Tris(2-ethylhexyl) 2-(acetyloxy)propane-1,2,3-tricarboxylate

Toxicity to aquatic algae and cyanobacteria

Description of key information

The toxicity to aquatic algae was assessed in a test with Pseudokirchnerella subcapitata (reported as Selenastrum capricornutum) according to OECD 201 (2010):
EC50(72h) > 100 mg/L (based on growth rate and yield)
NOEC(72h) ≥ 100 mg/L (based on growth rate and yield)
LOEC(72h) > 100 mg/L (based on growth rate and yield)

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

The acute toxicity to aquatic algae and cyanobacteria of tris(2-ethylhexyl) 2-(acetyloxy)propane-1,2,3-tricarboxylate was tested according to OECD guideline 201 and EU Method C.3 in an Algal Growth Inhibition Limit Test with the freshwater green algae Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum) as test organism (2010). The study was conducted under certificated GLP compliance. Since the test item is not soluble in test water, a water accommodated fraction of the only test concentration of nominal 100 mg test item/L was tested. Thus, no concentration above the solubility limit of the test item in the used test water was tested. Additionally, a control was tested in parallel. Thus, a limit test in accordance with the OECD Series on testing and assessment No. 23 was performed to demonstrate that the test item has no inhibitory effect on the growth of the test organism up to the solubility limit in the used test water. The study encompassed 2 treatment groups (1 dose rate of the test item, control) with three replicates per test concentration and six replicates for the control. At test start 50 mL of the test concentration were inoculated with 5000 algal cells per mL test medium. These cells were taken from an exponentially growing pre-culture, which was set up 4 days prior to the test start under the same conditions as in the test. For the determination of the LOEC and the NOEC after 72 hours, the calculated growth rates and yields at the only test concentration were tested for significant differences compared to the control values. However, the software was not able to calculate NOEC and LOEC values. Analysis of the yield and growth rate of the algal population within 72 h exposure period gave the following results: The NOErC (72h) and the NOEyC (72h) were determined to be at least nominal 100 mg test item/L. The NOEC values might even be higher than this concentration, but concentrations in excess of nominal 100 mg test item/L or the limit of solubility have not been tested according to the recommendations of the test guidelines. The LOErC (72h), the LOEyC (72h), the ErC50 (72h) and the EyC50 were clearly higher than nominal 100 mg test item/L (mean measured: clearly higher than 79 mg/L). No toxic effects against algae were observed at the limit of water solubility under these exposure conditions.