Undecan-4-olide

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

84 µg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

58.5 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

8.4 µg/L

Assessment factor:

100

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

5.85 µg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

80 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

5.341 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.534 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:

1.019 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

66.7 mg/kg food

Assessment factor:

300

Additional information

Environmental fate and pathways:

The registered substance is readily biodegradable, has low mobility in soils, and is not bioaccumulable according to CLP and PBT criteria. Regarding volatilisation, it is assumed that the registered substance will volatilise slowly from water surfaces under environmental conditions.

Aquatic toxicity:

Acute and chronic data on the registered substance are available for three aquatic trophic levels: algae, aquatic invertebrates and fish and are summarised below.

- Algae: 72h-ErC50 = 7.218 mg/L; 72h-ErC10 = 1.669 mg/L.

- Aquatic invertebrates: 48h-EC50 = 5.85 mg/L; 21d-EC10 = 1.02 mg/L.

- Fish: 32d-EC10 = 0.84 mg/L.

Among all data available, the fish seems to be the most sensitive species further to chronic exposure with a 32d-EC10 value at 0.84 mg/L. As chronic data are available, the acute fish study does not need to be conducted.

To assess the toxicity of the registered substance to microorganisms a weight of evidence approach was used with four studies. The first and second studies were performed on the registered substance and no toxicity were observed. The third and fourth studies were performed on a similar substance, a linear saturated 4-hydroxycarboxylic acid derived-lactone with 10 carbons (one carbon less in the aliphatic chain than the registered/target substance). Both substances have the same mechanism of action (MechoA 2.1) and share a common basic structure. The source substance is considered adequate for read-across purpose (please refer to the RAAF document in IUCLID section 13 for detailed justification). The lowest EC50 value, determined at 800 mg/L, was chosen as key value for the chemical safety assessment of the registered substance.

Sediment toxicity:

In the absence of any ecotoxicological data for sediment-dwelling organisms, the PNECs sediment were calculated using the Equilibrium Partitioning Method (EPM). This method uses the PNEC water for aquatic organisms and the suspended matter/water partitioning coefficient as inputs. As the chemical safety assessment, based on this screening method, indicates RCR sediment lower than 1.0, no sediment toxicity tests with benthic organisms need to be done.

Terrestrial toxicity:

With a Koc value at 599.8 L/kg and a log Kow value lower than 5.0, the substance does not have a high potential to adsorb to soil. The substance is readily biodegradable so is not persistent in the environment, and is not very toxic to aquatic organisms with E(L)C50 values greater than 1.0 mg/L. Therefore, according to section R.7.11.5.3., Chapter R.7c of the ECHA Guidance on information requirements and chemical safety assessment (version 3.0, June 2017), the substance should be classed as a soil hazard category 1, and thus, the Equilibrium Partitioning Method (EPM) has been used as a screening assessment, for assessing the hazard to terrestrial organisms. As RCR soil are lower than 1.0, no toxicity testing for soil organisms need to be done.

Conclusion on classification

No existing Harmonised Classification

Self-classification:

1 mg/L < acute E(L)C₅₀ < 10 mg/L; 0.1 mg/L < chronic EC₁₀ < 1 mg/L; readily biodegradable; log Kow = 3.6.

The registered substance is classified as Category Chronic 3 for the environment according to the Annex VI of the Regulation (EC) No 1272/2008 (CLP).