Did the Occupational Safety and Health Administration say cloth face masks offer no COVID-19 protection and lower the wearer's available oxygen to dangerously low levels? No, that's not true. Numerous OSHA publications recommend the masks as a means to protect others, as protection from touching the face and as an effective way to keep asymptomatic carriers from spreading droplets. Moreover, no OSHA publication warns that cloth masks will cause a wearer to experience oxygen starvation.
The claims originated in a video posted on YouTube on June 15, 2020, titled "OSHA SAYS MASKS DON'T WORK -- AND VIOLATE OSHA OXYGEN LEVELS -- The Healthy American, Peggy Hall" (archived here) which opened:
Hey friends, it's Peggy Hall here with HealthyAmerican.org and I want to share with you a very important video that somebody sent me from his workplace."
She offers a screen share of a page from the Occupational Safety and Health Administration (OSHA) and highlights a paragraph stating that face masks:
Will not protect the wearer against airborne transmissible infectious agents due to loose fit and lack of seal or inadequate filtration."
But right above that on the OSHA page is this wording:
Masks are worn in public over the nose and mouth to contain the wearer's potentially infectious respiratory droplets produced when an infected person coughs, sneezes, or talks and to limit the spread of SARS-CoV-2, the virus that causes Coronavirus Disease."
Hall appears to be cherry-picking the information she wants her viewers to see. For example, at 6:44 in the video, she points to a line in the California state guidelines for face-covering: "Cloth face covers are not protective equipment," meaning they are not lumped in with personal protective equipment such as N-95 respirators. From that she extrapolates, "Cloth masks offer no protection."
But the paragraph right above that states:
Cloth face covers can help protect persons around the user of the cloth face cover when combined with physical distancing and handwashing."
The definition of useful protection is in question. Hall dismisses cloth face masks because they do not sufficiently seal tight around the wearer's face, as N-95 respirators do. At the same time, the CDC and OSHA give the coverings value because one's mask minimizes the danger to others, and others' masks minimize danger to oneself.
OSHA's June 10, 2020 online FAQ section further contradicts Hall's claim that masks are ineffective. The agency addresses the role masks play in preventing viral spread from asymptomatic carriers. The agency recommends that
... employers encourage workers to wear face coverings at work. Face coverings are intended to prevent wearers who have COVID-19 without knowing it (i.e., those who are asymptomatic or pre-symptomatic) from spreading potentially infectious respiratory droplets to others. This is known as source control."
It is consistent with the Centers for Disease Control and Prevention (CDC) recommendation for all people to wear cloth face coverings when in public and around other people, and wearing cloth face coverings conserves personal protective equipment (PPE), such as surgical masks, for health care settings where such equipment is needed most.
OSHA is neither mandating nor banning masks in the workplace, according to the June 10 update.. Employers still may choose whether to allow employees to wear cloth face coverings based on the specific circumstances present at the work site. Some employers may determine that wearing cloth face coverings presents a hazard. For example, cloth face coverings could become contaminated with chemicals used in the work environment, causing workers to inhale the chemicals that collect on the mask. In that case, OSHA gives employers the go-ahead to provide other protection such as face shields and/or surgical masks. Guidelines state:
Like cloth face coverings, surgical masks and face shields can help contain the wearer's potentially infectious respiratory droplets and can help limit spread of COVID-19 to others."
Note that cloth face coverings are not considered PPE -- as the California state guidelines point out -- and cannot be used in place of respirators. Learn more about cloth face coverings on the CDC website.
Hall believes a second reason to not wear masks is possible oxygen starvation if the oxygen percentage inside the mask drops below 19.5 percent. For two reasons this is unlikely, if guidelines are followed. If, as she says, the cloth mask is too loose around the edges to be protective, it would not cut off oxygen. The two outcomes are contradictory. Hall gives no proof that a single person in a cloth face mask has faltered for lack of air.
Next, even snug-fitting N-95 respirator masks that hug the skin will not choke off air supply as long as the wearer has a finger to raise a seam or corner of the mask. The same is true of a lightweight cloth mask. Healthfeedback.org looks at the claim of hypoxia (not enough oxygen) and hypercapnia (too much carbon dioxide) inside the mask:
Face masks help to limit contact with infectious droplets which carry pathogens. However, the materials used for face masks are still porous enough to allow gas molecules such as oxygen and carbon dioxide to pass through, and they do not significantly impair gas exchange to the point of causing hypercapnia. No scientific evidence supports the claim that using face masks weakens the immune system."
According to Health Feedback, there is cause for concern about asphyxia and carbon dioxide overdose only if the face-covering is plastic. Because plastic is not porous enough to allow for quick air exchange, unlike cloth face masks, it poses a genuine suffocation risk as cases in the past have demonstrated, and warning labels on plastic bags are used to remind people of this risk.
Hall plays a video clip of a man sticking a gas monitor measuring atmospheric oxygen content into his face mask and then getting alarmed when it registers more carbon dioxide and less oxygen in his exhaled breath. This is the stuff of simple seventh-grade science class: The lungs take up oxygen from the inhaled air and they send back out breaths containing more carbon dioxide. Lead Stories previously debunked the hypercapnia rumor in an article titled Fact Check: Hypercapnia Does NOT Occur From Constant Use Of A Mask As Advised During The COVID-19 Outbreak
A video from Vox disputes Hall's contention that face masks don't offer enough protection to counter the inconvenience. It shows a person coughing into his crooked elbow, into his hand and through different types of masks. It gives visible proof of the value of a covered lower face. Not only do drops (from sneezing, coughing, shouting or talking) spray outward, they may spray upward where they hang in the air as aerosolized droplets for someone to pass by and inhale even after the cougher has gone. Or as the CDC states, "Your cloth face covering may protect them. Their cloth face covering may protect you."
At least one anti-mask website doesn't show respect to people who wear masks. Hall appears on the GreenMedInfo webpage above an editorial that says people who insist on wearing masks are "Whacko Conspiracy Theorists." The headline reads:
Mask wearers of the world, take them off--you have nothing to lose but your insanity. On May 29, the World Health Organization announced that masks should only be worn by healthy people if they are taking care of someone infected with COVID-19. If you do not have any respiratory symptoms such as fever, cough or runny nose, you do not need to wear a mask."
They attribute this quote to Dr. April Baller, a World Health Organization infection control expert who is quoted as saying,
Masks should only be used be worn by caretakers or by people who are sick with symptoms of fever and cough."
But contrary to GreenMedInfo, Baller appears on June 5, 2020 on the ABC News Chicago broadcast saying quite the opposite about protective masks. Baller is on record as encouraging the wide use of masks to prevent spread among the general public. She encourages making fabric coverings at home. WHO's advice, which matches that of OSHA and the CDC, reflects the increasing evidence that COVID-19 can be spread by people before they have symptoms, she said.
What (the masks) do is they prevent a person who may actually have the disease from transmitting it to somebody else," Baller said.
And although Hall did not mention it, here is a bonus reason to wear a mask: It also prevents the wearer from touching his or her face, which is a known vector of infection transmission.