Ethyl palmitate

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: Category Approach

Justification for type of information:

See attached report in Section 0 "Categories" or Section 13 "Assessment reports" for justification and rationale of the category approach

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Remarks:

WAF

Basis for effect:

mortality

Table 1: Results from key studies performed on the source substances of the category

Common name	CAS	Fatty acid chain length	Type of alcohol	MW	Appareance	Short-term toxicity to aquatic invertebrates
Isopropyl myristate	110-27-0	C14	Isopropanol	270,46	Liquid	Experimental result: EC50(48h) > 0.05 mg/L (meas. limit of WS)
Isopropyl palmitate	142-91-6	C16	Isopropanol	298.51	Liquid	Experimental result: EC50(48h) > 3000 mg/L (nom., dissolved TS)
Ethyl linoleate	544-53-4	C18:2	ethanol	308,5	Liquid	no data
Ethyl oleate	111-62-6	C18:1	ethanol	310.52	Liquid	no data
Fatty acids, C16-18, butyl esters	85408-76-0	C16-18	Butanol	312.53 – 340.58	Paste	Experimental result: EL50(48h) > 100 mg/L (nom.WAF)
Fatty acids, C16-18 and C18-unsatured, isobutyl esters	84988-79-4	C16-18, C18:1	Isobutanol	312.53 – 340.58	Liquid	Experimental result: EL50(48h) > 100 mg/L (nom., WAF)
Isopropyl isostearate	68171-33-5	C18iso	Isopropanol	326.56	Liquid	no data

Similar ecotoxicity profile

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 the tests on daphnids were performed on the dissolved fraction (obtained for example by filtration) to avoid such mechanical effects. These tests on dissolved fractions show no adverse effects of the category members to Daphnia magna.

The low biodisponibility of these substances due to their low water solubility can explain the lack of adverse effects to invertebrates in short-term ecotoxicity tests.

Target substance conclusion

Based on the results obtained, the 48h-EC50 for Daphnia magna of the source substances was considered to be higher than their limit of solubility in the test medium (measured., limit of water solubility).

 

Validity criteria fulfilled:

yes

Conclusions:

Based on the results obtained on the category members, the 48h-EL50 for Daphnia magna of the target substance "Ethyl Palmitate" was considered to be higher than 100 mg/L (nom., WAF/soluble fraction).
Ethyl Palmitate 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 was performed in order to provide informations on the Ethyl Palmitate.

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.

Key studies on 4 source chemicals of the category are available for short term toxicity to aquatic invertebrate. These experimental studies were performed according to EU Method C.2. and EU Guideline 92/69/EWG (1992) on Daphnia magna species. The 48h-EC50 or EL50 were determined as > 0.05 mg/L (measured water solubility) for isopropyl myristate, > 100 mg/L (nominal / WAF /soluble fraction tested) for Fatty acids C16 -18 butyl ester and Fatty acids C16 -18 and C18 unsatd isobutyl esters, and > 3000 mg/L (nom./ WAF / soluble fraction tested) for isopropyl palmitate.

When tested up to their limit of solubility, it can be stated that the substances of the category have no adverse effect to Daphnia Magna exposed during 48 hours. Based on the experimental data, the category members have low toxicity to aquatic invertebrates.

The key studies on Daphnia magna covered the fatty acids chain lengths from C14 to C18 (saturated and unsaturated) linked by an ester function to alcohol (from C3 to C4). Considering the molecular weight and the similarity of the structures, the 48-EC50 > 100 mg/L (nom., WAF / soluble fraction) can be attributed to the target substance “Ethyl Palmitate".

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

Description of key information

Based on the available experimental studies on the source substances and the category approach, the target substance Ethyl palmitate was considered to induce no adverse effect when exposed to Daphnia Magna during a short term period. The 48h-EL50 was defined as > 100 mg/L (nom. / WAF / soluble fraction).

Hence, acccording to CLP criteria, the registered substance Ethyl Palmitate was not classified for short-term toxicity to aquatic invertebrates.

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 Ethyl palmitate

The category group covers alcohols linked with fatty acid chains (unsatured and satured), via an ester function. This category includes monoconstituent chemicals and UVCB substances, with varying acid chain lengths (from C14 to C18) and alcohol types (including isopropanol, butanol and isobutanol). This approach was performed in order to provide sufficient information for physical-chemical, ecotoxicological and toxicological characterizations of ethyl palmitate. Based on structural and physical-chemical similarities, available experimental studies from source chemicals could be used for the target substance, ethyl palmitate.

