Respirator assigned protection factors — federal OSHA and Cal/OSHA, with maximum use concentrations
Assigned protection factors (APFs) for each respirator class under federal OSHA (29 CFR 1910.134 Table 1) and Cal/OSHA (8 CCR 5144), and — the derived layer — the maximum use concentration (MUC) each respirator class supports for a given substance, computed as APF × the applicable exposure limit. The regulation itself states the formula ('The MUC can be determined mathematically by multiplying the assigned protection factor... by the required OSHA permissible exposure limit'), but nobody publishes the computed per-substance table, and OSHA and Cal/OSHA limits differ up to 10× for 66 substances — so the same respirator is adequate federally and inadequate in California for the same job. Answers 'what APF does a half mask have', 'what respirator do I need for styrene at 300 ppm', and 'is my respirator sufficient under Cal/OSHA'. Pairs with the existing workplace-exposure-limits asset (1,184 records, two authorities) — the MUC pages are that asset multiplied through this one.
Records40
Sources2
Verified
Review by
LicenceUS federal and California regulatory text; facts not copyrightable, sections quoted with citation.
The data
| Respirator type | Facepiece | Operating mode | Assigned protection factor | Jurisdiction | Conditions |
|---|---|---|---|---|---|
| Supplied-Air Respirator (SAR) or Airline Respirator | Full facepiece | Continuous flow mode | 1,000 | 29 CFR 1910.134 | |
| Supplied-Air Respirator (SAR) or Airline Respirator | Half mask | Continuous flow mode | 50 | 29 CFR 1910.134 | |
| Supplied-Air Respirator (SAR) or Airline Respirator | Helmet/hood | Continuous flow mode | 25/1,000 | 29 CFR 1910.134 | The employer must have evidence provided by the respirator manufacturer that testing of these respirators demonstrates performance at a level of protection of 1,000 or greater to receive an APF of 1,000. This level of performance can best be demonstrated by performing a WPF or SWPF study or equivalent testing. Absent such testing, all other PAPRs and SARs with helmets/hoods are to be treated as loose-fitting facepiece respirators, and receive an APF of 25. |
| Supplied-Air Respirator (SAR) or Airline Respirator | Loose-fitting facepiece | Continuous flow mode | 25 | 29 CFR 1910.134 | |
| Self-Contained Breathing Apparatus (SCBA) | Full facepiece | Demand mode | 50 | 29 CFR 1910.134 | |
| Supplied-Air Respirator (SAR) or Airline Respirator | Full facepiece | Demand mode | 50 | 29 CFR 1910.134 | |
| Self-Contained Breathing Apparatus (SCBA) | Half mask | Demand mode | 10 | 29 CFR 1910.134 | |
| Supplied-Air Respirator (SAR) or Airline Respirator | Half mask | Demand mode | 10 | 29 CFR 1910.134 | |
| Self-Contained Breathing Apparatus (SCBA) | Helmet/hood | Demand mode | 50 | 29 CFR 1910.134 | |
| Air-Purifying Respirator | Full facepiece | 50 | 29 CFR 1910.134 | ||
| Powered Air-Purifying Respirator (PAPR) | Full facepiece | 1,000 | 29 CFR 1910.134 | ||
| Air-Purifying Respirator | Half mask | 10 | 29 CFR 1910.134 | This APF category includes filtering facepieces, and half masks with elastomeric facepieces. | |
| Powered Air-Purifying Respirator (PAPR) | Half mask | 50 | 29 CFR 1910.134 | ||
| Powered Air-Purifying Respirator (PAPR) | Helmet/hood | 25/1,000 | 29 CFR 1910.134 | The employer must have evidence provided by the respirator manufacturer that testing of these respirators demonstrates performance at a level of protection of 1,000 or greater to receive an APF of 1,000. This level of performance can best be demonstrated by performing a WPF or SWPF study or equivalent testing. Absent such testing, all other PAPRs and SARs with helmets/hoods are to be treated as loose-fitting facepiece respirators, and receive an APF of 25. | |
| Powered Air-Purifying Respirator (PAPR) | Loose-fitting facepiece | 25 | 29 CFR 1910.134 | ||
| Self-Contained Breathing Apparatus (SCBA) | Full facepiece | Pressure-demand or other positive-pressure mode (e.g., open/closed circuit) | 10,000 | 29 CFR 1910.134 | |
| Self-Contained Breathing Apparatus (SCBA) | Helmet/hood | Pressure-demand or other positive-pressure mode (e.g., open/closed circuit) | 10,000 | 29 CFR 1910.134 | |
