Acute effect: Health effect that occurs rapidly as a result of short-term exposures.
Aerosol: Fine liquid or solid particles suspended in a gas; for example, fog or smoke.
Aerosolization: The production of an aerosol/a fine mist or spray containing minute particles.
Agent: Historically, “agent” has referred to weaponized preparations of chemical or biological materials. This document follows that convention and refers only to chemicals used in deliberate attacks as “chemical agents” or “chemical warfare agents” (see also those entries); all others (no matter their hazard) are referred to simply as “chemicals” or “substances”.
Airborne hazard: Any harmful substance suspended in air that could lead to an exposure.
Asset: Structure or facility that has value and provides a service.
Animal: Animals include household pets, service and assistance animals, working dogs, livestock, fish, wildlife, exotic animals, zoo animals, research animals, and animals housed in shelters, rescue organizations, breeding facilities, and sanctuaries.
Boom: Physical barrier used to control the movement of a chemical substance. Booms are often used to control oil spills and are typically the first mechanical response equipment employed at a spill site.
Chemical detection technology: Any of a variety of both active and passive technologies that can detect one or more chemicals and record its concentration.
Chemical intoxicant: Any chemical, or its precursor, which through its chemical action on life processes can cause sensory irritation, temporary incapacitation, permanent harm, or death to humans or animals. This includes all such chemicals, regardless of their origin or of their method of production, and regardless of whether they are produced in facilities, in munitions or elsewhere.
Chemical warfare agent (CWA): A chemical substance that is intended for use in military operations to kill, seriously injure, or incapacitate people through its physiological effects. Excluded from consideration are riot control agents and smoke and flame materials. The agent may appear as a vapor, aerosol, or liquid; it can be either a casualty/toxic agent or an incapacitating agent.
Chronic effect: Health effect that occurs as a result of long-term exposure and is of long duration.
Cold zone: At an incident site, the uncontaminated area beyond the warm zone in which resources are assembled to support the response (green zone, support zone).
Containment: Mechanical actions taken to prevent the spread of a contaminant from a particular area or movement within the area.
Contamination: Deposition and/or absorption of chemicals on and by structures, areas, or materials and surfaces (e.g., soil, air, water, clothing, hair, skin) which renders them unfit for human use or dangerous to human and/or environmental health.
Contaminant dissolution: Chemical removal of surface contaminants from equipment by dissolving them in a solvent.
Critical infrastructure: Systems and assets, whether physical or virtual, so vital that the incapacity or destruction of such may have a debilitating impact on the security, economy, public health or safety, environment, or any combination of those matters, across any federal, state, tribal, territorial, or local jurisdiction. As established in the National Infrastructure Protection Plan, this includes the sectors of agriculture and food; drinking water and wastewater treatment systems; dams; public health and healthcare; emergency services; government and commercial facilities; defense industrial base; national monuments and icons; information technology; telecommunications; energy; nuclear reactors materials and waste; transportation systems; banking and finance; chemical; and postal and shipping.
Control zone: Area at a hazardous materials incident whose boundaries are based on safety and the degree of hazard. Control zones generally includes the hot zone (exclusion zone), warm zone (decontamination zone), and cold zone (support zone).
Corrosive: Able to destroy the texture or substance of a tissue by means of a chemical reaction.
Decontamination: Process of inactivating or removing a contaminant from humans, animals, plants, food, water, soil, air, areas, or items through physical, chemical, or other methods to meet a clearance goal. Decontamination applies to both disinfection and sterilization processes and generally occurs as part of cleanup/remediation.
Dependency: The one‐directional reliance of an asset, service, system, network, or collection thereof, within or across sectors, on input, interaction, or other requirement from other sources in order to function properly.
Direct contact hazards: Chemicals that can be hazardous to human or animal health upon direct dermal exposure, such as by the touching of surfaces (clothing, floors, walls, seats, turnstiles, handrails, etc.) on which the hazardous chemical is present.
Dispersal: The distribution of particles of one substance in a continuous phase of another substance. The two substances can be in the same or different states of matter (solid, liquid, or gas). As a result of dispersal, the concentration of the distributed substance is lowered.
