Captan

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6 August 1991 to 16 September 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1981

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The method used followed that described in the OECD Guidelines for Testing of Chemicals (1981) No. 406 "Skin Sensitisation" - Magnusson and Kligman Maximisation Test referenced as according to EEC method B.6 published in the regulation 440/2008. The testing using the OECD Test Guideline 406 and the EPA OPP 81-6/EU Method B.6 protocol was completed on 16 September 1991. The LLNA -method OECD 429 (July 2010) was not available by the time the study was conducted. The non-LLNA guinea pig test method is described in OECD 406/EU B.6.

Test material

Test material information

Constituent 1

Reference substance name:

Captan

EC Number:

205-087-0

EC Name:

Captan

Cas Number:

133-06-2

Molecular formula:

C9H8Cl3NO2S

IUPAC Name:

2-[(trichloromethyl)sulfanyl]-2,3,3a,4,7,7a-hexahydro-1H-isoindole-1,3-dione

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material: Captan, N-(trichloromethylthio)cyclohex-4-ene-1,2-dicarboximide
- Molecular formula: C9H8Cl3NO2S
- Molecular mass: 300.59
- Physical state: white powder
- Purity: 90.5 %
- Batch number: 4102
- Date of arrival: 9 July 1991
- Storage conditions: room temperature

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

- group of thirty (twenty treated and ten control) female guinea pigs of the Dunkin-Hartley strain
- Source: David Hall Ltd., Moston, Burton-on-Trent, Staffordshire, U.K.
- weight: 311 - 388 g
- age: eight to twelve weeks old
- free access to mains drinking water and food
- animal room temperature: 20 - 23°C- relative humidity: 52 - 61%

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

arachis oil

Concentration / amount:

50% (w/w) in arachis oil B.P.

Day(s)/duration:

2 d

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Induction 2

Route:

intradermal

Vehicle:

arachis oil

Concentration / amount:

three injections:
1) Freund´s Adjuvant plus arachis oil B.P. plus distilled water, ratio 1:1
2) 0.1% (w/v) in arachis oil B.P. ;
3) 0.1% (w/v) suuspension of test material in 1:1 preparation of Freund´s Adjuvant plus arachis oil B.P.

Day(s)/duration:

7 d

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Challenge

No.:

#20

Route:

epicutaneous, occlusive

Vehicle:

arachis oil

Concentration / amount:

Intradermal Induction: 0.1% (w/v) in arachis oil B.P. Topical Induction: 50% (w/w) in arachis oil B.P. Topical Challenge: (w/w) in arachis oll B.P.

Day(s)/duration:

2 d

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

A group of thirty guinea pigs was used for the main study, twenty test and ten control. Control animals were treated in the same way as test animals, except that captan was excluded from the induction phases.

Details on study design:

RANGE FINDING TESTS:
1) Selection of concentration for Intradermal Induction:
Four animals were intradermally injected with preparations of the test material: 5%; 1%; 0.5%; 0.1% (w/v) in arachis oil B.P. The highest concentration that did not cause local necrosis, ulceration or systemic toxicity, was selected for the intradermal induction stage of the main study.
2) Selection of Concentration for Topical Induction:
Two guina pigs (intradermally injected with Freund´s Complete Adjuvant nine days earlier) were treated with four preparations of the test material: 50%; 25%; 10%; 5% (w/w) in arachis oil B.P.
The highest concentration producing only mild to moderate dermal irritation after a 48-hour occlusive exposure, was selected for the topical induction stage of the main study.
3) Selection of Concentration for Topical Challenge:
Four preparations of test material (50%; 25%; 10%; 5% (w/w) in arachis oil B.P.) were applied occlusively to the flanks of two guinea pigs for a period of 24 hours.
These guinea pigs did not form part of the main study but had been treated identically to the control animals of the main study, up to day 14.
The highest non-irritant concentration of the test material was selected for the topical challenge stage of the main study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: two
- Exposure period: 9 d
- Test groups: 20 guinea pigs
- Control group: 10 guinea pigs
- Site: shoulder region
- Concentrations: Intradermal Induction: 0.1% (w/w) arachis oil B.P; Topical Induction: 50% (w/w) arachis oil B.P

B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day(s) of challenge: 21
- Exposure period: 24 h
- Test groups: 20
- Control group: 10
- Site: shoulder region
- Concentrations: 10% (w/w) arachis oil B.P
- Evaluation (hr after challenge): 24 h and 48 h

Challenge controls:

A topical challenge of 0.1 to 0.2 mL 10% captan (w/w) in arachis oil was applied to the shorn flank on day 21. The area was covered with an occlusive dressing for 24 hours. The area was examined 24 and 48 hours after the removal of the challenge dressing. Control animals were treated in the same way, except that captan was excluded from the induction phases.

Positive control substance(s):

no

Results and discussion

Positive control results:

The testing followed the OECD Test Guideline 406 (1981), a positive control was not required.

In vivo (non-LLNA)

Results

Results 1

Group:

positive control

Remarks on result:

not measured/tested

Remarks:

The testing followed the OECD Test Guideline 406 (1981), a positive control was not required.

