Ethyl palmitate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

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

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

Parameter:

% degradation (O2 consumption)

Value:

>= 82

Sampling time:

28 d

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	Biodegradation in water: screening tests
Isopropyl myristate	110-27-0	C14	Isopropanol	270,46	Liquid	Experimental result: 301B, 91.4% in 28 days, readily biodegradable
Isopropyl palmitate	142-91-6	C16	Isopropanol	298.51	Liquid	Experimental result: 301B, 91.3% in 28 days, readily biodegradable
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: ISO/ DIS method 10708, 82% in 28 days, readily biodegradable
Fatty acids, C16-18 and C18-unsatured, isobutyl esters	84988-79-4	C16-18, C18:1	Isobutanol	312.53 – 340.58	Liquid	Experimental result: 301D, 99% in 30 days, readily biodegradable
Isopropyl isostearate	68171-33-5	C18iso	Isopropanol	326.56	Liquid	Experimental result: 301B, 85.6% in 28 days, readily biodegradable

 

Similar biodegradation profile

All the members of the category (appart from ethyl linoleate and ethyl oleate) were assessed for their ready biodegradation in water. These experimental studies were performed according to OECD Guideline 301 or equivalent methods, based on respirometric measurements (Oxygen consumption or CO2 emission). Biodegradation results ranged from 82% to 99% within 30 days. So the substances of the category are considered as readily biodegradable. Since these ready biodegradation tests are performed in very stringent conditions, it can be anticipated that these substances will disappear very quickly in the environment. Similar structures of the members of the category, and suitable enzymatic processes present in the inoculum explain the ready degradation of the tested substances.

Conclusion on target substance

Biodegradation was assessed for most of the members of the category according to OECD 301B/301D guidelines or equivalent methods.

Based on the results obtained on the category members, the biodegradation of the target substance "Ethyl Palmitate" was considered to be ≥ 82% within 28 days and this substance is considered as readily biodegradable.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Based on the results available through the category approach and according to the CLP criteria, the registered substance “Ethyl palmitate" was considered as readily biodegradable with a level of biodegradation ≥ 82% within 28 days in ready biodegradation tests.

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.

Experimental studies showed that all the members of the category are readily biodegradable according to OECD 301 guidelines or equivalent methods, based on respirometric measurements (Oxygen consumption or CO2 emission). Similar structures of the members and suitable enzymatic processes present in the inoculum explain the ready degradation of the tested substances.

Based on the results available through the category approach and according to the CLP criteria, the registered substance “Ethyl palmitate” was considered as readily biodegradable with a level of biodegradation ≥ 82% within 28 days in ready biodegradation tests.

Description of key information

Based on the results available through the category approach and according to the CLP criteria, the registered substance “Ethyl palmitate" was considered as readily biodegradable with a level of biodegradation ≥ 82% within 28 days in ready biodegradation tests.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Justification and rationale of the category approach for Ethyl palmitate

The category group covers alcohols 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 physicochemical, ecotoxicological and toxicological characterizations of the ethyl palmitate. Based on structural and physic-chemicals 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.

Available studies for biodegradation in water: screening tests assessment

Isopropyl myristate CAS 110 -27 -0

Three reliable studies are available to estimate the biodegradation of isopropyl myristate. In the key study, the ready biodegradability of Isopropyl myristate was tested according to OECD 301B and to GLP . The biodegradation of 9.45 mg/L DOC of the tested substance was monitored for 28 days. After 28 days, 91.4% of the initial tested substance was degraded. This result is consistent with a supporting study, equivalent to OECD 301B, where 10 and 20 mg/L DOC of the tested substance were degraded to 81.7 and 90% respectively after 28 days. The last supporting study does not show ready biodegradation of isopropyl myristate. However this last result does not affect the conclusions concerning the ready biodegradation of isopropyl myristate due to the very stringent conditions of these ready biodegradation tests and the known variability of the inoculum. Indeed in ready biodegradation tests when one reliable study show ready biodegradation, the substance is considered as readily biodegradable, whatever other results.

Isopropyl palmitate CAS 142 -91 -6

The ready biodegradability of Isopropyl palmitate was tested in a CO2-evolution test according to OECD 301B and to GLP. After 28 days, 91.3% of the initial test substance was degraded. Based on this result, the substance Isopropyl Palmitate is considered as readily biodegradable.

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

One ready biodegradation study is available for Fatty acids, C16-18, butyl esters. This key ready biodegradability study was performed following the ISO method 10708 (BODIS test). During the 28-day test period, biodegradation reached 82%, based on O2 consumption. In conclusion, Fatty acids, C16-18, butyl esters can be considered as readily biodegradable according to OECD criteria.

Fatty acids, C16-18 and C18 unsaturated, isobutyl esters CAS No. 84988-79-4

Two ready biodegradation studies and one marine BODIS test are available for Fatty acids, C16-18 and C18 unsaturated, isobutyl esters.

The key ready biodegradability study was performed according to OECD guideline 301 D. After the 30-day test period, biodegradation reached 99%, based on O2 consumption, and the 10-day window criterion was met. Since the substance is a UVCB and thus consists of saturated and unsaturated constituents with different chain lengths, sequential (instead of concurrent) biodegradation can take place, and all constituents can be considered as readily biodegradable.

The supporting ready biodegradability study was performed according to ISO/ DIS method 10708 (BODIS test). During the 28-day test period, biodegradation reached 72%, based on O2 consumption. The supporting marine biodegradability study was performed following the guideline MARINE BODIS ISO/TC 147/SC 5/WG 4N 141. Natural seawater, fortified with mineral nutrients, was used as source of microorganisms. and biodegradation reached 75%, based on O2 consumption after 28 days. Based on all these results, the substance Fatty acids C16 -18 and C18 unsatured, isobutyl esters is considered as readily biodegradable.

Isopropyl isostearate CAS 68171 -33 -5

The key ready biodegradability study was carried following a procedure similar to OECD Guideline 310 and according to GLP. During the 28-day test period, biodegradation reached 85.6%, based on inorganic carbon analysis, and the 10-day window criterion was met. In conclusion, isopropyl isostearate (CAS No. 68171-33-5) can be considered as readily biodegradable according to OECD criteria.

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.

Most of the members of the category were tested according to OECD 301B/301D guidelines or equivalent methods, and these substances were found readily biodegradable, with values between 82 % and 99% of biodegradation within 28 days. The structural similarity of the tested substances, and suitable enzymatic processes present in the inoculum explain the ready biodegradation observed for the category members. Based on the results obtained on these source substances, the biodegradation of the target substance "Ethyl Palmitate" was considered to be ≥ 82% within 28 days and this substance is considered as readily biodegradable.

[Type of water: freshwater]