Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

In a good quality and reliable OECD guideline study conducted with C16-C18 TMAC, the ErC10 (0 -72 hours) and ErC50 of test substance for Pseudokirchnerella subcapitata were 0.094 and 0.155 mg a.i./L, respectively. The NOEC and LOEC for effect on algal growth and growth rate was determined to be 0.08 and 0.205 mg a.i./L, respectively.

Key value for chemical safety assessment

EC50/LC50 for freshwater algae:
0.155 mg/L
EC10, LC10 or NOEC for freshwater algae:
0.094 mg/L

Additional information

An OECD guideline study was conducted to determine the toxicity of exponentially growing algae Pseudokirchnerella subcapitata exposed to C16-C18 TMAC over an exposure period of 72 hours. In the definitive test the algae were exposed to the nominal concentrations of0.008, 0.019, 0.048, 0.120 and 0.300 mg a.i./L. Algal cell concentrations were determined spectrophotometrically. All the validity criteria were fulfilled. Analytical assessment was performed for the test substance in aqueous samples (i.e., OECD medium), at the beginning and end of the test. Procedures and instrumentation were based on High Performance Liquid Chromatography combined with mass spectrometry (LC-MS/MS). The test substance concentration decreased below 80% of the nominal and initial concentrations during the test. This is because surfactant based substances are known to bind to algae cells actually stimulating complete exposure. This is however not measurable analytically as removing the test substance entirely from the algae cells making it available for analysis is not always achievable. This difficulty is acknowledged in the OECD test guideline and a use of the measured initial concentration is therefore considered acceptable for this type of test substance. Under the study conditions, the ErC10(0 -72 hours) and ErC50of test substance for Pseudokirchnerella subcapitata were 0.094 and 0.155 mg a.i./L, respectively. The NOEC and LOEC for the effect on algal growth and growth rate was determined to be 0.08 and 0.205 mg a.i./L, respectively (Gyimesi M et al., 2012).