Alternative Test Methods:
Validation and Regulatory Status

Classical Local Lymph Node Assay (LLNA)
Description and references

EU: Endorsed as valid by ECVAM (2000)

US: Endorsed as valid by ICCVAM and recommended for use as a stand-alone substitute for the guinea pig sensitization test (1999)

OECD: TG 429 (2002)

International Standards Organization [ISO] 10993-10: Tests for Irritation and Sensitization (2002)

EU: Method B.42 in Annex to 440/2008/EC (2004, 2008)

US: EPA Health Effect Testing Guidelines on Skin Sensitization (2003)

Reduction

Refinement
(Does not require dermal hypersensitivity reactions be elicited in the animals; does not require administration of an adjuvant which causes pain and distress)

rLLNA (Reduced Local Lymph Node Assay: Limit Dose Procedure)
Description and references

EU: Endorsed by ECVAM as a substitute method for the LLNA to distinguish between skin sensitizers and non-sensitizers when used as part of a tiered testing strategy (2007).

US: When dose-response information is not required, ICCVAM recommends use of the LLNA limit dose procedure as for hazard identification to identify sensitizers and non-sensitizers. 

When dose-response information is required, ICCVAM recommended rLLNA be used as the initial testing procedure to identify sensitizers and non-sensitizers.

No information

Reduction
(Chemicals that test negative in the rLLNA will not proceed to the full LLNA test and therefore reduce animal use)