Will N95 Masks Keep Me Safe From COVID-19?
Everyone is talking about these masks. Where do I get one and do I need to?
In the wake of the COVID-19 (Corona virus) spreading, there's been a bombardment of news stories everywhere you look; every angle, idea, development, speculation and warning given breath in the 24-hour news cycle.
The item that piqued my interest as a safety professional was the news about people buying up and hoarding N95 particle respirators – so quickly that they are now unavailable for health professionals. What is the big idea? Is this paranoia or a mucky attempt at profiteering? Is this a meaningful prophylaxis or can I keep relying on my healing crystals?
Varieties of N95 masks are commonplace in industrial and medical settings, and are designed to filter particles larger than 0.3 microns. So, if the COVID virus itself is around 0.125 microns, you might think this would be like relying on a chain-link fence to stop a bullet – but there's a little more to it. The fibers in a filter have an electrostatic charge that attracts passing particles as air is drawn through, removing them from the inhaled air. Since COVID isn't just chilling in the air by itself, the particles and droplets it's riding on can be captured. In theory, and under ideal conditions, these type of filter masks should provide some degree of protection.
The N95 rating is a standard established by the National Institute for Occupational Safety and Health (NIOSH) that provides testing and classification standards for safety equipment. Without getting in the weeds on the meaning, the 'N' is for “Not oil resistant” and the 95 implies at least 95% efficiency in removal of particles 0.3 microns and greater. In other words, as much as 5% of particles can still be passing through with this rating. Generally these are considered light duty filters and wouldn't be used to protect the wearer from something critically hazardous such as asbestos. It's better than nothing, you bet; a scarf is also better than nothing. As we'll see there's more to consider.
The CDC has stated that there are plenty of products on the market that claim to be NIOSH approved, but aren't. Fashionable printed masks, for example, are categorically voided (source). Others may look legit but haven't actually undergone any testing. A sample of such fakes found they had up to 80% leakage!
It's easy to imagine shady companies manufacturing and distributing bogus masks, hoping to get overlooked in the fracas and divest before being found out. You can usually determine if they are the genuine article by verifying the TC number on the NIOSH website.
Donning counterfeit masks is potentially worse than nothing due to a psychological phenomenon called “risk compensation” which makes people behave less carefully if they believe they are protected. Be-masked individuals might not worry so much about washing their hands, touching their face or avoiding crowds – actions which are far, far more likely to help you avoid infection.
So should I be buying these masks up in bulk, holing up in my bunker and collecting my urine in jars? Eh – maybe, but it's probably not going to make a big difference.
Realistically, these masks can provide a degree of protection, but the rating-implied efficiency of 95% assumes it is a proper fit (and has been fit-tested), that the mask is worn perfectly and only once. As with all personal protective equipment, the effectiveness drops off precipitously when it's not used in correct fashion, to the point of offering almost no protection.
The common misuse is to have a mask that cannot seal to the face. If you have anything but a clean-shaven face it won't seal, and many disposable varieties have no ability to seal anyway. A surgical mask that is designed to protect you from “splashes or large droplets” is unlikely to offer much if any benefit to Average Joe going about his day. Moreover, these masks are designed to keep the wearer's droplets to themselves more than filtering them out of the environment. That is in contrast to valve style masks, which do not filter outbound air at all, making them useless if the intention is to keep from spreading your own aerosolized nastiness.
Unless you are in the belly of the beast, you probably don't need to panic and try to track down these masks. Wash your hands, stop touching your face so much, and maybe avoid crowded areas where possible. These are your best bets.
Nevertheless, if you go the mask route, detailed information on how to properly select and use respirators can be found in CSA standard Z94.4-2018 .