Everything You Need To Know About Respirators

Differences Between Respirators and Surgical Masks?

Respirators are designed to help reduce the wearer's respiratory exposure to airborne contaminants such as particles, gases or vapors. Particulate respirators are used to reduce exposure to particles that are small enough to be inhaled - particles less than 100 microns in size down to nanometre size. This includes airborne particles that may contain biological material e.g. coronaviruses, mould, mycobacterium tuberculosis etc.

Surgical masks (even those that meet Australian/NZ standards for surgical masks) do not have adequate filtering and/or filtering attributes to provide effective respiratory protection for the wearer to this range of particle sizes. They are designed to help prevent contamination of the work environment from particles generated by the wearer e.g. spit, mucous.

How Long Does a Filter Last?

There are many variables that can affect how often your filters may need to be changed:

  • The type of gas, vapours and particulates that are being dealt with
  • How often they are being used
  • How they are being stored or maintained
  • Infection control procedures may require masks/filters to be replaced after every us

On top of this every workplace is unique and needs to assess their specific situation to determine an adequate filter change schedule.

When Gas & Vapour (G&V) cartridges used on reusable respirators reach their capacity, it will no longer protect the wearer as the G&V will pass straight through to the wearer. Particulate filters will keep removing contaminants but will become harder and harder to breathe through, increasing discomfort.

When Do I Need To Change The  Filter/Cartridge?


  • The expiry date stamped on the sealed packet has expired
  • Once opened from original packaging, maximum use time is 6 months even if not used (gas & vapour cartridges)
  • When it becomes difficult to breathe comfortably (particulate filters)
  • When it becomes dirty or phuysical dmage occurs
  • When contaminants with good warning properties can be detected by smell or taste

P2 vs. N95 Respirators?

The terms P2 and N95 refer to types of respirators which meet different respirator classification systems that users in New Zealand my come across. In the AS/NZ standard, P2 respirators must have filter efficiency of at least 94% when tested. Whereas in the United States NIOSH classification, N95 respirators must have a filter efficiency of at least 95% when tested. 

Download a fit-guide poster for your workplace here

3M Particulate Respirators 'Wear It Right' Poster

Check out our range of 3M respirators