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

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

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:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: source, RA-A, CAS 62125-22-8, 1997, Danio rerio 96 h, RL2

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: source, RA-A, CAS 62125-22-8, 1997, Danio rerio 96 h, RL2

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: source, RA-A, CAS 19321-40-5, 1997, C. carpio 96 h, RL2

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: source, RA-A, CAS 19321-40-5, 1997, C. carpio 96 h, RL2

Description of key information

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

Additional information

No study investigating the short-term toxicity of fatty acids C18-C22 (even numbered), tetraesters with pentaerythritol to fish is available. Therefore, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read-across to the structurally related source substances 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8) and pentaerythritol tetraoleate (CAS 19321-40-5) 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 to be suitable representatives for the evaluation of the short-term toxicity of the target substance to fish. The read-across approach is justified in detail within the analogue justification in IUCLID section 13.

The first study investigated the short-term toxicity of2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8) to freshwater fish according to OECD 203 under semi-static conditions using Danio rerio as test organism. Nominal concentrations of 10, 18, 32, 56 and 100 mg/L were applied. A stock solution was prepared daily and diluted appropriately. No mortalities occurred after the test duration of 96 hours resulting in an LC50 of > 100 mg/L.

Short-term toxicity of pentaerytritol tetraoleate (CAS 19321-40-5) to freshwater fish was investigated in the second study. This study was conducted according to OECD 203 under static conditions using Cyprinus carpio as a test organism. A nominal test concentration of 100 mg/L was applied by preparing a stock solution in acetone. Blank and solvent controls were also tested. No mortalities occurred after the test duration of 96 hours resulting in an LC50 of > 100 mg/L.

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 short-term effects to fish 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.