Cyclopropanecarboxylic acid, 3-[(1Z)-2-chloro-3,3,3-trifluoro-1-propen-1-yl]-2,2-dimethyl-, (1R,3R)-rel-

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1984-01 to 1984-04-26

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

no justification for vehicle choice; pretest results not reported; lauryl sulphate pretreatment of application site omitted; no validity check (positive controls) reported; weight development not reported; purity of the test material not reported.

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

This study was performed at a time prior to the acceptance of the LLNA-test as a valid measure for skin sensitisation (OECD guideleine LLNA, TG 429 adopted in 2002).

Test material

Test material information

Constituent 1

Reference substance name:

reaction mass of (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid and (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid

EC Number:

614-283-9

Cas Number:

68127-59-3

Molecular formula:

C9H10ClF3O2

IUPAC Name:

reaction mass of (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid and (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid

Details on test material:

- Physical state: crystalline powder
- Colour: white
- Expiration date of the lot/batch: not reported
- Storage condition of test material: not reported

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Age at study initiation: 4 - 7 weeks
- Weight at study initiation: 303 - 418 g
- Housing: individually in stainless steel cages, 370 x 320 x 200 mm; floor and back: 12 mm square mesh, door: Makrolon (polycarbonate); 2 animals per cage, separated by a solid metal partition (equal compartments)
- Water: tap water ad libitum, via an automatic system
- Acclimation period: >= 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 - 18°C, constantly recorded
- Humidity (%): 40 - 45% relative, constantly recorded
- Air changes (per hr): 20 - 30
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: To: not reported

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: dimethylformamide (DMF); 3% DMF / corn oil mixture

Concentration / amount:

Intradermal pretest (sighting): up to 5% (w/v) in a mixture of DMF and corn oil
Topical (epicutaneous) pretest (sighting, for induction and challenge): suspensions of the test substance in DMF, 3 doses, concentrations not stated
Intradermal induction: 1% w/v suspension in a 3% DMF / corn oil mixture; 1% w/v suspension in a 1:1 preparation of Freund's Complete Adjuvant (FCA) plus 3% DMF / corn oil mixture
Epicutaneous induction: 75% (w/v) suspension in DMF
Challenge (epicutaneous): 10% (w/v) suspension in DMF
(In the report, all preparations were variantly described as suspensions or solutions, the former appears more likely)

Challenge

Route:

epicutaneous, occlusive

Vehicle:

other: dimethylformamide (DMF); 3% DMF / corn oil mixture

Concentration / amount:

Intradermal pretest (sighting): up to 5% (w/v) in a mixture of DMF and corn oil
Topical (epicutaneous) pretest (sighting, for induction and challenge): suspensions of the test substance in DMF, 3 doses, concentrations not stated
Intradermal induction: 1% w/v suspension in a 3% DMF / corn oil mixture; 1% w/v suspension in a 1:1 preparation of Freund's Complete Adjuvant (FCA) plus 3% DMF / corn oil mixture
Epicutaneous induction: 75% (w/v) suspension in DMF
Challenge (epicutaneous): 10% (w/v) suspension in DMF
(In the report, all preparations were variantly described as suspensions or solutions, the former appears more likely)

No. of animals per dose:

Intradermal induction pretest: 2 animals / dose, 3 doses
Topical (epicutaneous) induction pretest: 2 animals / dose, 3 doses
Topical (epicutaneous) challenge pretest: 2 animals / dose, 3 doses
Main test: 20 animals
Controls to main test: 10 animals

Details on study design:

RANGE FINDING TESTS:
Formulation: No rationale is given for the choice of 3% DMF in corn oil as the appropriate vehicle
Tolerability intradermal: Injection of the test substance in DMF / corn oil (3 concentrations of the test substance, up to 5% w/v) to the clipped skin of 2 animals each, to determine the highest well-tolerated concentration
Tolerability topical induction: Application of the test substance in DMF (3 concentrations, not specified) to the clipped skin of 2 animals each, to determine the highest concentration not producing excessive inflammation
Tolerability topical challenge: Application of the test substance in DMF (3 concentrations, not specified) to the clipped skin of 2 animals each that had been injected with FCA at least 14 days in advance, to determine the highest concentration not producing excessive inflammation or irritation after FCA pretreatment

MAIN STUDY
A. INTRADERMAL INDUCTION EXPOSURE
- No. of exposures: 1
- Exposure period: -
- Test groups: 1 group of 20 animals
- Control group: 1 group of 10 animals
- Site: 50 x 50 mm clipped area on scapular region, one row of three injections on either side of the mid-line
- Injections (0.1 mL each): i) FCA plus corn oil, ratio 1:1; ii) 1% suspension of the test substance in a 3% DMF / corn oil mixture; iii) 1% suspension of the test substance in a 1:1 preparation of FCA plus 3% DMF / corn oil mixture
- Injections of control animals (0.1 mL each): i) FCA plus corn oil, ratio 1:1; ii) corn oil ; iii) FCA plus corn oil, ratio 1:1
- Frequency of applications: 1
- Duration: 1 week
- Concentrations: 1% test substance in the media described above

