Fact check: Wearing a face mask will not cause hypoxia, hypoxemia or hypercapnia - USA TODAY

One Facebook post claims that wearing a mask for prolonged periods of time can drastically reduce the wearer's oxygen levels and result in carbon dioxide toxicity.

Another viral meme featuring three people wearing masks while walking on a beach says face mask wearing "reduces oxygen up to 60%" and "increases risk of CO2 poisoning.".

It is common for surgeons and other scientists or health care workers to wear face masks, particularly N95 respirators, for prolonged periods of time.

Neither the CDC nor the World Health Organization has issued warnings suggesting the use of surgical face masks would result in dangerous oxygen level depletion within the general public.

One Facebook post claimed "wearing a mask for an 8 hour shift can reduce your oxygen intake level to a 93 if you have healthy lungs ...

The same Facebook post claimed face masks "block your exhaling of carbon dioxide and then you breathe it back in … it destroys lung tissue." The viral meme suggests wearing a mask can increase a wearer's chance of carbon dioxide poisoning.

It's important to note that the majority of the time, with health care workers as an exception, the general public is not wearing face masks for prolonged periods of time, meaning a dangerous build-up of CO2 is unlikely

The CDC told Snopes that N95 respirators could cause the buildup of carbon dioxide over time, which can also be mitigated by feeding in oxygen or simply taking a break and removing the mask

But the same effects are not likely in people wearing cloth face masks, especially for the brief amount of time they are in public. 

There is no evidence to support that the general public — which doesn't typically wear masks for prolonged periods of time  — will experience significant reductions in oxygen intake level, resulting in hypoxemia. While CO2 can build up in face masks, it is unlikely that wearing a mask will cause hypercapnia, according to the CDC