Tetradecyl laurate

Endpoint summary

Additional information

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 Read Across Report (see IUCLID Section 13).

 

The aquatic toxicity data of some REACH registered LCAE category members are presented in the following table:

CAS	Short-term toxicity to fish	Short-term toxicity to aquatic invertebrates	Long-term toxicity to aquatic invertebrates	Toxicity to aquatic algae	Toxicity to microorganisms
2-ethylhexyl oleate (CAS# 26399-02-0)	--	EC50 (48 h) > 100 mg/L	NOEC (21 d) > 1 mg/L	EC50 (72 h) > 100 mg/L	--
Dodecyl oleate (CAS# 36078-10-1)	LL50 (96 h) > 100 mg/L	Data waiving	NOEC (21 d) ≥ 100 mg/L	NOELR (72 h) ≥ 100 mg/L	NOEC (3 h) ≥ 1000 mg/L
Fatty acids, C8-10, C12-18-alkyl esters (CAS# 95912-86-0)	LL50 (96 h) > 100 mg/L	Data waiving	NOELR (21 d) ≥ 10 mg/L	EC50 (72 h) > 1000 mg/L  NOELR (72 h) ≥ 1000 mg/L	EC10 (3 h) > 1000 mg/L
Fatty acids, C16-18, C12-18-alkyl esters (CAS# 95912-87-1)	LC50 (96 h) > 10000 mg/L	EL50 (48 h) > 100 mg/L	RA: CAS# 36078-10-1 CAS# 26399-02-0 CAS# 3687-45-4	RA: CAS# 36078-10-1 CAS# 26399-02-0	EC10 (30 min) > 10000 mg/L (KC3) RA: CAS# 36078-10-1
Tetradecyl myristate (CAS# 3234-85-3)	LC50 (96 h) > 100 mg/L (> 0.189 µg/L (measured))	EC50 (48 h) > 100 mg/L (> 0.128 µg/L (measured))	RA: CAS# 95912-86-0	NOELR (72 h) ≥ 100 mg/L	NOEC (28 d): ≥ 100 mg/L RA: CAS# 95912-86-0
Tetradecyl oleate (CAS# 22393-85-7)	RA: CAS# 36078-10-1 CAS# 3687-46-5	RA: CAS# 26399-02-0	RA: CAS# 36078-10-1 CAS# 26399-02-0	RA: CAS# 36078-10-1 CAS# 26399-02-0	RA: CAS# 36078-10-1

 

CSA: Chemical Safety Assessment

In accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5, grouping and read-across, the LCAE Category members are not considered to be harmful to aquatic organisms based on the results from available short-term studies with fish, aquatic invertebrates and algae and available long-term results on toxicity to aquatic invertebrates.

 

All category members are structurally similar and read-across was performed to the structurally most similar category member(s). The available studies cover the variability of the category with different alcohol and fatty acid chain lengths. The data gaps within the category were filled by interpolation and if necessary by extrapolation since the category members are characterized by a similar pattern in the ecotoxicological toxicity profile. No trend in toxicity was observed since no effects were recorded up to the limit of water solubility, hence the use of extrapolation does not decrease the confidence in the read across approach in this case. There is no convincing evidence that any one of the category members might lie out of the overall profile of this category.

The LCAE Category members are expected to be metabolized in aquatic organisms to a high extent (see IUCLID Section 5). Moreover, the enzymatic hydrolysis products (fatty acid and fatty alcohol) can be used as energy source and are major constituents of living organisms (e.g. part of the phospholipid bilayer, muscle tissue and liver). Considering this it is assumed that aquatic toxicity is unlikely to occur.

 

Short-term toxicity to fish

Short-term toxicity studies to fish conducted according to internationally accepted guidelines are available for the LCAE category members 9-Octadecenoic acid (9Z)-, decyl ester (CAS 3687-46-5), fatty acids, C16 - 18, C12 - 18-alkyl esters (CAS 95912-87-1), tetradecyl myristate (CAS 3234-85-3), fatty acids, C16 - 18, 2-hexyldecyl esters (CAS 101227-09-2), 2-octyldodecyl isooctadecanoate (CAS 93803-87-3), dodecyl oleate (CAS 36078-10-1) and fatty acids, C8 - 10, C12 - 18-alkyl esters (CAS 95912-86-0). No effects were observed up to the limit of water solubility. The available studies cover the variability of the category with different fatty alcohol, and representative fatty acid chain, lengths.

