Key facts
- P means strongly resistant to oil.
- 100 means at least 99.97% filtration in the NIOSH test.
- P100 filters may be used on filtering facepieces or reusable respirators.
- A P100 particle filter alone does not remove gases or vapours.
What P100 means
| Feature | Meaning |
|---|---|
| P | Strongly resistant to oil aerosols |
| 100 | At least 99.97% efficiency in the certification test |
| Approval | Look for NIOSH markings and a valid approval configuration |
Selecting P100 protection
A qualified assessment may select P100 for high-efficiency particle filtration or work involving oil aerosols. The facepiece type and assigned protection factor matter in addition to the filter class.
When cartridges combine P100 media with gas or vapour protection, the complete NIOSH-approved configuration and cartridge change schedule must be followed.
Important limits
- Does not supply oxygen
- Particle-only P100 filters do not remove gases or vapours
- Requires a correct seal on tight-fitting facepieces
- Cannot substitute for feasible engineering controls
Frequently asked questions
Is P100 better than N95?
P100 has higher test efficiency and oil resistance, but the correct choice depends on the assessed hazard, facepiece and fit.
Does P100 filter welding fumes?
It can filter particles in welding fume when used in an approved, suitable configuration, but it does not remove welding gases.
Does P100 protect against carbon monoxide?
No. A P100 particle filter does not remove carbon monoxide and does not supply breathable air.
Sources
This reference was prepared from the following primary public-health and regulatory sources:
- Filtering Facepiece RespiratorsNational Institute for Occupational Safety and Health
- Respirator Selection and UseNational Institute for Occupational Safety and Health