Results 2

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10% captan (w/w) in arachis oil B.P.

No. with + reactions:

20

Total no. in group:

20

Clinical observations:

Isolated incidents of hardened light brown-coloured scab and small superficial scattered scabs and desquamation. Oedema. The reactions extended beyond treatment sites during the study.

Remarks on result:

positive indication of skin sensitisation

Results 3

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

10% captan (w/w) in arachis oil B.P.

No. with + reactions:

18

Total no. in group:

20

Clinical observations:

Isolated incidents of hardened light brown-coloured scab and small superficial scattered scabs and desquamation. Oedema. The reactions extended beyond treatment sites during the study.

Remarks on result:

positive indication of skin sensitisation

Results 4

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

vehicle control: arachis oil

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No adverse reactions

Remarks on result:

no indication of skin sensitisation

Results 5

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

vehicle control: arachis oil

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No adverse reactions

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

Table 7.4.1-1 Magnusson Kligman maximisation study in the guinea pig: skin reactions of individual animals following topical induction with 50% w/w captan in arachis oil

 

Animal number	Skin reactions
	1 hour	24 hours
1”	2	1
2	2 Rt	1
3	2 Rt	1 Bd
4	2 Rt	0
5	2 Rt	1 RtBd
6	2 Rt	0
7	1 Rt	0 Bd
8	Ta	0
9	1 Rt	0
10	1 Rt	0
11	1	0
12	?eBs	0 Bd
13	2 Rt	1 Rt
14	1 Rt	0 Bd
15	?eBs	0 Bd
16	2 Rt	1
17	1 Rt	1
18	?eBs	?eBd
19	Ta	1
20	1 Rt	1 RtBd

0 = no reaction; 1 = scattered mild redness; 2 = moderate and diffuse redness.

Rt = residual test material; Ta = test material adhered to treatment site preventing accurate evaluation of erythema;

?e = adverse reactions prevent accurate evaluation of erythema;

Bs = bleeding; Bd = dried blood.

 

Table 7.4.1-1 Magnusson Kligman maximisation study in the guinea pig: skin reactions of individual animals following topical challenge with 10% w/w captan in arachis oil

 

Animal number	Skin reactions (hours after removal of dressing)
	24 h		48 h
	Test	Vehicle	Test	Vehicle
1	2	0	?eD	0
2	2 R	0	2 Rd	0
3	2 R	0	1 R	0
4	?eWeSp	0	?eSt	0
5	?eWe	0	2 ROeSP	0
6	2 Oe	0	2 ROeSP	0
7	2 R	0	?eDR	0
8	2	0	1	0
9	1	0	0	0
10	1	0	0	0
11	2	0	1	0
12	?eDWeR	0	2 RD	0
13	2	0	1 RD	0
14	2 R	0	1 RD	0
15	2 R	0	2 R	0
16	2	0	1 R	0
17	1	0	1 D	0
18	2	0	1	0
19	?eDWe	0	2 SsD	0
20	1	0	1 D	0

0 = no reaction; 1 = scattered mild redness; 2 = moderate and diffuse redness.

R = extended reaction; ?e = adverse reactions prevent accurate evaluation of erythema;

We = well defined; erythema surrounding test site; Sp = hardened light brown coloured scab;

Oe = oedema extends ventrally below; treatment site; D = desquamation;

St = hardened dark brown/black coloured scab; Cr = superficial cracking of the epidermis;

Ss = small superficial scattered scabs.

 

Following challenge with the test material positive skin responses were noted in 16 and 14 animals after 24 and 48 hours, respectively. Adverse reactions prevented the accurate evaluation of erythema at test material sites in 4 of the 20 animals at 24 hours. At 48 hours, these reactions persisted in one animal and increased in severity in the other three animals. At no time were adverse reactions noted at the vehicle control sites in test animals or at any sites of control animals.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Under the conditions of the Magnusson Kligman test, captan produced a 100% sensitisation rate in the guinea pig and was considered as an extreme sensitiser. In accordance with the provisions of regulation 1272/2008, Annex I, 3.4 captan is classified as Skin Sens. category 1 with H317 ‘May cause an allergic skin reaction’

Executive summary:

A study was performed to assess the skin contact sensitisation potential of the test material in the albino guinea pig. The method used followed that described in the OECD Guidelines for Testing of Chemicals (1981) No. 406 "Skin Sensitisation" - Magnusson and Kligman Maximisation Test referenced as according to EEC method B.6 published in the regulation 440/2008. Twenty test and ten control animals were used for the main study. Based on the results of sighting tests, the concentrations of test material for the induction and challenge phases were selected as follows: Intradermal Induction: 0.1% (w/v) in arachis oil B.P. Topical Induction: 50% (w/w) in arachis oil B.P. Topical Challenge: 10% (w/w) in arachis oll B.P. The test material produced a 100% (20/20) sensitisation rate and in accordance with regulation 1272/2008, Annex I, 3.4 captan is classified as Skin Sens. category 1 with (H317) ´May cause an allergic skin reaction’