| Supplied-Air Respirator (SAR) or Airline Respirator | Full facepiece | Pressure-demand or other positive-pressure mode | 1,000 | 29 CFR 1910.134 | |
| Supplied-Air Respirator (SAR) or Airline Respirator | Half mask | Pressure-demand or other positive-pressure mode | 50 | 29 CFR 1910.134 | |
| Air-Purifying Respirator | Quarter mask | 5 | 29 CFR 1910.134 | ||
| Supplied-Air Respirator (SAR) | Full facepiece | Continuous flow mode | 1,000 | Title 8, Section 5144 | |
| Supplied-Air Respirator (SAR) | Half mask | Continuous flow mode | 50 | Title 8, Section 5144 | |
| Supplied-Air Respirator (SAR) | Helmet/hood | Continuous flow mode | 25/1,000 | Title 8, Section 5144 | The employer must have evidence provided by the respirator manufacturer that testing of these respirators demonstrates performance at a level of protection of 1,000 or greater to receive an APF of 1,000. This level of performance can best be demonstrated by performing a Workplace Protection Factor (WPF) or simulated WPF study or equivalent testing. Absent such testing, all other PAPRs and SARs with helmets/hoods are to be treated as loose-fitting facepiece respirators, and receive an APF of 25. |
| Supplied-Air Respirator (SAR) | Loose-fitting facepiece | Continuous flow mode | 25 | Title 8, Section 5144 | |
| Self-Contained Breating Apparatus (SCBA) | Full facepiece | Demand mode | 50 | Title 8, Section 5144 | |
| Supplied-Air Respirator (SAR) | Full facepiece | Demand mode | 50 | Title 8, Section 5144 | |
| Self-Contained Breating Apparatus (SCBA) | Half mask | Demand mode | 10 | Title 8, Section 5144 | |
| Supplied-Air Respirator (SAR) | Half mask | Demand mode | 10 | Title 8, Section 5144 | |
| Self-Contained Breating Apparatus (SCBA) | Helmet/hood | Demand mode | 50 | Title 8, Section 5144 | |
| Air-Purifying Respirator | Full facepiece | 50 | Title 8, Section 5144 | ||
| Powered Air-Purifying Respirator (PAPR) | Full facepiece | 1,000 | Title 8, Section 5144 | ||
| Air-Purifying Respirator | Half mask | 10 | Title 8, Section 5144 | This APF category includes filtering facepieces, and half masks with elastomeric facepieces. | |
| Powered Air-Purifying Respirator (PAPR) | Half mask | 50 | Title 8, Section 5144 | ||
| Powered Air-Purifying Respirator (PAPR) | Helmet/hood | 25/1,000 | Title 8, Section 5144 | The employer must have evidence provided by the respirator manufacturer that testing of these respirators demonstrates performance at a level of protection of 1,000 or greater to receive an APF of 1,000. This level of performance can best be demonstrated by performing a Workplace Protection Factor (WPF) or simulated WPF study or equivalent testing. Absent such testing, all other PAPRs and SARs with helmets/hoods are to be treated as loose-fitting facepiece respirators, and receive an APF of 25. | |
| Powered Air-Purifying Respirator (PAPR) | Loose-fitting facepiece | 25 | Title 8, Section 5144 | ||
| Self-Contained Breating Apparatus (SCBA) | Full facepiece | Pressure-demand or other positive-pressure | 10,000 | Title 8, Section 5144 | |
| Supplied-Air Respirator (SAR) | Full facepiece | Pressure-demand or other positive-pressure | 1000 | Title 8, Section 5144 | |
| Supplied-Air Respirator (SAR) | Half mask | Pressure-demand or other positive-pressure | 50 | Title 8, Section 5144 | |
| Self-Contained Breating Apparatus (SCBA) | Helmet/hood | Pressure-demand or other positive-pressure | 10,000 | Title 8, Section 5144 | |
| Air-Purifying Respirator | Quarter mask | 5 | Title 8, Section 5144 |
Where this came from
Every record above links the page it was taken from and quotes the sentence that states it. These are the 2 sources this dataset was assembled from.
- ecfr.govhttps://www.ecfr.gov/current/title-29/subtitle-B/chapter-XVII/part-1910/subpart-I/section-1910.134
- dir.ca.govhttps://www.dir.ca.gov/title8/5144.html
Machine-readable
- data.jsonThe whole dataset — every record with its source URL and source quote.
- Open Knowledge Format bundleOne JSON object per line — every record's frontmatter and quoted span exactly as it is held here, in one fetch.
- How this is made and checkedWhat "verified against source" does and does not mean.