Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

The long-chain aliphatic ester (LCAE) category covers mono-esters of a fatty acid and a fatty alcohol. The category contains both mono-constituent and UVCB substances. The fatty acid carbon chain lengths range is C8 - C22 (even- and un-even numbered, including saturated, unsaturated, branched and linear chains) esterified with fatty alcohols with chain lengths from C8 - C22 (even-numbered, including saturated, unsaturated, branched and linear) in varying proportions to mono-esters. The available data allows for an accurate hazard and risk assessment of the category and the category concept is applied for the assessment of environmental fate and environmental and human health hazards. Thus, where applicable, environmental and human health effects are predicted from adequate and reliable data for source substance(s) within the group, by interpolation to the target substances in the group (read-across approach), applying the group concept in accordance with Annex XI, Item 1.5, of Regulation (EC) No 1907/2006. In particular, for each specific endpoint the source substance(s) structurally closest to the target substance is/are chosen for read-across, with due regard to the requirements for adequacy and reliability of the available data. Structural similarities and similarities in properties and/or activities of the source and target substance are the basis of read-across. A detailed justification for the grouping of chemicals and read-across is provided in the technical dossier (see IUCLID Section 13).The terrestrial toxicity data of the LCAE category members are presented in the following table.

CAS

Toxicity to soil macroorganisms except arthropods

Toxicity to terrestrial arthropods

Toxicity to terrestrial plants

Toxicity to soil microorganisms

59231-34-4 (a)

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

36078-10-1

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

95912-86-0

Study ongoing according to OECD 222

--*

--*

Weight of Evidence (WoE)

 

95912-87-1

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

91031-91-3

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

85116-88-7

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

3234-85-3

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

22393-85-7

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

101227-09-2

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

72576-80-8

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

3687-45-4

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

17673-56-2

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

96690-38-9

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

93803-87-3

Study ongoing according to OECD 222

--*

--*

Weight of Evidence (WoE)

 

17671-27-1

RA: CAS 95912-86-0

RA: CAS 93803-87-3

--*

--*

Weight of Evidence (WoE)

 

(a) Category members subject to the REACh Phase-in registration deadline of 31 May 2013 are indicated in bold font.

(b) Substances that are either already registered under REACh or not subject to the REACh Phase-in registration deadline of 31 May 2013 are indicated in normal font. Lack of data for a given endpoint is indicated by “--“.

* According to the Guidance on information requirements and chemical safety assessment, Chapter R.7c: Endpoints specific Guidance (ECHA, 2008) the Chemical Safety Assessment (CSA) according to Annex I of Regulation (EC) No 1907/2006 will be based on the outcome of a single long-term earthworm study according to OECD 222 for two substances representing the variability of the category. The CSA will be re-evaluated based on the outcome of the two ongoing studies.

Currently no data are available investigating the terrestrial toxicity of the LCAE category members. Two studies according to OECD 222 for the category members Fatty acids, C8-10, C12 -18-alkyl esters (CAS 95912-86-0) and 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) (for other regulatory purposes) are still ongoing.The dossier will be updated as soon as possible and the Chemical Safety Assessment according to Annex I of Regulation (EC) No 1907/2006 will be re-evaluated based on the outcome of the new studies. The on-going studies cover the variability of the category with different alcohol components and representative fatty acid chain lengths. Thus, the data gaps can be confidently covered by interpolation. The category member Fatty acids, C8 - 10, C12 - 18-alkyl esters (CAS 95912-86-0) represents the lower end of the category whereas 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) is representative for the upper end of the category. All LCAE category members are expected to have a similar behaviour in the environment based on their physico-chemical properties such as low water solubility (< 0.05 mg/L) and high potential for adsorption to soil particles (log Koc > 5). Moreover, the category members are all readily biodegradable indicating that they will be rapidly degraded in the terrestrial environment. Thus, if exposure occurs, the main route for uptake is via ingestion of soil material. Dermal uptake via pore water is not considered to be a relevant exposure pathway based on the very low water solubility. However, the smallest substance of the category (Fatty acids, C8 - 10, C12 - 18-alkyl esters) represents a worst case for the uptake via dermal absorption since the substance is expected to be the most water soluble of all the category members. The water solubility is negatively correlated with the C-chain lengths of the fatty acid and fatty alcohol (Lide, 2005). Whereas, 2-octyldodecyl isooctadecanoate is representative as one of the category members with the highest potential for adsorption (log Koc: 10.49; Müller, 2011). Thus, the two main routes of exposure for terrestrial organisms are covered by studies with the two representative category members. However, after absorption, the LCAE category members are expected to be enzymatically hydrolyzed by carboxylesterases yielding the corresponding alcohol and fatty acid. QSAR estimations using BCFBAF v3.0 support the expected rapid biotransformation of this substance with BCF/BAF values of 0.89 - 14.07 and 0.90 - 314 L/kg were obtained, respectively. The metabolism of the hydrolysis products is well established and not of concern in terms of bioaccumulation (for further information see chapter 5.3 of the technical dossier). Summarizing, the LCAE category members are expected to be rapidly hydrolyzed to the respective fatty acid and fatty alcohol. Both hydrolysis products are supposed to be satisfactory metabolized in terrestrial organisms. Therefore, the potential for bioaccumulation is low.Available acute and chronic aquatic toxicity tests to fish, invertebrates, algae and microorganisms showed no adverse effects occurred in the range of the water solubility of the substance (< 0.05 mg/L). These results obtained support the assumption that the LCAE category members are likely to show no toxicity to terrestrial organisms. The available data for toxicity to aquatic microorganisms for the LCAE category members supports the determination of a lack of toxicity to soil microorganisms. No inhibition of respiration rate of aquatic microorganisms was observed in any of the available studies for the LCAE category members. The Guidance Document (ECHA, 2012, page 125) states that a test on soil microbial activity will only be additionally necessary for a valid PNEC derivation if inhibition of sewage sludge microbial activity has occurred and this is clearly not the case. This is supported by further evidence from literature data. This data showed that soil microorganism communities are well capable of degrading fatty acid esters (Hita et al., 1996 and Cecutti et al., 2002) and use them as energy source (Banchio & Gramajo, 1997). Based on the available information, effects on soil microorganisms are not expected to be of concern, and consequently, no further testing is required. In conclusion the Chemical Safety Assessment according to Annex I of Regulation (EC) No 1907/2006 for the terrestrial compartment will be re-evaluated based on the outcome of the ongoing studies.

A detailed reference list is provided in the technical dossier (see IUCLID, section 13) and within CSR.