Dimethyl sulfoxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: 1a: GLP, OECD Guideline 404

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl sulfoxide

EC Number:

200-664-3

EC Name:

Dimethyl sulfoxide

Cas Number:

67-68-5

Molecular formula:

C2H6OS

IUPAC Name:

dimethyl sulfoxide

Test material form:

liquid

Details on test material:

Chemical registery number : CAS 67-68-5 / EC 200-664-3
Chemical name : dimethyl sulfoxide (DMSO)

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: New Zealand White, Grimaud frères selection S.A.S., La Corbière, Roussay, France
- Age at study initiation:  2 to 4 months
- Weight at study initiation:  3.0 ± 0.3 kg
- Housing:  individually in Pajon cages (50 cm x 57 cm x 75 cm)
- Diet (e.g. ad libitum): free access to 110C pelleted diet (SAFE, Villemoisson,  Epinay-sur-Orge, France)
- Water (e.g. ad libitum): Drinking water ad libidum
- Acclimation period: t least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18+/-3
- Humidity (%): 30-70
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light):12/12

IN-LIFE DATES: From: To:

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

0.5ml

Duration of treatment / exposure:

4 hour(s)

Observation period:

The skin was examined approximately 1 hour, 24, 48 and 72 hours after removal of the dressing
The study was ended on day 4 in the absence of persistent irritation reactions

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 6cm² of the anterior left flank (application for 3 minutes), the anterior right flank (application for 1 hour) or the posterior right flank (application for 4 hours) of the animals
- Type of wrap if used: adhesive hypoallergenic aerated semi-occlusive dressing and a restraining bandage

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 48h

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible within: 72h

Results 4

Irritation parameter:

edema score

Basis:

other: All animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

After a 3-minute exposure (one animal) No cutaneous reactions were observed.
After a 1-hour exposure (one animal) No cutaneous reactions were noted.
After a 4-hour exposure (three animals) A very slight or well-defined erythema (grade 1 or 2) was noted on day 1 in all animals, persisting until day 2 in one animal and until day 3 in another one.

Applicant's summary and conclusion

Interpretation of results:

slightly irritating

Remarks:

Not classified as irritant (CLP)

Conclusions:

DIMETHYLSULFOXIDE was slightly irritant when applied topically to rabbits.

Executive summary:

The acute dermal irritation of DMSO (batch No. 15/11/06; purity: 99.98%) was evaluated in rabbits according to OECD 404 guideline. DMSO was applied undiluted to the skin of 3 New-Zealand White albino rabbits and held in contact by means of a semi-occlusive dressing. The test item was first evaluated on a single animal. The durations of exposure were 3 minutes, 1 hour and 4 hours. Since the test item was neither severely irritant nor corrosive on this first animal, it was then applied simultaneously for 4 hours to two other animals.

Mean scores over 24, 48 and 72 hours for each animal were for erythema and for oedema. Animals were then observed daily until day 15.

After a 3-minute exposure, no cutaneous reaction was observed. After a 1-hour exposure, no cutaneous reactions were noted. After a 4-hour exposure (three animals), a very slight or well-defined erythema (grade 1 or 2) was noted on day 1 in all animals, persisting until day 2 in one animal and until day 3 in another one.

Under the experimental conditions, DMSO was considered as non-irritant when applied topically to rabbits.