Ricin can be detected in cosmetics at 0.005 μg/mL in the analytical sample using lateral flow
devices (LFDs). Wheat germ, an ingredient used in skin care products is also a potential source
of wheat lectin. False positives were observed when wheat lectin was added to LFDs from two
manufacturers, irrespective of whether the LFD was specific for ricin, Staphylococcus
enterotoxin B (SEB), or botulinum toxin. In contrast, pea and peanut lectins did not cause
false positives. Substitution of the buffer supplied with the LFDs with a buffer containing 2.5%
non-fat milk powder eliminated the occurrence of false positives. This substitution increased
the LOD to 0.01 μg/mL ricin, which is an acceptable level for screening cosmetics for
contamination by ricin.