Methanesulphonic acid

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study with acceptable restrictions

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1995

Reference 2

Reference Type:

publication

Title:

HPVIS, IUCLID Data Set for Methanesulphonic acid, CAS no. 75-75-2

Author:

US-EPA

Year:

2003

Bibliographic source:

HPV Chemicals Challenge Program OPPT NCIC 201-14249B

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

modified grading timings for evaluation

GLP compliance:

yes

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

Methanesulphonic acid

EC Number:

200-898-6

EC Name:

Methanesulphonic acid

Cas Number:

75-75-2

Molecular formula:

CH4O3S

IUPAC Name:

methanesulfonic acid

Details on test material:

- Name of test material (as cited in study report): methane sulfonic acid
- Physical state: water white to pale yellow liquid
- Composition of test material, percentage of components: 70 % in water
- Lot/batch No.: M12E
- Storage condition of test material: room temperature (away from direct sunlight)

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Sprague-Dawley Inc. (P.O. Box 29176, Indianapolis, Indiana 46229)
- Weight at study initiation: 429.6±18.8 g (males), 400.5±27.6 g (females)
- Housing: single
- Diet (e.g. ad libitum): Teklad Guinea Pig Diet
- Water (e.g. ad libitum): tap water
- Acclimation period: 4 days


ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

water

Induction 2

Concentration / amount:

Induction: 35 % MSA
Challenge: 17.5 % MSA

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

water

Challenge 2

Concentration / amount:

Induction: 35 % MSA
Challenge: 17.5 % MSA

No. of animals per dose:

10 males, 10 females (controls: 5 males, 5 females)

Details on study design:

RANGE FINDING TESTS:
A preliminary study was conducted in order to determine the concentrations to be tested in the main study. The irritation potential of methane sulfonic acid (MSA) 70 % at levels of undiluted, 50 %, 25 %, 10 %, 5 %, 2.5 %, 1.0 % and 0.5 % was evaluated in 2 groups of 4 animals each. Four levels of test substance were evaluated per animal. Dilutions were obtained with distilled water (w/v). 0.3 ml of the different concentrations were applied into 25 mm Hill Top Chambers, which were placed on the animals clipped back for 6 hours. On the next day the animals were depilated and two hours later examined for irritation, according to the grading scores (0: no reaction; : slight, patchy erythema; 1: slight but confluent or moderate patchy erythema; 2: moderate erythema; 3: severe erythema with or without edema). Another examination was performed 40 hours after exposure. Undiluted 70 % produced grades of 2,1 and ± with edema, blanching, and scabbing on two sites, 50 %, 25 %, 10 %, 5 %, 2.5 %, 1.0 % produced grades of ±, while 0.5% produced grades of ± and 0. A 50 % w/v concentration of MSA 70% in distilled water was chosen for use at induction for the test group. The level was chosen as the highest concentration causing no greater than mild to moderate primary irritation.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Test groups: 0.3 ml of the test substance
- Control group: 0.3 ml vehicle
- Site: left shoulder
- Frequency of applications: on day 1, 7 and 14
- Duration: 14 days
- Concentrations: 50 % (w/v of MSA 70%)


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 28
- Exposure period: 24 hours
- Test groups: 0.3 ml of test substance
- Control group: 0.3 ml of test substance
- Site: right flank
- Concentrations: 25 % (w/v of MSA 70%)
- Evaluation (hr after challenge): 24 hours

Challenge controls:

No extra group necessary: control group was challenged with test substance, as well, because induction exposure with distilled water is not expected to induce any sensitization.

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

17.5 %

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no clinical signs

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 17.5 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no clinical signs.

Results 2

Reading:

2nd reading

Hours after challenge:

40

Group:

test chemical

Dose level:

17.5%

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

no clinical signs

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 40.0. Group: test group. Dose level: 17.5%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no clinical signs.

Any other information on results incl. tables

None of the test animals responded with a skin grade that would have been suggestive of sensitization. No data on clinical signs was revealed.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information