Hazmat Specialist cheat sheet

Seven clues to hazard identification: occupancy, container shape, markings/labels, placards, shipping papers, sensory clues (sight, sound, odor), and human behavior (victims, responders).

NFPA 704 quadrant order: blue = health, red = flammability, yellow = instability, white = special hazards (OX, W with slash, SA).

DOT hazard classes 1-9: explosives, gases, flammable/combustible liquids, flammable solids, oxidizers/organic peroxides, toxic/infectious, radioactive, corrosive, miscellaneous.

UN hazard-identification number (Kemler) first digit = hazard type (2 gas, 3 liquid, 4 solid, 5 oxidizing, 6 toxic, 7 radioactive, 8 corrosive); doubled digit = increased intensity.

GHS pictograms: flame, flame over circle, exploding bomb, gas cylinder, corrosion, skull and crossbones, exclamation mark, health hazard, environment.

Recognition precedes identification: establish what is present and its state before attempting name-level identification.

Container failure indicators: bulging, frost/ice formation, discoloration, vapor clouds, puddling, hissing, and rising water fog behavior.

Physical state drives behavior: gases disperse and are inhalation hazards; liquids pool and generate vapor; solids may release dust or sublimate.

Vapor density >1 sinks and collects in low areas; <1 rises. Air = 1.0.

Vapor pressure in mmHg or kPa indicates volatility; higher vapor pressure = greater vapor generation and inhalation risk.

Specific gravity >1 sinks in water; <1 floats. Water-soluble materials dissolve and spread in waterways.

Flash point = lowest temperature at which a liquid gives off ignitable vapor; fire point is slightly above it.

Flammable range (LEL-UEL): concentrations below LEL are too lean, above UEL too rich to ignite.

Boiling point below ambient means a liquid becomes a gas on release; a boiling liquid expanding vapor explosion (BLEVE) requires a confined liquid heated above its boiling point.

IDLH = concentration immediately dangerous to life or health; used to select respirator class and set entry limits.

Water reactivity: alkali metals, metal hydrides, and some chlorosilanes react violently; never apply water without confirming compatibility.

ICS is built on common terminology, modular organization, management by objectives, an incident action plan, and span of control of 3-7 (optimal 5).

Command is established by the first-arriving unit; command transfers face-to-face with a briefing and is announced on the tactical channel.

Hazmat Group/Sector reports to Operations; typical hazmat assignments are entry, backup, decon, research, and safety.

Unified Command is used when multiple agencies with jurisdiction (fire, law enforcement, EMS, public health) share incident authority.

National Incident Management System (NIMS) and the Incident Command System are the U.S. standard under the National Response Framework.

Incident Action Plan objectives are written in SMART form (specific, measurable, achievable, relevant, time-bound).

Levels of response: awareness (recognize/isolate/notify), operations (defensive), technician (offensive entry), specialist (technical support).

Documentation includes the tactical worksheet, personnel accountability, exposure records, and the after-action review.

Initial isolation default for unknown: at least 50 m (150 ft) in all directions; expand downwind and for fire involvement.

ERGO 2024 isolation distances supersede earlier guides; always use the current edition and the specific guide number on the orange-bordered pages.

Establish hot (exclusion), warm (contamination reduction), and cold (support) zones; the decon corridor crosses the warm zone.

Command post, staging, and rehab stay in the cold zone, upwind and uphill.

Control zones are marked with barrier tape, traffic cones, and a single entry/exit control point staffed by a control officer.

Personnel accountability: everyone entering the hot zone is logged by name, SCBA pressure/time, and task.

Specialists (industrial hygienists, chemists, toxicologists, radiation and explosives technicians) provide data and recommendations but do not assume command unless assigned.

Public protective actions: evacuate, shelter-in-place, or protect-in-place; choose based on time, plume, and population.

Risk = probability of an adverse outcome x severity of that outcome; risk assessment compares hazard with exposure and safeguards.

Hazard is the inherent property of a material; risk is the chance it will harm someone under current conditions.

ALARA (as low as reasonably achievable) governs radiological and carcinogen exposure decisions.

Acute vs. chronic: acute effects appear immediately (corrosive burns, asphyxia); chronic effects appear after repeated or delayed exposure (hepatotoxins, carcinogens).

Toxicological terms: TLV-TWA (8-hour), TLV-STEL (15-minute), TLV-C (ceiling, never exceed), PEL (OSHA), REL (NIOSH).

