We use HEPA filters when we Clean Up Mold
When doing different types of restoration work we will set in the space what we call air scrubbers. These air scrubbers are HEPA filter units that collect air borne particles that their size is 300 times smaller than the diameter of a human hair. To a HEPA filter, catching a one-micron particle is like stopping a cotton ball with a door screen. When doing mold remediation we use these air scrubbers but we also will use HEPA vacuums to clean surfaces and trap the particles.
HEPA filters were invented during World War II to remove and capture radio active dust particles that would present a health hazard to researchers. It was invented to protect the human respiratory system. HEPA filters are the top form of air filtration.