cyproconazole (ISO); (2RS,3RS;2RS,3SR)-2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Jul 2005 to 31 Aug 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1992

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Version / remarks:

2003

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: JMAFF 59 NohSan No. 4200, January 28

Version / remarks:

1985

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

Currently no LLNA study is available for assessment. The Buehler test has been carried out as an animal test to predict human sensitization for over a decade and is recommended by international test guidelines such as OECD.

Test material

Test material information

Constituent 1

Reference substance name:

2-(4-chloro-phenyl)-3-cyclopropyl-1-[1,2,4]triazol-1-yl-butan-2-ol

Cas Number:

94361-06-5

Molecular formula:

C15H18ClN3O

IUPAC Name:

2-(4-chloro-phenyl)-3-cyclopropyl-1-[1,2,4]triazol-1-yl-butan-2-ol

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Remarks:

Albino

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: Young adult
- Weight at study initiation: 298-460 g at experimental start
- Housing: The animals were group housed in suspended stainless steel caging with mesh floors or plastic perforated bottom caging which conform to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals DHEW (NIH). Litter paper was placed beneath the cage and was changed at least three times per week.
- Water: ad libitum
- Acclimation period: 10 or 22 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-22
- Photoperiod (hrs dark / hrs light): 12/12
- IN-LIFE DATES: 26 Jul 2005 to 31 Aug 2005

Study design: in vivo (non-LLNA)

Induction

Route:

epicutaneous, occlusive

Vehicle:

CMC (carboxymethyl cellulose)

Concentration / amount:

75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water

Day(s)/duration:

Day 0, 7, and 14: Occlusive dressing for 6 hours

Challenge

Challenge 1

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

CMC (carboxymethyl cellulose)

Concentration / amount:

75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water) in test animals

Day(s)/duration:

Day 27: Evaluation for a sensitization response after 24 and 48 hours

Adequacy of challenge:

highest non-irritant concentration

Challenge 2

No.:

#2

Route:

epicutaneous, occlusive

Vehicle:

CMC (carboxymethyl cellulose)

Concentration / amount:

75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water in naive control animals

Day(s)/duration:

Day 27: Evaluation for a sentization response after 24 and 48 hours

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

Preliminary Irritation Group: 4
Test Group: 20
Naive Control Group: 10

Details on study design:

RANGE FINDING TESTS:

MAIN STUDY
A. INDUCTION EXPOSURE
- Exposure period: 6 hours
- Test groups: 75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water
- Control group: Untreated
- Site: The left side of each test animal using an occlusive 25 mm Hill Top Chamber
- Frequency of applications: Once each week for three weeks
- Concentrations: Four-tenths of a gram of a 75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water

B. CHALLENGE EXPOSURE
- Test groups: Test Animals (75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water
- Control group: Naive Control Animals (75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water
- Site: On the right side of each test animal
- Concentrations: Four-tenths of a gram of a 75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water
- Evaluation (hr after challenge): 24 and 48 hours

OTHER:
Body weight: Individual body weights of the animals were recorded prior to the initial induction and again the day after the challenge application.

Challenge controls:

Not performed

Positive control substance(s):

yes

Remarks:

alpha-Hexylcinnamaldehyde

Results and discussion

Positive control results:

The positive response observed in the historical positive control validation study with alpha-Hexylcinnamaldehyde (HCA) validates the test system used in this study

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water

No. with + reactions:

5

Total no. in group:

20

Clinical observations:

Very faint erythema

Remarks on result:

no indication of skin sensitisation

Remarks:

Irritation cleared from all affected sites by 48 hours.

Results 2

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water

No. with + reactions:

3

Total no. in group:

10

Clinical observations:

Very faint erythema

Remarks on result:

no indication of skin sensitisation

Remarks:

Naive Control Animals. Irritation cleared from all affected sites by 48 hours.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

75% w/w mixture of HCA in mineral oil

No. with + reactions:

4

Total no. in group:

9

Clinical observations:

Faint to very faint erythema

Remarks on result:

positive indication of skin sensitisation

Remarks:

persisting at 48h

Results 4

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

75% w/w mixture of HCA in mineral oil

No. with + reactions:

3

Total no. in group:

5

Clinical observations:

Very faint erythema

Remarks on result:

no indication of skin sensitisation

Remarks:

Historical Naive Control Animals. Irritation persisted at one of these sites through 48 hours

