Respirator assigned protection factors

The respiratory protective devices (RPD) can protect workers only if their protective properties are adequate to the conditions in the workplace. Therefore, specialists have developed criteria for the selection of proper, adequate respirators, including the Assigned Protection Factors (APF) - the decrease of the concentration of harmful substances in the inhaled air, which (is expected) to be provided with timely and proper use of a certified respirator of certain types (design) by taught and trained workers (after individual selection with a tight-fitting mask and fit testing), when the employer performs an effective respiratory protective device programme. The imperfection of technological processes, machines and other equipment can lead to air contamination with harmful substances in the workplace. Protecting of the workers' health in this situation may be achieved by different means, listed below in order of decreasing of their effectiveness: If the use of these methods is impossible, or if their use did not reduce the concentration of harmful substances to a safe value, workers must use respirators. These respirators must be sufficiently effective, and they should correspond to known or expected conditions at the workplace. However, the sole reliance on personal protective equipment for personnel is considered the least effective means of controlling hazards, for reasons including: non-usage of the respirators in the contaminated atmosphere; leakage of unfiltered air through the gaps between the mask and face; and delayed replacement of gas cartridges. Different terms may be used to describe the protective properties of respirators: Penetration = (the concentration of harmful substances under mask) / (concentration outside the mask); Efficiency = ( (concentration outside the mask) - (the concentration of harmful substances under mask) ) / (concentration outside the mask) = 1 - Penetration; Protection Factor (PF) = (the concentration of harmful substances on the outside of the mask) / (concentration under mask) = 1 / Penetration.

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Respirator fit test

A respirator fit test checks whether a respirator properly fits the face of someone who wears it. The fitting characteristic of a respirator is the ability of the mask to separate a worker's respiratory system from ambient air. This is achieved by tightly pressing the mask flush against the face (without gaps) to ensure an efficient seal on the mask perimeter. Because wearers cannot be protected if there are gaps, it is necessary to test the fit before entering into contaminated air. Multiple forms of the test exist.

Masque N95

droite|vignette|200x200px| Masque N95 Le masque N95 est un masque de protection anti-particules avec un filtre, répondant à la classification de filtration de l'air de l'agence américaine NIOSH (National Institute for Occupational Safety and Health). Il filtre au moins 95 % des particules en suspension dans l'air mais n'est pas résistant à l'huile et ne filtre ni les gaz ni les vapeurs, tout comme le FFP2, son équivalent européen (qui filtre au moins 94 % des particules) ou le masque KN95 de Chine.

Powered air-purifying respirator

A powered air-purifying respirator (PAPR) is a type of respirator used to safeguard workers against contaminated air. PAPRs consist of a headgear-and-fan assembly that takes ambient air contaminated with one or more type of pollutant or pathogen, actively removes (filters) a sufficient proportion of these hazards, and then delivers the clean air to the user's face or mouth and nose. They have a higher assigned protection factor than filtering facepiece respirators such as N95 masks.