Are Fiberglass Air Filters Safe?

Fiberglass air filters are not as strong as pleated filters. Their cardboard frames are easily bent, which can cause the filter to collapse in on itself. Additionally, the material is not tightly woven, making it unable to capture microscopic particles. It is recommended that fiberglass filters be replaced every 30 days.

In our experience, there is usually no major concern about the detachment of fibers from the filter. The contribution of a fiberglass air filter from a heating or air conditioning furnace to the overall level of fiberglass particles suspended in air or dust in a building is likely to be negligible, probably below the limits of detection by other than the most rigorous means. It will also be negligible compared to the contribution of other sources of fiberglass, such as building insulation on unprotected roofs or walls. We offer pleated air filters with MERV 8, MERV 11 and MERV 13 ratings, and they can be ordered in any quantity.

These filters can capture 300 fiber particles per cubic meter of air from synthetic filters and 700 for fiberglass filters. MERV 11 air filters can remove even finer particles, including bacteria-sized particles along with mold spores and car fumes. Fiberglass air filters with a MERV rating of 1 to 4 can generally remove larger particles from the air, such as pet hair, dust bunnies, and cheerleader pom-poms. However, they are not effective at preventing harmful particles from entering your home and lungs.

Air filters are rated on a MERV scale of 1 to 20; the higher the number, the finer the particles that can be filtered out of the air. It is important to note that fiberglass air filters become better at filtering out dust as they become more loaded with debris. A team of scientists analyzed whether commercially available filters shed fibers both in laboratory and real-world settings. In fact, most of the fiberglass found in building air and dust seems to originate from building insulation, especially when there is traffic or air movement in and out of areas where fiberglass insulation is exposed, and even more so if that insulation is mechanically damaged, for example, by walking on it.

Finding the right MERV rating means finding the right balance between a filter that can remove most allergens without sacrificing airflow. Using high-quality air filters, a programmable thermostat, and making sure that furniture or curtains don't block airflow are important steps you should take to lower your energy bills.