The Hierarchy of Controls

Respiratory Protective Equipment (RPE) is just one means of protecting people from potentially hazardous materials, gases, pathogens and vapors in the air.

In fact, RPE is often referred to as the last line of defense’ against respiratory hazards.

Thinking of RPE in these terms is helpful in two ways:

  1. If it fails - due to not being adequate for the hazard, or suitable for the wearer, for example – then there is no barrier between the wearer and the hazardous substance entering their lungs; and
  2. It is the last means of risk protection in the hierarchy of controls.


The hierarchy

The traditional hierarchy of controls for hazards shows us that when faced with hazards in the workplace, there is a proper order of response to best minimise risk and keep employees safe.

  • Elimination
    Can the task be removed completely?
  • Substitution
    Can an alternative substance be handled that is less hazardous?
  • Engineering Controls
    Can the hazard be isolated – e.g. through adequate air ventilation?
  • Administrative Controls
    Can the risk be reduced through implementing regulations, such as timed working in hazardous areas?
  • Personal and Respiratory Protective Equipment (PPE and RPE)

Can the worker be protected sufficiently against harm through specially designed workwear?


A practical example

Alex is a stonemason and is about to start working on a luxury quartz kitchen worktop. When cutting quartz, silica dust is produced – which is extremely hazardous to health if inhaled. Extended exposure to silica dust can lead to scarring on the lungs, shortness of breath, occupational asthma and silicosis – a deadly lung disease.

Running through the hierarchy of controls we can see whether Georgina requires RPE in this situation.

  • Elimination
    Even were Georgina to buy smaller slabs of quarts, she would still need to cut it for corners, joins and sink holes. There is no way of stopping cut quartz from producing silica dust either, so elimination is not possible
  • Substitution
    Replacing the quartz with a less hazardous material could be an option – however, the designer has particularly requested quartz in this case, so substation is not an option
  • Engineering Controls
    Cutting the quartz in a well-ventilated area, such as in Georgina’s garden, should help reduce the amount of silica dust she is exposed to, but will not remove the risk completely
  • Administrative Controls
    Limiting the length of time Georgina spends cutting the quartz in any one go should also help reduce the level of risk, but again would not remove it completely
  • RPE
    Even with cutting the quartz outside in short bursts, Georgina would potentially be breathing in a considerable amount of silica dust. Wearing a suitable dust mask respirator to filter out the particles, such as the DSM18 Easimask® would prevent any hazardous particles entering her lungs.

Running through the hierarchy shows us that while certain actions can be taken to minimise risk, in her situation RPE would be essential for protecting her health.


Please note:

Most FFP3 respirators used in the healthcare environment are tight-fitting (whether single-use, half-face or full-face). Tight-fitting respirators of any kind require Fit Testing before first being used to ensure that the make/model of respirator suitably fits the wearer’s face. Not Fit Testing a respirator could lead the employee to have a false-confidence that they are protected from respiratory hazards, when in fact they are still breathing in contaminated air.

Fit Testing staff members required to use tight-fitting respirators before use is a legal requirement for the employer.  Failure to do so could endanger staff health and lead to a considerable fine.