2-ethylhexyl 3,5,5-trimethylhexanoate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

no hazard identified

Marine water

Hazard assessment conclusion:

no hazard identified

STP

Hazard assessment conclusion:

no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:

no hazard identified

Sediment (marine water)

Hazard assessment conclusion:

no hazard identified

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Due to the low water solubility of test item (< 1 µg/L at 20 °C) acute toxicity to aquatic organisms is unlikely. A long term daphnia reproduction study was performed confirming that up to the maximum water solubility (20 µg/L nominal, 8.6 µg/L measured) no mortality or effects on reproduction occurred.

The substance had no toxic effect on the growth of the algae (average growth rate and yield of Pseudokirchneriella subcapitata ) during the test period of 72 hours up to its solubility limit in the test water under the present test conditions. The test was performed at a loading rate of 100 mg/L. The microscopic examination of the algal cells at the end of the test showed no difference between the algae growing at the undiluted filtrate and the algal cells in the control. The shape and size of the algal cells were obviously not affected by the test item up to at least this concentration.

In the toxicity control of the ready biodegradability study with the test item, the run of the curve of the oxygen consumption over the 28-day exposure period correlated very well with the oxygen demand of the two added substances, i.e. test item and reference item. Within 14 days of exposure, biodegradation amounted to 37%. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration of 100 mg/L because biodegradation in the toxicity control was >25% within 14 days. The IC0 is reported as > 100 mg/l loading rate. Consequently, no hazard for STP was identified. For internal risk assessment on site a PNEC for STP was derived using an assessment factor of 10 in line with ECHA Guidance on information requirements and chemical safety assessment, Chapter R.10.

In summary, the test item did not show any aquatic toxicity at its maximum water solubility in all studies performed, and thus no hazard to aquatic organisms was identified.

Data for marine species are not available but given the low water solubility, also aquatic marine species are unlikely to be affected by the test substance. No data on sediment or soil organisms are available for this substance and such data are not required at this tonnage band. However, considering that the substance is highly biodegradable (59% degradation in an OECD 301F-study) toxicity to sediment and soil organisms is unlikely and exposure to sediment and soil is not an intended use and thus not likely to occur.

Conclusion on classification

Due to lack of aquatic toxicity within limits of the test item is not classifiable for acute aquatic toxicity.

Even though the substance has a log Pow of 7.164 and is not readily biodegradable, it was found being inherently biodegradable showing 59% biodegradation within 28 days in an OECD 301F study (pass level for ready biodegradability is 60%). Additionally, the substance did not show toxic effects to daphnia magna in a reproduction toxicity study to invertebrates (NOEC >= 8.6 µg/L) as well as on Algae pseudokirchnerella subcapitata (NOEC >= 100 mg/L loading rate) and thus does not require classification for acute or chronic aquatic toxicity according to CLP (Regulation EC No 1272/2008).