LBX98

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Justification for type of information:

No data are available for the target substance. Acute oral LD50 values of 121mg/kg bw, 242 mg/kg bw and 207 mg/kg bw are reported for o-, m- and p-cresols, respectively. Acute oral LD50 values of ~980 mg/kg bw are reported for xylenol and ethylphenol. Data therefore demonstrate greater toxicity for the cresols compared to mixed xylenol isomers and mixed ethylphenol isomers, with some evidence that o-cresol is the more toxic of the cresol isomers. Based on the closest structural similarity, read-across using the xylenol study is required for this endpoint. No dermal toxicity data are available for any Category substance; a waiver is appropriate for the target substance for this endpoint based on the proposed classification of the target substance as corrosive. Robust inhalation toxicity data are available for any Category substance; a waiver is appropriate for the target substance for this endpoint based on the proposed classification of the target substance as corrosive. Experimental data for o-, m- and pcresols, 2,4-xylenol and 2,6-xylenol show that classification for skin corrosivity is appropriate. Data for 3,5-xylenol do not indicate that classification for skin irritation or corrosivity are required. Classification for skin corrosivity is therefore proposed for the target substance based on the weight of evidence and following a worst case approach. Experimental data for o-, m- and p-cresols and 3,5-xylenol show severe eye irritation. Classification for severe eye damage is therefore proposed for the target substance based on the weight of evidence. Skin sensitisation studies report negative results for p-cresol and 3,5-xylenol and a positive result for 2,4-xylenol. Classification for skin sensitisation is therefore proposed for the target substance based on the weight of evidence and following a worst-case approach.

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: CFR/USA, Title 16, Section 1500.41

Principles of method if other than guideline:

according to the Consumer Product Safety Commission/USA: 24 h exposure

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 2,4-xylenol and 2,5-xylenol

EC Number:

905-287-4

Cas Number:

1638758-52-7

Molecular formula:

(CH3)2C6H3OH

IUPAC Name:

Reaction mass of 2,4-xylenol and 2,5-xylenol

Test material form:

solid: bulk

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS- Source: J. Scheele, Werl/Germany- Age at study initiation: no data- Weight at study initiation: no data- Housing: mesh metal cage- Diet: ad libitum - Water: ad libitumENVIRONMENTAL CONDITIONS- Air-conditioned room- Temperature (°C): 22 +-1 °C- Photoperiod (hrs dark / hrs light): 12 / 12

Test system

Type of coverage:

occlusive

Preparation of test site:

other: shaved intact and abraded

Vehicle:

other: Polyethylene glycol (PEG) 400

Controls:

not required

Amount / concentration applied:

TEST MATERIAL- Amount(s) applied (volume or weight with unit): 500 mg mixed with 0.5 mL PEGVEHICLE- Amount(s) applied (volume or weight with unit): 0.5 mL

Duration of treatment / exposure:

24 h

Observation period:

14 days

Number of animals:

6

Details on study design:

TEST SITE- Area of exposure: 2.5 cm x 2.5 cm - Type of wrap if used: gauze/mull soaked with the test suspension, fixed with adhesive bandage ("Elastoplast") SCORING SYSTEM: numerical scoring system of effects according to Draize (erythema, oedema, other lesions such as necrosis)(ETAD recommendation)- EVALUATION: Reading after 24 and 72 h and calculation of a "Primary Irritation Index" = Sum of effects (erythema and oedema) at both time points for each animal divided by 24 (4 effects values each, 6 animals).The ranking system of the "Primary Irritation Index" was as follows (based on ETAD recommendation): 0.0 - 0.5 not irritating0.6 - 3.0 slightly irritating3.1 - 5.0 moderately irritating5.1 - 8.0 severely irritating

Results and discussion

In vivo

Results

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Remarks:

(6 animals)

Time point:

24/48/72 h

Score:

0.25

Max. score:

8

Reversibility:

fully reversible

Remarks on result:

probability of mild irritation

Irritant / corrosive response data:

Slight oedema in 3/6 animals (24 h after application), no effects after 72 h, no difference between intact and scarified skin

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated informationCriteria used for interpretation of results: EU

Executive summary:

The above results are suitable to be used for read across for Reaction mass of 2,4-xylenol and 2,5-xylenol, due to the category being based on structural similarity and comparable physicochemical properties, leading to similar (eco)toxicological properties.