Any other information on results incl. tables

Table 1. Body weights (test substance)

Animal No.	Sex	Initial (g)	Day after Challenge (g)
26864	M	437	558
26865	M	416	502
26866	M	421	642
26867	M	392	605
26868	M	413	680
26869	M	426	633
26870	M	460	643
26871	M	412	647
26872	M	396	546
26873	M	374	533
26874	M	427	613
26875	M	416	558
26876	M	410	588
26877	M	439	606
26878	M	378	544
26879	M	391	596
26880	M	361	597
26881	M	360	573
26882	M	364	498
26883	M	353	496

Table 2. Body weights (naive group)

Animal No.	Sex	Initial (g)	Day after Challenge (g)
26884	M	386	559
26885	M	369	590
26886	M	394	512
26887	M	387	557
26888	M	362	533
26889	M	391	604
26890	M	333	565
26891	M	298	467
26892	M	416	649
26893	M	394	620

Table 3. Induction phase skin reactions scores (test substance)

Induction Number	1		2		3
Concentration^1	75%		75%		75%
Amount Applied(g)	0.4		0.4		0.4
Hours^2	24	48	24	48	24	48
Animal No.
26864	0.5	0	0	0	0.5	0
26865	0	0	0.5	0	0	0
26866	0.5	0	0	0	0	0
26867	0	0	0	0	0	0
26868	0.5	0	0.5	0	0.5	0
26869	0	0	0	0	0	0
26870	0	0	0	0	0	0
26871	0	0	0.5	0	0	0
26872	0	0	0	0	0.5	0
26873	0	0	0.5	0	0	0
26874	0	0	0.5	0	0	0
26875	0	0	0	0	0	0
26876	0	0	0	0	0	0
26877	0	0	0	0	0	0
26878	0.5	0	0	0	0	0
26879	0.5	0	0	0	0	0
26880	0	0	0.5	0	0	0
26881	0.5	0	0	0	0.5	0
26882	0	0	0	0	0	0
26883	0.5	0	0	0	0	0

¹ Four-tenths of a gram of a 75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water was applied.

² Hours after induction dose.

Table 4. Challenge phase skin reactions scores (test substance)

Animal No.	Hours after Application
	24	48
26864	0.5	0
26865	0	0
26866	0	0
26867	0	0
26868	0.5	0
26869	0	0
26870	0	0
26871	0	0
26872	0	0
26873	0	0
26874	0	0
26875	0	0
26876	0	0
26877	0	0
26878	0	0
26879	0.5	0
26880	0	0
26881	0	0
26882	0.5	0
26883	0.5	0

Table 5. Challenge phase skin reactions scores (test substance), naive control group

Animal No.	Hours after Application
	24	48
26884	0.5	0
26885	0	0
26886	0	0
26887	0	0
26888	0	0
26889	0.5	0
26890	0	0
26891	0	0
26892	0	0
26893	0.5	0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on these findings and on the evaluation system used, the test substance is not considered to be a contact sensitizer.

Executive summary:

In a study performed in accordance with OECD TG 406 and GLP principles, a dermal sensitization test was conducted with guinea pigs to determine the potential of the test substance to produce sensitization after repeated topical applications. A 75% w/w mixture of the test substance in a 1% w/w solution of carboxymethylcellulose (CMC) in distilled water was topically applied to twenty guinea pigs, once each week for a three-week induction period. Twenty-seven days after the first induction dose, a challenge dose of the test substance at its highest non- irritating concentration (HNIC, determined in the preliminary irritation screen to be a 75% w/w mixture of the test substance in a 1% w/w solution of CMC in distilled water) was applied to a naive site on each guinea pig. A naive control group (ten animals) was maintained under the same environmental conditions and treated with the test substance at challenge only. Approximately 24 and 48 hours after each induction and challenge application the animals were scored for a sensitization response (erythema).

The test animals and naive control animals showed no incidences of positive response (scores greater than 0.5 after 24 and 48 hours. The test animals showed a severity of 0.13 and the naive control animals showed a severity of 0.15 ( Sum of the erythema scores divided by the number of animals evaluated).

Based on the results of this study, the test substance is not considered to be a contact sensitizer. The positive response observed in the historical positive control validation study with alpha-Hexylcinnamaldehyde Technical (HCA) validates the test system used in this study.