Types of Respirators
If you are required by your employer to use a respirator in the workplace, your employer must previously select which type or types of respirators you will be wearing according to the environment conditions of the workplace. This is stipulated by the Occupational Safety and Health Administration (OSHA) Standards, and forms part of the responsibilities your employer has to be compliant with. It is very important to know the type of respirator you will be using since you will be medically evaluated for its use by a respirator clearance test.
Respirators might be classified into different categories depending on the feature to be considered. But in general there are two main types of respirators: air-purifying respirators and atmosphere-supplying respirators. The first remove contaminants from the air using filters, canisters and cartridges, while breathing. The latter type provides clean air from an uncontaminated source.
A second category of respirators considers the way a respirator fits the user’s face. Therefore, there are tight-fitting respirators and loose-fitting respirators. Tight-fitting respirators need a seal between the respirator and the person’s face and/or neck in order to operate correctly. This is why anything that interferes with this seal, like facial hair and facial accessories, can lead to leaks of contaminated air. On the other hand, loose-fitting respirators can provide protection without respirator-to-face seal. Only workers who will be wearing tight-fitting respirators need to be fit tested before use. However, both types require a respirator medical clearance, since they still can represent a health or safety risk for the employee.
Now, a third classification for respirators takes into consideration the parts of the face that are covered by them. Hence, respirator types can be divided into half facepiece respirators and full facepiece respirators. Half facepiece respirators cover only the mouth and the nose, and can be further divided into filtering and elastomeric half facepiece respirators. In the case of filtering half-facepieces (informally called N95s), the whole respirator acts as the filter, they are disposable and do not offer protection against non-particulate contaminants such as gases and vapors. Elastomeric half-facepieces can be cleaned and reused, and can offer protection against particulate hazards, and also non-particulate hazards (gases and vapors) if equipped with proper cartridges. In contrast, a full facepiece respirator provides higher protection to the user since it covers the whole face and eyes. This means that these respirators also protect against liquid splashes and eye-irritating gases.
Considering all these classifications, some respirators are combinations of these types. For example, personal air-purifying respirators, known as PAPR, use filters to clean the air. They can be either half or full facepiece, and can be loose-fitting or tight-fitting. In the case of atmosphere-supplying respirators, they can also be half or full facepiece and loose or tight fitting. If the source of clean air is portable, they are regarded as self-contained breathing apparatus (SCBA), but if the respirator provides air from a source, connected through a long hose, such as a cylinder or compressor, they are considered as airline respirators.
Last but not least, let’s talk about the classification of filters used in respirators. You may have heard of N95 or P100 respirators. The first part of these names (the letter) makes reference to the respirator’s ability to work when exposed to oils. N means “No resistant to oil”, R means “Resistant to oil”, and P means “strongly resistant to oil, or oil-proof”. The second part (the number), refers to the percentage of protection against the most-penetrating particles. Filters that remove at least 95% of particles are given a rating of 95. Filters that can remove at least 99% of the particles are given a 99 rating. And if they filter at least 99.7% of the particles, they are conferred a 100 rating.
What to consider before your respirator clearance test?
In case you will be exposed to hazardous contaminants at your workplace, it is mandatory for your employer to medically evaluate you for respirator use. This is carried out through a respirator clearance test, which consists of completing a questionnaire about your past and current health and work conditions.
Before answering the questionnaire, your employer must indicate the type of respirator, chemical exposure, work effort, environment conditions, respirator usage, protective equipment and any other description of your job. So knowing the types and the usage of respirators will give you some knowledge to detect whether the respirator you were assigned to is the correct one to protect you properly.