This STP describes the Determination of CBRN Base Gases (Ammonia) Service Life Test; Air-Purifying Escape Respirators test in sufficient detail that a person knowledgeable in the appropriate technical field can select equipment with the necessary resolution, conduct the test and determine whether or not the product passes the test.
This document defines the procedure (CET‑APRS‑STP‑CBRN‑0407) used by NIOSH to evaluate the service life of air‑purifying escape respirators when exposed to ammonia base gases. It specifies the equipment, test conditions, and acceptance criteria required to meet 42 CFR Part 84 certification standards.
The procedure outlines required test equipment (e.g., Miller Nelson Model 401 flow‑temperature‑humidity system, EdgeTech Dew Prime II hygrometer, Air‑Sentry IMS ammonia analyzer), safety precautions, calibration requirements, and detailed steps for setting up the test chamber, establishing ammonia concentrations, recording resistance measurements, and determining pass/fail outcomes.
| Miller Nelson Model 401 flow capacity | 20 to 200 L/min ±2% |
|---|---|
| EdgeTech Dew Prime II hygrometer temperature range | -50 °C to 130 °C ±0.2 °C |
| Air‑Sentry IMS ammonia analyzer range (Model 10R‑NH3‑4000M) | 1 to 3000 ppm ±0.1 % FS |