Free Hazmat Awareness Exam Flashcards

Class 1 - Explosives. Orange is reserved exclusively for the explosives class (Divisions 1.1-1.6); no other DOT hazard class uses an all-orange background.

Class 2.1 - Flammable gas. Red is the flammability color; the number 2 distinguishes it from Class 3 (flammable liquid), which is also red but numbered 3.

Class 2.2 is green; Class 2.3 is white with a skull-and-crossbones symbol. Both are gases (number 2), but color and symbol separate 'safe to be near' from 'poisonous.'

4.1 = flammable solid (red/white stripes), 4.2 = spontaneously combustible (white over red), 4.3 = dangerous when wet (blue). All three are solids, but the ignition trigger differs.

A fully yellow placard is Class 5.1 (Oxidizer) - a substance that intensifies combustion of other materials, even if not itself flammable. Class 5.2 (Organic Peroxide) is in the same Hazard Class 5 but uses a red-over-yellow placard (red top half, yellow bottom half, per 49 CFR 172.519), not an all-yellow one.

Class 6.1 (Toxic/Poison) shows a skull and crossbones on white; Class 6.2 (Infectious Substance) shows biohazard-style crescents on white. Both are white and numbered 6, so the symbol - not the color - is the tell.

Yellow top over white bottom, with the black trefoil radiation symbol. It is the only DOT class placard that combines yellow and white.

Class 8 - Corrosive. The white/black split and pouring-liquid graphic distinguish it from Class 9, which uses black-and-white vertical stripes instead.

Blue = health hazard, Red = flammability, Yellow = instability/reactivity, White = special hazard symbol (e.g., OX for oxidizer, W with a slash for water-reactive, SA for simple asphyxiant). Each colored quadrant is rated 0 (no hazard) to 4 (severe/extreme).

The material is water-reactive - do not apply water to control it. Confusing this with the plain OX (oxidizer) or SA (simple asphyxiant) symbols could lead a responder to use the wrong, and dangerous, extinguishing approach.

Rail uses a waybill or consist; highway shipments use a bill of lading. Air shipments use an air waybill and water shipments use a dangerous cargo manifest - the transport mode determines the document name.

Section 5 covers firefighting measures; Section 4 covers first aid measures. Section 2 (hazard identification) and Section 6 (accidental release measures) round out the highest-value sections for a quick field reference.

Upwind avoids inhaling airborne vapor, uphill avoids pooling of heavier-than-air gases and contaminated runoff, and upstream avoids waterborne contamination. Together they form the standard Awareness-level positioning rule.

Time (limit exposure duration), distance (maximize separation from the hazard), and shielding (use a barrier such as a vehicle or structure). This triad is the core self-protection concept for Awareness-level responders, who carry no chemical PPE.

Isolating establishes a perimeter around the hazard to keep bystanders out; denying entry is the active enforcement of that perimeter (barrier tape, personnel, signage) so no one crosses in. Both are core Awareness-level actions.

The cold zone - used for command, staging, and support functions. The hot zone (contamination area) and warm zone (decon corridor) require Operations- or Technician-level training and PPE.

Shelter-in-place. Evacuation is preferred for prolonged or persistent releases with clear escape routes; shelter-in-place fits fast-clearing plumes or immobile populations.

Close and seal HVAC systems, windows, and doors to limit infiltration of outside air. For a heavier-than-air vapor, occupants should then move to an upper interior room, away from ground-level infiltration points.

Move crosswind first, then work toward upwind of the release - moving straight upwind back through the plume can increase exposure. This differs from the standard staging rule of simply approaching upwind from the start.

Notify dispatch and the emergency response system, and request a hazmat team. Awareness responders recognize and report - they do not wait to attempt mitigation themselves.

The lowest temperature at which a liquid gives off enough vapor to ignite. A low flash point (below ambient temperature) means the material can ignite easily under normal conditions - a key flammability indicator.

It is heavier than air and will sink into low areas - basements, ditches, storm drains - creating pooling hazards away from the release point. A vapor density less than 1 means the gas rises and disperses instead.

Vapor density compares a gas's weight to air (greater than 1 sinks, less than 1 rises); specific gravity compares a liquid's weight to water (greater than 1 sinks in water, less than 1 floats). Confusing the two is a common exam trap.

Boiling Liquid Expanding Vapor Explosion - a pressurized vessel ruptures from heat exposure (often fire impinging on a tank above the liquid line), releasing a fireball and flying debris with little warning. It is a leading hazard associated with propane and other flammable-gas cargo tanks.

