Particulate Filter types

Different Standards have different classification and efficiency levels for particulate filters. See below for a high-level summary of AS/NZS 1715:2009 and AS/NZS ISO 17420.2:2021 types and classes. Refer to the relevant standard for further information.

Particle filters trap and hold particles from the air flowing through them. As a filter is used, it becomes loaded with the contaminant and eventually clogs. This makes it difficult for the air to flow through the filter indicating that the filter should be replaced.

Under AS/NZS ISO 17420.2:2023 particle and combination filters for unassisted and assisted RPD will be one of the following particle filter classes. There are five classes of particle filters based on their efficiencies from low (class F1) to high (class F5)

AS/NZS ISO 17420.2:2021 6.10.1.2.2 Table 7
Filter Class Efficiency % Penetration %
F5 ≥99.99 ≤0.01
F4 ≥99.90 ≤0.1
F3 ≥99.00 ≤1.0
F2 ≥95.00 ≤5.0
F1 ≥80.00 ≤20.0

 

For AS/NZS 1715, there are 3 particulate filter ratings as below.

  • Class P1 filters – RPE with P1 filters are used against mechanically generated particulates, e.g. from drilling, crushing, sanding, grinding. Three types of Class P1 filter RPE are generally available, i.e. powered type, replaceable filter type and disposable type.
  • Class P2 filters – RPE with P2 filters are used for protection against mechanically or thermally generated particulates or both, e.g. metal fumes, bushfire smoke. Three types of Class P2 RPE are generally available, i.e. powered type, replaceable filter type and disposable type.
  • Class P3 filters – These are used for protection against highly toxic or highly irritant particulates, such as beryllium. Two types of Class P3 RPE are generally available, e.g. powered type and replaceable filter type. For P3 filter classification, a full facepiece is required for nonpowered RPE, but either a head covering or full facepiece for a PAPR. When a P3 filter is used in a half facepiece, a protection factor equivalent to a P2 filter is achieved.
AS/NZS 1716:2012 4.3.5 Filtering efficiency – Negative Pressure

Filter Class

 Efficiency % Penetration %

P3

 ≥99.95 ≤0.05
P2 ≥94.00

≤6.0
P1 ≥80.00

≤20.0

 

AS/NZS 1716:2012 6.3.2 Filtering efficiency –Powered Air Purifying Respirator (PAPR) Positive Pressure

Filter Class

 Efficiency % Penetration %

PAPR-P3

 ≥99.95 ≤0.05
PAPR-P2 ≥99.00

≤1.0
PAPR-P1 ≥95.00

≤5.0

 

Reference/s for further information and detail:

  • AS/NZS 1715:2009 – Selection, use and maintenance – Section 4.2.3
  • AS/NZS 1716:2012 – Respiratory Protective Devices – Section 4.2.3 & 6.3.2
  • SA/SNZ TS ISO 17420.2:2023 –Requirements for Filtering RPD – 6.10.1.2
  • SA/SNZ TS ISO 16975.1:2023 – Selection, use and maintenance – Annex A