Thus, most of the data gaps can be covered by interpolation. For the category members containing fatty acids and fatty alcohols > C18 the data gaps were filled by extrapolation. This approach is justified since it is very unlikely that toxicity occurs based on the nature of the substances, i.e. the LCAE category members are characterized by very low water solubility limiting the dissolved (bioavailable) concentration in the water phase to an extent that aquatic toxicity is unlikely to occur. Moreover, it is known from literature that very long chain alcohols (> C16) and long chain fatty acids (> C14) are not harmful to aquatic organisms. The toxicity of long chain fatty acids correlates with the hydrophobicity (log Kow) of the substance (Onitsuka et al., 1989). A “cut-off” point of log Kow 4.2 was established where aquatic toxicity is of negligible concern. No toxicity of fatty acids was observed for substances with log Kow > 4.2. The same was shown for long-chain alcohols (> C16). Due to the limited water solubility and low environmental concentration acute effects to fish are very unlikely (OECD, 2006).

 

Long-term toxicity to fish

There are no long-term fish studies available for the LCAE category members. The chemical safety assessment according to Annex I of Regulation (EC) No 1907/2006 does not indicate the need to investigate further the long-term toxicity to fish. Thus, in accordance to Annex IX, column 2 no further long-term toxicity test to fish is proposed. Available short-term studies for fish, aquatic invertebrates and algae, all indicate no potential for aquatic toxicity. Moreover NOEC values obtained from algal growth studies and daphnia reproduction studies are clearly above the limit of water solubility. As there was no sign that invertebrates are less sensitive than fish in the short-term tests, it cannot be expected that a long-term test with fish will generate different results than the existing long-term tests with aquatic invertebrates. Due to their ready biodegradability it is not likely that aquatic organisms will be exposed to the LCAE category members since they will be ultimately degraded in sewage treatment plants. Thus, based on the above mentioned results, it can be excluded that any substance within the category will exhibit chronic toxicity to fish up to the limit of water solubility. Hence due to animal welfare reasons and to avoid unnecessary vertebrate tests, no further long-term test with fish was proposed.

 

Short-term toxicity to aquatic invertebrates

Short-term toxicity studies with aquatic invertebrates are available for the category members2-ethylhexyl laurate (CAS 26399-02-0), fatty acids, C16 - 18, C12 - 18-alkyl esters (CAS 95912-87-1), tetradecyl myristate (CAS 3234-85-3), fatty acids, C16 - 18, 2-hexyldecyl esters (CAS 101227-09-2), 2-hexyldecyl oleate (CAS 94278-07-6) and 2-octyldodecyl isooctadecanoate (CAS 93803-7-3).No toxicity was observed up to the limit of water solubility in the available studies. The available studies cover the variability of the category with different fatty alcohol and representative fatty acid chain lengths. Most of the data gaps were covered by interpolation. Extrapolation was only conducted for the substances with longer chain fatty acids (≥ C16) and alcohols (≥ C18) which can be adequately justified for the short-term toxicity to fish endpoint due to the lack of toxicity and similar profile. In conclusion the LCAE category members are of low acute toxicity to aquatic invertebrates.

 

Long-term toxicity to aquatic invertebrates

Four long-term toxicity studies with aquatic invertebrates are available for the LCAE category members 2-ethylhexyl laurate (CAS 26399-02-0), dodecyl oleate (CAS 36078-10-1), fatty acids, C8 - 10, C12 - 18-alkyl esters (CAS 95912-86-0) and (Z)-octadec-9-enyl oleate (CAS 3687-45-4). No effects were observed up to the limit of water solubility. Moreover, one expert statement is available for 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) showing that the study is technically not feasible (Bogers, 1998). It was not possible to determine the concentrations of the test substance analytically. It was further stated that it would be unlikely that bioavailable concentrations will ever occur in the water phase due to the characteristics of the substance (log Kow > 7). The high hydrophobicity (log Kow > 7) is characteristic for all category members. Thus, it can be expected that the bioavailability in the water phase is negligible.

