Self-Contained Breathing Apparatus (SCBA)
SCBAs have a full facepiece with an Assigned Protection Factor (APF) of 10,000. APFs are used to select the appropriate class of respirators that will provide the necessary level of protection.
| Type of Respirator1,2 |
Quater Mask |
Half Mask |
Full Facepiece |
Helmet-Hood | Loose-Fitting Facepiece |
|---|---|---|---|---|---|
| 1. APR | 5 | 103 | 50 | - | - |
| 2. PAPR | - | 50 | 1,000 | 25/1,0004 | 25 |
| 3. SAR/AR * Demand mode * Continuous flow mode * Pressure-demand or other positive pressure mode |
- - - |
10 50 50 |
50 1,000 1,000 |
- 25/1,000 - |
- 25 - |
| 4. SCBA *Demand Mode *Pressure-demand or other positive pressure mode (e.g., open/closed circuit) |
- - |
10 - |
50 10,000 |
50 10,000 |
- - |
Notes:
- 1 Employers may select respirators assigned for use in higher workplace concentrations of a hazardous substance for use at lower concentrations of that substance, or when required respirator use is independent of concentration.
- 2 The assigned protection factors in Table I are only effective when the employer implements a continuing, effective respirator program as required by this section (29 CFR 1910.134), including training, fit testing, maintenance, and use requirements.
- 3 This APF category includes filtering facepieces, and half masks with elastomeric facepieces.
- 4 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.
- 5 These APFs do not apply to respirators used solely for escape. For escape respirators used in association with specific substances covered by 29 CFR 1910 subpart Z, employers must refer to the appropriate substance-specific standards in that subpart. Escape respirators for other IDLH atmospheres are specified by 29 CFR 1910.134(d)(2)(ii).
SCBAs provide the following key features, advantages, and disadvantages:
Key Features
- Provides very pure, dry compressed air to full facepiece mask via a hose.
- Air is exhaled to the environment.
- By law, this type of respirator must be worn whenever entering environments immediately dangerous to life and health (IDLH) or when information is inadequate to rule out IDLH atmosphere.
- Fit testing is required.
Advantages
- Provides highest level of respiratory protection.
- Several different types are available depending on need.
- Offers improved mobility over Supplied-Air Respirators.
- Provides both respiratory and eye protection.
Disadvantages
- They are heavy to wear.
- Limited oxygen supply limits the duration of use.
- Fit testing is required.
- Communication can be difficult.
Knowledge Check Choose the best answer for the question.
2-7. By law, which type of respirator must be worn whenever entering an IDLH environment or when information is inadequate to rule out an IDLH atmosphere?
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