Most gas-mask manufacturers and retailers agree with Homeland Security Secretary Tom Ridge that gas masks are not included in public hands. Experts say they are too difficult for civilians to meet and use it properly. Most cannot be worn with glasses or with men with beards.
The alternative is to escape hood – essentially a plastic bag with a rubber dam neck and particle/chemical filter. Unlike a gas mask, which requires an adjustable strap with caution so that no leak-proof seal between the face and the mask, hood seals escaping pretty much automatic in the neck after it was drawn on. You can buy a gas mask hood through https://www.gasmaskpro.com/gas-masks/civilian-adult-nbc-protective-hood-and-blower-system.
ILC Dover, the company that makes NASA spacesuits, has introduced civilian escape hood. Scape is called, it is packaged in a container around as long and slightly wider than a box of tissues.
Scape is what is called the unit "positive pressure". A small motor is activated when the hood is pulled from the box. The motor sucks air through a series of filters and into the tent.
Other civilian models including the Gas Mask Hood by Mine Safety Appliances, one of the leading manufacturers of respirators, and this Survivor Quick2000, the type purchased for federal workers on Capitol Hill.
These devices combine a product that has been marketed to frequent travelers in recent years: a veil of smoke. Smoke hoods are specifically designed to protect against the deadly carbon monoxide during the fire. They do not protect against nerve gas. No mask or hood lasts forever. Filters that finally will be clogged.