Overview#
A fire service dispatcher receives a call: a freight truck has overturned and the driver reports a chemical smell. The placard reads "1993 - FLAMMABLE LIQUID, N.O.S." The dispatcher needs immediate guidance: how far to isolate, what protective actions to recommend, whether to advise shelter-in-place or evacuation. Looking through a physical guidebook while the caller is on the line is not fast enough when lives are on the line. The Chemical Register gives dispatchers instant access to response guidance for 3,400+ hazardous materials by any identifier they might see on the scene: UN number, CAS number, chemical name, trade name, or even common informal names like "battery acid".
The system is designed for PSAP dispatchers who are not chemists. Zero chemistry expertise is required to get actionable guidance in seconds.
Open Standards#
- UN Recommendations on the Transport of Dangerous Goods (UN TDG): UN numbers (e.g. UN1830) from the UN Model Regulations are the primary transport identifier used to look up hazardous materials and route searches directly to the correct ERG guide.
- DOT/PHMSA Emergency Response Guidebook (ERG): Guide numbers, isolation distances (small spill, large spill, fire), and initial protective-action distances are drawn directly from the ERG published by the US Department of Transportation, which is the field reference that first responders already carry.
- UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS): The nine standardised GHS pictogram codes (GHS01, GHS09), signal words (Danger/Warning), hazard statements (H-codes), and precautionary statements (P-codes) are stored and displayed per the UN GHS Purple Book, sourced via the PubChem PUG-View API.
- NFPA 704 (Standard System for the Identification of the Hazards of Materials for Emergency Response): Health, flammability, and reactivity ratings on the 0, 4 scale, plus special-hazard symbols, are stored and displayed as NFPA 704 Fire Diamond values for rapid fire-service hazard assessment.
- US EPA/NOAA Acute Exposure Guideline Levels (AEGL): The three-tier AEGL-1, AEGL-2, and AEGL-3 thresholds (alongside IDLH values) are stored per chemical and fed directly into the Gaussian plume dispersion model to calculate population-protective evacuation zones.
- CAS Registry Number standard (CAS RN): CAS Registry Numbers, maintained by the Chemical Abstracts Service, are stored as a canonical chemical identifier and accepted as a primary search key alongside UN numbers and common names.
- GeoJSON (RFC 7946): Evacuation-zone plume polygons generated by the dispersion integration service are expressed as GeoJSON Polygon geometries, enabling direct consumption by mapping and geofence services.
Last Reviewed: 2026-02-05 Last Updated: 2026-04-14
Key Features#
Comprehensive Chemical Index#
3,400+ chemicals indexed with complete ERG coverage plus a wide range of industrial chemicals. Search by any identifier including UN number, CAS number, chemical name, trade name, or common names. "Battery acid" finds sulfuric acid. Dispatcher-friendly interface requiring no chemistry background.
ERG Compatibility#
Guide numbers and isolation distances from the DOT/PHMSA Emergency Response Guidebook. Standard response procedures, firefighting guidance, and first aid instructions aligned with the physical guidebook format responders already work with.
Visual Hazard Identification#
Nine GHS pictograms for at-a-glance hazard recognition and NFPA 704 Fire Diamond ratings for standard fire service hazard assessment. Visual indicators support rapid hazard communication to field units, even under time pressure.
Dispersion Model Integration#
AEGL thresholds feed directly into atmospheric plume modelling for evacuation zone calculations during chemical releases. Real-time weather data integration supports context-aware protective action recommendations for any release scenario.
Use Cases#
- Emergency Dispatch: Look up chemicals during emergency calls and relay response guidance, isolation distances, and PPE requirements to responding units without specialist chemistry knowledge
- Field Response: Access chemical safety data on mobile devices during active HAZMAT incidents for on-scene decision support
- Pre-Incident Planning: Research chemical inventories at fixed facilities for emergency response planning and community risk assessment
Integration#
Integrates authoritative chemical data from CAMEO Chemicals (NOAA/EPA), PubChem (NIH), and the Emergency Response Guidebook (DOT/PHMSA). Connects with CAD and dispatch systems, weather services, and atmospheric dispersion modelling tools.