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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1979 (exact period not noted)
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report which meets basic scientific principles (Klimish et al., 1997).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
not applicable
Principles of method if other than guideline:
The animals were acclimated to the laboratory for at least four days before they were used (five days in OECD 406).The test animals are initially exposed to the test substance by epidermal application (induction exposure). The test material was applied to the same site of test animal once each week for a total of three applications. The control animals were maintained without treatment until primary challenge application (following OECD 406 control animals should be treated sham and then receive the challenge exposure). Following a rest period of 10 to 14 days (induction) the animals were exposed to a challenge dose.
GLP compliance:
no
Remarks:
The study was performed prior to the adoption of the test guideline specified
Type of study:
Buehler test
Justification for non-LLNA method:
Study was conducted in 1979, the Local Lymph Node Assay (LLNA; TG 429) was adopted in 2002.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): CR-39 Monomer
- Molecular formula (if other than submission substance): No
- Molecular weight (if other than submission substance): No
- Smiles notation (if other than submission substance): No
- InChl (if other than submission substance): No
- Structural formula attached as image file (if other than submission substance): not applicable
- Substance type: pure active substance
- Physical state: clear colourless liquid
- Analytical purity: 100% commercial product
- Impurities (identity and concentrations): Acrolein, Allyl Alcohol, Diallyl Carbonate
- Composition of test material, concentration of components detected by chromatography (from a conversation letter of PPG Industries and Analytical laboratory in Barberton Tech Center, 1979-03-15)(most likely the same batch of the test material which was used in the skin irritation studies described under 7.3.1. Endpoint, was used in the present sudy because the analytical reports in both studies are identical :
Sample H-6916:
Acrolein before testing 42.5 ppm, after testing 42.0 ppm
Allyl Alcohol before testing 28.2 ppm, after testing 27.4 ppm
Diallyl Carbonate before testing 2399 ppm, after testing 1499 ppm
- Isomers composition: data not available
- Purity test date: (see above the conversation letter)
- Lot/batch No.: Sample 1: H-6916 (received from PPG Industries on January 2, 1979)
- Expiration date of the lot/batch: data not available
- Radiochemical purity (if radiolabelling): Not applicable
- Specific activity (if radiolabelling): Not applicable
- Locations of the label (if radiolabelling): No
- Expiration date of radiochemical substance (if radiolabelling): No
- Stability under test conditions: No significant changes in monomer composition during the testing period (see 7.31. Endpoint)
- Storage condition of test material: data not available
- Other:

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Murphy Breeding Laboratories, Inc., R. R. 3, Box 445, Plainfield, Indiana 46168.
- Age at study initiation: data not available
- Weight at study initiation: 300 - 400 gm at the time of delivery (determined by the supplier, seven days prior to study initiation).
- Housing:singly in wire mesh cages suspended above the droppings throughout the study.
- Diet (e.g. ad libitum): Purina Guinea Pig Chow was available ad libitum throughout the study.
- Water (e.g. ad libitum): The animals were maintained on medicated water containing 4% of sulfaethoxypyridazine (6.25% S.E.Z.R, American Cyanamid) for four days. At the end of this period they were furnished with non-medicated water ad libitum
- Acclimation period: at least four days
The animals were of a size that would easily fit into the restrainers used throughout the study.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): data not available
- Humidity (%): data not available
- Air changes (per hr): data not available
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: To: data not available

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.4 mL (undiluted) was used in the group of test animals. Based on specific density 1.143 of test material the concentration used was 0.4572 mg/mL. In pilot studyCR-39 Monomer was tested as undiluted, and as 50%, 25%, and 10% v/v solution in acetone.
Challenge
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.4 mL (undiluted) was used in the group of test animals. Based on specific density 1.143 of test material the concentration used was 0.4572 mg/mL. In pilot studyCR-39 Monomer was tested as undiluted, and as 50%, 25%, and 10% v/v solution in acetone.
No. of animals per dose:
20 test animals;
10 control animals (were maintained without treatment until primary challenge application).
4 pilot study animals (one animal per dose)
Details on study design:
RANGE FINDING TESTS:

Four additional guinea pigs were used for a pilot study to determine the highest non-irritating concentration which could be applied for the primary challenge : For this purpose CR-39 Monomer was tested as undiluted, and as 50%, 25%, and 10% v/v solution in acetone.
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Test groups: test material 0.4 mL (undiluted)
- Control group: without treatment
- Site: The upper left quadrant of the backs of the test guinea pigs was clipped using electric clippers. On the following day the patches were applied using a Parke-Davis Readi Bandage coverlet with a 20 x 20 mm Webril swatch moistened with test material. The guinea pigs were placed in restrainers and rubber dental damming was placed over the animals' backs and secured to the restrainers with clips. After an exposure period of six hours, the patches were removed and the animals were returned to their cages.

