Nonyl acetate

Toxicity to aquatic algae and cyanobacteria

Key value for chemical safety assessment

EC50 for freshwater algae:

1.8 mg/L

EC10 or NOEC for freshwater algae:

0.78 mg/L

Additional information

The effects of nonyl acetate on the growth of the unicellular green alga, Pseudokirchneriella subcapitata, were determined during a 72-hour growth inhibition toxicity test conducted in accordance with OECD Chemicals Testing Guideline No. 201 Alga, Growth Inhibition Test (adopted 23 March 2006) (Annex 5 corrected 28 July 2011).

All validity criteria were met therefore the test was considered valid.

Based on geometric mean measured test concentrations, the 72-hour EyC50 and the 0-72 hour EbC50 and ErC50 values were calculated to be 1.2, 1.0 and 1.8 mg/L, respectively.

The corresponding EC10 values for yield, biomass and specific growth rate after 72 hour were 0.033, 0.038 and 0.78 mg/L.

The corresponding NOEC values for yield, biomass and specific growth rate after 72 hours were <0.065, 0.065 and 0.31 mg/L, respectively.

The preferred observational end point in this study is algal growth rate inhibition because it is not dependent on the test design (ECHA guidance Chapter R.7b v1.1) and classification should be based on the ErC50 (EU CLP regulation No 1272/2008 and its adaption 286/2011). In terms of the NOEC and EC10 values, there is a preference for use of the EC10 value because it is derived from the dose response curve. In contrast the NOEC depends on the experimental design (e.g. the concentrations used in the test). Thus the 72-h EC50 and EC10 based on growth rate are used for classification purposes.