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How to select the right type of respiratory protection
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How to select the right type of respiratory protection

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Source: ED 6160 “Les appareils respiratoire” (respiratory equipment), published by INRS in July 2017

Filtering or powered respirators, self-contained breathing apparatus, emergency escape breathing devices, self-rescuers and more... All of these are classified as respiratory protective equipment! The question is: when should you use them, and most importantly, how do you choose the best equipment to offer you maximum protection?

Here is a good practice guide to help you select the right type of respiratory protection.

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When do you need to use respiratory protection?

Before you make the wearing of respiratory protective equipment (RPE) mandatory, it is essential to implement other prevention solutions such as finding substitutes for hazardous substances or installing air purification techniques (closing off processes, trapping pollutants, ventilating the premises, etc.). If it is not possible to put these measures in place, or if they are insufficient, you will need to provide respiratory protective equipment.

Respiratory protective equipment is used:

  •     If there is a risk that a person’s health will be altered as a result of inhaling air that is polluted by gases, vapours, dust and aerosols or by oxygen-depleted air in the workplace;
  •     When intervening to tackle a fire or gas leak, and in closed spaces where the atmosphere may become dangerous due to inhalation;
  •     In closed areas with an insufficient oxygen supply (contaminated areas).

There are many types of respiratory protective equipment suitable for each situation and specific field. They work by putting a physical barrier between the polluted atmosphere in the workplace and the worker’s face (respiratory tract, eyes, skin). These devices are classed as Personal Protective Equipment, so it is important to make the right choice to ensure you are properly protected.

Carry out an assessment of the workstation

You need to define the conditions of use beforehand:

  •     Oxygen level
  •     Type of pollutants (gas, vapours, dust, etc.)
  •     Toxicity of the pollutants
  •     Worst-case-scenario concentrations of each type of pollutant in the air
  •     Occupational Exposure Limits (OELs), if appropriate
  •     Dimensions of the particles in the case of aerosols
  •     Physical activity of the user
  •     Duration of the work to be carried out
  •     Related risks (projection of fluids, fire, etc.)

Respiratory equipment selection guide

There are two broad categories of respiratory protective equipment:

Self-contained breathing apparatus

  •     The equipment supplies breathable air from an external source. The user is not dependent on the ambient air
  •     Can be used in closed and confined spaces
  •     Always use this type of protection if there is any doubt about the quality of the air, and in all atmospheres with an oxygen level <17%

Filtering respirators

  •     The equipment filters and purifies the contaminated air. The user breathes the ambient air.
  •     The ambient air must contain between 17 and 21% oxygen

To help you determine the type of respiratory protective equipment best suited to your needs, we have provided a decision-making chart based on the following questions:

  •     In what situation will the respiratory protective equipment be used?
  •     What is the oxygen level during the period of work?  Note: a normal oxygen level is between 17 and 21%
  •     What type of pollutant is involved and how toxic is it?
  •     What is the OEL, or permissible concentration level of the pollutant?

 

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Respiratory equipment selection guide

Determine the level of protection

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Class of filter efficiency for filtering respirators (gas masks)
Class of filter efficiency for filtering respirators (gas masks)

After selecting the equipment family (filtering or powered respirator, self-contained breathing apparatus, emergency escape breathing devices or self-rescuers), you need to determine the minimum required Protection Factor (PF).

Minimum required PF = Concentration of contaminant outside the facepiece / Permissible concentration of contaminant inside the facepiece, or OEL.

To ensure sufficient protection, the Nominal Protection Factor (NPF) and the Assigned Protection Factor (APF) must be greater than the minimum required Protection Factor (PF).

For example: when selecting a filtering respirator (gas mask), you need to choose the most appropriate equipment based on the protection levels shown in the table and select the right filter (type and class).

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Class of self-contained breathing apparatus
Class of self-contained breathing apparatus

After selecting the equipment family (filtering or powered respirator, self-contained breathing apparatus, emergency escape breathing devices or self-rescuers), you need to determine the minimum required Protection Factor (PF).

Minimum required PF = Concentration of contaminant outside the facepiece / Permissible concentration of contaminant inside the facepiece, or OEL.

To ensure sufficient protection, the Nominal Protection Factor (NPF) and the Assigned Protection Factor (APF) must be greater than the minimum required Protection Factor (PF).

For example: when selecting self-contained breathing apparatus, you need to choose the most appropriate equipment based on the protection levels shown in the table and select the right filter (type and class).

Did you know?

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Did you know?
Did you know?
  •     For carbon monoxide (CO) protection, we recommend that you use self-contained breathing apparatus.
  •     For self-contained breathing apparatus that can be used for very high concentrations of pollutant, or if the oxygen level is below normal, you will need a full-face respirator with self-contained compressed air breathing apparatus with a positive pressure demand valve.

Equipment suited to the work situation

Once you have determined the appropriate family of respiratory protective equipment, you need to be able to adapt the equipment to the work situation. It is essential to involve  future users in the selection process because they are the people who are best able to describe their activity.

The following parameters need to be taken into account:

  •     Physical characteristics of the wearer (beard, face scars, etc.) that will determine the size and type of protection (helmet, hood, facepiece, etc.)
  •     Whether the person wears glasses or contact lenses, because there are special devices for attaching glasses
  •     Work patterns: air line breathing systems are better suited to more intense work; powered respirators can be used if the flow is sufficient to offset the negative pressure
  •     The length of time for which the equipment will be worn: it is better to choose powered filtering respirators if you need to wear them for more than 1 hour
  •     Visibility requirements: depending on the needs, we may recommend panoramic facepieces for improved visibility, single-use visors or hoods with a replaceable visor offering eye protection in case of projections
  •     Communication requirements: there are models with phonic membranes and voice amplifiers enabling communication in harsh conditions such as confined spaces
  •     Other personal protective equipment and accessories to be used: some types of equipment have integrated head, eye, ear and respiratory tract protection – they are useful for welding operations, for example.
  •     Decontamination requirements applicable to  respiratory protective equipment
  •     Thermal constraints
  •     Etc.

Carry out a fit test

Respirator fit tests are recommended to help you choose the right size and model for each wearer,  and to make sure the seal between the facepiece and the face is as airtight as possible.

To find out more, please read through document ED 6273 published by INRS.