Propane-1,2,3-triyl 3,5,5-trimethylhexanoate

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

Data waiving:

other justification

Justification for data waiving:

other:

Additional information

The chemical safety assessment according to Annex I of Regulation (EC) No. 1907/2006 does not indicate the need to investigate further the effects on sediment organisms. Experimental data on the toxicity of propane-1,2,3-triyl 3,5,5-trimethylhexanoate (CAS No. 56554-53-1) to sediment organisms are not available. Acute and chronic toxicity test on aquatic organisms show that the substance is not toxic to aquatic organisms up to the limit of water solubility. Thus, toxicity to sediment organisms is not expected to be of concern.

 

Intrinsic properties of the substance indicate low concern for sediment organisms. Propane-1,2,3-triyl 3,5,5-trimethylhexanoate (CAS No. 56554-53-1) reached 60% biodegradation after 28 days. Therefore, extensive biodegradation in biological Sewage Treatment Plants (STPs) is expected. After passing through conventional STPs, only low concentrations of this substance are likely to be (if at all) released into the environment.

Furthermore, the substance exhibits a log Koc value > 5 and is poorly soluble in water (< 0.05 mg/L). The Guidance on information requirements and chemical safety assessment, Chapter R7.b (ECHA, 2012) states that once insoluble chemicals enter a standard STP, they will be extensively removed in the primary settling tank and fat trap and thus, only limited amounts will get in contact with activated sludge organisms. Nevertheless, once this contact takes place, these substances are expected to be removed from the water column to a significant degree by adsorption to sewage sludge (Guidance on information requirements and chemical safety assessment, Chapter R.7a, (ECHA, 2012)) and the rest will be extensively biodegraded. Thus, discharged concentrations of these substances into the aqueous/sediment compartment are likely to be negligible. Considering this, the availability of propane-1,2,3-triyl 3,5,5-trimethylhexanoate (CAS No. 56554-53-1) in the sediment environment is expected to be very low, which reduces the probability of sediment organisms exposure.

 

Furthermore, according to the Guidance on information requirements and chemical safety assessment, Chapter R7.c (ECHA, 2012), the potential for bioaccumulation can be estimated from the log Kow value of the substance as a screening approach. Generally, at log Kow values > 6 a decrease in BCF values is observed, probably caused by the reduced uptake with the expected increasing molecular size of such substances. Even though experimental data evaluating bioaccumulation for substances with log Kow > 10 (such as propane-1,2,3-triyl 3,5,5-trimethylhexanoate (CAS No. 56554-53-1)) is not known, these substances are expected to have BCF values < 2000 L/kg (criterion used to consider a substance Bioaccumulative)(Guidance on information requirements and chemical safety assessment, Chapter 11 (ECHA, 2012). Based on the above information,no potential for bioaccumulation in sediment organisms is to be expected for propane-1,2,3-triyl 3,5,5-trimethylhexanoate.

 

Available acute and chronic aquatic toxicity tests on fish and aquatic invertebrates determined no adverse effects in the range of the water solubility of the substance. The acute toxicity of the substance was tested in a short-term study on Zebra fish (Danio rerio). Mortality or symptoms of intoxication were not observed (LC50 (96 h) >100% v/v (nominal)). A comparable result was reported by a chronic toxicity test on Daphnia magna. The study focused on the mortality and reproduction of the test animals and determined no toxic effects up to the limit of water solubility (NOEC (21 d): 100% v/v (nominal)).

 

Based on the currently available information, sediment toxicity is not expected for propane-1,2,3-triyl 3,5,5-trimethylhexanoate.