Bis(2-ethylhexyl) carbonate

Endpoint summary

Additional information

Reliable, relevant and adequate experimental data on the acute aquatic toxicity of Bis(2-ethylhexyl) carbonate to algae, invertebrates and fish are available from GLP guideline studies, performed according OECD guidelines 201, 202 and 203, respectively. 

Bis(2-ethylhexyl) carbonatedid not cause any toxic effects up to its water solubility limit in the acute aquatic toxicity tests covering three trophic levels. Thus,Bis(2-ethylhexyl) carbonateis considered to be non acute toxic to aquatic organisms.QSAR modelled ecotoxicity reference values (ERV) for acute aquatic toxicity as well as for chronic aquatic toxicity, calculated withECOSAR (v1.11) (US EPA, 1994), exceed the water solubility limit of the substance by factors of 37 and 3.7, respectively. Therefore, toxic effects to aquatic organisms can safely be judged as unlikely to occur based on experimental results as well as on reliable QSAR predictions. Considering in addition the poor water solubility, ready biodegradability andhigh Henry's law constant of Bis(2-ethylhexyl) carbonate, availability of the substance in the aquatic ecosystem can be expected to be low. Experimental data on aquatic bioaccumulation is lacking. However, from reliablein vitrodata on percutanous absorption via human skin, it can be assumed that the test substance has a low potential to cross biological membranes. Thus, a very low biological availability of the test substance can be expected for aquatic species as well. In conclusion, based on toxicity assessment as well as on availability likelihood, a hazard to the aquatic environment is not ascertainable and consequently the derivation of PNECs is dispensable.

 

Short-term fish

In a 96-hour acute toxicity GLP study according to OECD guideline 203 (Fish, Acute Toxicity Test) (1992),Danio reriowere exposed under semi-static conditions to Bis(2-ethylhexyl) carbonate at initial mean measured concentrations of 23.4 µg/L (the saturation concentration under test conditions). The water solubility of the test substance according to the sponsor of the study is < 0.03 mg/L. Nominal loading was 30 µg/L. The test item did not cause any toxic effects to the zebrafish. This study is classified as reliable without restriction and satisfies the guideline requirements for an acute toxicity study with fish.

LC50 (48 h) and NOEC (48 h) Danio rerio: > 23.4 µg/L, the saturation concentration under test conditions.

Thus, up to its solubility limit unter the test conditions of OECD guideline 203, substance Bis(2-ethylhexyl) carbonate is non acute toxic to fish.

 

Short term toxicity to aquatic invertebrates

In a 48-hour acute toxicity GLP study according to OECD guideline 202(Daphnia sp. Acute Immobilisation Test) (2004),Daphnia magnawere exposed under semi-static conditions to Bis(2-ethylhexyl) carbonate at initial mean measured concentrations of 19.7 µg/L (the saturation concentration under test conditions). The water solubility of the test substance according to the sponsor of the study is < 0.03 mg/L. Nominal loading was 30 µg/L. The test item did not cause any toxic effects to the daphnids. This study is classified as reliable without restriction and satisfies the guideline requirements for an acute toxicity study with invertebrates.

LC50 (48 h) and NOEC (48 h)Daphnia magna: > 19.7 µg/L, the saturation concentration under test conditions.

Thus, up to its solubility limit unter the test conditions of OECD guideline 202 substance Bis(2-ethylhexyl) carbonate is non acute toxic to invertebrates.

 

Toxicity to aquatic algae and cyanobacteria

In a 72-hour toxicity GLP study according to OECD guidelines 201 (Alga, Growth Inhibition Test) (1984), cultures of Desmodesmus subspicatus were exposed under static conditions to Bis(2-ethylhexyl) carbonate at initial mean measured concentrations of 21.4 µg/L (the saturation concentration under test conditions). The water solubility of the test substance according to the sponsor of the study is < 0.03 mg/L. Nominal loading was 30 µg/L. The test item did not cause any toxic effects to the algae. This study is classified as reliable without restriction and satisfies the guideline requirements for a toxicity study with algae.

ErC50, EbC50 and NOEC (72 h)Desmodesmus subspicatus: > 21.4 µg/L, the saturation concentration under test conditions.

Thus, up to its solubility limit unter the test conditions of OECD guideline 201 substance Bis(2-ethylhexyl) carbonate is non acute toxic to aquatic algae.

 

Toxicity to microorganisms

In studies conducted according to OECD Guideline 301 (F and B) the test substance proved to be not inhibitory to microorganisms. The highest tested concentration was 100 mg/L.

 

Long-term toxicity

According to REACH Regulation (Annex IX, 9.1, column II) long-term toxicity testing shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the effects on aquatic organisms. The test substance is readily biodegradable, highly insoluble in water and evaporates quickly from water (Henry's Law), resulting from these, availability of the substance in the aquatic ecosystem can be expected to be low. Experimental data on aquatic bioaccumulation is lacking. However, from reliablein vitrodata on percutanous absorption via human skin, it can be assumed that the test substance has a low potential to cross biological membranes. Thus, a very low biological availability of the test substance can be expected for aquatic species as well. Bis(2-ethylhexyl) carbonate did not cause any effects up to its water solubility limit in the acute aquatic toxicity tests covering three trophic levels. Missing aquatic toxicity is also likely in consideration of QSAR modelled ecotoxicity reference values (ERV). A valid QSAR model has been used to estimate the aquatic toxicity following the “Guidance on information requirements and chemical safety assessment Chapter R.10: Characterisation of dose [concentration]-response for environment”.

 

Organism	Duration	End Point	Predicted mg/L
Fish	96-hr	LC50	2.274
Daphnid	48-hr	LC50	3.775
Green Algae	96-hr	EC50	1.152
Fish		Chronic	0.110
Daphnid		Chronic	1.411
Green Algae		Chronic	0.584

 

 

Calculated with ECOSAR (v1.11), the ERV for acute aquatic toxicity is 1.152 mg/L, determined by the predicted EC50 value for aquatic algae and the ERV for chronic aquatic toxicity is 0.110 mg/L, determined by the predicted chronic NOEC for fish. The predicted chronic ERV exceeds the water solubility limit of the substance by a factor of 3.7. Thus, long-term toxic effects to aquatic organisms are unlikely to occur. As based on toxicity assessment as well as on availability likelihood, a long-term toxicity hazard is not ascertainable, the conduct of long-term toxicity studies is not justified in accordance with REACH Regulation (Annex IX, 9.1, column II).

 

Reference:

U.S. EPA. (1994). ECOSAR: A computer program for estimating the ecotoxicity of industrial chemicals based on structure-activity relationships. EPA-748- R-002. Office of Pollution Prevention and Toxics, National Center for Environmental Publications and Information, Cincinnati, OH.