Reaction mass of butyl diphenyl phosphate and dibutyl phenyl phosphate and tributyl phosphate

Endpoint summary

Additional information

Test result on different species covering different trophic levels and different durations of exposure are available for the test substance of concern (DBPP).

Short-term toxicity data (96h LC50) on 5 different fish species are available, based on 4 different studies. The most recent study (Goodband and Mullee, 2011) is regarded as key study with and LL50 (96h) of 1.8 mg/L. Additionally, there is one 14 -day test with survival and loss of equilibrium as endpoints (Thompson and Forbis, 1979). Effect values were in the same range as those determined after 96 hrs of exposure. With regard to long-term toxicity, there is an ELS-test available in which the fish were exposed for 60 days with the aim to find a Maximum Allowable Tolerance Concentration, based on the evaluation of hatchability of eggs, percentage survival of the fry, growth and growth rate of the fry (both as length and as weight), morphology and behavioural aspects (Boudreau and McAllister, 1980). From that study it was concluded that the NOEC was above 0.11 mg/L as there were no signficant effects up to the highest tested dose.

With regard to invertebrates, different tests assessing the acuteaquatic toxicity towards Daphnia magna are available (Goodband and Mullee, 2011; McAllister et al., 1978; Heidolph et al., 1982; LeBlanc, 1980). The most recent study was determined as the Key study with an EL50 (48h) of 1.4 mg/L as this study is performed according to the most recent guidelines. Additionally, one long-term (21-day) study with Daphnia magna was carried out in 1980 (Altshul et al., 1980) to find the Maximum Tolerable Concentration (MTC) of DBPP for Daphnia magna. The study was carried out according to then existing guidelines and can be regarded as a well-performed study (K2). There were no effects on any of the sublethal endpoints evaluated. Based on the effects on survival (21-days), an EC10 of 0.106 mg/L was determined.

Two algal studies are available, one carried out in 1978 according to then existing guidelines (Hollister and Shuba, 1978) and a recent study (2011) carried out according to existing guidelines and under GLP (Vrijenhoef and Mullee, 2011). The latter study is regarded as the key study and the results from that study is used in further risk assessment. The relevant EC50 value for algae (& DBPP) was 9.6 mg/L, the EC10 was 3.5 mg/L.

Based on the described acute and chronic toxicity information for aquatic organisms it can thus be concluded that Daphnia magna (thus invertebrates) are the most sensitive organisms with an EL50 of 1.4 mg/L (48hr) and an EC10 of 0.106 mg/L (21-days).