Hazmat Technician cheat sheet

UN hazard classes run 1 through 9: 1 explosives, 2 gases, 3 flammable liquids, 4 flammable solids, 5 oxidizers/organic peroxides, 6 toxic/infectious, 7 radioactive, 8 corrosive, 9 miscellaneous.

ERG 2024 guide pages: yellow-bordered pages list ID numbers numerically, blue-bordered pages list materials alphabetically, orange guide pages give isolation and protective action distances.

NFPA 704 quadrant order is health (blue, left), flammability (red, top), instability (yellow, right), special hazards (white, bottom).

Placard colors: red = flammable, green = nonflammable gas, yellow = oxidizer, white = poison or corrosive, blue = dangerous when wet, orange = explosive.

DOT hazard class 6.1 covers toxic solids/liquids; 6.2 covers infectious substances; 2.3 covers toxic gases with LC50 <= 5000 ppm.

Pipeline markers show the commodity name, operator, and emergency phone, but do not show quantity, pressure, or direction of flow.

Cameo chemicals provide reactivity, protective clothing, and evacuation guidance keyed to a specific substance pair.

A substance that is both flammable and toxic requires the flammability guide for firefighting and the toxicity guide for PPE and isolation decisions.

Container shape cues: DOT-4BA cylinders = flammable gas; MC-331 = pressurized flammable gas; MC-307 = corrosive liquid; non-pressure tank cars = flammable liquid.

Vapor density > 1 means the gas is heavier than air and collects in low areas; < 1 means it rises and disperses upward.

Specific gravity > 1 means the liquid sinks in water; < 1 means it floats and spreads on the water surface.

Vapor pressure rises with temperature; higher vapor pressure means a greater tendency to produce vapor and a higher inhalation hazard.

Flammable range is bounded by the LEL and UEL; below LEL the mixture is too lean, above UEL too rich, to ignite.

Flash point is the lowest temperature at which a liquid gives off enough vapor to ignite; a lower flash point means greater fire hazard.

IDLH is the maximum concentration from which a worker could escape within 30 minutes without irreversible health effects or escape-impairing symptoms.

Water solubility drives plume behavior: highly soluble gases (ammonia) hug the ground and water, low-solubility gases (chlorine) travel farther before dissolving.

Boiling point below ambient temperature means the material is a gas at room temperature and will form a vapor cloud on release.

Corrosives are classified by pH extremes; strong acids and bases both cause tissue damage, and neutralization reactions are exothermic.

OSHA 29 CFR 1910.120 (HAZWOPER) sets training, medical surveillance, PPE, and emergency response requirements for hazardous waste operations.

HAZWOPER levels: Level A = fully encapsulating suit with SCBA; Level B = SCBA with chemical-resistant clothing; Level C = air-purifying respirator with chemical-resistant clothing; Level D = work uniform.

The Incident Command System is mandated by NIMS; the Incident Commander holds overall authority and delegates safety, operations, planning, logistics, and finance.

CERCLA (Superfund) authorizes federal response and cost recovery for releases; EPCRA requires community right-to-know reporting and planning.

DOT 49 CFR 172 covers hazard communication: shipping papers, placards, labels, and emergency response information.

The Emergency Planning and Community Right-to-Know Act requires Local Emergency Planning Committees and facility reporting of hazardous chemicals.

NFPA 472/1072 define hazardous materials responder competencies and the technician-level knowledge and skills.

A site safety plan documents hazards, PPE, decontamination, medical monitoring, and emergency procedures before entry.

Post-incident critique and termination reporting are required elements of a documented response under HAZWOPER.

Level A suits are fully encapsulating and vapor-protective; Level B offers splash protection with SCBA but is not vapor-tight.

Chemical protective clothing selection depends on permeation, degradation, and penetration data for the specific chemical; no single suit resists all chemicals.

SCBA provides the highest respiratory protection; air-purifying respirators are prohibited in IDLH, oxygen-deficient, or unknown atmospheres.

Decontamination sequence: gross decon, secondary decon, then removal of PPE; do not let contaminated runoff spread to clean areas.

Decon solutions: soap and water for most chemicals; dilute bleach for biological agents; never mix bleach with ammonia or acids.

Heat stress is a major risk in encapsulated suits; work-rest cycles and medical monitoring reduce heat casualty risk.

Do not use air-purifying respirators for substances with poor warning properties or that are absorbed through the skin.

Decontamination corridor layout: hot zone, warm zone with decon line, cold zone; flow is one-way from hot to cold.

PPE donning order: suit, boots, gloves taped, then SCBA, then hood and facepiece; doffing reverses the order with decon between steps.

Combustible gas indicators read percent LEL; calibrate with the target gas or a correction factor, and remember they do not measure oxygen or toxicity.

Oxygen meters read percent O2; normal is 20.9%, and atmospheres below 19.5% or above 23.5% are unsafe.

Colorimetric tubes give a specific reading for a named chemical; results depend on pump strokes and tube shelf life.

Photoionization detectors read total volatile organics but cannot identify a specific compound without library matching.

