4,7-dichloroquinoline

Endpoint summary

Description of key information

The study reports of a series of patch tests performed on process operators operating in a chemical plant using the test chemical. 6 workers developed dermatitis of the face and were employed in jobs involving the charging the test chemical to a hot reaction vessel. The workers were patch tested initially with 50% test chemical in petrolatum. The reactions were read at 72 hours as ++ positive. The patch test was again repeated with 5% test chemical in petrolatum and reactions were observed and scored at 48 and 96 hours. Patch tests on normal controls were negative. Of the 6 workers tested only 4 workers showed positive reactions at 48 as well as at 96 hours. Further investigations indicated that the dermal reactions were only seen in workers charging the test chemical to a hot reaction vessel, but not amongst other workers handling the test chemical. Upon investigation it was observed that the test chemical could sublime at high temperatures, and this property of the chemical could be a possible reason for development of facial dermatitis in workers involved in charging the test chemical. Based on the observations, reactions, it can be considered that the occupational exposure to the test chemical can cause dermatitis to the operators, so the test chemical should be handled with proper care. Hence, it can be considered to be sensitizer to skin.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Human maximization test was perfiormed to determine the sensitization potential of the test chemical

GLP compliance:

not specified

Type of study:

patch test

Justification for non-LLNA method:

No data available

Species:

other: Human

Strain:

not specified

Sex:

not specified

Details on test animals and environmental conditions:

No data available

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

5% in petrolatum

Adequacy of induction:

not specified

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

5% in petrolatum

Adequacy of challenge:

not specified

No. of animals per dose:

6 workers

Details on study design:

RANGE FINDING TESTS:

MAIN STUDY
A. INDUCTION EXPOSURE
- Test groups: 6 workers
- Concentrations: 5% in petrolatum

B. CHALLENGE EXPOSURE
- Test groups: 6
- Concentrations: 5% in petrolatum
- Evaluation (hr after challenge): 48 and 96 hours

Challenge controls:

No data available

Positive control substance(s):

not specified

Positive control results:

No data available

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5%

No. with + reactions:

2

Total no. in group:

4

Clinical observations:

reappearance of the original rash in case 1 and 2

Remarks on result:

positive indication of skin sensitisation

Results of the patch tests

	48hr	96hr
1	++	++
2	++	++
3	+	-
4	-	-
5	Not performed
6	Not performed

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Based on the observations, reactions, it can be considered that the occupational exposure to the test chemical can cause dermatitis to the operators, so the test chemical should be handled with proper care. Hence, it can be considered to be sensitizer to skin.

Executive summary:

The study reports of a series of patch tests performed on process operators operating in a chemical plant using the test chemical. 6 workers developed dermatitis of the face and were employed in jobs involving the charging the test chemical to a hot reaction vessel. The workers were patch tested initially with 50% test chemical in petrolatum. The reactions were read at 72 hours as ++ positive. The patch test was again repeated with 5% test chemical in petrolatum and reactions were observed and scored at 48 and 96 hours. Patch tests on normal controls were negative. Of the 6 workers tested only 4 workers showed positive reactions at 48 as well as at 96 hours. Further investigations indicated that the dermal reactions were only seen in workers charging the test chemical to a hot reaction vessel, but not amongst other workers handling the test chemical. Upon investigation it was observed that the test chemical could sublime at high temperatures, and this property of the chemical could be a possible reason for development of facial dermatitis in workers involved in charging the test chemical. Based on the observations, reactions, it can be considered that the occupational exposure to the test chemical can cause dermatitis to the operators, so the test chemical should be handled with proper care. Hence, it can be considered to be sensitizer to skin.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Various studies have been reviewed to determine the degree of dermal sensitization caused by the test chemical. These include in vivo studies performed on guinea pigs as well as humans for the test chemical. The results are mentioned below:

The study reports of a series of patch tests performed on process operators operating in a chemical plant using the test chemical. 6 workers developed dermatitis of the face and were employed in jobs involving the charging the test chemical to a hot reaction vessel. The workers were patch tested initially with 50% test chemical in petrolatum. The reactions were read at 72 hours as ++ positive. The patch test was again repeated with 5% test chemical in petrolatum and reactions were observed and scored at 48 and 96 hours. Patch tests on normal controls were negative. Of the 6 workers tested only 4 workers showed positive reactions at 48 as well as at 96 hours. Further investigations indicated that the dermal reactions were only seen in workers charging the test chemical to a hot reaction vessel, but not amongst other workers handling the test chemical. Upon investigation it was observed that the test chemical could sublime at high temperatures, and this property of the chemical could be a possible reason for development of facial dermatitis in workers involved in charging the test chemical. Based on the observations, reactions, it can be considered that the occupational exposure to the test chemical can cause dermatitis to the operators, so the test chemical should be handled with proper care. Hence, it can be considered to be sensitizer to skin.

This case study is supported by a guinea pig maximization test performed to evaluate the dermal sensitization potential of the test chemical. 20 male guinea pigs and 10 male guinea pigs were used as test and control animals. The study was carried out according to OECD 406 Guidelines. Dosages were chosen based on the results of dose-finding experiments. 0.1 ml of the test chemical was applied intracutaneously to the skin of the test groups.One week later, topical application of a plaster containing 0.5 ml undiluted test chemical was fixed by alu fole (occlussive condition). 3 weeks after intradermal induction, the guinea pigs were challenged with 0.5 ml of 12%- and 0.5 ml of 25%-solution of the test chemical under semi-occlusive conditions for 24 hours. Afterwards treatment areas were rinsed with physiological saline-solution. Reading were carried out 48 and 72 hours post start of the challenge and the evaluation was done by comparison of the reacting animals between test and control group. No mortality occurred, body weight development was comparable between test and control animals. 14/20 test animals gave positive reactions 48 hours after challenge with 25 % solution, 7/20 test animals gave positive reactions 72 hours after challenge with 25% solution. 3/20 test animals gave positive reactions 48 hours after challenge with 12 % solution, 1/20 test animals gave positive reactions 72 hours after challenge with 12% solution. Control animals showed no reaction at any time point. Based on these readings, the test chemical can be considered to be sensitizing to skin.

Based on the available results the test chemical can be considered to be sensitizing to skin and classified under the category “Skin Sensitizer 1” as per CLP Regulation.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the available results the test chemical can be considered to be sensitizing to skin and classified under the category “Skin Sensitizer 1” as per CLP Regulation.