Hexadecanedioic acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

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

Adequacy of study:

key study

Study period:

1989-02-14 to 1989-02-20

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

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:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dodecanedioic acid

EC Number:

211-746-3

EC Name:

Dodecanedioic acid

Cas Number:

693-23-2

Molecular formula:

C12H22O4

IUPAC Name:

dodecanedioic acid

Details on test material:

Dodecanedioic acid of Hüls AG, purity ca. 99 %; impurities: homologous dicarboxylic acids, total 1 %

Test animals

Species:

rabbit

Strain:

other: small white russian

Details on test animals or test system and environmental conditions:

TEST ANIMALS:
- Strain: Small white Russian, Chbb-SPF
- Source: Dr. Karl Thomae GmbH, Biberach (Germany)
- Sex: male
- Weight at study initiation: 2.2 - 2.4 kg

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Amount / concentration applied:

Concentration: 50 %
ADMINISTRATION/EXPOSURE
- Preparation of test substance: 0.5 g ground in mortar, wetted with 0.5 ml deionized water
- Area of exposure: 6 cm2
- Occlusion: mull patch, elastic dressing - Removal of test substance: washing with warm water - Post exposure period: 6 days

Duration of treatment / exposure:

4 hours

Observation period:

6 days

Number of animals:

3

Details on study design:

EXAMINATIONS
- Examination time points: 1, 24, 48, 72 hours, and 6 days after patch removal; evaluation based on readings 1-4
- Scoring system: OECD Guideline; evaluation: VCI notes on safety data sheet and Appendix VI of 79/831/EEC

Results and discussion

In vivo

Results

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 1h, 24h, 48h,72h, 6 days

Score:

0

Max. score:

0

Irritant / corrosive response data:

AVERAGE SCORE
- Erythema: 0.0
- Edema: 0.0
REVERSIBILITY: not applicable

Other effects:

No reaction was observed

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on a read across (category approach), no classification regarding the skin irritation is required for hexadecanedioic acid.