Flame ionization detectors respond to hydrocarbons; they do not detect non-carbon gases such as ammonia or hydrogen sulfide.

PID lamps: 10.2 eV detects most aromatics; 11.7 eV detects many aliphatics; lower eV lamps detect fewer compounds.

Sampling strategy: background reading, then perimeter, then source; document location, time, instrument, and reading.

Air monitoring instruments must be calibrated and bump-tested before use; log calibration and results.

Detector tubes and PIDs give real-time screening; laboratory analysis is required for definitive identification and exposure documentation.

Confinement keeps the material within the incident area; containment stops the release at its source.

Diking, damming, and diversion keep liquid spills from reaching drains and waterways; absorbents and booms contain on water.

For a leaking cylinder, position the leak upward if possible to release vapor rather than liquid, and use a compatible patch or kit.

Overpack drums are used for damaged containers; the overpack must be compatible with the material and labeled with the original hazard information.

Do not use water on water-reactive materials (e.g., sodium, calcium carbide); use dry chemical or appropriate agent.

Flammable liquid fires: use foam; water fog may be used to cool exposures but not to extinguish the pool fire directly.

Plug, patch, and clamp kits are matched to container type: drum kits for drums, cylinder kits for gas cylinders, pipe kits for piping.

Vapor suppression: foam blanket, water fog, or vapor-suppressing agents reduce downwind concentrations.

Containment of a gas release is generally not possible; control is by isolation, ventilation, and dispersal rather than physical capture.

Establish command, isolate the area, and identify hazards before committing resources; the first-arriving officer establishes command until relieved.

Isolation distances: initial isolation for a small spill is often 50 m (150 ft); for a large spill, 100 m (330 ft) or more, per ERG guidance.

Defensive operations keep responders outside the hot zone; offensive operations require trained technicians in appropriate PPE.

The Incident Action Plan documents objectives, tactics, resources, and safety for each operational period.

Unified command brings together agencies with jurisdiction; each retains authority over its own resources.

Span of control is typically 3 to 7 subordinates per supervisor, with 5 as the target.

The safety officer has authority to halt operations that present imminent danger, independent of the IC.

Evacuation versus shelter-in-place: shelter-in-place is preferred for short-duration, fast-moving vapor clouds; evacuation for longer-duration or large-area events.

The planning section develops the IAP and tracks resources; the logistics section orders and supplies resources.

CBRNE categories: chemical, biological, radiological, nuclear, and explosive; each has distinct detection and PPE requirements.

Chemical agents: nerve agents (sarin, VX) inhibit acetylcholinesterase; blister agents (mustard) cause delayed skin injury; blood agents (cyanide) block cellular respiration.

Nerve agent antidote: atropine for muscarinic effects and pralidoxime (2-PAM) for reactivation; administer per medical direction.

Cyanide antidote: hydroxocobalamin or sodium thiosulfate; support oxygenation.

Biological agents of concern include anthrax, smallpox, plague, and botulinum toxin; symptoms often delayed and presentation may be epidemiologic.

Radiological detection uses survey meters and dosimeters; time, distance, and shielding are the primary protection principles.

Improvised explosive devices: establish an exclusion zone, look for secondary devices, and use robots or remote tools where possible.

Illicit drug labs present flammable solvents, toxic gases, and explosion hazards; do not enter without PPE and law enforcement coordination.

Suspicious packages: isolate, do not handle, and notify appropriate authorities; treat as a potential CBRNE device until proven otherwise.

Rescue versus recovery: rescue is a viable victim with a chance of survival; recovery is retrieval of a deceased victim, which is a slower, deliberate operation.

Victims must be decontaminated before transport to prevent secondary contamination of hospitals and EMS.

Triage in a contaminated scene: prioritize life threats, but decontaminate before moving into the cold zone.

Ambulatory victims can self-decon with soap and water; non-ambulatory victims require assisted decon by trained responders in PPE.

Do not remove victim clothing in the hot zone without containment; clothing removal reduces contamination substantially.

Gross decontamination removes the majority of contamination; secondary decon refines it; document decon for each victim.

Medical monitoring of responders includes vital signs, symptoms, and exposure history; heat stress and chemical exposure are tracked.

Victim decon runoff must be contained and disposed of per regulations; do not let it enter storm drains.

Communicate decontamination status to receiving hospitals so they can prepare and avoid secondary exposure.

Product control includes confinement, containment, recovery, and disposal of the released material.

Recovery methods: absorbents, vacuum trucks, skimmers, and neutralization, chosen for compatibility with the material.

Waste classification and disposal follow RCRA; hazardous waste must be manifested and transported by permitted carriers.

Termination activities: debrief, critique, documentation, equipment decontamination and restocking, and after-action reporting.

The after-action report captures timeline, decisions, resource use, and lessons learned for future responses.

Do not return to service until PPE and equipment are decontaminated, inspected, and restocked.

Cost recovery and documentation of response expenses support reimbursement and regulatory reporting.

Confirm the release is stopped and the area is safe before demobilization; verify with monitoring.

Debrief responders for exposure symptoms and complete medical surveillance documentation.