But science is always looking for new and better ways to test. Animals are expensive. What is cheaper are human skin cells. So eventually animal rights activists will count a win when animal testing stops completely because in vitro tests are just plain more accurate.
The researchers in a recent study tested 20 sensitizing chemicals (eugenol, isoeugenol, cinnamic alcohol, p-phenylendiamine, all the names you know and love) and 20 non-sensitizing chemicals(like salicylic acid, glycerol, lactic acid) and identified 200 genes with 'potent' discriminatory ability using human Dendritic cell-like line MUTZ-3, a human myeloid leukemia-derived cell.
No animals needed and they were able to successfully predict the threshold for sensitivity of those chemicals in humans anyway.
It doesn't mean all those PETA people need to stop getting naked in commercials just yet, but we're a step farther along the path to in vitro testing of everything.
Open access citation: Henrik Johansson, Malin Lindstedt, Ann-Sofie Albrekt and Carl AK Borrebaeck, 'A genomic biomarker signature can predict skin sensitizers using a cell-based in vitro alternative to animal tests', BMC Genomics 2011, 12:399 doi:10.1186/1471-2164-12-399