1,2-dichlorobenzene

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March to April 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Comparable to guideline study with acceptable restrictions (24h instead of 4h exposure (worst case); observation after 60min, 48h and 14 days was not conducted (scores of 24h were also assumed for 48h time point (worst case)); impervious instead of semi-occlusive patch was used; new calculation of scoring averages was necessary)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: ETAD guideline

Deviations:

yes

Remarks:

; application only on intact skin

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

; 24h instead of 4h exposure (worst case); observation after 60min, 48h and 14 days was not conducted (scores of 24h were also assumed for 48h time point (worst case)); impervious instead of semi-occlusive patch was used; new calculation of

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,2-dichlorobenzene

EC Number:

202-425-9

EC Name:

1,2-dichlorobenzene

Cas Number:

95-50-1

Molecular formula:

C6H4Cl2

IUPAC Name:

1,2-dichlorobenzene

Details on test material:

- Analytical purity: 1,2-dichlorobenzene, chemically pure (no further data)

Test animals

Species:

rabbit

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hacking & Churchill, Huntingdom, Great Britain
- Weight at study initiation: 3-4 kg
- Housing: separately in standard cages
- Diet (e.g. ad libitum): Z 222 from Hönig, Verden/Aller, Germany ad libitum
- Water (e.g. ad libitum): ad libitum

Test system

Type of coverage:

other: surgical gauze patch wrapped with an impervious material

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable

Amount / concentration applied:

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

Duration of treatment / exposure:

24h

Observation period:

timepoints: 24h, 72h and 7 days

Number of animals:

six

Details on study design:

TEST SITE
- Area of exposure: approximately 6 cm2
- Type of wrap if used: surgical gauze patch wrapped with an impervious material

SCORING SYSTEM:
according to Draize

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24h-72h

Score:

1.56

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24-72h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 days

Other effects:

none

Any other information on results incl. tables

Table: Evaluation results of skin reactions after 1,2-dichlorobenzene administration to rabbits

Animal No.	Symptoms	Time points for skin evaluation
		24 hours	48 hours*	72 hours	7 days
224	Erythema	2	2	1	0
224	Oedema	2	2	0	0
229	Erythema	1	1	0	0
229	Oedema	1	1	0	0
230	Erythema	2	2	1	1
230	Oedema	1	1	1	0
231	Erythema	2	2	1	1
231	Oedema	1	1	1	0
232	Erythema	2	2	2	1
232	Oedema	1	1	1	0
233	Erythema	2	2	1	1
233	Oedema	1	1	1	0
Average (24h,48h,72h)	Erythema	1.56			--
Average (24h,48h,72h)	Oedema	1			--

* : not observed; same scores assumed as for 24h time point (worst case)

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant)

Conclusions:

According to the non-reversible irritation at the end of the observation period of 7 days, 1,2-dichlorobenzene should be classified and labelled as Category 2 (irritant) (EU-GHS).

Executive summary:

Thyssen, 1979 (Bayer study report)

An acute dermal irritation/corrosion study was conducted according to ETAD guideline (deviation: application only on intact skin) and similar to OECD Guideline 404. According to the OECD guideline, the study was performed with the following deviations: 24h exposure period instead of 4h exposure period (worst case); observation after 60min, 48h and 14 days was not conducted (scores of 24h were also assumed for 48h time point (worst case)); impervious instead of semi-occlusive patch was used.

Six New Zealand White rabbits were exposed to 0.5 mL 1,2-dichlorobenzene for 24 hours. Observation time points were 24h, 72h and 7 days after removal of the patch.

The mean erythema score between 24h and 72h was 1.56. Irritation was not fully reversible within 7 days. For the mean oedema score between 24h and 72h, a value of 1 was calculated. The effects were fully reversible within 7 days.

According to the non-reversible irritation at the end of the observation period of 7 days, 1,2-dichlorobenzene should be classified and labelled as Category 2 (irritant) (EU-GHS).