The available study with the category member 2-ethylhexyl oleate is characterized as an ester of a C8 (branched) alcohol and C18:1 fatty acid thus covering the LCAE category members containing a small chain alcohol component (C8-C14) and category members containing fatty acids with a chain lengths of C18 (unsaturated and saturated). The second study with the category member dodecyl oleate (CAS 36078-10-1) is covering the LCAE category members with a fatty acid chain length of C16-C18 and fatty alcohol chain lengths C10iso-C14. The third study with the category member fatty acids, C8 - 10, C12 - 18-alkyl esters (CAS 95912-86-0) is essential for the assessment of the long-term toxicity to aquatic invertebrates for the category members characterized by fatty acid chain length of C8-C14 and fatty alcohol chain lengths of C12-C14. Additionally, the fourth study with (Z)-octadec-9-enyl oleate was performed to cover the upper end of the LCAE category members characterized by fatty acid chain lengths of C16-C22 and fatty alcohol chain lengths of C18-C22. The structural variety of the LCAE category members is sufficiently covered by the available studies. All results do not lie out of the overall ecotoxicological profile of the category. Since the available chronic studies did not show chronic toxicity to aquatic invertebrates and it is known from literature (Onitsuka et al., 1989; OECD, 2006) that fatty acids and fatty alcohols are not harmful to aquatic organisms as justified in the endpoint summary for the acute fish endpoint, the LCAE category members are not harmful to aquatic invertebrates.

 

 

Toxicity to aquatic algae

Studies with aquatic algae are available for the LCAE category members 2-ethylhexyl laurate (CAS 26399-02-0), dodecyl oleate (CAS 36078-10-1), tetradecyl myristate (CAS 3234-85-3), 2-hexyldecyl oleate (CAS 94278-07-6), 2-octyldodecyl isooctadecanoate (CAS 93803-7-3) and fatty acids, C8 - 10, C12 - 18-alkyl esters (CAS 95912-86-0). No toxicity was observed up to the limit of water solubility in the available studies. The available studies cover the variability of the category with different alcohol components and representative fatty acid chain lengths. The assessment of the lower end of the category is supported by the study with fatty acids, C8 - 10, C12 - 18-alkyl esters. Most of the data gaps were estimated by interpolation. Extrapolation was conducted for the substances with longer chain fatty acids (≥ C16) and alcohols (≥ C18) like adequately justified for the short-term toxicity to fish endpoint mentioned above. In conclusion the category members are of low toxicity to aquatic algae.

Toxicity to microorganisms

Toxicity to microorganisms was investigated for the category members dodecyl oleate (CAS 36078-10-1), fatty acids, C8 - 10, C12 - 18-alkyl esters (CAS 95912-86-0), fatty acids, C16 - 18, C12 - 18-alkyl esters (CAS 95912-87-1) and 2-octyldodecyl isooctadecanoate (CAS 93803-7-3).

The study with fatty acids, C16 - 18, C12 - 18-alkyl esters (CAS 95912-87-1) was not considered to be reliable since only one single species (Pseudomonas putida) was tested and the test method did not meet today’s standard. Nevertheless, no effects on O2-consumption were observed. This result is in line with the results obtained from the other available studies. They were performed according to OECD 209. In some cases a toxicity control from the biodegradation study was used to derive a NOEC. No effects on respiration of activated sludge microorganisms were observed in all available studies and no inhibition of the biodegradation was recorded in the biodegradation studies. The studies cover the variability of the category members regarding the fatty acid and fatty alcohol chain length. In combination with results from the available biodegradation studies it can be concluded that no effects on the STP microorganism community and the subsequent degradation process in sewage treatment plants is anticipated for the LCAE category members.

 

Conclusion

No effects on aquatic organisms were observed in the available studies for the LCAE category members in any of the three trophic levels (fish, daphnia, algae) for substances within the category up to the limit of water solubility, neither in the short-term toxicity tests nor in long-term tests with aquatic invertebrates. The LCAE category is a robust category with a large amount of reliable data which allows a conclusive overview about the overall ecotoxicity profile of all category members. In each case of read-across, the best suited read-across was chosen. Nevertheless, as it can be seen in the data matrix of the category justification in IUCLID Section 13, all reliable data in the category support the hazard assessment of each category member by showing a consistent pattern of results.

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