Fatty acids C18-C22 (even numbered), tetraesters with pentaerythritol

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Remarks:

Summary of available data used for the endpoint assessment of the target substance

Adequacy of study:

key study

Justification for type of information:

Please refer to the Analogue Justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

immobilisation

Remarks on result:

other: source, RA-A, CAS 85711-45-1, Oleon, 2013, D. magna reproduction 21 d, RL1

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

other: mean age of first brood

Remarks on result:

other: key, source, RA-A, CAS 85711-45-1, Oleon, 2013, D. magna reproduction 21 d, RL1

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Remarks on result:

other: key, source, RA-A, CAS 85711-45-1, Oleon, 2013, D. magna reproduction 21 d, RL1

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 135 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Remarks on result:

other: source, RA-A, CAS 71010-76-9, Exxon, 2012, D. magna 21 d, RL1

Description of key information

No effects up to the limit of water solubility; read-across.

Additional information

No study investigating the long-term toxicity of fatty acids C18-C22 (even numbered), tetraesters with pentaerythritol to aquatic invertebrates is available. Therefore, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read-across to the structurally related source substances fatty acids, C16-18 and C18-unsaturated, esters with pentaerythritol (CAS 85711-45-1) and decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9) is applied.

Based on the high degree of similarity between the structural and physico-chemical properties of the target and source substances, the source substances are considered as suitable representative for the evaluation of the short-term toxicity of the target substance to aquatic invertebrates. The read-across approach is justified in detail within the analogue justification in IUCLID section 13.

A study investigating the long-term toxicity of fatty acids, C16-18 and C18-unsaturated, esters with pentaerythritol (CAS 85711-45-1) to aquatic invertebrates is available. The study was conducted under semi-static conditions according to OECD 211 using Daphnia magna as test organism. A water-accommodated fraction (WAF) was prepared with a loading rate of 1 mg/L (nominal). No significant effect on reproduction, mean age of first brood and immobilisation was observed in the treatment throughout the test period of 21 d. A difference between the mean length of the control and treatment group was < 10% (i.e. 6.04%) and is therefore be considered as biologically not relevant. Hence, the 21 d-NOELR is determined to be ≥ 1 mg/L on the basis of the nominal test concentration. A second study investigated the long-term toxicity of decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9) to aquatic invertebrates. The study was conducted under semi-static conditions according to OECD 211 using Daphnia magna as test organism. A loading rate of 135 mg/L (nominal) was applied in the limit test. The water-accommodated fraction (WAF) solution was prepared by adding the appropriate amount of test substance with subsequent stirring and sampling of the aqueous portions (WAFs) through the outlet at the bottom of the vessels. No significant effect on reproduction was observed in the treatment throughout the test period of 21 d. Hence, the 21 d NOELR is determined to be >= 135 mg/L on the basis of the nominal test concentration.

In addition, aquatic toxicity of the substance is unlikely to occur due to the low bioavailability of the substance in water. Due to the high potential for adsorption, the substance can be effectively removed in conventional sewage treatment plants (STPs) by sorption to biomass. The low water solubility (< 0.518 mg/L at 20 °C, OECD 105) and high estimated log Kow (> 10, QSAR, VEGA 1.1.3) indicate that the substance is highly lipophilic. If released into the aquatic environment, the substance undergoes extensive sorption on organic matter. Thus, the bioavailability in the water column is reduced rapidly. The relevant route of uptake of the substance in aquatic organisms is expected to be predominantly by ingestion of particle bound substance. However, as the substance has a high molecular weight of 1370.31 – 1426.42 g/mol, it is unlikely that it is readily absorbed, due to the steric hindrance of crossing biological membranes. Following the ‘rule of 5’ (Lipinski et al., 2001), developed to identify drug candidates with poor oral absorption based on criteria regarding partitioning (log Kow > 5) and molecular weight (> 500 g/mol), the substance is considered to be poorly absorbed after oral uptake (Hsieh & Perkins, 1976).

Based on the available results from structurally related source substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which are characterized by a similar ecotoxicological profile and comparable structure, a low bioavailability of the substance in water and a steric hindrance of crossing biological membranes, it can be concluded that fatty acids C18-C22 (even numbered), tetraesters with pentaerythritol will not exhibit long-term effects to invertebrates up to the limit of water solubility.

References

Hsieh, A. and Perkins, E. G. (1976). Nutrition and Metabolic Studies of Methyl Ester of Dimer Fatty Acids in the Rat. Lipids, 11(10):763-768.

Lipinski et al. (2001). Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings. Adv. Drug Del. Rev. 46: 3-26.