CBRN key terms

A chemical, biological, radiological, or nuclear substance or device capable of causing mass casualties, disruption, or contamination. The four families differ sharply in how they are detected, how responders are protected, and how casualties are treated.

A highly toxic organophosphate that blocks acetylcholinesterase and causes a cholinergic crisis. Effects include pinpoint pupils, heavy secretions, bronchoconstriction, and seizures, and small dermal exposures can be fatal.

A blister agent, such as sulfur mustard, that damages skin, eyes, and airways on contact. Signs may appear hours after exposure, so casualties can contaminate others and require decontamination before treatment.

A chemical that injures the alveolar-capillary membrane and causes noncardiogenic pulmonary edema, often after a quiet interval. Phosgene is the classic example, and casualties can deteriorate suddenly hours after exposure.

A poisonous substance produced by a living organism, such as ricin or botulinum toxin. Some toxins can be dispersed as aerosols or placed in food and water and are regulated as select agents.

Fine solid or liquid particles suspended in air that can be inhaled deep into the lungs. Particles in the respirable size range bypass upper-airway defenses, making aerosolization a common method of weaponizing biological and chemical agents.

The tendency of a contaminant to remain hazardous in an area over time, shaped by volatility, weather, and surface type. Persistent hazards require larger exclusion zones, longer protective posture, and more thorough decontamination.

A device that spreads radioactive material using conventional explosives or another dispersal method. The main consequences are contamination, fear, and economic disruption rather than acute radiation injury to most exposed people.

The process of determining whether a hazardous agent is present, and often roughly how much. Detection answers the question of presence but may not confirm exactly which agent or material is involved.

The process of confirming the specific agent or material present, usually with advanced field or laboratory methods. Identification guides medical treatment, decontamination choices, and legal or evidentiary actions.

The repeated or continuous measurement of hazard levels over time or across an area. Monitoring supports decisions about zone boundaries, responder re-entry, and when an incident is stable enough to scale down.

A laboratory method that amplifies specific genetic sequences to detect or confirm a pathogen. It offers high sensitivity and specificity and is central to confirming biological agents in reference laboratories.

A method that identifies radioactive isotopes by measuring the energies of gamma rays they emit. It distinguishes specific radionuclides in a sample and supports decisions about contamination control and medical care.

The highest level of chemical protective clothing: a fully encapsulating, vapor-protective suit worn with self-contained breathing apparatus. It is used where the highest respiratory and skin hazards are expected.

A respirator that supplies breathing air from an onboard cylinder, independent of the surrounding atmosphere. It gives the highest respiratory protection and is essential in oxygen-deficient or unknown-concentration environments.

A respirator that removes contaminants from ambient air through filters or cartridges instead of supplying clean air. It requires adequate oxygen and a known contaminant with an appropriate, approved canister.

The movement of a chemical through protective material at the molecular level, which eventually causes breakthrough. Permeation data guide the selection of suit and glove materials and their safe wear time.

Physiological strain caused by protective clothing that traps heat and blocks sweat evaporation. It can progress to heat exhaustion or heat stroke and requires work-rest cycles, hydration, and medical monitoring of responders.

The removal or neutralization of hazardous material from people, equipment, and surfaces to reduce exposure. It protects casualties, responders, and facilities and limits contamination spread beyond the incident scene.

The rapid removal of most contamination, typically by stripping clothing and washing with water, before more thorough processing. It is fast and prioritizes saving lives over complete cleanup.

Immediate, improvised decontamination performed without a formal setup when life safety demands it. It may involve simply removing clothing and rinsing with available water before the casualty enters care.

A structured, systematic process using designated stations, controlled runoff, and verified methods. It achieves a higher level of cleanliness for responders and casualties before transport or re-entry.

Collecting and holding the water and materials generated during decontamination so contaminants do not enter storm drains, soil, or waterways. Environmental rules generally require it, and it protects the surrounding community.

A substance that counteracts the toxic effects of a poison, ideally given soon after exposure. Availability, timing, and route of administration strongly influence casualty outcomes in chemical incidents.

An anticholinergic drug that blocks muscarinic effects of nerve agent poisoning, such as secretions and bronchoconstriction. It is given in escalating doses until secretions dry and is paired with an oxime.

A drug such as pralidoxime that reactivates acetylcholinesterase inhibited by nerve agents if given before the enzyme ages. It is administered with atropine, and often a benzodiazepine, in severe poisoning.

A cyanide antidote that binds cyanide to form cyanocobalamin, which is then excreted. It is often preferred in smoke inhalation because it does not impair oxygen delivery the way methemoglobin-forming antidotes can.

A blocking agent given after a radioiodine release to saturate the thyroid and reduce uptake of radioactive iodine. It protects only the thyroid and only when taken within the appropriate time window.

Sorting casualties by urgency so limited resources save the most lives. In CBRN incidents, triage must also account for contamination, delayed symptom onset, and decontamination before treatment.

A standardized, scalable management structure used to control personnel and resources at an incident. It provides common terminology, clear roles, and a manageable span of control across agencies.

A command arrangement in which agencies with jurisdiction or responsibility jointly set objectives and strategy for an incident. It preserves each agency's authority while producing one coordinated plan.

The number of subordinates or resources one supervisor can effectively manage, commonly three to seven. Exceeding it degrades communication and safety, so the organization is expanded.

The area where contamination is present or expected and where only fully protected responders operate. Entry requires control, monitoring, and a defined exit route into the warm zone.

The OSHA standard for hazardous waste operations and emergency response, covering training, medical surveillance, and site safety. It sets responder competency levels and requires an incident command structure at hazardous material incidents.

A grouping of federal or state agencies that provides a specific capability, such as public health or mass care, under the National Response Framework. ESFs organize resources and reduce duplication during a response.

A regulatory program controlling possession, use, and transfer of biological agents and toxins with potential for severe harm. It imposes registration, security, and reporting requirements on laboratories and other facilities.

A systematic assessment of the threats a community faces, its exposure and susceptibility, and its capacity to cope. Results prioritize planning, training, and resource investments.

A discussion-based exercise in which participants talk through a simulated scenario and their roles. It tests plans and reveals gaps without deploying resources, making it efficient for orientation and coordination.

An operations-based exercise that deploys actual personnel and equipment to test response capabilities under realistic conditions. It is the most resource-intensive type and usually follows smaller functional exercises.

A document summarizing what happened in an exercise or incident, what worked, and what needs improvement. Its improvement plan assigns corrective actions, owners, and deadlines.