A m15 gas masks is a piece of equipment that protects the wearer from toxic gases and particles. It covers the nose, mouth and sometimes eyes and is worn by military personnel, police officers and first responders. It is effective only when used with the proper cartridge or filter for the chemical hazard the mask is intended to protect against. It is possible to purchase filters for many different chemicals but each one is designed to be used against a specific type of hazard.
There are a number of different factors that can affect the fit and efficiency of a gas mask including: face shape, temperature, humidity, deformation of rubber parts of the mask, contaminating substances (fuels, solvents, lubricants), unexpected physical activity, prolonged periods of wear, cleaning and storage. It is important to understand these limitations and to perform regular maintenance and inspection of the mask in order to ensure continued safety and effectiveness.
Before Haldane and his team came up with innovations in protecting soldiers from poisonous gases, it was recommended that they carry urine-soaked handkerchiefs to hold to their mouths. This simple remedy could help a soldier avoid becoming incapacitated by noxious gas inhalation, but it wouldn’t provide protection against smoke or other harmful particles. A more advanced option is the Self-Contained Breathing Apparatus (SCBA) that is commonly used by firefighters. These are heavy and require extensive training and maintenance to operate. They can also only be used for short periods of time and need to be frequently refilled with air, usually from outside.