Late last month, the Center for Disease Control announced a recommendation to double up on masks to stay safe, but more details and suggestions have been announced.

The CDC’s new stipulations include how to layer the masks, which masks should be used, and which should not be layered. “For a mask to fit tightly, it must sit over your nose, under your chin, and against your cheeks without any gaps,” says the CDC. Disposable masks should be worn under a cloth mask, not vice versa. Research shows that this is the most effective way to ensure protection against COVID.

According to a study done by the CDC, double masking by wearing a cloth mask over a disposable mask can reduce the wearer’s exposure to contaminated particles by around 90%. A cloth mask only blocks 51% of particles, and a surgical mask only blocks 56%.

The CDC stresses the point of not double masking KN95 masks. Paul Hickey, the President of PuraVita Medical, a manufacturer of KN95 masks, explains that “KN95 masks are designed to be a respirator. A respirator is designed to create an airtight seal around your face, so you only breathe air that comes in through the respirator material, and the air you breathe out only goes through the respirator material.” Hickey explains that double masking KN95 masks can cause trouble breathing, which is very dangerous.

Sam Barone, MD, Chief Medical Officer of BioPharma and President of Halodine, explains that layering KN95 masks can alter the designed fit of the mask, and create spaces for material to slip through.

Anthony Fauci, MD, says that Americans are not required to wear two masks and that “the CDC’s updated guidelines are simply a recommendation”. Fauci explains that the CDC is saying, wear one mask at a minimum.