Exposure pathways: inhalation, dermal absorption, ingestion, and injection (puncture). Dermal exposure is often underestimated.

Estimate downwind impact from plume behavior, wind speed/direction, stability class, and terrain; dense gases hug low ground.

Risk-benefit analysis drives the decision to enter: no property is worth a life; defensive operations are the default until risk is justified.

Detection sequence: detect, then classify, then identify, then quantify. Simple instruments first, then more specific tools.

Four-gas meter typically measures oxygen (19.5-23.5% normal), LEL (% of lower explosive limit), carbon monoxide, and hydrogen sulfide.

Combustible gas indicators are calibrated to a reference gas (often methane or hexane); correct readings for other vapors using response factors.

Photoionization detectors (PID) respond to volatile organic compounds; lamp energy (10.6 eV typical) determines which compounds ionize.

Colorimetric tubes are compound-specific and semi-quantitative; pump stroke count and tube lot matter.

Flame ionization detectors (FID) respond to hydrocarbons; they do not detect non-hydrocarbon gases.

Radiation instruments: survey meters (mR/hr or µSv/hr) for dose rate; contamination probes (cpm) for surface contamination; alpha detection requires a probe close to the surface.

Corrosivity: pH paper or meters indicate acid/base strength; readings are qualitative and instrument-specific.

Level A: fully encapsulating suit with SCBA - highest respiratory and skin protection; required for unknown or highly toxic/corrosive atmospheres.

Level B: SCBA with chemical-resistant clothing - highest respiratory protection, lesser skin protection.

Level C: air-purifying respirator with chemical-resistant clothing - only when atmosphere is known, IDLH not exceeded, and oxygen is adequate.

Level D: work uniform, no respiratory protection - support functions only, never for hazmat entry.

OSHA 29 CFR 1910.120 requires a written respiratory protection program, fit testing, medical evaluation, and annual training.

SCBA rated 30, 45, or 60 minutes; actual working time is reduced by stress and exertion (often 50-60% of rated time).

Suit selection considers permeation (molecular breakthrough), degradation (material damage), and penetration (physical leaks).

Decontaminate and inspect PPE after use; document suit material, model, and exposure duration.

Decon methods: gross (scraping, wiping), primary (gross wash with detergent/water), secondary (rinse), and tertiary (final rinse).

Decon corridor: tool drop, gross decon, primary decon, secondary decon, doffing, medical monitoring, and rehabilitation.

Decon solution choice depends on the contaminant: soap and water for most; bleach for biological; never mix incompatible agents.

Decon of ambulatory vs. non-ambulatory patients differs; non-ambulatory requires a litter and a dedicated team.

Runoff must be contained and disposed of per environmental regulations; never allow it to enter storm drains.

Technical decontamination is for responders and equipment; emergency decontamination is a rapid, improvised wash for victims.

Decon effectiveness is verified by monitoring (PID, pH, radiation probe) before doffing and release.

Doffing order: remove outer gloves, suit, boots, inner gloves last; avoid self-contamination.

Product control = controlling the release at or near the source: absorption, adsorption, diking, diverting, and damming.

Absorption uses materials that soak up liquid (vermiculite, sand, pads); adsorption uses materials that adhere to the surface (activated carbon).

Diking contains liquid on a surface; damming blocks a waterway; diversion redirects flow away from sensitive areas.

Overpacking: place a damaged container inside a larger compatible container with absorbent.

Plugging and patching: use compatible plugs, patches, and sealants; never patch a container that is bulging or under pressure without expert guidance.

Vapor suppression: water fog, foam, and covers reduce vapor generation; foam blankets flammable liquid pools.

Flammable liquid control: use AFFF or alcohol-resistant foam (AR-AFFF) on polar solvents; water alone spreads many flammable liquids.

Containment of gases: use water fog to knock down water-soluble vapors; never use water on water-reactive gases.

Confinement = limiting the spread of a released material; containment = keeping it in a defined area.

Structural confinement: close doors, windows, HVAC, and use the building envelope to limit spread.

Diking and damming: earthen berms, sandbags, and commercial booms control liquid flow.

Diversion: use trenches, pipes, or barriers to move product to a safe collection area.

Vapor confinement: use vapor-suppressing foam, water fog, or temporary enclosures.

Containment of water-reactive materials: exclude water and use dry inert absorbents (sand, dry earth).

Containment of cryogenic liquids: contain in a diked area and allow controlled boil-off; never seal a container that can build pressure.

