cis-4-tert-butylcyclohexyl acetate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

1.2 µg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

12 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.12 µg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

1.2 µg/L

STP

Hazard assessment conclusion:

no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.393 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.039 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:

0.078 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

66.67 mg/kg food

Assessment factor:

300

Additional information

Environmental fate and pathways

Based on the biodegradation studies (OECD Guideline 301 D), the registered substance is considered readily biodegradable. Two hydrolysis products were identified: acetate and 4 -tert-Butylcyclohexanol.Acetate can be considered as readily biodegradable too but insufficient data are available to assess the readily biodegradation of 4-tert-butylcyclohexanol. However, over 60% biodegradation were observed after 28 days. The parent and hydrolysis products are not persistent in the environment.The bioconcentration factor (BCF) of the registered substance was estimated using a QSAR predictions with a maximum value at 335 L/kg whole body weight, therefore the substance is not bioaccumulable according to CLP (BCF < 500) and PBT criteria (BCF < 2000). Finally, based on a read-across approach, the adsorption coefficient (log Koc) of the registered substance can be determined at 3.51 (OECD Guideline 121, EU Method C.19). This result indicates that the substance is environmentally slightly mobile (according to P.J. McCall et al., 1980).

Aquatic toxicity

One acute experimental study and four QSAR predictions are available to assess the aquatic toxicity of the registered substance.

The experimental study (Harlan, 2013), performed on the registered substance on aquatic invertebrates Daphnia magna, was not considered reliable due to major methodological deficiencies. Therefore, QSAR prediction for this endpoint, and all other endpoints required, were performed using iSafeRat® High-Accuracy-Quantitative Structure-Activity Relationship (KREATIS, 2020). Toxic effects below the solubility limit were predicted on algae and fish in acute conditions. For algae, the 72h-ErC50 value was predicted at 1.2 mg/L. For fish, the 96h-LC50 value was predicted at 2.6 mg/L. Finally, the toxicity values for daphnia in acute conditions (48h-EC50) and activated sludge (30-180min EC50) were predicted as greater than the limit of solubility within the exposure period of the tests.

Conclusion on classification

No harmonised classification is available for the registered substance.

The lowest E(L)C50 value of the registered substance for aquatic organisms is comprised between 1 and 10 mg/L (lowest value at 1.2 mg/L). However, as the substance is readily biodegradable, with predicted BCF values lower than 500, the registered substance is not classified for the environment according to the CLP Regulation (Annex I of the Regulation (EC) No 1272/2008 (CLP)).