We have known bleach kills mold. This study shows that bleach also reduces allergenic properties of mold.
A little bleach and water does a good job of killing surface mold. But mold like other allergens has allergenic properties dead or alive. In a recent study conducted at National Jewish Medical and Research Center and published in the Journal of Allergy and Clinical Immunology researchers have found that the bleach not only kills the mold but actually denatures or neutralizes the mold spores.
In the study researchers grew the common fungus aspergillus fumigatus on building materials. Then they sprayed the mold with a diluted bleach solution (1 part bleach to 16 parts water). They also used Tilex Mold and Mildew Remover and then used diluted water as a control. They found that the bleach solution and the Tilex killed the mold spores. When they looked at the treated mold spores in an electron microscope, the spores were smaller and lacked the surface structures present in healthy spores. Additional tests were run indicating that the spores were no longer allergenic.
The researchers then allergy tested eight aspergillus – allergic individuals with solutions containing the spores of both the bleach treated and the Tilex treated surfaces. Seven of the eight individuals did not react to the spores treated with bleach and six of the eight did not react to the spores treated with Tilex.
Granted these were laboratory conditions. Additional study would need to be done by testing field applications, but these results are certainly encouraging for the use of bleach and water as an integral part of any allergen control program.