Ethyl 2,3-epoxy-3-phenylbutyrate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.008 mg/L

Assessment factor:

500

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.084 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

8.4 µg/L

Assessment factor:

5 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

10 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.214 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.021 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.038 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

23.3 mg/kg food

Assessment factor:

30

Additional information

Freshwater aquatic organisms

Short-term aquatic toxicity data are available for each of the three freshwater trophic levels (fish, daphnia and algae). The observed L(E)C₅₀ values were:

96-hour LC₅₀ for freshwater rainbow trout (Oncorhynchus mykiss) = 4.2 mg/L

48-hour EC₅₀ for freshwater invertebrate (Daphnia magna) = 52 mg/L

72-hour growth rate EC₅₀ (ECr₅₀) for freshwater algae (Pseudokirchneriella subcapitata) = 36 mg/L

When only short-term toxicity data are available, an assessment factor of 1000 is typically applied on the lowest L(E)C₅₀ to derive a PNEC for freshwater. The lowest L(E)C₅₀ is the fish 96-hour LC₅₀ of 4.2 mg/L. However, due to animal welfare reasons in this study (Harlan 41104030) fish that were considered likely to die (e.g. moribund or suffering severe sub-lethal effects) were humanely killed and classed as mortalities for the following observational timepoints.

Introduction of the moribund category to the OECD fish acute test has been shown to lower the median lethal concentration (LC₅₀) derived on fish declared as moribund compared to conventional LC₅₀ values (Rufli 2012). Based on the results of the Rufli study, the assessment factors for LC₅₀moribund may, on average, be lowered by a factor of 2 to set safe concentrations. Thus for derivation of PNECaquatic an assessment factor of 500 instead of the standard 1000 has been adopted.

PNEC secondary poisoning was derived from the available information on a 2 year repeated dose toxicity. The NOAEL of 35 mg/kg bw/day (chronic, rat) was converted to concentration (NOEC) by multiplying by a factor of 20 (based on age of rats, > 6 weeks) and by applying an assessment factor of 30 (based on the duration of the study) as described in Guidance R.10 8. For Soil and sediment PNECs, wet weight PNECs were calculated with using equilibrium partitioning as described in Guidance R.10 & R.16, conversion to dry weight was performed with factor of 4.6 (1.13 soil).

Conclusion on classification

Ethyl 2,3-epoxy-3-phenylbutyrate is classified as R51/53 according to Directive 67/548/EEC (DSD) and Aquatic Chronic 2 (H411) according to Regulation 1272/2008/EC and Adaptation 286/2011/EC (CLP) based on the 96 hr fish LC₅₀ which is > 1 to ≤ 10 mg/L, and the fact that the substance is not "rapidly biodegradable" in the aquatic environment.