Hazardous Materials and Fire Risk Management
Identifying the hazard
Use the SDS (GHS-aligned, 16 sections) and DOT hazard classes, plus NFPA 704 marking - health, flammability, instability, special - on a 0–4 scale. Physical properties decide behavior: flash point and boiling point define liquid class (NFPA 30 Class IA: FP < 73 °F and BP < 100 °F; IB: FP < 73 °F and BP ≥ 100 °F; IC: FP ≥ 73 °F and < 100 °F; II and IIIA/IIIB above that). Vapor density tells you where vapors travel - heavier-than-air vapors migrate along floors, into pits, and to distant ignition sources. Flammable range (LFL/UEL) explains inerting and purging.
Special hazards
Water-reactive and pyrophoric materials reject water-based suppression. Oxidizers and organic peroxides can decompose without oxygen. Liquefied flammable gases under flame impingement can BLEVE. Static ignition of low-conductivity liquids requires bonding and grounding plus controlled flow velocity.
Storage and handling
Separate incompatible materials, control ignition sources, ventilate, contain spills, and limit quantities per NFPA 30 and local fire code. Cabinets and inside storage have aggregate limits; containers must be approved and closed.
Risk management
Move through hazard identification, risk estimation, control selection (hierarchy: eliminate, substitute, engineer, administrate, PPE), and monitoring. Techniques include HAZOP, fault trees, fire risk assessment, ALARP, and business continuity/property protection standards for emergency management.
Worked example
A liquid with a flash point of 0 °F and boiling point of 133 °F: FP < 73 °F and BP ≥ 100 °F, so it is Class IB - storage, container, and ventilation requirements follow from that classification, not from the chemical name.
Traps
Confusing specific gravity (liquid vs water) with vapor density (vapor vs air); forgetting that combustible liquids can be heated above flash point; assuming water is always acceptable; ignoring water-reactive metals and oxidizer decomposition.