How Can I Tell If a Replacement Air Filter Is HEPA?

Find HEPA filters in locations including operating rooms, nuclear labs and workplaces.

Invented during World War II to keep radioactive particles from escaping the laboratories, a high-efficiency particulate air (HEPA) filter stops mold spores from growing, as well as some viruses and bacteria. You will find HEPA filters used in factories, workplaces, hospital operating rooms, as well as in personal respirators. For the household, you will find HEPA filters in vacuum cleaners and air purifiers. Since the Food and Drug Administration (FDA) does not have national health standards in place for air filters, it takes closer examination when determining if a replacement air filter is a true HEPA filter.

Things You'll Need

• Air filter

Instructions

1. Locate the particulate size prepared by the manufacturer on your air filter label. A true HEPA filter captures at least 99.97 percent of all particles that enter it starting with size 0.3 microns in diameter and higher. A genuine HEPA filter must have this factual information in writing and may also include the words, "absolute HEPA" and "true HEPA." Words such as "HEPA-like" or "hospital-grade HEPA" mean you do not have a true HEPA filter.

2. Check to make certain you have a replacement filter made for a vacuum cleaner with a completely sealed system, when looking for a HEPA filter. A HEPA filter in a vacuum cleaner will have one or more outer filters to catch large hair, dust and dirt particles, and another filter inside of the larger ones to catch smaller and any other dust particles it can trap. This prevents dust and other contaminants from reentering the air. Regular vacuum cleaners only trap some dirt and dust and rearrange the rest in your home.

3. Look at the cost of the replacement air filter. True HEPA filters cost more than HEPA-type filters and other filter types.

Tips & Warnings

• Purchase your replacement HEPA air filter at hardware, discount, home improvement stores and online.

References

• Asthma and Allergy Foundation of America: Air Filters
• The Johns Hopkins Autopsy Resource: Autopsy Room Procedures
• Explain That Stuff: HEPA Filters
• Conservation Online: WAAC Newsletter Health and Safety
• CA.gov California Environmental Protection Agency: Air Cleaning Devices for the Home
• The Office of Health, Safety and Security: DOE Standard Specification for HEPA Filters Used by DOE Contractors

Resources

• U.S. Environmental Protection Agency: Air Pollution Control Technology Fact Sheet
• Direct Industry: HEPA Filters