg/L loading rate WSF.