Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read Across Category

Test organisms (species):

Daphnia magna

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks on result:

other: filtered

Table 1: Results of the key study of each source substances of the category

Name	CAS	Fatty acids chain length	Type of alcohol	MW	Appareance	Short-term toxicity to aquatic invertebrates
Fatty acids, C8-16, 2- ethylhexylesters	135800-37-2	C8-16	2 -Ethylhexanol	256.42 – 368.65	Liquid	Experimental result: EC50(48h) > 100 mg/L (nom.,filt.) Dapnia Magna
Fatty acids, coco, 2-ethylhexyl esters	92044-87-6	C12-14	2-ethylhexanol	312.53 – 340.60	liquid	No data
2-Ethylhexyl palmitate	29806-73-3	C16	2-ethylhexanol	368.65	Liquid	No data
Fatty acids, C16-18 and C18-unsatd., 2- ethylhexylesters	85049-37-2	C16-18, C18:1	2- Ethylhexanol	368.65 – 396.7	Liquid	Experimental result: EL50 (48h) > 2047 mg/L Acartia tonsa
Fatty acids, C16-18, 2-ethylhexyl esters	91031-48-0	C16-18	2-ethylhexanol	368.65 - 396.7	Liquid	No data
2-Ethylhexyl oleate	26399-02-0	C18:1	2- Ethylhexanol	394.67	Liquid	Experimental result: EC50(48h) > 100 mg/L (nom.,filt.) Daphnia magna
2-Ethylhexyl stearate	22047-49-0	C18	2-ethylhexanol	396.7	Liquid	No data

 

Similar ecotoxicity profile

Based on the experimental data, the category members have low toxicity to aquatic invertebrates.

Due to their very poor water solubility, these substances are difficult for aquatic testing. If undissolved test material is not properly removed from test vessels, it may cause physical effects, such as immobilization of Daphnia by getting trapped into an oil film. These effects do not reflect real toxicity of the test substance towards the organisms. Therefore many tests onDaphnidswere performed on filtrated solutions to avoid such mechanical effects. These tests on filtrated solutions show no adverse effects of the category members to Daphnia magna.

 

The combined factors of the low biodisponibility of these substances due to their low water solubility, with their easy and fullmetabolisationcan explain the lack of adverse effects to invertebrates in short-term ecotoxicity tests.

 

Target substance conclusion

Based on the results obtained on the category members, the 48h-EC50 for Daphnia magna of the target substance "Isostearate2 -ethyl hexyl" was considered to be higher than 100 mg/L(nom., filtrated).

Validity criteria fulfilled:

yes

Conclusions:

Based on the results obtained on the category members, the 48h-EC50 for Daphnia magna of the target substance "Isostearate 2 -ethyl hexyl" was considered to be higher than 100 mg/L(nom., filtrated).
The target substance was Not Classified for Short Term Toxicity to Invertebrates.

Executive summary:

According to the Regulation (EC) NO. 1907/2006, Annex XI, 1.5, A Read-Across Category for "Long Chain Fatty Acid, 2-ethylhexyl esters" was performed in order to provide informations on Isostearate 2-Ethylhexyl .

This category was based on common and shared properties as:

-   common functional group,

-   common precursors and the likelihood of common impurities resulting from common process of manufacturing,

-   chemically structurally similar breakdown products obtained via the same biological processes into the organisms, and

-   constant pattern in the changing of the potency of the properties across the category.

Two key studies, considered as relevant and reliable, were performed on Daphnia magna  according to EU Method C.2 with the Fatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2) and the 2-Ethylhexyl oleate (CAS 26399-49-0). The EC50 values were quantified higher than 100 mg/L (nominal, filtered) after 48 hours of exposure to the tested substances. No effect was observed up to solubility limit. Above this limit, some physical effects may occur induced by undissolved test material.

The result of a key study on Acartia tonsa with the Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2) which was reported as an EL50(48h) > 2047 mg/L also demonstrated the lack of toxicity of member substances to marine invertebrates.

The key studies on Daphnia magna covered the fatty acids chain lengths from C8-16 to C18 unsat. 2-Ethylhexyl esters. Considering the molecular weight and the chain length, the 48-E50 > 100 mg/L (nom., filtrated) can be attributed to the target substance “Isostearate, 2-Ethylhexyl”  .

Hence, the target substance was not classified for short-term toxicity to aquatic invertebrates.

Description of key information

Based on the category approach and the available key studies on the source substances, the EC50 value for 48 hours exposure to Daphnia magna was defined as greater than 100 mg/L (nom. filtered) for the target substance Isostearate 2 -ethylhexyl.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Justification and rationale of the category approach for the Isostearate, 2-ethylhexyl :

This category group covers 2-ethyl hexyl esters linked with fatty acid chains (C8 to C18) unsatured and satured. This category includes monoconstituent substances and UVCB substances varying fatty acid chain length. This category was made in order to provide sufficient information for physicochemical, ecotoxicological and toxicological characterization of the Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters (CAS No 85186-76-1)

The category group includes:

- Fatty acids, C8-16, 2-ethylhexyl esters (CAS No 135800-37-2)

- Fatty acids, coco, 2-ethylhexyl esters (CAS No 92044-87-6)

- 2-Ethyl hexyl palmitate (29806-73-3)

- Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS No 85049-37-2)

- Fatty acids, C16-18, 2-ethylhexyl esters (CAS No 91031-48-0)

- 2-Ethylhexyl oleate (CAS No 26399-02-0)

- 2-Ethyl hexyl stearate (CAS No 22047-49-0)

Target substance for Category Approach : Fatty acids, C14-18 and C18-unsatd., branched and linear, 2-ethylhexyl esters (CAS No 85186-76-1)

In accordance with article 13 (1) of Regulation (EC) No. 1907.2006, “information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met. In particular for human toxicity, environmental fate and ecotoxicity, information shall be generated whenever possible by means other than vertebrate animal tests which includes the use of information from structurally related substances (grouping or read across)”. Therefore, the available experimental data were collected and evaluated according to Annex XI requirements.

