Polyamide wax

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.2 mg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.18 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.02 mg/L

Assessment factor:

500

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:

860 mg/kg sediment dw

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

86 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:

171.5 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

27.8 mg/kg food

Assessment factor:

90

Additional information

The derived PNECs are for reference only. As the substance is not classified a quantitative assessment comparing PNEC against PEC is not required.

In addition, these PNECs should be treated with caution as the results come from studies conducted using Water Accommodated Fractions (WAFs). WAFs may be used in cases where the test item is a mixture and is poorly soluble in water and in permitted auxiliary solvents and surfactants. Exposures to the test organisms can be expressed in terms of the original concentration of test item in water at the start of the mixing period (loading rate) irrespective of the actual concentration of test item in the WAF.

Given that toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, the results of the aquatic toxicity tests conducted were based on nominal loading rates only.

PNECs derived from studies conducted using WAFs should be viewed with caution as partitioning in the environment will make the comparison with a PEC meaningless (according to the ECHA Guidance; Guidance on information requirements and chemical safety assessment Chapter R.7b: Endpoint specific guidance).

Conclusion on classification

Based on the available test data the substance is not classified for the environment.

The substance is not a long-term aquatic hazard and is not classified for aquatic chronic toxicity based on the results of a Daphnia magna reproduction study, which showed no toxic effects and gave a No Observed Effect Loading Rate (NOELR) of 100 mg/l.

This result is above the classification criteria for non-rapidly degradable substances for which there are adequate chronic toxicity data (≤0.1 mg/l for Chronic 1 and >0.1 to ≤1 mg/l for Chronic 2).

Loading rates from WAF studies can be used directly for classification.

The substance is not classified for aquatic acute toxicity based on the results of acute testing. The acute studies were conducted using WAF. The test substance was therefore tested at the limit of its water solubility. The nominal concentrations have been taken as the Loading Rate, to be considered comparable to a concentration for a pure substance.

The most sensitive species in acute testing was algae. The EC50 of the test material for both cell growth inhibition and growth rate reduction were between 18 and 32% of its water soluble fraction (taken as loading rate of 100 mg/l). The EL50 can therefore be considered to be 18 - 32 mg/l, which is above the classification criteria for acute toxicity.

In addition, estimates for aquatic toxicity made for the three main components of the substance, using the EPI Suite program ECOSAR gave EC/LC50 above the predicted water solubility of the components.

A 'safety-net' classification of Chronic 4 is not required as although the substance is not readily biodegradable and has log Kow >4, it has been assessed to have low potential for bioaccumulation and has a chronic toxicity NOEC > water solubility.