The method is In the main body of the document.
If the test article cannot be tested in its natural state and prepared according to an appropriate associated annex, then it should be extracted using both polar and non-polar extracts.
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. Additional animals may be required for preliminary tests. The number of animals may need to be doubled for weak sensitizers as suggested in OECD 406.
The fur should be clipped 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 tests:
Main test:
Two Phases
Test group consists of 10 animals. Control group consists of 5 animals. If the response to the vehicle is uncertain a separate solvent group is needed.
Induction Phase:
The test material is applied to clipped sites on the left upper back area with soaked patches if a liquid or directly if a solid. Apply the highest concentration that caused slight erythema but didn’t otherwise affect the animals in the preliminary topical test for 6 hours. Repeat the procedure 3 consecutive days a week 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 (+/- 1) 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 exposure. 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.
If the test article cannot be tested in its natural state and prepared according to an appropriate associated annex, then it should be extracted using both polar and non-polar extracts.
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. Additional animals may be required for preliminary tests. The number of animals may need to be doubled for weak sensitizers as suggested in OECD 406.
The fur should be clipped 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 tests:
- Not required for topical medical devices or undiluted extracts using usual vehicles.
- Used to establish the dosing concentrations in the main test.
- Three animals exposed to 4 different concentrations under appropriate patches for 6 hours.
- Score application sites 24 and 48 hours post patch removal
Main test:
Two Phases
Test group consists of 10 animals. Control group consists of 5 animals. If the response to the vehicle is uncertain a separate solvent group is needed.
Induction Phase:
The test material is applied to clipped sites on the left upper back area with soaked patches if a liquid or directly if a solid. Apply the highest concentration that caused slight erythema but didn’t otherwise affect the animals in the preliminary topical test for 6 hours. Repeat the procedure 3 consecutive days a week 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 (+/- 1) 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 exposure. 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.
