2-Propenoic acid, 2-methyl-, C6-12-alkyl esters

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Method in accordance with OECD Guideline, GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Principles of method if other than guideline:

other: modified Buehler-test (1965)

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

The study was conducted before the LLNA was implemented in the OECD guideline.

Test material

Test material information

Constituent 1

Reference substance name:

Methacrylic acid

EC Number:

201-204-4

EC Name:

Methacrylic acid

Cas Number:

79-41-4

Molecular formula:

C4H6O2

IUPAC Name:

2-methylprop-2-enoic acid

Details on test material:

purity: 98.5 % (0.001% max hydroquinone CAS 123-31-9; 0.027 max MEHQ, CAS 150-76-5)
Haskell number 19762
Clear liquid
Lot 5-031342

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals and environmental conditions:

Body weight 336-428 grams obtained from Davidson Mill Farm, Jamesburg, NJ. Aniamls individually identified by color coding.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

water

Induction 2

Concentration / amount:

0.4 ml; the first induction application was a 20% dilution in water ; the second and third induction applications was 15% in water. The challenge
application was 10% in water.

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

water

Challenge 2

Concentration / amount:

0.4 ml; the first induction application was a 20% dilution in water ; the second and third induction applications was 15% in water. The challenge
application was 10% in water.

No. of animals per dose:

20: test substance
10: vehicle control
5: positive control
5: naive positive control

Details on study design:

A group of twenty animals was closely clipped over the induction site on their left flank one day prior to intiation and repeated as necessary.
There were three induction applications

Positive control substance(s):

yes

Remarks:

99+% DNCB

Results and discussion

Positive control results:

The positive control (DCNB) induced and challenged as an 0.1% w/v concentration in a 50% ethanol: 0.9% saline solution is a skin sensitizer in albino
guinea pigs. After challenge application of the positive control article, no dermal irritation was observed for the naive postive control animals.

In vivo (non-LLNA)

Results

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10% in deionized water challenge concentration

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 10% in deionized water challenge concentration. No with. + reactions: 0.0. Total no. in groups: 20.0.

Any other information on results incl. tables

Test article group: no dermal irritation to eschar was observed during the induction phase of the study. After the challenge application no redness was observed other than slight patchy redness exhibited at 48 hrs by 2/20 animals. The incidence of sensitization was 0/20 and the severity was 0.0, 0.5 and 0.0 for 24, 48 and 72 hours, respectively.

Vehicle control group:

No dermal irritation to eschar was observed during the induction phase of the study. After the challenge application no redness was observed other than slight patchy redness exhibited at 48 hrs by 2/10 animals, and 3/10 animals at 72 hours. The vehicle site did not exhibit any redness.

Positive control group: see above

Naive positive control group: see above

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

In a valid guideline study, MAA was not a dermal sensitizer in albino guinea pigs. Methacrylic Acid did appear to be a skin irritant at
concentrations of 15% and above.
It was also concluded that a 0.1% w/v concentration of DNCB in a 50% ethanol: 0.9% saline solution produced delayed contact hypersensitivity in
albino guinea pigs.

Executive summary:

In a valid guideline study, MAA was not a dermal sensitizer in albino guinea pigs. Methacrylic Acid did appear to be a skin irritant at concentrations of 15% and above.

It was also concluded that a 0.1% w/v concentration of DNCB in a 50% ethanol: 0.9% saline solution produced delayed contact hypersensitivity in albino guinea pigs.