Q&A: Gregory Rutledge on initial testing of KN95 respirators for public health officials

Across Massachusetts, public health officials and others are working to secure personal protective equipment (PPE) to ensure the safety of health care providers and others working directly with Covid-19 patients. N95 respirators and face masks, which are regulated by the U.S. government, have been in short supply, leading some entities and states, including the Commonwealth of Massachusetts, to secure KN95 respirators as an alternative.

KN95 respirators are regulated by the Chinese government under specifications similar to N95 respirators in the U.S., and have been approved for emergency use in some circumstances by the FDA. (N95 respirators seal against the face and protect the wearer from small-particle aerosols in the environment. Face masks are not form-fitting but protect both the wearer and those around them from splashes and exchanges of large droplets.)

To try to gauge the effectiveness of the respirators in the state’s stockpile, public health officials turned to the Massachusetts Manufacturing Emergency Response Team (M-ERT) initiative for help rapidly analyzing materials and products. At MIT, Professor Gregory Rutledge is part of that initiative; he has donated the services of his lab, which includes specialized equipment to generate and analyze aerosols, to test the filtration efficiency and breathability of materials used, or proposed for use, in respirators or masks.

Rutledge spoke with MIT News about the testing his lab is conducting, why he got involved, and the early gap his testing helped to fill. He described how entities may use this kind of data to inform decision-making and guidance, such as that issued by the Massachusetts Department of Public Health (DPH) and the Massachusetts Emergency Management Agency (MEMA) on April 24. However, he cautioned against drawing overly broad conclusions, noting that early analyses such as his involve certain limitations.