Fatty acids, C6-19-branched, zinc salts

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Limited study details are provided, preGLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1977

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

no

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

Neodecanoic acid

EC Number:

248-093-9

EC Name:

Neodecanoic acid

Cas Number:

26896-20-8

IUPAC Name:

2-ethyl-2,5-dimethylhexanoic acid

Details on test material:

- Name of test material (as cited in study report): Versatic 10
- Substance type: liquid

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: Internal strain, no additional details provided

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Shell Toxicology Laboratory

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

unchanged (no vehicle)

Induction 2

Concentration / amount:

0.1 ml test material in 50:50 Freund's complete adjuvant and corn oil

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Challenge 2

Concentration / amount:

0.1 ml test material in 50:50 Freund's complete adjuvant and corn oil

No. of animals per dose:

5 per sex per dose

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE - INTRADERMAL INJECTION
- No. of exposures: 2
- Exposure period: 1 week
- Test groups: single group
- Control group: Freund's complete adjuvant or corn oil
- Site: each side of the midline in the shorn skin of the shoulder region

B. INDUCTION EXPOSURE - TOPICAL APPLICATION
- No. of exposures: 2
- Exposure period: 1 week after intradermal injection
- Test groups: single group
- Control group: Freund's complete adjuvant or corn oil
- Site: each side of the midline in the shorn skin of the shoulder region
- Concentrations: 0.1 ml via occluded patch.

C. CHALLENGE EXPOSURE
- No. of exposures: Single 24 hour exposure
- Day(s) of challenge: 2 weeks after topical application
- Test groups: yes
- Control group: yes
- Site: 3x3 cm area on flank
- Evaluation (hr after challenge): 24 and 48 hours after removal

Results and discussion

In vivo (non-LLNA)

Results

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1 ml

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Not sensitizing

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.1 ml. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: Not sensitizing.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Neodecanoic acid is not sensitizing.

Executive summary:

In this study, neodecanoic acid was examined for skin sensitization potential in the guinea pig maximization procedure of Magnusson and Kligman.

 

A preliminary screen was carried out to determine the concentrations of test material to be used for intradermal induction, topical induction, and topical challenge. Two male and female guinea pigs were used for each test concentration.

 

Groups of ten male and ten female guinea pigs were used for the test and a further five males and five females as controls. 

 

Induction was accomplished in two stages. 

 

1) Intradermal injection

Two rows of three injections were made, one on each side of the midline in the shorn skin of the shoulder region. 

 

2) Topical application

One week after the intradermal injections, the same area was clipped free from hair. A 4x4 cm patch of filter paper was soaked in a solution of the test material and placed over the injection sites and covered with an occlusive dressing. The dressing was left in place for 48 hours. 

 

The challenge procedure was carried out two weeks after topical induction. Challenge was accomplished by topical application of the test material to the flank of animals via an occluded patch. The challenge lasted 24 hours. 

 

Immediately after the challenge, and then again at 24 and 48 hours later, each animals was examined for signs of skin sensitization.

 

At no point was there any evidence of skin sensitization produced by neodecanoic acid.