O,O,O-triphenyl phosphorothioate

Endpoint summary

Additional information

Note: The substance is currently under evaluation as part of the Community Rolling Action Plan 2016 (Member State: The Netherlands). Studies required in the final decision are ongoing.

 

Short-term toxicity tests for three trophic levels are available. No toxic effects occur at the range of water solubility. All available acute tests show that the substance does not exert adverse effects to aquatic organisms up to the limit of solubility in water (0.020 mg/L at 20 °C, BASF 2013).

One long-term toxicity study on daphnids with O,O,O-triphenyl phosphorothiate is available (BASF, 2021). In the key study a stock solution was prepared using a solid-liquid (slow-stir) saturator technique to achieve the saturation concentration of 7.24 µg/L. No significant mortality or any other additional significant adverse effects or abnormal behavior were observed in any of the test treatments. The test substance did not have a chronic toxic effect on Daphnia magna up to the saturation concentration of 7.24 μg/L.

A chronic toxicity study on daphnids according to OECD guideline 211 under considering the OECD no 23 guidance document was performed with O,O,O-triphenyl phosphorothioate in a lower purity ( > 25%; BASF 2015). The test showed no effects up to the saturation concentration (undiluted filtrate with a loading rate of 5.5 mg/L (WAF)). Based on these data it can be expected that the 21d-NOEL is higher than the saturation concentration using a loading rate of 1 mg/L (WAF). Furthermore, in a BCF study performed with the substance of lower purity (> 25%) no adverse effects on fish were observed during 56 days of exposure in concentrations within the solubility range of the test substance (Gakushuin University 1999). The test concentrations of the test substance were verified in this test. 

 

In a 3h acute toxicity study sewage sludge micro-organisms were exposed to the test item at nominal concentrations of 100 mg/L in accordance with OECD guideline 209 (Ciba-Geigy 1988). The IC50 value based on respiration rate was > 100 mg/L after a 3h contact time. No effects were observed up to the highest test concentration of 100 mg/L (nominal). A study with O,O,O-triphenyl phosphorothioate in a lower purity (purity > 25%) supports this results. In this acute toxicity study sewage sludge micro-organisms were exposed to the test item at nominal concentrations of 1000 mg/L for 3h in accordance with OECD guideline 209 (RCC 1997). The IC50 value based on respiration rate was > 1000 mg/L after a 3h contact time. The NOEC was 320 mg/L.

 

Based on the available data on aquatic toxicity it can be stated that the substance is neither acutely harmful nor harmful at chronic exposure up to its limit of solubility in water. The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate low concentrations.