Effectiveness of laundry washing agents and conditions in the removal of cat and dust mite allergen from bedding dust.

BACKGROUND There is limited information about the removal of allergens by laundry washing. OBJECTIVE The purpose of this investigation was to determine the dynamics of the removal of mite allergen (Der p 1) and cat allergen (Fel d 1) from bed dust during simulated laundry processes. METHODS Three studies were performed. The first compared combinations of 4 laundry agents (water alone, soap, detergent with enzymes, and detergent without enzymes), 4 temperatures (15 degrees, 25 degrees, 45 degrees, and 60 degrees C), and 3 extraction times (5, 20, and 60 minutes). The second study examined allergen extraction by 11 common brands of detergents at 25 degrees and 45 degrees C for 5 minutes. The third study compared 4 detergents containing enzymes before and after the denaturation of their enzymes. To measure the quantity of allergens extracted, each study used an ELISA assay as well as a more sensitive but semiquantitative Halogen immunoassay to detect any allergens remaining after the simulated laundry extraction. RESULTS Study 1 showed that detergents extracted more of both Fel d 1 and Der p 1 than either soap or water alone and that almost all allergens were extracted within 5 minutes at 25 degrees. However, washing at 60 degrees C extracted slightly more Fel d 1 and denatured Der p 1, resulting in lower residual amounts of both allergens. Study 2 showed that all of the commercial detergents performed similarly. Study 3 showed that the presence of enzymes in detergent formulations did not produce a significant effect on the extraction of allergens. CONCLUSION Using detergent solutions at 25 degrees for at least 5 minutes was sufficient to extract most mite and cat allergen from dust of bedding.