Hexadecanedioic acid

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

1. HYPOTHESIS FOR THE CATEGORY APPROACH (ENDPOINT LEVEL)
Dicarboxylic acids are organic compounds that contain two carboxylic acid functional groups. They have the general type formula HOOC-(CH2)n-COOH. The present defined category comprises dicarboxylic acids with straight carbon chain having a “n” value from 6 to 16.
The physical and chemical properties as well as the toxicology and environmental fate and effects show that substances in this category have a similar order of toxicological and environmental fate properties, which supports the grouping of these substances as a category. (see attached justification)

2. CATEGORY APPROACH JUSTIFICATION (ENDPOINT LEVEL)
There are number of unifying considerations justifying the similarity between these substances in some important aspects. These include:
(1) Similarity of Use: these dicarboxylic acids have several industrial uses in the production of adhesives, plasticizers, lubricants, copolymers (such as polyamides and polyesters), etc.
(2) Similarity of Functional groups: all these substances contain two common functional groups (2 carboxyl groups). The only difference between the substances of this group lies in the length of the carbon chain.
(3) Similarity of Physical / Chemical properties: the similarity of physical / chemical properties for these substances (see attached justification)
(4) Similarity of Metabolism: Dicarboxylic acids were shown to be rapidly absorbed from the gastrointestinal tract, introduced into the fatty acid catabolism and therefore extensively metabolized by the organism and excreted (Passi, S. et al, 1983).
(5) Similarity of Mammalian Toxicity: The constituents of this class have similar toxicological properties. They are not acutely toxic, irritating to skin or sensitizing. However, they all present, except for dodecanedioic acid, irritating effects on the eyes (from moderate to high effects). They do not produce systemic effects in repeated dose studies. They are neither mutagenic nor carcinogenic and do not produce developmental/reproductive toxicity. (see attached justification)
(6) Similarity of Environmental Toxicity and Fate Properties: The substances in this category have similar environmental effects properties. The environmental effects data are similar for most category members in that most members do not exhibit acute toxicity. (see attached justification)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sebacic acid

EC Number:

203-845-5

EC Name:

Sebacic acid

Cas Number:

111-20-6

Molecular formula:

C10H18O4

IUPAC Name:

sebacic acid

Details on test material:

- Name of test material (as cited in study report): Sebacic Acid
- Substance type: White powder
- Physical state: Solid
- Storage condition of test material: Room temperature

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

- The test substance was added direct into the study beaker.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Supplier: laboratory breeding
- Feeding: three times a week with green algae (Selenastrum capricornutum)
- During the treatment period the animals were not fed
- Light: 12/16 hours of light/dark
- During the test the animals were kept in the dark

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

251 mg/L of CaCO3

Test temperature:

22°C

pH:

6.5-77

Dissolved oxygen:

7.0-8.0 mg/L

Nominal and measured concentrations:

-Test concentration nominal: 100 mg/L

Details on test conditions:

TEST CONDITIONS
- Test vessels: silylated glass beakers
- 20 animals / concentration
- One group of 20 animals was treated only with reconstituted water
- Age at the beginning of test < 24 hours

TEST MEDIUM / WATER PARAMETERS
- Dilution water according to ISO 6341 - 1982
- sum of calcium and magnesium ions: 25 mmol/L
- Ca/Mg ratio 4/1
- Na/K ratio 10/1

EFFECT PARAMETERS MEASURED
- Observation of immobilization at 24 and 48 hours.
- Parameter checking of dissolved oxygen, pH and temperature at 0 and 48 hours

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No animals were immobilized in the control group and in the treated one.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions the substance did not cause immobilisation up to a limit test nominal concentration of 100mg/l.

Executive summary:

The toxicity to aquatic invertebrates of the test substance was evaluated according to OECD Guideline 202. The test organisms were examined in a negative control and in a definitive test group with treatment of the test item at the nominal concentration 100 mg/l. No test organisms were immobilised in the negative control group of the definitive test group. In this limit test no immobilisation of the water fleas were observed and the EC50 was therefore determined to be >100mg/l.