Ethyl palmitate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

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:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Remarks:

WAF

Basis for effect:

growth rate

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	Toxicity to aquatic algae
Isopropyl myristate	110-27-0	C14	Isopropanol	270,46	Liquid	Experimental result: ErC50(72h) > 0.05 mg/L (meas.Limit of WS)
Isopropyl palmitate	142-91-6	C16	Isopropanol	298.51	Liquid	no data
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	no data
Fatty acids, C16-18 and C18-unsatured, isobutyl esters	84988-79-4	C16-18, C18:1	Isobutanol	312.53 – 340.58	Liquid	Experimental result: ErC50(72h) > 100 mg/L (nom., WAF)
Isopropyl isostearate	68171-33-5	C18iso	Isopropanol	326.56	Liquid	no data

Similar ecotoxicity profile

Based on the experimental data, the category members have low toxicity to aquatic algae. Additionally, the exposure concentrations of aquatic organisms are expected to be low due to the very low water solubility of the category members. 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 decreasing algae growth by increased turbidity of test solutions, or algae cells getting trapped into oil film or by particles. These effects do not reflect real toxicity of the substances towards the organisms. Therefore the tests are performed on filtrated solutions obtained from WAF to avoid such mechanical effects. These tests performed on filtrated solution show a 72h-EC50 (biomass or growth rate) > 100 mg/L (nom., filtrated) and demonstrated no adverse effects to algae.

 

Conclusion on target substance

Based on the results obtained with the category members, the 72h-EC50(biomass or growth rate) of the target substance "Ethyl Palmitate" to the freshwater algae was considered to be higher than 100 mg/L (nom., filtrated).

Validity criteria fulfilled:

yes

Conclusions:

Based on the category approach and the results obtained on source substances, the 72h-EC50(biomass or growth rate) of the target substance "Ethyl Palmitate" to the freshwater algae was considered to be higher than 100 mg/L (nom., filtrated).
Hence the target substance was not classified for acute toxicity to aquatic algae according to CLP criteria.

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.

Two key and reliable studies were performed according to EU Method C.3 on Isopropyl myristate and on Fatty acids, C16-18 and C18-unsatured, isobutyl ester.

The EC50 (biomass or growth rate) for the green algae, Desmodesmus subspicatus, during 72 hours exposure period was defined as > 0.05 mg/L (limit of water solubility for isopropyl myristate) and > 100 mg/L (nominal, filtered for fatty acids, C16-C18 and C18unsatured, isobutyl esters). So no toxicity to algae was observed for the tested substances up to their limit of solubility.

These studies covered the variability of the fatty acid chain length in the category from C14 to C18. Considering the molecular weight and the similarity of structures between the tested substances and the target substance, the toxicity of the target substance “Ethyl Palmitate” to the freshwater green algae can be established as 72h-EC50 (biomass or growth rate > 100 mg/L (nom., filtrated).

Hence, Ethyl Palmitate was not classified for acute toxicity to aquatic algae according to CLP criteria.

Description of key information

According to the experimental studies, none of the assessed source substances has shown adverse effect to the growth of algae up to their limit of solubility. Based on the category approach and the results obtained on source substances, the 72h-EC50(biomass or growth rate) of the target substance "Ethyl Palmitate" to the green algae was considered to be higher than 100 mg/L (nom., filtrated).

Hence the target substance was not classified for acute toxicity to aquatic algae according to CLP criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

The category group covers alcohol linked to fatty acid chains unsatured and satured, via an ester function. This category includes mono-constituent chemicals and UVCB substances with varying acid chain lengths (from C14 to C18) and alcohol types (ethanol, 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 toxicity to aquatic algae

Isopropyl myristate CAS 110 -27 -0

In the key study, Desmodesmus subspicatus was tested as a limit test according to EU Method C.3 and to GLP. No effects on cell growth were stated at concentrations up to the water solubility (ErC50 > 0.05 mg/L) in the filtered solutions, while presumably physical effects were observed in the emulsion without filtration. Hence, the 72h-ErC50 value was defined as higher than 100 mg/L (nominal, filtrated).

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

One study is available on the algal toxicity of Fatty acids, C16-18 and C18 unsaturated isobutyl esters. This key study was performed as a limit test according to the EU guideline 92/69/EWG and GLP (Berger, 1995). The test organism Scenedesmus subspicatus was exposed to the test substance in a static system for 72 hours, at the nominal test concentration 100 mg/L. The test was performed with and without separation of undissolved test material. With undissolved test substance present, algal growth was significantly inhibited. However, when the undissolved phase was separated, no effects on growth were observed. The inhibition of the algal growth can be thus regarded as associated to physical effects caused by the undissolved material present. It can be concluded that the substance has no toxic effects on test organism up to its limit of solubility.

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.

Two key and reliable studies were performed with Isopropyl myristate and Fatty acids C16 -18 & C18 unsat. isobutyl esters, according to EU Method C.3 and EU guideline 92/69/EWG respectively. The EC50 (biomass or growth rate) for the green algae, Desmodesmus subspicatus, during 72 hours exposure period was defined as > 0.05 mg/L (limit of water solubility for isopropyl myristate) and > 100 mg/L (nominal, filtered, for the fatty acids, C16 -18 and C18unsat., isobutyl esters). So no toxicity to algae was observed for the tested substances up to their limit of solubility.

These studies covered the variability of the fatty acid chain length in the category from C14 to C18. Considering the molecular weight and the similarity of structures between the tested substances and the target substance, no toxicity is expected from the target substance “Ethyl Palmitate” to the freshwater green algae and a 72h-EC50 (biomass or growth rate > 100 mg/L (nom., filtrated) can be established.

Hence, Ethyl Palmitate was not classified for acute toxicity to aquatic algae according to CLP criteria.