(Z)-octadec-9-enol

Toxicity to aquatic algae and cyanobacteria

Description of key information

non-toxic at the limit of solubility (read-across)

Additional information

No reliable measured data are available for long-term toxicity of (z)-octadec-9-enol to algae.

(Z)-octadec-9-enol has been estimated, by expert judgement based on read-across from other taxonomic groups and the alcohols Category, to be non-toxic at the limit of solubility to the algal taxonomic group. Therefore the EC₅₀ value is >0.042 mg/L.

Discussion of trends in the Category of C6-24 linear and essentially-linear aliphatic alcohols:

The data for single carbon chain length LCAAs show toxicity to increase from an ErC₅₀ of 80 mg/L for C6 to 0.33 mg/L for C12. The C14 and C16 LCAAs were not toxic to algae, indicating a toxicity cut-off at C14 and above. Two of the studies determined NOECs that are suitable for assessing long-term toxicity. A NOEC of 11 mg/L has been reported for hexan-1-ol based on measured exposure concentrations. A test with dodecanol resulted in a 72-h EC₀ (equivalent to a NOEC) value of 0.085 mg/L.

Other algal studies used a WAF methodology and/or used test concentrations greater than the limit of water solubility and/or did not report a NOEC or equivalent statistic.

The data for mixed carbon chain length LCAAs (commercial products) shows that substances containing LCAAs with carbon numbers in the ranges of C7-9 to C12-15 exerted toxicity at concentrations of between 3.1 and 0.043-0.092 mg/L. At these concentrations all the constituents are likely to have been fully dissolved. For the C12-18 and C14-15 multi-constituent substances there was evidence of toxic effects in tests conducted on water-accommodated fractions prepared at loading rates that will have exceeded the solubility of some constituents.