Inhalation - chemicals absorbed through the lungs reach the bloodstream almost immediately. This is why respiratory protection and staging upwind are top priorities at a hazmat scene.

Hydrogen cyanide. Odor is an unreliable primary detection method since it requires exposure to detect, but recognizing known odor signatures supports hazard recognition from a safe distance.

It indicates hydrogen sulfide (H2S), but H2S causes olfactory fatigue - the sense of smell is quickly overwhelmed and stops detecting the gas even as concentration rises to lethal levels. Responders should never rely on odor alone to judge safety.

A strong acid (pH 0-2), classified as a DOT Class 8 corrosive. Strong bases fall at the opposite end of the scale (pH 12-14); both extremes destroy tissue and require corrosive-rated PPE, not turnout gear.

The yellow section - the numeric index of UN/NA ID numbers, cross-referencing each to a guide number. If you only have the chemical name, use the blue (alphabetical) section instead.

The blue section - the alphabetical index of chemical and shipping names. It points to the same numbered orange guide page that the yellow (numeric) section would.

The orange section - the numbered guide pages themselves, which list potential hazards, public safety actions, and emergency response recommendations for that guide number.

The green section. It provides Table 1 (initial isolation and protective action distances, including chemical-warfare agents), Table 2 (water-reactive materials that produce TIH gases), and Table 3 (large-spill distances for six common TIH/PIH gases carried in large tanks or rail cars).

CHEMTREC (1-800-424-9300) is an industry-run hotline providing chemical product and technical information. The NRC (1-800-424-8802) is the federal, Coast Guard-run hotline for mandatory reporting of oil and chemical spills. One informs; the other is a legal reporting requirement.

ERG Guide 111 (Mixed Load/Unidentified Cargo) - the first guide in the orange section, used when the material cannot be identified by placard, shipping papers, or ID number. It provides generic protective actions until the substance is positively identified.

An annual hazardous chemical inventory report filed by facilities that store chemicals above threshold quantities, submitted to the Local Emergency Planning Committee (LEPC) and State Emergency Response Commission (SERC) by March 1 each year.

Flammable liquids such as gasoline - the MC-306 (older) or DOT-406 (current) cargo tank. The oval shape and thin shell are the visual identifiers.

A round, heavily built cross-section rather than an oval one - the MC-331 pressure cargo tank. Its rounded profile reflects the higher internal pressure of liquefied gases compared to the thin-walled MC-306/DOT-406.

A double-walled, heavily insulated jacket that keeps refrigerated liquids such as liquid oxygen or nitrogen at extremely low temperatures. It looks visually bulkier than a standard cargo tank because of the insulation layer.

It is likely a DOT-412 corrosives tank. The external reinforcing rings add structural strength against the corrosive, often pressurized contents inside.

They are pressure or general-service tank cars, commonly used for gases and pressurized or flammable liquids. DOT-111's vulnerability in derailment fires (historically used for crude oil and ethanol) drove the newer DOT-117 design.

As a stronger, thicker-shelled replacement for older DOT-111 cars used to haul crude oil and ethanol, following derailment fires that exposed the DOT-111's vulnerability to puncture and rupture.

Roughly 119 gallons (liquid) or 882 pounds (solid) under DOT rules - packages at or below that size are non-bulk, while cargo tanks, rail tank cars, and intermodal tanks above it are bulk containers.

Recognize the hazard, protect self and others, notify the emergency response system, and secure the area (isolate and deny entry). Awareness responders do not mitigate the hazard themselves.

Diking, damming, and diverting is defensive product control - an Operations-level skill; plugging and patching is offensive product control - a Technician-level skill. Awareness training and equipment cover neither; the role stops at isolation and notification.

No - decontamination is an Operations-level (or higher) task requiring specific training and equipment. Awareness responders may assist with gross self-rescue, but they do not run a decon line.

They lack both the specialized training and the chemical-protective equipment required for hot-zone (exclusion zone) entry. Entering without it risks creating an additional victim instead of a rescue.

No. Turnout gear is designed to resist heat and flame, not chemical permeation - it offers little to no protection against most hazardous materials. This is a frequently tested Awareness-level misconception.

The ICS-201 Incident Briefing form. It summarizes the situation, objectives, organization, and resources for anyone stepping into a role on the incident.

Conditions (what is happening), exposures (what or who is at risk), and resources (what is needed to respond). It is the first structured assessment an Awareness-level responder performs on arrival.

A formal transfer of command - the outgoing responder briefs the incoming one (often using the ICS-201) on conditions, actions taken, and resources committed, so no information is lost in the handoff.