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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Comparable to guideline study with acceptable restrictions: - In this study only a mean score, primary cutenous irritant index, was calculated, which was used for the classification of the test substance according to the AFNOR scale. This is not according to OECD. - According to the guideline, a single dose is applied to the skin of the animals. In this study two patches with the dose were applied to the skin of the animals. -According to the guideline, the test material should be removed at the end of the exposure time. In this study, it was not mentioned, if this was done. - According to the guideline tabulation of irritation response data for each individual animal for each observation time period should be stated. In this study only a mean score including all investigated animals was given.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
Evaluation of the cutaneous-irritation potential of 56 compounds
Author:
Guillot, J.P. et al.
Year:
1982
Bibliographic source:
Fd. Chem. Toxic. Vol. 20: 563-572

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
See "Rationale for reliability"
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Dimethyl sulfate
- Physical state: Colourless liquid
- pH: approx. 1.0
No further information on test material was stated.

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Roucher SA, Couhé
- Weight at study initiation: ca. 2.5 kg
No further information on test animals was stated.

Test system

Type of coverage:
semiocclusive
Preparation of test site:
shaved
Vehicle:
water
Controls:
not specified
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: A dose of 0.5 ml of the organic phase of a 50/50 (v/v) aqueous solution of dimethyl sulfate was applied onto two approx. 6 cm^2 gauze pads.
No further information on amount/concentration was stated.
Duration of treatment / exposure:
4 hr
Observation period:
Macroscopic observation were made at 1, 24, 48, and 72 hr after patch removal.. Further readings at day 7 and day 14 were added in cases of pronounced irritation, to evaluate the possible reversibility of the lesions.
Number of animals:
6 male rabbits
Details on study design:
TEST SITE
- Area of exposure and type of wrap if used: Each rabbit was clipped over the back and flanks with a fine toothed electric clipper (Aesculap Type V 42 947), to give a precise cut (height 0.05 mm) without causing mechanical irritation of the skin. For the application of the test item, two sterile four-layered hydrophilic-gauze pads were placed on the skin of each rabbit, one pad on the right flank and one on the left side. The pads were held in place with adhesive tape.

REMOVAL OF TEST SUBSTANCE
Nothing was stated


SCORING SYSTEM: Each treated area was scored for erythema and oedema using a numerical system (0-4 in each case according to severity) based on that described by Draize, Woodard & Calvery (1948).

No further details on study design were stated.

Results and discussion

In vivo

Results
Irritation parameter:
other: Primary cutaneous irritation index
Basis:
mean
Time point:
other: 1, 24, 48, 72 hours
Score:
5.98
Max. score:
8
Reversibility:
not fully reversible within: 14 days
Irritant / corrosive response data:
The lesions showed only slight regression by day 14, when erythema was still clearly visible and oedema was occasionally recorded.
Other effects:
No data

Any other information on results incl. tables

The scores obtained for erythema and oedema at both of the treated sites in all six animals at the reading times were totalled. The sum obtained was then divided by the total number of readings to provide a mean score termed the primary cutaneous irritation index (PCI). The total number of readings (erythema + oedema) were 48 corresponding to two application sites on six animals at 1, 24, 48 and 72 hr after removal of the patches. The slightly different AFNOR scale (PCI below 0.5, non-irritant; 0.5 - 3. slightly irritant; 3 -5, moderately irritant; 5 - 8, severly irritant) was used to interpret the results.

Applicant's summary and conclusion

Interpretation of results:
corrosive
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Dimethyl sulfate was considered to be corrosive.
According to the criteria specified by Directive 67/548/EEC and subsequent regulations, the test item is classified as skin corrosive.
According to the EC Regulation No. 1272/2008 and subsequent regulations, the test item is classified as Category 1A.