This category group includes:

- Isopropyl myristate CAS 110-27-0

- Isopropyl palmitate CAS 142-91-6

- Ethyl linoleate CAS 544-35-4

- Ethyl oleate CAS 111-62-6

- Fatty acids, C16-18, butyl esters CAS 85408-76-0

- Fatty acids, C16-18 and C18-unsatured, isobutyl esters CAS 84988-79-4

- Isopropyl isostearate CAS 68171-33-5

- Target substance : Ethyl palmitate CAS 628-97-7

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 experimental studies for short-term toxicity to aquatic invertebrates

Isopropyl myristate CAS 110-27-0

Two experimental studies were available for assessment of acute toxicity to daphnids. The key study was performed acccording to EU Method C.2. Daphnids were exposed to the nominal concentration of 100 mg/L during 48 hours. No adverse effect on the daphnids mobility was observed during the exposure period when they are exposed up to the limit of solubility of the tested substance (water solubility limit = 0.05 mg/L).

The supporting study was performed according to DIN 38412, part 11. Daphnids were exposed under static conditions during 48 hours to nominal concentrations up to 1000 mg/L. The 48h-EL50 was defined to be 100 mg/L (nom.) and this toxicity is due to physical effects since evidence of undissolved material was observed at 100 mg/L and higher test concentrations.

Isopropyl palmitate CAS 142 -91 -6

In the key study, the acute toxicity of Isopropyl palmitate to Daphnia magna was tested under static conditions according to EU Method C.2 and to GLP, and using a solution of test material at 1000 and 3000 mg/L (nominal) after the removal of the undissolved material. No immobilisation of the daphnids were observed, however animals swam at the surface in both tested concentrations. Analytical retrieval of solved substance was below 0.1%. The 48h-EL50 was reported as > 3000 mg/L (nom.).

Fatty acids, C16 -18, butyl esters CAS 85408-76 -0

One study is available on the short-term toxicity of Fatty acids, C16-18, butyl esters to aquatic invertebrates. This key study was performed as a limit test according to EU Method C.2 and GLP. The test organisms Daphnia magna was exposed to the test material in a static system for 48 hours, at the nominal concentration of 100 mg/L, prepared as water accommodated fractions (WAF) followed by a step of fitration to recover the dissolved fraction. No immobilisation was observed and the 48h-EL50 was > 100 mg/L (nom.).

Fatty acids, C16 -18 and C18-unsatured isobutyl esters CAS 84988-79-4

The key study conducted with Fatty acids, C16-18 and C18-unsaturated isobutyl esters was performed as a limit test according to EU guideline 92/69/EWG and GLP. The test organism Daphnia magna was exposed to the test substance in a static system for 48 hours. Three different methods were applied for the preparation of test solutions: 1) direct addition of 100 mg/L without separation of undissolved test material, 2) direct addition of 100 mg/L followed by a separation of undissolved test material and 3) 3 to 5 fold saturation concentration without separation of undissolved material. Immobilisation was observed only in the test solutions prepared using the first method, and was therefore probably due to physical effects caused by the large amount of undissolved test material present in this test solution. With the separation of undissolved test material and with 3 to 5 fold saturation, no adverse effects were observed. It can be concluded that the test substance has no toxic effects on Daphnia magna up to the limit of its solubility. A 48h-EL50 > 100 mg/L (nom.) is reported.

Conclusion

According to the Regulation (EC) NO. 1907/2006, Annex XI, 1.5, a Read-Across Category for "Long Chain Fatty Acid (from C14 to C18) and short chain alcohol esters (from C2 to C4) " was performed in order to provide information on Ethyl Palmitate.

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.

Key studies on 4 source chemicals of the category are available for short term toxicity to aquatic invertebrate. These experimental studies were performed according to EU Method C.2. and EU Guideline 92/69/EWG (1992) on Daphnia magna species. The 48h-EC50 or EL50 were determined as > 0.05 mg/L (measured water solubility) for isopropyl myristate, > 100 mg/L (nominal / WAF /soluble fraction tested) for Fatty acids C16 -18 butyl ester and Fatty acids C16 -18 and C18 unsatd isobutyl esters, and > 3000 mg/L (nom./ WAF / soluble fraction tested) for isopropyl palmitate. When tested up to their limit of solubility, it can be stated that the substances of the category have no adverse effect to Daphnia Magna exposed during 48 hours. Based on the experimental data, the category members have low toxicity to aquatic invertebrates

Based on the available experimental studies on the source substances and the category approach, the target substance Ethyl palmitate was considered to induce no adverse effect when exposed to Daphnia Magna during a short term period and the 48h-EL50 was defined as > 100 mg/L (nom. / WAF / soluble fraction).