| Condition of use or concentration of airborne EtO (ppm) |
Minimum required respirator | |
| Equal to or less than 50 |
(a) | Full facepiece respirator with EtO approved canister, front- or back-mounted. |
| Equal to or less than 2,000 | (a) | Positive-pressure supplied air respirator, equipped with full facepiece, hood or helmet, or |
| (b) | Continuous-flow supplied air respirator (positive pressure) equipped with hood, helmet or suit. | |
| Concentration above 2,000 or unknown concentration (such as in emergencies) | (a) | Positive-pressure self-contained breathing apparatus (SCBA), equipped with full facepiece, or |
| (b) | Positive-pressure full facepiece supplied air respirator equipped with an auxiliary positive-pressure self-contained breathing apparatus. | |
| Firefighting | (a) | Positive pressure self-contained breathing apparatus equipped with full facepiece. |
| Escape | (a) | Any respirator described above. |
| Note: | Respirators approved for use in higher concentrations are permitted to be used in lower concentrations. |