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Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

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.

No toxic effects occur at the range of water solubility.

The test substance exhibits a very low water solubility (0.020 mg/L at 20°C, BASF 2013). Therefore, bioavailability to aquatic organisms is strongly limited.

All available acute tests for the test substance markedly show that toxic effects only occur far beyond the limit of water solubility.

In a 96-h acute toxicity study of the test item to zebra-fish (Brachydanio rerio) under static conditions the NOEC and LC50 was estimated to be higher than the saturation concentration (undiluted filtrate with a nominal loading rate of 100 mg/L ) (RCC, 2002).

The 48-hr-EC50 of the test item to Daphnia magna under static conditions was determined to be higher than the saturation concentration (undiluted filtrate with a nominal loading rate of 100mg/L), (RCC 2002)

In a 72 hour acute toxicity study of the test item to cultures of Desmodesmus subspicatus the NOErC and ErC50 values based on growth rate were at the saturation concentration and above, respectively (based on undiluted filtrate with a nominal loading rate of 100mg/L) (Noack, 2013).

As supporting information studies on O,O,O-triphenylphosphorotioate in a lower purity ( > 25%) can be used. Valid acute data are available for three trophic levels. The test substance is poorly soluble in water and is a mixture of several components, the undiluted filtrate of water accomodated fraction (WAF) of the test substance at a loading rate of 100 mg/l was tested. In the acute tests no effect was observed with the saturated solution (undiluted filtrate up to 100 mg/L nominal test item concentrations) (fish: RCC 1997, Daphnia: Ciba Geigy 1996). Since the test substance is of low water solubility (< 0.1 mg/L) it can be stated that there are no acute toxicity effects in the range of water solubility. A study to determine the toxicity to algae is also available. No effects were observed in a toxicity study with algae conducted according to OECD guideline 201 (RCC, 1997). The ErC50 after 72 hours of exposure was determined as above and the NOEC equal or above the saturation concentration with the undiluted filtrate based on 100mg/L nominal concentration (RCC, 1997).

No long-term toxicity test to aquatic organisms are available. A chronic toxicity study on daphnids according to OECD guideline 211 under consideration of the OECD no 23 guidance document was performed (BASF, 2015) with O,O,O-triphenylphosphorotioate in a lower purity ( > 25%)

showing no effects up to the saturation concentration (undiluted filtrate with a loading rate of 5.5mg/L (WAF)). Based on these data it can be expected that NOEC and EC for the major constituent CAS 597-82-0 is higher than the saturation concentration using a loading rate of 1mg/L (WAF). Furthermore, in a BCF study according to (GAKUSHUIN UNIVERSITY 1999) 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 CAS 597 -82 -0. The test concentrations of CAS 597 -82 -0 were verified in this test.

In a 3-hr acute toxicity study (Ciba-Geigy 1988) sewage sludge micro-organisms were exposed to the test item at nominal concentrations of 100 mg/L in accordance with OECD 209. The IC50 value based on respiration rate was > 100 mg/L after a 3 h contact time. No effects were observed up to the highest test concentration of 100mg/L (nominal). A study with O,O,O-triphenylphosphorotioate in a lower purity (purity > 25%) supports this results. In this acute toxicity study sewage sludge micro-organisms (RCC 1997) were exposed to the test item at nominal concentrations of 1000 mg/L for 3 hours in accordance with OECD 209. The IC50 value based on respiration rate was > 1000 mg/L after a 3 h contact time. The NOEC was 320 mg/L and EC20 403 mg/L.

Based on the available data on aquatic toxicity it can be stated that the substance shows no toxic effects in the range of water solubility.