NIOSH Pocket Guide — NIOSH Pocket Guide to Chemical Hazards
NIOSH Publication; CDC · Occupational Exposure Reference
At a Glance
A chemical exposure reference used for air monitoring, IDLH checks, PPE discussion, physical properties, symptoms, routes of exposure, and sustained hazmat operations.
What This Means for Firefighters
The NIOSH Pocket Guide is where hazmat technicians and safety officers often turn after the first ERG-driven decisions are made. It does not replace the ERG during the initial phase of a transportation incident. Instead, it helps the incident move into a more technical phase: air monitoring interpretation, exposure limit comparison, respiratory protection discussion, symptoms, target organs, routes of exposure, physical properties, incompatibilities, and first aid information.
NIOSH describes the guide as general industrial hygiene information for hundreds of chemicals and substance groupings. For fire departments, that means it is useful when the team has a known product and needs to compare meter readings with PEL, REL, IDLH, or other exposure information. It also helps explain why a substance behaves the way it does: vapor density, boiling point, flash point, solubility, incompatibilities, and routes of exposure can all change zone control and PPE decisions.
Fireground Impact
- Use the NIOSH Pocket Guide when the product is known and the incident has moved beyond basic ERG lookup into air monitoring and exposure evaluation.
- IDLH values can help validate respiratory protection decisions, especially when choosing between SCBA, supplied air, or lower levels of respiratory protection after monitoring.
- Physical property data can help predict vapor travel, runoff behavior, confined-space accumulation, and incompatibility concerns.
Department Impact
- Train hazmat technicians to read PEL, REL, TLV, IDLH, vapor density, flash point, symptoms, target organs, and incompatibility fields correctly.
- Pair NIOSH data with meter limitations. A number is only useful if the meter is appropriate, calibrated, and interpreted against the right substance.
- Use the guide during post-incident review to check whether monitoring, PPE, decon, and medical surveillance decisions matched the actual chemical.
Key Requirements
- Chemical names, synonyms, CAS/RTECS data, DOT ID and guide numbers where listed
- NIOSH RELs, OSHA PELs, and IDLH values
- Physical description and chemical properties
- Measurement methods, PPE, respirator recommendations, incompatibilities, symptoms, target organs, and first aid information
- Use as a reference, not a complete substitute for SDS, ERG, monitoring strategy, or medical direction
Who Must Comply
- Hazmat technicians performing air monitoring and product research
- Incident safety officers and hazmat group supervisors
- Industrial hygienists supporting emergency operations
- Training officers teaching sustained hazmat operations
Records to Keep
- Air monitoring logs with instrument type, calibration status, location, time, and readings
- Product identity confirmation from SDS, shipping papers, facility representative, or container label
- PPE and respiratory protection decisions tied to monitoring results and reference values
Source Notes
- CDC/NIOSH states that the Pocket Guide gives general industrial hygiene information for hundreds of workplace chemicals and chemical groups.
- NIOSH lists data such as RELs, OSHA PELs, IDLH values, physical properties, measurement methods, PPE, respirator selection, incompatibilities, exposure routes, symptoms, target organs, and first aid information.
Compliance Checklist
Practical steps for working toward NIOSH Pocket Guide compliance. General guidance — verify against the official source for your jurisdiction.
- Confirm the exact chemical before applying exposure limits or IDLH values
- Compare meter readings to the correct units and substance-specific limits
- Use NIOSH data with SDS, ERG, facility information, and command objectives
- Document monitoring locations and times so readings can be reconstructed later
- Reassess respiratory protection when conditions, ventilation, product identity, or monitoring data change
Common Misunderstandings
- PEL, REL, TLV, and IDLH are not interchangeable. They come from different sources and answer different exposure questions.
- A low meter reading does not prove the atmosphere is safe if the instrument does not detect the chemical involved.
- The NIOSH Pocket Guide is not the first book to use for initial transportation isolation distances. That is the ERG's role.
Official Sources
Always confirm current text and applicability with the official source — this page is a training summary, not legal advice.