Iodonium, bis[4-(1,1-dimethylethyl)phenyl]-, hexafluorophosphate(1-) (1:1)

Toxicity to aquatic algae and cyanobacteria

Description of key information

EC50 (96 h) = 72 µg/L (growth rate) and 57 µg/L (yield) for Pseudokirchnerella subcapitata (OECD 201)
NOEC (96 h) = 10 µg/L (growth rate) and 10 µg/L (yield) for Pseudokirchnerella subcapitata (OECD 201)

Key value for chemical safety assessment

EC50 for freshwater algae:

72 µg/L

EC10 or NOEC for freshwater algae:

10 µg/L

Additional information

The short-term toxicity of PF-6 (CAS 61358-25-6) was investigated in a GLP guideline study. The static test was performed according to OECD 201 (Kimmel, 2012) with the green algae Pseudokirchnerella subcapitata. The undiluted filtrate was used as a stock solution for preparation of the filtrates of 1:100 and 1:220. The filtrates of 1:460, 1:1000, 1:2200, 1:4600 and 1:10000 were prepared by a further serial dilution with test water. The test item concentration in the test samples was determined by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). At the start of the test, the analytically determined concentrations of PF-6 in the test media (dilutions 1:2200, 1:1000, 1:460, 1:220 and 1:100) were 39.9, 88.6, 218, 415 and 971 μg/L, respectively. During the test period of 96 hours, a decrease of test item concentration in the test media occurred which is probably related to adsorption to negatively charged algal cells. At the end of the test, 0.40 to 52% of the initially measured concentrations were found. The EC50 was calculated to be 72 µg/L (growth rate) and 57 µg/L (yield) and the NOEC was determined at 10 µg/L for both basis of effect based on the measured concentrations.