3,5,5-trimethylhexyl acetate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

7.7 µg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

77 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.77 µg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

77 µg/L

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:

2.895 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.29 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:

0.573 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

The aquatic toxicity of the test item 3,5,5-trimethylhexyl acetate was tested in short-term tests on the toxicity to algae, daphnids and fish. The tests were conducted under GLP and followed OECD TG 201, 202 and 203, respectively. The LC50 value in the fish study was 7.7 mg/L, whereas the EC50 values in the studies with invertebrates and algae were greater than the geometric means of measured concentrations at the highest concentration that was possible to maintain in the test systems. The PNECs hence were based on the LC50 value of 7.7 mg/L observed in the acute fish toxicity test. The effect of the test item on microorganisms was assessed via a toxicity control with 100 mg/L test item in a ready biodegradability test. No information on sediment toxicity and terrestrial toxicity is available, thus the equilibrium partitioning method was applied for PNEC derivation.

 

Conclusion on classification

CLP Regulation:

Aquatic acute toxicity:

All three L(E)C-50 results unanimously indicate values > 1.0 mg/L, thus no classification under CLP applicable.

Aquatic chronic toxicity:

According to Table 4.1.0 in the 2nd Amendment of Regulation (EC) No 1272/2008, for substances for which adequate chronic toxicity data are not available, Aquatic Chronic Toxicity Category 1 applies if L(E)C-50 < 1.0 mg/L and the substance furthermore is not rapidly degradable and/or the experimentally determined BCF≥ 500 (or, if absent, the log Kow≥ 4). As the log Kow was determined to be 4.6 (predicted BFC > 500), and the LC-50 for fish (7.7 mg/L) is within the bracket 1.0 mg/L < LC-50 < 10 mg/L, Aquatic Chronic Toxicity Category 2 applies to the test item based on acute toxicity data.

The only long-term study available is the algal growth inhibition study, which resulted in a ErC10(72h) = 0.65 mg/L. Based on this long-term toxicity value and the fact that the substance can be regarded as rapidly degradable, Aquatic Chronic Toxicity Category 3 applies based on the chronic algae value.