Octanoic acid, 1,1'-(1,3-propanediyl) ester

Short-term toxicity to fish

Description of key information

Testing of acute toxicity to fish can be omitted because the substance is of such low water solubility that aquatic toxicity is unlikely to occur. Indeed, no effects on aquatic plants and on daphnia using water-accommodated fractions of 1,3-propanediol dicaprylate were observed. Long-term toxicity testing of fish is not considered necessary because 1,3-propanediol dicaprylate is readily biodegradable. There is no risk for bioconcentration in fish because fish can hydrolyse carboxylic esters,  low BCF/BAF values indicate that the substance is rapidly metabolised and excreted by organisms. The LC50 (96h) is predicted to be >100 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

The water solubility of propanediol dicaprylate was determined to be less than 0.01 mg/L. The specific rules for adaptation for the standard information requirements of Regulation EC 1907/2006 of December 30, 2006 state that the test for acute toxicity to fish does not need to be conducted if there are mitigating factors indicating that aquatic toxicity is unlikely to occur. Such mitigating factors may be that test substance is highly insoluble in water or it is too large to cross biological membranes.

 

Further information is given in the endpoint-specific guidance published by ECHA in May 2008 (Guidance on information requirements and chemical safety assessment: Chapter R.7b: Endpoint 2/2 specific guidance): Decisions on non-testing of acute toxicity based on insolubility shall be taken on a case-by-case basis for substances with a water solubility of less than 1 mg/L. A long-term aquatic toxicity study on fish shall be considered if acute testing is omitted because of insolubility.

 

Propanediol dicaprylate is predicted to have no acute toxicity for the following reasons:

a) It is highly insoluble in water (< 0.01 mg/L)

b) It does not cause adverse effects on daphnia and aquatic plants

c) It can be metabolized in fish via enzymatic ester hydrolysis (Barron, 1999), low BCF/BAF values indicate that the substance is rapidly metabolised and excreted

c) It is readily biodegradable

d) The limited information on the building blocks does not indicate a hazard for toxicity to fish.

 

The following information on acute toxicity of building blocks was retrieved:

 

Acute toxicity of 1,3-propanediol to goldfish (Carassus auratus): LC50 (24h) > 5000 mg/L (Bridie, 1979)

This study is taken from a publication in Water Research in 1979. The authors of the study worked for the Koninklijke/Shell Laboratory in the Netherlands. It is described that the test was conducted in accordance with the American Public Health Association guideline for static acute toxicity tests of 1971 and that the test item concentration was measured. This report describes the results of more than 50 chemicals derived from petroleum. In cases where the highest dose of 5000 mg/L was non toxic, the study was terminated after 24h instead of 96h. Limited details on the procedure and the results are given.

 

Acute toxicity of 1,3-propanediol to fathead minnows (Pimephales promelas):

LC50 (96h) > 9720 mg/L

This information is taken from the environmental data summary on 1,3-propanediol published by DuPont Tate & Lyle Bio Products. OECD testing guideline 203 is given as a reference. It is not possible to assess this information for validity.

 

Acute toxicity of fatty acids to red killifish (Oryzias latipes)

A QSAR model for toxicity to red killifish was derived from experimental data on the fatty acids and their salts. The LC50 for decanoic acid LC50 (96h) in (Oryzias latipes) was determined to be 54 mg/L (Onitsuka, 1989). This value is higher than the water solubility of 1,3-propanediol dicaprylate.