Phosphoric acid, mono- and di-isotridecyl esters, potassium salts

Short-term toxicity to aquatic invertebrates

Description of key information

Based on the results of the read across study, the 48 h EL50 of the test substance to daphnia is considered to be 85 mg/L (i.e., corresponding to 85% SS, prepared at a loading rate of 100 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

85 mg/L

Additional information

A study was conducted to determine the short-term toxicity of the read across substance, mono- and di- C12 -18 PSE, Na+, to aquatic invertebrates according to OECD Guideline 202 and EU Method C.2, in compliance with GLP. Twenty daphnids per group (four replicates, five daphnids per replicate) were exposed to a control and to 10 (medium alone), 18, 32, 56 and 100% of the SS and mobility was assessed. The total exposure period was 48 hours and the experiment was realised under the static conditions. Due to the complex nature of the test substance, specific analyses proved to be difficult to obtain and, after consultation with the sponsor, it was decided to analyse the Total Organic Carbon (TOC) concentration as a surrogate measure. Samples for TOC concentrations were taken at the start and after 48 hours of exposure. The TOC analysis performed on samples taken from 10, 18, 32, 56 and 100% of the SS should be regarded as indicative because of the low carbon concentrations. Effect parameters were based on the percentages of the saturated solution prepared at a loading rate of 100 mg/L. The study met the acceptability criteria prescribed by the study plan and was considered valid. Based on the results of the read across study, the 48 h-EL50 was at 85% of a saturated solution prepared at a loading rate of 100 mg/L (95% confidence interval between 73 and 97% of the SS) (Bouwman, 2017).