Workplace respirator testing
Respirators, also known as respiratory protective equipment (RPE) or respiratory protective devices (RPD), are used in some workplaces to protect workers from air contaminants. Initially, respirator effectiveness was tested in laboratories, but in the late 1960s it was found that these tests gave misleading results regarding the level of protection provided. In the 1970s, workplace-based respirator testing became routine in industrialized countries, leading to a dramatic reduction in the claimed efficacy of many respirator types and new guidelines on how to select the appropriate respirator for a given environment.
Example of measurement of efficiency of the respirator (in the workplace). Description: (1) personal sampling pump, (2) the cassette and the filter for determining the concentration (in the breathing zone), (3) the sampling line (from the breathing zone), (4) the cassette and the filter to determine the concentration (under a mask), and (5) the sampling line (from the mask).
Protection factors (PFs) of powered air-purifying respirators (PAPRs) with loose-fitting facepiece (hood or helmet). These data led to the assigned PF being lowered from 1000 to 25 PEL (USA), and from 1000 to 40 OEL (UK)
The Lepestok filtering half-mask, viewed from the inner side of the semi-finished product. The effectiveness of this filtering facepiece was overestimated by orders of magnitude. For the period 1956 to 2015, over 6 billion respirators were produced.[citation needed]
The central detail of the Liquidators' medal, with traces of alpha (α) and beta (β) particles and gamma (γ) rays over a drop of blood.
A respirator is a device designed to protect the wearer from inhaling hazardous atmospheres including fumes, vapours, gases and particulate matter such as dusts and airborne pathogens such as viruses. There are two main categories of respirators: the air-purifying respirator, in which respirable air is obtained by filtering a contaminated atmosphere, and the air-supplied respirator, in which an alternate supply of breathable air is delivered. Within each category, different techniques are employed to reduce or eliminate noxious airborne contaminants.
Lab worker wearing a powered air-purifying respirator
Types of respirators by physical form. Click to enlarge.
Workplace protection factor (PF) of filtering facepiece, measured in real time with two optical dust meters. In-facepiece dust concentration is changed dozens of times in a matter of minutes due to changes of the size of the gaps between the mask and face.
A simple Dräger escape respirator. This model has no hood, and instead comes with noseclips to ensure the wearer breathes only through the filter.
