The Envo mask, from side profile. Shown with halo headgear straps and envo mask shield.

Envo mask is a reusable N95 respirator (elastomeric respirator) that features a soft gel face seal. The envo mask is a NIOSH certified N95 respirator.

Unlike most reusable respirators, it's relatively easy to hear someone talking that's wearing the Envo mask. The Envo mask has an exhalation valve. The company ships each mask with a valve plug which can be used to seal the exhalation valve. A filter cover that lacks an exhalation valve is available as an optional accessory.

The Envo mask is made by Sleepnet Corporation, a company that had been manufacturing masks for sleep apnea. The envo mask received its first NIOSH certification in September of 2019. According to a news article, founder Tom Moulton got the idea to create the Envo mask after working a demolition project and becoming frustrated with the poor quality of most disposable masks:

“There’s got to be a better way,” Moulton thought to himself. He started working with his Sleepnet engineers to create what he thought might be a construction-type mask using his AIRgel.. -Interview with Sleepnet founder

Pros and Cons

The big advantage of the Envo mask is the gel cushion seal. Many people find it very comfortable. However, it doesn't fit everyone and the head harness and neck strap being one continuous loop does not allow independent adjustment -- allowing fit to fluctuate during wear. Fit testing is important.

The downside, from a cost perspective is not only the upfront cost of the facepiece, which is about double that of standard elastomeric respirators, but that the manufacturer recommends replacing the filter after every 8 hours of use at over $2/filter. Thus, the total cost of ownership is actually greater than for filtering facepiece disposable N95s, if you follow those directions. By contrast the cartridges for an elastomeric respirator (e.g., MSA Advantage 290 respirator, a NIOSH approved N95 without exhalation valve) can be used for up to a year or more without replacement in an environment that has low levels of particulate air pollution (e.g., healthcare) -- making total cost of ownership orders of magnitude less than for the Envo mask.


Some videos about the Envo mask:

News articles


3M HF-800 head strap attached to Envo Mask

One complaint that some Envo Mask users have is with the strap options that are provided. The ear hooks can be painful if actually used on the ears for an extended period and the halo strap can twist up easily while trying to position it on the crown of the head.

Reddit user ninjak2k replaced his straps with a set from a 3M HF-802sd face mask, allowing him to use the rigid head harness. He found that "since the straps are set at a fixed length, it's much easier to get the mask back on the face with the right position and tension."

See also