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Ecotoxicological information

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Additional information

Short-term toxicity to aquatic organisms

Experimental acute toxicity results of tributyl citrate are available for aquatic invertebrates (Boettcher and Wydra, 2010) and aquatic algae (Boettcher and Wydra, 2010). The short-term toxicity to fish was predicted by means of ECOSAR v1.00 (EPIWIN prediction, by US-EPA), using the SAR for esters.

Daphnia magna was used as test organisms in a static immobilisation test for 48 hours according to OECD Guideline 202 and EU Method C.2. At a concentration of 100 mg/L all animals were found to be immobile and the EC50 (48h) was determined to be 66.89 mg/L.

The toxicity of tributyl citrate towards aquatic algae and cyanobacteria was tested according to OECD Guideline 201 and EU Method C.3 with Pseudokirchneriella subcapitata as test organisms. After an exposure time of 72 h, the following results are reported concerning the growth rate of the algae: an EC50 of 100.4 mg/L, the NOEC as 6.0 mg/L with the associated LOEC of 9.7 mg/L. With regard to yield of biomass the EC50 (72h) was determined as 23.86 mg/L with the same NOEC and LOEC values as presented before.

The short-term toxicity to fish was predicted by ECOSAR v1.00, which resulted in a LC50 (96h) of 6.80 mg/L, concerning SAR for ester and suggesting only a low toxicity concern. The experimentally determined water solubility of the substance (102.7 mg/L, Frischmann, 2011) as well as the logPow of 3.50 (Frischmann, 2011) were used as input.

Long-term toxicity to aquatic organisms

No chronic investigations were performed regarding toxicity towards aquatic biota for tributyl citrate. Taken into account the available experimental results, the substance can be considered to be rapidly degraded in the aquatic environment and the bioaccumulation potential is low. With respect to animal welfare, no long-term study is intended in accordance with REACH Regulation.

Toxicity to aquatic microorganisms

Since the substance was found to be readily biodegradable (Feil, 2010), no activated sludge respiration inhibition test needs to be conducted in accordance with REACH, Annex VIII, Section 9.1.4, Column 2. Furthermore, in the toxicity control of the biodegradation test conducted according to OECD Guideline 301 F no inhibition of the activated sludge was observed and the PNEC STP can be calculated with the help of the applied test concentration (Guidance from ECHA, Chapter R.10, Part R.10.4.2, 2008).