The patches were reapplied to the same site once each week for a total of three applications. The same site was shaved the day before each application was made. A new vial of CR-39 Monomer was used for each application.

On the day following application, the clipped areas were depilated with Neet Cream Hair Remover (Whitehall Laboratories, Inc., New York, N.Y. 10017). The depilatory was allowed to remain on the sites for 15 to 30 minutes and was then washed off with warm (ca. 37°C) tap water.

- Frequency of applications: once each week
- Duration: three weeks
- Concentrations: 0.4 mL
The patch sites were scored for irritation four to five hours later.
After an exposure period (three week) followed two-week rest period

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: after two-week rest period (day 28 approx.)
- Exposure period: 6 hours
- Test groups: test material 0.4 mL (undiluted)
- Control group: test material0.4 mL (undiluted)
- Site: After a two-week rest period a fresh application site for primary challenge was prepared by clipping the lov/er left quadrant of the backs of the test and control guinea pigs.
- Concentrations: 0.4 mL
- Evaluation (hr after challenge): On the next day the sites were depilated and scored within two to three hours (24-hour reading). The sites were scored again for a 48-hour reading without additional depilation.


OTHER:
Challenge controls:
were treated in the same manner as test animals during challenge exposure
Positive control substance(s):
no

Results and discussion

Positive control results:
no

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
0.4 mL
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
no reaction
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.4 mL. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no reaction.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
0.4 mL
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
no reaction
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.4 mL. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: no reaction.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0.4 mL
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no reaction (only 9 animals were evaluated due to a death during the study
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 24.0. Group: other: untreated controls. Dose level: 0.4 mL. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no reaction (only 9 animals were evaluated due to a death during the study.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0.4 ml
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no reaction (only 9 animals were evaluated due to a death during the study)
Remarks on result:
other: see Remark
Remarks:
Reading: 2nd reading. . Hours after challenge: 48.0. Group: other: untreated controls. Dose level: 0.4 ml. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no reaction (only 9 animals were evaluated due to a death during the study).
Group:
positive control
Remarks on result:
not measured/tested

Any other information on results incl. tables

Irritative effects noted during the pilot test of CR-39 Monomer included one grade of ± and three grades of 0 as undiluted; four grades of 0 as a 50% v/v solution in acetone; four grades of 0 as a 25% v/v solution in acetone; and four grades of 0 as a 10% v/v solution in acetone. During the primary challenge of CR-39 Monomer as undiluted in the main study, reactions noted in the test animals at the 24-hour reading included twenty grades of 0. At the 48-hour reading twenty grades of 0 were noted in the test animals. For the control animals nine grades of 0 were noted at the 24-hour and 48-hour readings. One control guinea pig was found dead in the restrainer during the challenge application.

"The death of one animal in the study may not necessarily be indicative of test material toxicity. Occasionally an animal on this type of test may die due to trauma related to the restraint procedure. While additional veterinary medical and toxicological information would be necessary to absolutely confirm the cause of death of this particular animal, the fact that no mortalities were noted in the test animals (which received four doses of 0.4 mL of CR-39 monomer), and the mortality was in a control animal (which received only one dose of 0.4 mL of the material) during restraint suggests the death was probably due to the restraint procedure." (from a conversation letter between M.B. Vinegar and Dr. A. Plilip Leber from 1979 -02 -27, included in the present study ) 

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
When tested according to the method of Buehler, CR-39 Monomer produced no positive responses at the 24 or 48-hour readings in any of the test or control animals.
Executive summary:

The study was conducted to evaluate the potential of CR-39 Monomer to induce delayed contact hypersensitivity in guinea pigs. The sample used in this study was received from PPG Industries, Inc. on January 2, 1979. CR-39 Monomer is a clear liquid. The procedure used was based on that of Buehler.

The test included three phases: induction phase, when test material is applied to hair free skin of test animals for 6 hours occlusive each week for a total of three application; two-week rest period during which an immune response may develop and challenge phase during which the immune system if sensitized react hypersensitive.

20 test animals and 10 control animals were used in the study. 0.4 mL of test material undiluted was used in the induction phase and in the challenge phase. Treated skin sites were scored according scale as described in the Buehler test method. 24 and 48 -hour readings were performed after the challenge applications.

No positive responses were found at the 24 or 48 -hour reading in any of the test or control animals.