What Is the Difference Between Mold and Mildew?
Mildew is mold. The EPA's mold course says molds are also called fungi or mildew, and that they are neither plants nor animals but part of the kingdom Fungi. University of Missouri Extension describes mildew as a thin, black or sometimes white growth produced by mold that can be found on many different surfaces.
University of Missouri Extension says the molds that cause mildew flourish wherever it is damp, warm and poorly lighted or where air is not circulated, such as cellars, crawl spaces and clothing closets, and on shower curtains and damp clothes. University of Georgia Extension says mildew usually begins to grow when relative humidity remains at 60 percent and the temperature is 60 degrees Fahrenheit or higher, and typically appears on bathroom tile or on leather or plastic goods stored in closets.
Humidity brings it back. University of Georgia Extension says mildew can return when dampness again approaches 60 percent relative humidity or higher, leaving people in a never-ending cycle of cleaning, that the right cleaning solution depends on the surface, and that solutions containing household bleach should be used with extreme caution. On health, the CDC says it is not necessary to determine what type of mold is growing in a home, because all molds should be treated the same with respect to potential health risks and removal.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Medical referenceThe EPA's mold course says molds are also called fungi or mildew, and are neither plants nor animals but part of the kingdom Fungi. US EPA ↗
- Medical referenceUniversity of Missouri Extension describes mildew as a thin, black or sometimes white growth produced by mold that can be found on many different surfaces. University of Missouri Extension ↗
- Medical referenceUniversity of Missouri Extension says the molds that cause mildew flourish in damp, warm, poorly lighted places with poor air circulation, such as cellars, closets and shower curtains. University of Missouri Extension ↗
- Medical referenceUniversity of Georgia Extension says mildew usually begins to grow at 60 percent relative humidity and 60 degrees Fahrenheit or higher, typically on surfaces such as bathroom tile. University of Georgia Cooperative Extension ↗
- Medical referenceUniversity of Georgia Extension says the right mildew cleaning solution depends on the surface, and solutions containing household bleach should be used with extreme caution. University of Georgia Cooperative Extension ↗
- Medical referenceUniversity of Georgia Extension says mildew can return once dampness again approaches 60 percent relative humidity or higher. University of Georgia Cooperative Extension ↗
- Government sourceThe CDC says it is not necessary to identify the type of mold in a home, because all molds should be treated the same with respect to health risks and removal. CDC ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.