Copper dichloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable study report which meets basic scientific principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Materials and methods

Principles of method if other than guideline:

BASF Test
Before OECD Guideline 404 was established in 1982, skin irritation was tested using an internal method (BASF test). White Vienna rabbits were used. 2 animals were treated for 1, 5, 15 minutes and 2 other animals for 20 hours with 80% aqueous copper chloride using occlusive conditions. An application site of 2.5 x 2.5 cm was covered with test substance on a patch. After the application time of 1, 5 and 15 minutes, the skin was washed with an aqueous Lutrol solution (50%).

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Copper chloride

EC Number:

231-842-9

EC Name:

Copper chloride

Cas Number:

7758-89-6

Molecular formula:

ClCu

IUPAC Name:

copper (I) chloride

Details on test material:

- Name of test material: Kupfer-I-Chlorid
- Molecular formula: CuCl
- Molecular weight: 98.999
- Smiles notation: [Cu]Cl
- InChl: 1S/ClH.Cu/h1H;/q;+1/p-1
- Analytical purity: 98 - 99%

Test animals

Species:

rabbit

Strain:

Vienna White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2.54 - 3.25 kg

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

no

Amount / concentration applied:

Concentration: 80%

Duration of treatment / exposure:

1, 5, 15 minutes and 20 hours

Observation period:

8 days

Number of animals:

2 per treatment

Details on study design:

TEST SITE: back

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Remarks:

15 min exposure

Basis:

mean

Remarks:

2 animals

Time point:

other: 24/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Results 2

Irritation parameter:

edema score

Remarks:

15 min exposure

Basis:

mean

Remarks:

2 animals

Time point:

other: 24/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects

Results 3

Irritation parameter:

erythema score

Remarks:

20 h exposure

Basis:

mean

Remarks:

2 animals

Time point:

other: 24/72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 8 d

Results 4

Irritation parameter:

edema score

Remarks:

20 h exposure

Basis:

mean

Remarks:

2 animals

Time point:

other: 24/72 h

Score:

2.5

Max. score:

4

Reversibility:

not fully reversible within: 8 d

Any other information on results incl. tables

The test substance led to severe skin irritation in both animals when treated for 20 hours. To evaluate the skin irritation potential of the test substance, the scores of the 20 hour incubation have been used, but the scores for the 15 min incubation have been also taken into account. Based on the mean values calculated for the 20 -hour exposure, the substance has to be judged as highly irritant to skin.

Animal		Exposure period: 15 minutes
		Erythema	Edema	Additional findings
01	24 h	0	0
	72 h	0	0
	Mean score	0	0
02	24 h	0	0
	72 h	0	0
	Mean score	0	0

Animal		Exposure period: 20 hours
		Erythema	Edema	Additional findings
01	24 h	2	3	Parchment-like necrosis
	72 h	2	3	hard, relocatable necrosis
	8 d	-	-	hard, relocatable necrosis
	Mean score	2	3
02	24 h	2	2	Parchment-like necrosis
	72 h	2	2	Leather-like necrosis
	8 d	-	-	Leather-like necrosis
	Mean score	2	2

Justification for read-across from copper chloride to copper dichloride:

Acute toxicity, irritation and sensitisation data for copper dichloride have been read across from the closely analogous substance copper chloride. These substances are chemically similar; copper dichloride contains only cupric copper and ionic chlorine, whereas copper chloride contains cuprous copper and ionic chlorine. Available data on (cuprous) dicopper oxide and (cupric) copper oxide show that cuprous copper is inherently more acutely toxic and irritant than the cupric form (neither compound is a skin sensitiser). The results of an acute oral toxicity test available in the public literature (Singh and Junnarkar, 1991) confirm that this principle can also be applied to the cuprous and cupric chlorides. On this basis, and in order to minimise animal testing, a worst-case approach has been adopted in which data generated using copper choride has been directly read across to copper dichloride.

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item is considered to be a skin irritant.
Classification according to Directive 67/548/EEC: Irritant (Xi). R38, Irritating to skin.
Classification according to CLP/GHS: H315 “Causes Skin Irritation” Category 2.

Executive summary:

The test item is considered to be a skin irritant. Based on the results of this study, the test item could be deemed corrosive to the skin. However, the exposure period used (20 h) was excessive when compared to modern guidelines. In reviewing the recent skin sensitisation study, although irritation was observed in the guinea pig, corrosivity was not observed at any time in the study. Taken together, it is concluded that there is insufficient evidence to classify the test item as corrosive.