Dispersant: Chemical and physical treatments that speed the dispersion of a substance. In oil spills, dispersants are often surfactants and/or solvent compounds that reduce the interfacial tension between oil and water, allowing the oil to break up into small droplets that can be dispersed into the water column and that promote biodegradation.
Emergency Operations Center (EOC): Physical location at which the coordination of information and resources to support domestic incident management activities normally takes place. An EOC may be a temporary facility or located in a more central or permanently established facility, perhaps at a higher level of organization within a jurisdiction. EOCs may be organized by major functional disciplines (e.g., fire, law enforcement, and medical services), by jurisdiction (e.g., Federal, state, tribal, territorial, or local), or by some combination thereof.
Emergency respite site: Location along an evacuation route that can support transportation of assisted evacuees and self-evacuees.
Emergency shelter: Site that assists in providing immediate lifesaving and sustaining care until conditions stabilize and full services can be established at more permanent shelter (mass care) locations; they generally have limited supplies and services.
Emergency Support Function (ESF): The structure for coordinating federal interagency support for response to an incident.
Environmental sampling: Sampling conducted for the purpose of detecting the presence of a specific substance.
Evacuation: Immediate egress or escape of people from an area that contains an imminent threat, an ongoing threat, or a hazard to lives and property.
Evacuation assembly point: Temporary location set up for evacuation embarkation and transportation coordination.
Exposed: Individuals that have come into contact with a chemical substance.
Exposure: Contact with a chemical, either directly or via another substance contaminated with a chemical.
Exposure level: Measured or estimated amount of a substance (e.g., chemical) to which an individual or populations of individuals is exposed, usually expressed as concentration over a defined period (e.g., ppm for one hour).
Family Assistance Center (FAC): Facilities established 24-48 hours after an incident, that provide information about missing or unaccounted persons and the deceased and serve as a private “one-stop shop” of human services for affected populations.
Family Reception Center (FRC): Centralized, temporary locations set up immediately post-incident for families and friends seeking trusted/official sources of information about loved ones.
Fatality management: Coordination of several organizations (e.g., law enforcement, healthcare, emergency management, medical examiner, etc.) to ensure the proper recovery, handling, identification, transportation, tracking, storage, and disposition of human remains.
First responder: Designation for an individual who, in the course of their professional duties of responding to emergencies, and in the early stages of an incident, is responsible for the protection and preservation of life, property, evidence, the environment, and for meeting basic human needs.
Hazard: Something that is potentially dangerous or harmful, often the root cause of an undesired outcome.
Hazardous waste: Waste with properties that make it dangerous or capable of having a harmful effect on human health or the environment.
Hot zone: The area immediately surrounding the incident site in which primary contamination may occur (also known as Red zone, exclusion zone).
Hospital Family Information Center/Family Support Center (FIC/FSC): Healthcare facility-based location that provides initial support to families arriving after an incident that assist with reunification, notification, and providing information.
Incident: An occurrence, caused by either human action or natural phenomenon, that may cause harm and require action, which can include major disasters, emergencies, terrorist attacks, terrorist threats, wild and urban fires, floods, hazardous materials spills, nuclear accidents, aircraft accidents, earthquakes, hurricanes, tornadoes, tropical storms, war related disasters, public health and medical emergencies, cyber attacks, cyber failure/accident, and other occurrences requiring an emergency response.
Incident Commander (IC): Individual responsible for all incident activities, including the development of strategies and tactics and the ordering and release of resources. The IC has overall authority and responsibility for conducting incident operations and is responsible for managing all incident operations at the incident site.
Incident Command Post (ICP): The field location where the primary functions are performed. The Incident Command Post may be co-located with the incident base or other incident facilities.
Incident Command System (ICS): A standardized on-scene emergency management construct specifically designed to provide for the adoption of an integrated organizational structure that reflects the complexity and demands of single or multiple incidents, without being hindered by jurisdictional boundaries.
Industrial agent: Chemical developed or manufactured for use in industrial operations or research by industry, government, or academia. These chemicals are not primarily manufactured for the specific purpose of producing human casualties or rendering equipment, facilities, or areas dangerous for use by humans. Hydrogen cyanide, cyanogen chloride, phosgene, chloropicrin, and many herbicides and pesticides are industrial chemicals that also can be chemical agents.
Infrastructure: The basic facilities, services, and installations needed for the functioning of a community or society, such as transportation and communications systems, water and power lines, and public institutions including schools, post offices, and prisons.
