Does Bleach Kill Mold?

On hard surfaces it can, but killing mold is not the goal. A CDC fact sheet on mold cleanup says to use a bleach solution of no more than 1 cup, or 8 ounces, of household laundry bleach per gallon of water to kill mold on surfaces, and a CDC public service message warns never to mix bleach, or products containing bleach, with ammonia or products containing ammonia. The EPA says using a chemical or biocide that kills mold, such as chlorine bleach, is not recommended as a routine practice during mold cleanup, though professional judgment may indicate its use in some cases, for example when immune-compromised people are present.

Dead mold still causes problems. The EPA says dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed. OSHA says porous materials that are wet and have mold growing on them may have to be discarded, because mold can infiltrate them and grow in their empty spaces and crevices, where it can be difficult or impossible to remove completely.

On the product side, the EPA's pesticide registration manual defines a fungicide as a substance that destroys fungi and fungal spores pathogenic to humans or other animals in the inanimate environment, and its index of pesticide registration notices lists its guidance for antimicrobial pesticide products with mold-related label claims as Draft PR Notice 2012-X.