Methyl 12-hydroxyoctadecanoate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

no hazard identified

Marine water

Hazard assessment conclusion:

no hazard identified

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

1.4 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

no hazard identified

Sediment (marine water)

Hazard assessment conclusion:

no hazard identified

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Conclusion on classification

In the absence of adequate aquatic chronic toxicity information from all three trophic levels, the classification was based on short-term aquatic toxicity values (72-h NOELR = 100 mg/L in algae, 48-h NOELR = 100 mg/L in daphnids, 96-h NOEC = 1,000 mg/L in fish). Based on the results of these three tests conducted on an analogue substance, no toxicity was observed in any of the three trophic levels; furthermore,there is no evidence that the acute toxicity tests do not provide a true measure of the intrinsic toxicity of the substance. The substance was shown to be readily biodegradable (i.e., 80% degradation in 28 d, meeting the 10-day window) and therefore is not expected to be persistent in the environment. The substance is composed of a methyl ester of a fatty acid, and is expected to be rapidly metabolised in vertebrates, indicating that the potential for bioaccumulation may be much lower than that predicted by the partition coefficient (log Kow = 6.69).  Therefore, although both the predicted bioconcentration factor (BCF = 511 L/kg w.w.) and the predicted octanol-water partition coefficient (log Kow = 6.69) are above the thresholds for possible environmental classification (BCF≥ 500 and log Kow ≥ 4, respectively), food chain exposures and bioaccumulation of the substance are not of concern due to the non-persistence of the substance in the environment. In summary, there is no evidence that the acute toxicity tests do not provide a true measure of the intrinsic toxicity of the substance, which is not expected to be persistent or bioaccumulative in the environment. Therefore, the substance was not assigned a Category Chronic 4 classification and was not otherwise classified with respect to the aquatic environment.