The method is in the main body of the document.
Sample preparation is to be performed as per the associated annexes depending on if the test material is a solid, liquid or extract.
Healthy albino guinea pigs of either sex from a single strain between 300 and 500 grams should be used. Females shall be nulliparous and not pregnant.
The number of animals used should be a minimum of 10 test animals for a powder, liquid or each extraction vehicle. A minimum of 5 control animals for a powder, liquid or for each extraction vehicle. If a preliminary irritation is necessary, additional animals are required. The required number of animals may need to be doubled for weak sensitizers as suggested in OECD 406.
The fur should be clipped the day prior to treatment (dosing).
Dosages:
If the sample is a liquid saturate a woven patch, or if a solid apply directly under an occlusive dressing for 6 hours. The animals are wrapped or restrained to ensure the dressing stays in place for the duration of the dose period.
Preliminary test:
Main test:
Two Phases
The test group consists of 10 animals and the control group consists of 5 animals. If the response to the vehicle is uncertain a separate solvent group is needed.
Induction Phase:
The test sample is applied to clipped sites on the left upper back area with soaked patches if a liquid and directly if a solid. Apply the highest concentration (if applicable) that caused slight erythema but didn’t affect the animals in the preliminary topical test for 6 hours. The dosing procedure should be repeated weekly for 3 weeks. The control animals receive the vehicle or carrier in a similar manner as the test article.
Challenge Phase:
Apply the highest concentration that caused no erythema in the preliminary test to sites not previously exposed shaved sites (i.e. flank) of both the test and the control animals 14 days after the completion of the induction phase for 6 hours to patches as before and under an occlusive dressing.
Observe the dosed sites of all animals 24 and 48 +/- 2 hours after the patches are removed. At least 2 hours prior to the 24 hour observation, shave the sites or depilate them with a commercial hair remover and wash and dry the skin. Grading is on a 5 point scale ranging from no(0), very slight(1), well-defined(2), moderate(3), to severe(4) for both erythema and edema. Grades in test animals greater than the grades observed in the control animals indicate sensitization. Questionable results may warrant a rechallenge 7 days later following the same procedures.
Sample preparation is to be performed as per the associated annexes depending on if the test material is a solid, liquid or extract.
Healthy albino guinea pigs of either sex from a single strain between 300 and 500 grams should be used. Females shall be nulliparous and not pregnant.
The number of animals used should be a minimum of 10 test animals for a powder, liquid or each extraction vehicle. A minimum of 5 control animals for a powder, liquid or for each extraction vehicle. If a preliminary irritation is necessary, additional animals are required. The required number of animals may need to be doubled for weak sensitizers as suggested in OECD 406.
The fur should be clipped the day prior to treatment (dosing).
Dosages:
If the sample is a liquid saturate a woven patch, or if a solid apply directly under an occlusive dressing for 6 hours. The animals are wrapped or restrained to ensure the dressing stays in place for the duration of the dose period.
Preliminary test:
- Used to establish the dosing concentrations in the main test.
- 3 animals are exposed to 4 different concentrations (if applicable) of the test sample under appropriate patches for 6 hours.
- The application sites are scored 24 and 48 hours post patch removal.
Main test:
Two Phases
The test group consists of 10 animals and the control group consists of 5 animals. If the response to the vehicle is uncertain a separate solvent group is needed.
Induction Phase:
The test sample is applied to clipped sites on the left upper back area with soaked patches if a liquid and directly if a solid. Apply the highest concentration (if applicable) that caused slight erythema but didn’t affect the animals in the preliminary topical test for 6 hours. The dosing procedure should be repeated weekly for 3 weeks. The control animals receive the vehicle or carrier in a similar manner as the test article.
Challenge Phase:
Apply the highest concentration that caused no erythema in the preliminary test to sites not previously exposed shaved sites (i.e. flank) of both the test and the control animals 14 days after the completion of the induction phase for 6 hours to patches as before and under an occlusive dressing.
Observe the dosed sites of all animals 24 and 48 +/- 2 hours after the patches are removed. At least 2 hours prior to the 24 hour observation, shave the sites or depilate them with a commercial hair remover and wash and dry the skin. Grading is on a 5 point scale ranging from no(0), very slight(1), well-defined(2), moderate(3), to severe(4) for both erythema and edema. Grades in test animals greater than the grades observed in the control animals indicate sensitization. Questionable results may warrant a rechallenge 7 days later following the same procedures.