Joint Information Center (JIC): Focal point for the coordination and provision of information to the public and news media concerning the Federal response to the emergency.
Large-scale incident: A designation to distinguish a significant event from day-to-day responses. This is generally an incident that because of the magnitude, complexity, toxic potency or deliberate nature requires federal assets and exceeds the response capability of state, tribal, territorial, and/or local agencies.
Lead Federal Agency (LFA): The federal agency that leads and coordinates the overall federal response to an emergency.
License Use Agreement: An agreement that allows one party (the licensee) to use the property of the owner (the licensor).
Local government: Public entities responsible for the security and welfare of a designated area as established by law. Includes county, municipality, city, town, township, local public authority, school district, special district, intrastate district, council of governments, regional or interstate government entity, or agency or instrumentality of a local government; an Indian tribe or authorized tribal organization, a native village or native cooperation; or a rural community, unincorporated town or village, or other public entity; state governments are separate entities and are not included in the definition of local government.
Media: Refers to the air, water, soil, or surface that has been or is potentially contaminated by a chemical substance.
Medical countermeasure (MCM): A regulated pharmaceutical product, medical device, or intervention used to combat the effects of chemical, biological, radiological, or nuclear incidents.
Memorandum of Agreement (MOA): A conditional agreement where the transfer of funds for services is anticipated between signatories; these signatories have agreed to work cooperatively together toward an agreed upon objective.
Memorandum of Understanding (MOU): A non-enforceable document that outlines the intentions of its signatories to pursue a common goal.
Mitigation: Activities designed to reduce or eliminate risks to persons or property, or to lessen the actual or potential effects or consequences of an incident. Mitigation measures may be implemented prior to, during, or after an incident.
Model: A physical, conceptual, or mathematical approximation of a real phenomenon.
Morbidity: The incidence of illness/injury in a population and/or a geographic location.
Mortality: The incidence of death or the number of deaths in a population and/or a geographic location.
National Incident Management System (NIMS): System mandated by HSPD-5 that provides a consistent, nationwide approach for federal, state, tribal, territorial, and local governments; private sector; and non-governmental organizations to work effectively and efficiently together to prepare for, respond to, and recover from domestic incidents, regardless of cause, size, or complexity.
National Response Framework (NRF): The Homeland Security Act of 2002 and the HPSD-5 directed the DHS to develop an NRF, a guide to how the nation responds to all types of disasters and emergencies.
Natural attenuation: A variety of physical, chemical, or biological processes that, under favorable conditions, act without human intervention to reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater.
Nerve agents: Substances that interfere with the proper function of the nervous system.
Neutralization: Chemical and physical treatments neutralize, solidify, precipitate, etc. the substance, reducing its risk to human and environmental health.
Non-Pharmaceutical Intervention (NPI): A public health intervention that people and communities can take to help prevent spread of illness or contamination. Examples of NPIs include personal protective equipment, social distancing, quarantine, travel restrictions, school closures, product recall, evacuation, and shelter-in-place.
Nonpersistent: Describes a chemical substance that dissipates quickly in the environment and is therefore considered to be a short-term hazard. For chemical agents, nonpersistent chemicals lose their ability to cause casualties 10 to 15 minutes after release.
Normalcy: Pre-event condition and/or operation status.
Oxidizer: A chemical which supplies its own oxygen, and which helps other combustible material burn more readily.
Persistent: Describes a chemical substance that is resistant to evaporation and environmental degradation through chemical, biological, and phytolytic routes and therefore is likely to pose long-term hazards to humans, animals, and/or the environment. Persistent chemicals often resist decontamination efforts. For chemical agents, persistent chemicals retain casualty-producing effects for an extended period, usually anywhere from 30 minutes to several days after release.
Personal Protective Equipment (PPE): Protective clothing, helmets, gloves, face shields, goggles, facemasks and/or respirators or other equipment designed to minimize exposure and protect the wearer from injury due to chemical exposure or the spread of contamination.
Post-Traumatic Stress Disorder (PTSD): A mental health condition triggered by either experiencing or witnessing a traumatizing event.
Populace: All the inhabitants of a place; population.
Presidential Policy Directive (PPD): Mechanism for issuing Presidential decisions on national security matters.
