Ethyl palmitate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

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 document in section 0 "Categories" or section 13 "Assessment reports" for justification and rationale of the category approach

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

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 fish
Isopropyl myristate	110-27-0	C14	Isopropanol	270,46	Liquid	Experimental result: LC50(96h) > 1000 mg/L (nom.)
Isopropyl palmitate	142-91-6	C16	Isopropanol	298.51	Liquid	Experimental result: LC50(96h) > 10000 mg/L (nom.)
Ethyl linoleate	544 -35-4	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: LC50(96h) > 10000 mg/L (nom.)
Fatty acids, C16-18 and C18-unsatured, isobutyl esters	84988-79-4	C16-18, C18:1	Isobutanol	312.53 – 340.58	Liquid	Experimental result: LC50(96h) > 10000 mg/L (nom.)
Isopropyl isostearate	68171-33-5	C18iso	Isopropanol	326.56	Liquid	Experimental result: LC50(96h) > 100 mg/L (nom.)

Similar ecotoxicity profile

Based on the experimental data, the category members show no toxicity to aquatic fish organisms.

Additionally, the exposure concentrations of the aquatic organisms are expected to be low due to the low water solubility, and in both short and long-term studies, no effect occurred up to the water solubility limit.

These tested substances are also expected to be metabolized in the aquatic organisms; they are first hydrolyzed by lipases (Mattson and Volpenhein, 1972) resulting in free fatty acid and alcohols, which are absorbed from the intestine into blood stream. Fatty acids are either metabolized via Beta-oxidation pathway in order to generate energy for cell or reconstituted glyceride esters stored in the fat depots in the body. Ethanol is primarily metabolized in the liver. Consequently, the combined factors of low biodisponibility of these substances due to their low water solubility, with their easy and full metabolisation, can explain the lack of adverse effects to fish in short-term tests.

 

Conclusion on the target substance

Five studies were performed on the category members in order to assess the acute toxicity to fish. Different species were used as Lepomis Macrochirus,Cyprinus Carpio and Danio Rerio. They were exposed to high concentrations in the conditions of standardised methods. The different LC50 values were > 100 mg/L (nom.), or >1000 mg/L (nom.), or > 10000 mg/L (nom.), according to the highest tested concentration.

Based on these results, the 96h-LC50 for freshwater fish of the target substance "Ethyl Palmitate" was considered to be higher than 100 mg/L(nom.).

 

Validity criteria fulfilled:

yes

Conclusions:

Based on the available key studies performed on the category members, the 96h-LC50 to freshwater fish was defined higher than 100 mg/L.
According to the CLP criteria, the registered substance is not classified for short-term toxicity to fish.

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.

All the members of the category were tested to assess their toxicity to fish, appart from Ethyl linoleate. No toxicity was observed and the LC50 were found > 100 mg/L (nom.), or > 1000 mg/L (nom.), or > 10000 mg/L (nom.), according to the highest tested concentration in the tests.

These source substances (long fatty acids alcohols esters) are expected to be fully metabolized in aquatic organisms in order to provide energetic resources or to be stored at fat deposit. So the combined factors of their low biodisponibility due to their low water solubility, with their ease and full metabolisation can explain the lack of adverse effects to fish.

None of the fish acute toxicity tests on the source substances, showed adverse effects up to the highest concentration used. Based on the category approach, the target substance, Ethyl Palmitate, was considered as not toxic to fish under short- term exposure conditions, with a 96h-LC50 > 100 mg/L (nom.).

Hence Ethyl palmitate was not classified for short-term toxicity to fish according to CLP criteria.

Description of key information

Based on the available key studies performed on the category members, the 96h-LC50 to fish was defined higher than 100 mg/L.

According to the CLP criteria, the registered substance is not classified for short-term toxicity to fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

Justification and rationale of the category approach for Ethyl palmitate

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, utanol and isobutanol). This approach was performed in order to provide sufficient information for physicochemical, 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 studies for short term toxicity to fish

Isopropyl myristate CAS 110-27-0

Two studies were performed on isopropyl myristate in order to assess the potential acute toxicity to fish. The key study was performed according to the EPA 660/3 -75 -009 (Methods for acute toxicity tests with fish, macroinvertebrates and amphibians) and GLP compliance. Bluegill (Lepomis Macrochirus) were exposed to test substance during 96 hours under static condition at 21 -23°C. They were exposed to 0, 78, 130, 220, 360, 600 and 1000 mg/L. No mortality was observed during the exposure period, hence, the LD50 was defined to be higher than 1000 mg/L(nom.). The supporting study was performed on the carp (Cyprinus Carpio). Fishes were exposed during 48 hours under static conditions to 0 and 1000 mg/L of test substance. No mortality was observed and the LC50 was defined to be higher than 1000 mg/L (nom.).

Isopropyl palmitate CAS 142 -91 -6

In the key study, the acute toxicity of Isopropyl palmitate to the zebra fish (Danio rerio) was tested under semi-static conditions according to ISO 7346 -1 at the following concentrations: 1000, 3000 and 10000 mg/L. There were no toxic or sublethal effects observed in the species tested after an incubation period of 96 hours at any concentration. The LC50 was defined to be higher than 10000 mg/L (nom.).

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

The key study conducted with Fatty acids, C16-18, butyl esters was performed according to the guideline ISO 7346-1. The test organisms Danio Rerio were exposed to the test substance in a semi-static system for 96 hours, at the nominal concentrations of 1000, 3000 and 10,000 mg/L. No mortality was observed at any of the tested concentrations, and the LC50 was defined as higher than 10000 mg/L (nom.)

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

One short-term fish toxicity study is available for Fatty acids, C16-18 and C18 unsaturated, isobutyl esters (CAS No. 84988-79-4). This key study was performed according to the guideline ISO 7346-1 (similar to OECD 203), in a semi-static system, using Brachydanio Rerio as the test organism. The fishes were exposed to nominal test concentrations of 100, 300, 1000, 3000 and 10,000 mg/L during 96 hours. No mortality was observed at any of the tested concentrations, and the LC50 was reported to be higher than 10,000 mg/L.

Isopropyl isostearate CAS 68171 -33 -5

One study is available on the short-term fish toxicity of isopropyl isostearate. This key study was performed as a limit test according to OECD guideline 203, in a static system, using Cyprinus carpio as test organism. The fish were exposed to the nominal test concentration of 100 mg/L, prepared using the dispersant Tween-80. No mortalities were observed at the tested concentration, during the 96-hour test period, and the LC50 was reported to be higher than 100 mg/L.

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.

Reliable key sudies are available to assess the acute toxicity to fish for all the category members appart from ethyl linoeate and ethyl oleate. No toxicity was observed after 96h of exposure to the highest tested concentrations in the different tests (100 or 1000 or 10000 mg/L expressed as nominal). The combined factors of the low biodisponibility of the category members due to their low water solubility, with their ease and full metabolisation can explain the lack of adverse effects of these substances to fish. Based on the results obtained on the source substances, the target substance, Ethyl Palmitate, was considered as not toxic to fish under short term exposure conditions with a LC50 > 100 mg/L (nom.).