COVID-19 masks don’t provide protection from vog

  • Photo illustration/Chelsea Jensen

Face coverings and masks used to prevent the spread of COVID-19 do not provide protection from sulfur dioxide or vog.

“Some of the N95 masks can help a little when there’s ash and particulate matter in the air, but for sulfur dioxide (SO2) you really need a more advanced respirator,” said Diana Felton, State Toxicologist with the Department of Health’s Hazard Evaluation and Emergency Response Office. “We just want people to be aware of that while we still encourage wearing masks to prevent the spread of COVID, it’s not going to help with the sulfur dioxide or vog.”

That’s because SO2 and sulfate aerosols are far smaller than the respiratory droplets that carry the novel coronavirus. Respiratory droplets are typically 5 to 10 micrometers while vog particles are less than 2.5 micrometers in diameter.

“The particles are so small that they could fit right through” the material, said Felton. Vog and SO2 are “far smaller than a respiratory droplet.”


Leave a Reply

Your email address will not be published. Required fields are marked *


By participating in online discussions you acknowledge that you have agreed to the Star-Advertiser's TERMS OF SERVICE. An insightful discussion of ideas and viewpoints is encouraged, but comments must be civil and in good taste, with no personal attacks. If your comments are inappropriate, you may be banned from posting. To report comments that you believe do not follow our guidelines, email