Monitor containment boundaries with appropriate instruments; do not assume containment is complete.

Mitigation options: absorption, adsorption, diking, diversion, dilution, dispersion, and neutralization.

Neutralization: acid + base -> salt + water; always add acid to water, never water to acid, and control heat generation.

Oxidation: sodium hypochlorite or hydrogen peroxide can destroy some contaminants; byproducts must be evaluated.

Solidification/stabilization: mix with cement, fly ash, or proprietary agents to immobilize waste.

Ventilation and flaring are used in industrial settings; never vent a flammable gas into an ignition source.

Thermal destruction (incineration) and biological treatment are large-scale options; field use is limited.

Dilution is not the solution to pollution: dilution may reduce concentration but spreads the material.

Mitigation selection considers compatibility, reaction products, heat, gas generation, and disposal pathway.

Chlorine and ammonia leaks: use compatible kits (A, B, C) matched to the container type; never use a kit on a container that is bulging or on fire.

Plugging: wooden plugs, rubber plugs, and magnetic patches seal small holes; the plug must be compatible with the product.

Patching: use a compatible patch and clamp for pipe and drum punctures; confirm no pressure buildup before applying.

Overpacking a drum: place the damaged drum inside a salvage drum with absorbent; do not overpack a leaking cylinder without expert guidance.

Pipe repair: use clamps, sleeves, and pipe-repair kits; isolate and depressurize where possible.

Cylinder leaks: valve leaks may be controlled by tightening the packing nut or using a valve cap; never attempt to repair a cylinder that is bulging or on fire.

Flange and gasket leaks: use compatible gasket material and torque to specification.

After any repair, monitor the repair point and the container for pressure, temperature, and leak recurrence.

CBRNE = chemical, biological, radiological, nuclear, and explosive agents.

Chemical agents: nerve (sarin, VX - cholinesterase inhibitors), blister (mustard, lewisite), blood (cyanide), and choking (phosgene, chlorine).

Biological agents: anthrax (Bacillus anthracis), smallpox (variola), plague (Yersinia pestis), botulinum toxin, and ricin.

Radiological dispersal device (dirty bomb) spreads radioactive material; it is primarily a contamination and psychological event.

Explosive attack indicators: secondary devices targeting responders, unusual timing, and remote detonation.

Scene indicators of a chemical release: unexplained casualties with similar symptoms, dead animals/birds, unusual odors, and unexplained vapor or mist.

Nerve agent antidote: atropine and pralidoxime (2-PAM); use autoinjectors per protocol.

Notification: FBI, state health department, and local emergency management; preserve the scene for law enforcement evidence.

OSHA 29 CFR 1910.120 (HAZWOPER) covers hazardous waste operations and emergency response; 1910.120(q) covers emergency response.

HAZWOPER training: awareness level, operations level, technician level, specialist level, and incident commander.

NFPA 470 (2022) combines NFPA 472 and 473; it defines competencies for hazardous materials/weapons of mass destruction responders.

NFPA 1991 covers vapor-protective suits; NFPA 1992 covers liquid-splash suits; NFPA 1994 covers CBRN protective ensembles.

DOT 49 CFR 172 covers hazard communication, placarding, and shipping papers; 49 CFR 173 covers packaging.

EPA 40 CFR 355 (SARA Title III) requires notification of releases of extremely hazardous substances; CERCLA requires reporting of hazardous substance releases.

Medical surveillance is required for HAZWOPER employees; exposure records are retained for 30 years.

Safety officer authority: can stop operations when conditions are unsafe; the safety officer reports to the incident commander.

Life threats first: airway, breathing, circulation, then decontamination; do not delay critical interventions for decon.

Decon before transport: remove contaminated clothing (removes a large fraction of contaminant) and wash with soap and water.

Nerve agent exposure: atropine for muscarinic effects (bradycardia, secretions, bronchospasm) and pralidoxime (2-PAM) for nicotinic effects; give per protocol.

Cyanide exposure: hydroxocobalamin or sodium thiosulfate; support oxygenation.

Corrosive exposure: irrigate eyes and skin with copious water for at least 15-20 minutes; do not neutralize on the skin.

Inhalation injury: remove from exposure, give oxygen, and monitor for delayed pulmonary edema (phosgene, nitrogen oxides).

Contaminated patients should be treated in a designated decon area, not in the ambulance or emergency department.

Document exposure, decon, and treatment; notify the receiving hospital of the contaminant and decon status.