B. TOPICAL (EPICUTANEOUS) INDUCTION EXPOSURE
- No. of exposures: 1
- Exposure period: 48 hours
- Test / control groups: same animals as above
- Site: Same area on scapular region, clipped again (no pre-tretment with sodium lauryl sulphate to create a local irritation)
- Application: 0.25 mL of a suspension of the test substance in DMF applied to a filter paper (40 x 20 mm) held in place by surgical tape (80 x 40 mm). Tape covered by adhesive bandage approx. 200-300 mm x 50 mm, which was wrapped (once only) by self-adhesive PVC tape No 92 (300 x 25 mm)
- Application of control animals: Same as above, with DMF only
- Frequency of applications: 1
- Duration: 2 weeks
- Concentrations: 75% test substance in DMF

C. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day of challenge: day 21, 3 weeks after intracutaneous and 2 weeks after topical induction
- Exposure period: 24 hours
- Site: areas approx. 150 x 50 mm on both flanks, clipped free of hair
- Test groups: 0.05 mL of a 10 % suspension of the test substance in DMF applied to a filter paper (10 x 15 mm) stitched to a piece of 0.5 mm rubber sheeting (120 x 50 mm approx.). Occlusive dressing covered by adhesive bandage approx. 250 x 75 mm, so that the test substance touched a previously unexposed site on the left flank. Secured by self-adhesive PVC tape (300 x 25 mm).
- Control group: Same as above
- Concentration: 10% w/v suspension in DMF
- Evaluation (hr after challenge): 24 and 48 hours after removal of the occlusive dressing (48 and 72 hours from the start of challenge)
- Quantification: grading of erythematous reactions using a 4-point scale, similar to that of Magnusson & Kligman; percentage of responding control animals subtracted from percentage of responding test animals to calculate the net response.

Challenge controls:

None reported

Positive control substance(s):

not specified

Remarks:

Reliability check of the method: not reported

Results and discussion

Positive control results:

None reported

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.05 mL of a 10% w/v suspension in DMF

No. with + reactions:

2

Total no. in group:

20

Clinical observations:

faint erythema, grade 1: scattered diffuse redness

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.05 mL of a 10% w/v suspension in DMF. No with. + reactions: 2.0. Total no. in groups: 20.0. Clinical observations: faint erythema, grade 1: scattered diffuse redness.

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0.05 mL of a 10% w/v suspension in DMF

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.05 mL of a 10% w/v suspension in DMF. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.05 mL of a 10% w/v suspension in DMF

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

faint erythema, grade 1: scattered diffuse redness

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0.05 mL of a 10% w/v suspension in DMF. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: faint erythema, grade 1: scattered diffuse redness.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.05 mL of a 10% w/v suspension in DMF

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

faint erythema, grade 1, doubtful

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0.05 mL of a 10% w/v suspension in DMF. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: faint erythema, grade 1, doubtful.

Results 5

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

none

Remarks on result:

not measured/tested

Results 6

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

0

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

none

Remarks on result:

not measured/tested

Any other information on results incl. tables

Two out of twenty animals of the test group (nos. 101 and 103) showed faint erythema (grade 1, scattered, mild redness) after 24 hours, which was no longer visible after 48 hours.

One out of ten control animals (no 128) had grade 1 erythema after 24 hours and 48 hours, the latter reading was marked as "doubtful".

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material was classified not to be a sensitiser to guinea pig skin under the conditions of the assay. The study report is relevant, reliable witht restrictions and adequate for risk assessment, classification and labeling.

Executive summary:

The sensitising properties of the test material (a powder) were assessed according to a method similar to OECD 406 in 30 female Dunkin Hartley albino guinea pigs in a Magnusson-Kligman guinea-pig maximisation test. For intradermal induction, the test substance (1% w/v in DMF / corn oil) was injected with and without Freund’s complete adjuvant. Topical induction (7 days later) was performed with a 75% w/v suspension of the test material in DMF applied under an occlusive dressing for 48 hours. As a challenge (on day 21 of the test), 0.05 mL of a 10% w/v suspension in DMF were applied for 24 hours under an occlusive dressing. 24 and 48 hours after the removal of the dressing, erythema scores were read and the number of responding animals recorded.

The study report has certain shortcomings (reliability checks, results of pilot study, and body weights not reported). The omission of the lauryl sulphate pretreatment at the topical induction site may be explained by the fact that the test substance was found to be a slight irritant to rabbit skin (same report).

Twenty-four hours after the removal of the challenge application, faint erythema was observed in 2 / 20 animals in the treated group, and in 1 / 10 animals in the control group, which results in a net sensitisation response of 0%. After 48 hours, a faint (doubtful) erythema was only seen in one control animal.

The results indicate the test material as not being sensitiser to guinea pig skin.