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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: test procedure in accordance with company standards
Justification for type of information:
1. HYPOTHESIS FOR THE CATEGORY APPROACH (ENDPOINT LEVEL)
No reproducible, significant variation in local effects on skin and eye between members of the category have been reported but rather strong irritation or even corrosive effects. Therefore, the general hypothesis for the category approach that xylenol isomers exert qualitatively and quantitatively similar toxicity effects applies for the endpoint "skin irritation / corrosion".

2. CATEGORY APPROACH JUSTIFICATION (ENDPOINT LEVEL)
Available data for two xylenol isomers and a mixture of isomers indicate a mostly strong reactivity with tissues of skin and eye. All 6 isomers as well as xylenol (mixed isomers) are classified as Skin Corr. 1B according to Annex VI of Regulation (EC) No 1272/2008 (CLP Regulation). See attached read-across justification for further information.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1961
Report Date:
1961

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
1 - 10 applications of diluted or undiluted material to the intact or abraded skin of rabbits
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline

Test animals

Species:
rabbit
Strain:
not specified

Test system

Type of coverage:
not specified
Preparation of test site:
abraded
Remarks:
or intact skin
Vehicle:
other: Dipropylene glycol methyl ether (Dowanol DPM)
Controls:
not specified
Amount / concentration applied:
undiluted, or 10% solution in Dowanol DPM
Duration of treatment / exposure:
1 or repeated applications
Observation period:
21 days
Number of animals:
not specified
Details on study design:
undiluted material: 1 application on intact and abraded belly skin, respectively
10% solution in Dowanol DPM: 10 applications on intact ear and belly skin; 3 applications on abraded belly skin

In addition patch tests with undiluted material and short exposure duration (0.5, 1, 5, and 10 min)

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
other: hyperemia, edema, necrosis
Remarks:
based on clinical observation
Reversibility:
not fully reversible within: 21 days
Remarks on result:
probability of severe irritation
Irritation parameter:
erythema score
Remarks:
intact and abraded skin
Basis:
animal #1
Time point:
24/48/72 h
Score:
>= 2 - <= 3
Max. score:
4
Reversibility:
fully reversible within: 21 days
Remarks on result:
probability of severe irritation
Remarks:
interpretation of non-guideline gradings
Irritation parameter:
edema score
Remarks:
intact and abraded skin
Basis:
animal #1
Time point:
24/48/72 h
Score:
3
Max. score:
4
Reversibility:
fully reversible within: 21 days
Remarks on result:
probability of moderate irritation
Remarks:
interpretation of non-guidline gradings
Irritant / corrosive response data:
See Table 1 and 2 below.

Any other information on results incl. tables

Table 1: Skin irritation study with exposure of rabbit skin to 3,5-xylenol

Material

Condition

Number of applications

Site

Response

Undiluted

Intact

1

Belly

Slight hyperemia and edema with moderate necrosis. Skin healed with moderate scear in 21 days.

Undiluted

Abraded

1

Belly

Slight hyperemia and edema with moderate necrosis. Skin healed with moderate scear in 21 days.

10% solution in Dowanol DPM

Intact

10

Ear

No irritation observed

10% solution in Dowanol DPM

Intact

10

Bell

Very slight hyperemia and slight to moderate exfoliation. Skin normal in 21 days.

10% solution in Dowanol DPM

Abraded

3

Belly

Slight exfoliation only. Skin essentially normal in 21 days.

Table 2: Patch test with short exposure of rabbit skin to 3,5-xylenol

Material

Exposure duration (min)

Response

Undiluted

0.5

Essentially no irritation

Undiluted

1

Slight hyperemia

Undiluted

5

Slight hyperemia with moderate burn

Undiluted

10

Moderate hyperemia with moderate burn

Applicant's summary and conclusion

Interpretation of results:
Category 1B (corrosive) based on GHS criteria
Remarks:
5 - 10 Minutes of skin contact may cause burns.
Conclusions:
5 - 10 Minutes contact of the rabbit skin to 3,5-xylenol can cause burns and skin necrosis indicating a skin corrosion potential of the substance.
Executive summary:

In a non-guideline in vivo skin irritation study a single application of undiluted 3,5-xylenol on intact or abraded belly skin of rabbits caused slight hyperemia and edema with moderate necrosis. The skin healed with moderate scear within 21 days. 10 Applications of a 10% solution in dipropylene glycol methyl ether (Dowanol DPM) did not induce irritation of the intact rabbit ear but evoked very slight hyperemia and slight to moderate exfoliation on intact belly skin. These effects were reversible within 21 days. Three applications of the diluted solution on abraded belly skin resulted in slight exfoliation only. The skin appeared to be essentially normal after 21 days. 5 - 10 Minutes contact of the rabbit skin to 3,5-xylenol can cause burns and skin necrosis indicating a skin corrosion potential of the substance.

This result can be transferred to the target test item 2,5-xylenol based on high structural similarities in the read-across category of xylenol isomers (see 'Read-across statement' in section 13.2).