Benzene, 1-chloro-2,3-dimethyl-

Endpoint summary

Description of key information

A weak and reversible skin irritation was observed in one out of three animals in the key study. The reaction was not severe enough to require classification. An older supporting study reports very slight edema and/or erythema persisted at two sites and desquamation at the end of study. However, the test item was not sufficiently characterised (purity not specified) and may differ from that of current production processes.

Both key and supporting study reported a mild and minimal eye irritation, respectively, which was in both studies not severe enough to require classification.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

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:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

24 April 2002

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Millbrook Breeding Labs, Amherst, MA, USA
- Age at study initiation: at least 10 weeks
- Weight at study initiation: 2.22-2.27 kg
- Housing: individually
- Diet: TEK 8630 Rabbit Diet, Harlan Teklad, Madison, WI, USA, ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/- 2.8
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

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

Duration of treatment / exposure:

Initial test for possible corrosive property: 3 min, 1 h, 4 h
Confirmatory test: 4 h

Observation period:

up to 72 h

Number of animals:

Initial test: 1, confirmatory test: 2

Details on study design:

TEST SITE
- Area of exposure: 6 cm2 per patch
- % coverage: 100 %
- Type of wrap if used: gauze, held in place with non-irritating tape

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no

OBSERVATION TIME POINTS
(indicate if minutes, hours or days) 1, 24, 48 and 72 h post exposure

SCORING SYSTEM:
- Method of calculation:according to guideline

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0.22

Max. score:

4

Reversibility:

fully reversible within: 72 h

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects observed

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

mean

Time point:

24 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 72 h

Remarks on result:

probability of weak irritation

Irritation parameter:

erythema score

Basis:

mean

Time point:

48 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 72 h

Remarks on result:

probability of weak irritation

Irritation parameter:

erythema score

Basis:

mean

Time point:

72 h

Score:

0

Max. score:

4

Reversibility:

other: no effect observed

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, a weak and reversible skin irritation was observed in one out of three animals.

Executive summary:

The test substance, 1-chloro-2,3-dimethylbenzene, was evaluated for its potential to produce Primary Skin Irritation after a single topical 4 hour application to the skin of New Zealand White rabbits. The test substance is considered a negligible irritant.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 10 Dec 2003 to 13 Dec 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

24 April 2002

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Millbrook Breeding Labs, Amherst, MA,USA
- Age at study initiation: at least 10 weeks
- Weight at study initiation: 2.06-2.23 kg
- Housing: individually
- Diet: TEK 8630 Rabbit Diet, Harlan Teklad, Madison, WI, USA, ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated right eye served as internal control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml

Duration of treatment / exposure:

24 h

Observation period (in vivo):

1, 24, 48 and 72 h post exposure

Number of animals or in vitro replicates:

3

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): with 0.9 % sodium chloride
- Time after start of exposure: 24 h

SCORING SYSTEM: according to guideline

TOOL USED TO ASSESS SCORE: hand-slit lamp /fluorescein treatment 24 h post exposure

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects observed

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: no effects observed

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

0.66

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects observed

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

48 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

72 h

Score:

0

Max. score:

3

Reversibility:

other: no effects observed

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the test substance was mildly irritating to the eyes

Executive summary:

The test article, 1-chloro-2,3-dimethylbenzene, was evaluated for its potential to produce an irritating effect on the ocular tissue of New Zealand White rabbits, when administered according to the procedures detailed in the study protocol. Mild conjunctival redness and minor chemosis presented at the 1 hour time point. All irritation and swelling resolved by the 72 hour observation point. Based on the methods employed, the test article is considered to be a mild irritant to the ocular tissue of New Zealand White rabbits.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The test substance, 1-chloro-2,3-dimethylbenzene, was evaluated for its potential to produce Primary Skin Irritation after a single topical 4 hour application to the skin of New Zealand White rabbits in a study according to OECD guideline 404. The test substance was considered a negligible irritant.

These findings are contradicted by a less reliable study, which obsered very slight edema and/or erythema persisting at two sites and desquamation was evident at all three treated sites at study termination. However, the purity of the test item was not specified and may differ from that of current production processes.

Therefore, the findings of the key study are considered adequate for the (non)-classification of the submission substance.

The test article, 1-chloro-2,3-dimethylbenzene, was evaluated for its potential to produce an irritating effect on the ocular tissue of New Zealand White rabbits in a study according to OECD guideline 405. Mild conjunctival redness and minor chemosis were present at the 1 hour time point. All irritation and swelling resolved by the 72 hour observation point. Based on the methods employed, the test article is considered to be a mild irritant. The effects were not severe enough to require classification. These findings are supported by a less reliable study, showing minimal eye irritation.

Justification for classification or non-classification

In reliable studies, the test item produced minimal skin and mild eye irritation in vivo. The effects were not severe enough to require a classification for irritation according to the criteria of Regulation (EC) No 1272/2008.