Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

not chronically toxic to Daphnia magna in the range of solubility

Key value for chemical safety assessment

Additional information

In a chronic toxicity test on Daphnia magna reproduction according to OECD 211 O,O,O-triphenylphosphorotioate in a lower purity (purity > 25%) was investigated at saturation concentration(BASF 2015). As the test substance is a UVCB substance which is sparingly soluble in water, the test solution was prepared following general guidance provided in OECD 23 in order to generate a water accommodated fraction of the test substance in test medium (undiluted filtrate up to a loading rate of 5.5 mg/L). This substance is a complex substance containing as major component CAS 597-82-0 > 25%. As no adverse effects were observed up to the highest tested applied concentration it can be assumed that also CAS 597-82-0 does not cause adverse effects at saturation concentration below or equal to a loading rate of 1mg/L, correspondingly.

An older study on chronic toxicity to Daphnia (Wildlife International, 2003) with O,O,O-triphenylphosphorotioate in a lower purity (purity > 25%) is available and was re-evaluated for validity and considering the latest recommendations of OECD No. 23: Guidance Document on the Aquatic Toxicity Testing of Difficult Substances and Mixtures it is concluded that the study suffers from major flaws which are related to improper preparation of the test solutions resulting in the presence of undissolved test substance in the test vessels. Since the test item (EC 421-820-9) is a multi-constituent substance, test solutions for aquatic ecotoxicity tests should be prepared as water accommodated fractions (WAF) as recommended by OECD No. 23: Guidance Document on the Aquatic Toxicity Testing of Difficult Substances and Mixtures (the available acute tests on fish, Daphnia and algae were prepared as WAF solutions resulting in NOECs > 100 mg/L). In the present test, the test solutions were prepared as dilutions of a solvent stock solution. Measured concentrations of the stock solutions were 94 -97% of nominal but the measured test solutions were 38 -88% of nominal. This level of variability in the analytical results is typically indicative of undissolved substance. The report also confirms the visual presence of undissolved substance in the diluters. The OECD No. 23 guidance document explicitly discourages both the use of solvents and serial dilution when testing multi-component substances. Therefore, the study is not reliable and was not further considered in the ecotoxicological risk assessment.

This study (Wildlife International, Ltd., 2003) was invalidated due to major flaws related to improper preparations of the test solutions. To adequately adress the substance' toxic potential a chronic toxicity study on daphnids according to OECD guideline 211 under consideration of OECD guidance no 23 was performed showing no effects at saturation concentration up to a loading rate of 5.5mg/L (WAF).

Overall, it can be concluded that O,O,O- triphenyl thiophosphate is not chronically toxic to Daphnia magna in the range of solubility.