Summary of available studies on source substances for short-term toxicity to aquatic invertebrates

Fatty acids, C8-C16, 2-ethylhexyl esters CAS No 135800-37-2

The key study was performed according to the EU-method C.2 and to GLP under static conditions (Wierich 1998). Different preparation methods of test solution with dilution water were applied and tested on Daphnia magna. Effects on mobility of the daphnids (about 50 %) were reported for the medium which contained 100 mg/L test substance without further separation of the undissolved test substance (measured concentration at the start of the test: 12.41 mg/L). After filtration of the test solution no effect on mobility was stated (measured concentration at the start of the test: 0.04 mg/L). Therefore, it can be stated, that the observed effects are most likely physical and not systemic effects. The resulting EC50(48h) was reported as >100 mg/L (nominal, filtered).

In a supporting study (Scholz 1995), which was also performed according to EU method C.2 under GLP-conditions, the effect of the test substance was tested on Daphnia Magna using a WAF (preparation of test solution via centrifugation). An immobility of 18 and 30 % after 48 h was stated in the 3 and 100 mg/L test concentration (nominal, WAF), respectively. The measured concentrations were in a range of 0.09 - 0.3 mg/L and the water solubility of the test substance was determined as < 0.05 - 0.3 mg/L. So the analytical recovery of the test substance was in the upper part of the water solubility range. The authors stated, that it can not be excluded that the test solutions were partly/temporarily supersaturated. Therefore the observed effects could be due to physical effects of the test substance and an EL50(48h) > 100 mg/L (nominal loading rate) was given.

Another supporting study on toxicity to the marine species Acartia Tonsa with Fatty acids, C8-16, 2-ethylhexyl esters (tested using a WAF) reported an EL50(48h) >2000 mg/L (Gibson 1999).

In a further study with Acartia tonsa, the test organisms were exposed to the substance for 96 hours, and the number of produced eggs was determined. No significant difference from control was observed up to the test concentration of 25000 mg/L (Andersen, 1990).

Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters CAS No 85049 -37 -2

A key study on the marine species Acartia tonsa with the Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2), tested as WAF, reported an EL50(48h) > 2047 (CI : 1646 -2470) mg/L (Hudson 2000).

In a screening study performed also on Acartia tonsa by the same author (Hudson, 1998), a EL50(48h) > 1000 mg/L was reported (WAF, nominal).

2-ethylhexyl oleate CAS No 26399-02-0

The key study investigated the effects of 2-ethylhexyl oleate to the freshwater invertebrate Daphnia magna (Kuech and Wierich 1995). The study was performed according to the EU-method C.2 considering the VCI concept draft for the acute testing of poorly soluble substances for 48 h. The first approach without removal of the insoluble particles resulted in immobilization rates between 0 and 100% (mean: 25%). After removal of insoluble particles (filtration) no effects to Daphnia magna were observed. Thus, it can be stated that the insoluble particles of the test substance resulted in negative physical effects to the test species. No effects in the range of water solubility were observed. This resulted in an EC50 (48h) > 100 mg/L (nominal, filtered).

The supporting study was performed on the marine invertebrate Crangon Crangon, in which exposure at nominal dose of 0, 850, 1530, 2720, 4760 and 8500mg/L was performed during 94.5 hours. Based on the mortality, the LC50 was defined at 6800 mg/L (obtained by graphic estimation).

Conclusion on the target susbtance

According to the Regulation (EC) NO. 1907/2006, Annex XI, 1.5, A Read-Across Category for "Long Chain Fatty Acid, 2-ethylhexyl esters" was performed in order to provide informations on Isostearate 2-Ethylhexyl .

This category was based on common and shared properties as:

-   common functional group,

-   common precursors and the likelihood of common impurities resulting from common process of manufacturing,

-   chemically structurally similar breakdown products obtained via the same biological processes into the organisms, and

-   constant pattern in the changing of the potency of the properties across the category.

Two key studies, considered as relevant and reliable, were performed on Daphnia magna  according to EU Method C.2 with the Fatty acids, C8-16, 2-ethylhexyl esters (CAS 135800-37-2) and the 2-Ethylhexyl oleate (CAS 26399-49-0). The EC50 values were quantified higher than 100 mg/L (nominal, filtered) after 48 hours of exposure to the tested substances. No effect was observed up to solubility limit. Above this limit, some physical effects may occur induced by undissolved test material.

The result of a key study on Acartia tonsa with the Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2) which was reported as an EL50(48h) > 2047 mg/L also demonstrated the lack of toxicity of member substances to marine invertebrates.

The key studies on Daphnia magna covered the fatty acids chain lengths from C8-16 to C18 unsat. 2-Ethylhexyl esters. Considering the molecular weight and the chain length, the 48-E50 > 100 mg/L (nom., filtrated) can be attributed to the target substance “Isostearate, 2-Ethylhexyl”  .

Hence, the target substance was not classified for short-term toxicity to aquatic invertebrates.