Masks and Respirators for Non-medical Applications (Masks and Respirators Against Dust, Chemicals and Others)

The chapter describes the role of masks and respirators in preventing respiratory infections, mainly focusing on non-medical applications. Egyptians first used masks during mummification as a precaution against inhalation of harmful substances. During the Bubonic Plague and Industrial Revolution, masks were used as a precautionary method. The masks can be classified based on their use, design, and features. Masks can be used during surgical procedures or while interacting with patients to prevent exchanging fluids and particulate materials. Cloth and disposable masks are reusable, readily available, low cost, and often made with nonwoven polypropylene material. The masks evolve based on the classifications and recommendations made occasionally. Chemical, biological, and radiological agents also pose health risks and can be avoided by gas masks. Respirators like N95, R99, and P100 are highly effective respirators. Further, the respirators that filter out air contaminants and use filters or canisters are also discussed. Respirators offer clean air via remote sources (compressed air tanks) like airline respirators or have their oxygen supply, which is to be carried by the user. The respirators are used where the surrounding air is dangerous to life or if the oxygen level is too low. Half-face and full-face respirators are variations of respirators that provide protection. Fit, type, comfort, type of hazard, maintenance, and replacement are factors that help in mask selection. Moreover, breathability, straps, and weight should be checked before prolonged use. Various physical and mechanical principles, like electrostatic filtration, diffusion, inertia, etc., filter out the air contaminants. The masks are assessed by bacterial filtration efficiency, particle filtration efficiency, differential pressure or breathing resistance, flow resistance, fluid or splash resistance, flame resistance, fit well and sit comfortably, and reusability. Nonwoven fabrics like spun bond and melt-blown fabric are used to produce masks for medical applications and respirators. The cartridges and canisters used for removing gas and chemical vapours use activated carbon for purification. In continuation, mask standardization is also discussed. The International Organization for Standardization, International Electrotechnical Commission, and American Society for Testing and Materials are the standards used in the production of masks. In the current scenario, the organization must consider a life cycle perspective for better environmental management. Hence, the life cycle assessment of masks has been given, referring to various phases such as the Goal and Scope, Life Cycle Inventory, Life Cycle Impact Assessment, and Interpretation.