Prevention: Actions taken to avoid an incident or to intervene to stop an incident from occurring. Prevention involves actions taken to protect lives and property.
Primary contamination: The contamination of persons or equipment as a result of direct contact with a released substance.
Public Health Emergency (PHE): An incident, either natural or manmade, that creates a health risk to the public.
Reachback: Products, services, equipment, material, or human resources including subject matter experts from organizations that are not forward deployed.
Recovery: The development, coordination, and execution of service- and site-restoration plans; the reconstruction of government operations and services; individual, private-sector, non-governmental, and individual assistance programs to provide housing and promote restoration; long-term care and treatment of affected persons; additional measures for social, political, environmental, and economic restoration; evaluation of the incident to identify lessons learned; post-incident reporting; and development of initiatives to mitigate the effects of future incidents.
Recovery outcome: High‐level desired end‐state of a recovery effort, such as minimizing economic disruption and/or minimizing impacts to public health and safety.
Resuspension: A renewed suspension of insoluble particles after they have been precipitated, such as particles in water.
Regional Hub Reception Center (RHRC): Facilities where evacuees can receive assistance in identifying the most appropriate shelter location for their needs.
Remediation: Removal of pollution or contaminants from water and soil. Also, the reversing or stopping environmental damage from such pollution or contaminants.
Residual contamination: Amount of contaminant remaining after an area has been decontaminated. Levels of residual contamination may be below technological detection capabilities.
Resources: Personnel and major items of equipment, supplies, and facilities available or potentially available for assignment to incident operations and for which status is maintained. Available or potentially available funding may also be considered a resource.
Response: Actions taken immediately after discovery of a potential or actual occurrence of an incident, generally including Notification and First Response.
Restoration: The process of renovating or refurbishing a facility, bringing it back to an unimpaired or improved condition after decontamination, and making a decision to permit occupants to return.
Rinsing: Removes contaminants through dilution and solubilization, and may follow dissolving and surfactant treatments.
Risk: Probability that a substance or situation will produce harm under specified conditions. Risk is a combination of two factors: (1) the probability that an adverse incident will occur (such as a specific illness or type of injury); and (2) the consequences of the adverse incident.
Risk assessment: Gathering and analyzing information on what potential harm a situation poses and the likelihood that people or the environment will be harmed. A methodological approach to estimate the potential human or environmental risk of a substance that uses hazard identification, dose–response, exposure assessment, and risk characterization.
Risk communication: Interactive process of exchange of information and opinion among individuals, groups, and institutions. It often involves multiple messages about the nature of risk or expressing concerns, uncertainties, opinions, or reactions to risk messages or to legal and institutional arrangements for risk management.
Risk management: Process of identifying, evaluating, selecting, and implementing actions to reduce risk to human health and to ecosystems. The goal of risk management is scientifically sound, cost-effective, integrated actions that reduce or prevent risk while taking into account social, cultural, ethical, political, and legal considerations.
Sampling: Act of collecting representative portions of environmental materials and surfaces that help to specify the number, type, and location (spatial or temporal) of contamination.
Sampling and analysis plan: Plan that describes the methods, strategies, and analyses to be used for sampling a contaminated site.
Secondary contamination: Contamination of healthcare or other responding personnel or equipment as a result of contact with a contaminated person (victim/survivor), their personal effects/clothing, or equipment.
Service: The functions and capabilities provided by an asset or set of assets to the economy, government, or society.
Screening: Systematic examination or assessment, done especially to detect an unwanted substance, attribute, person, or undesirable material.
Shelter (mass care): Facility where evacuees receive disaster services from government agencies and/or pre-established volunteer organizations.
Shelter-in-place: Used when people are in or near an area that contains an imminent threat, an ongoing threat, or a hazard to lives and property, and evacuation would cause them to be at greater risk or cannot be performed.
Simulation: Imitation of characteristics, processes, or systems over time using another system.
Site characterization: Process of gathering site-specific data, including overall descriptions of the site, material types present at the site, potential human exposure pathways, and environmental conditions to estimate the extent of contamination. Site characterization occurs as an early step in consequence management.
Solidifier: Physical or chemical means used to change the physical state of a contaminant (such as from a liquid to a solid), immobilizing it and/or making it insoluble. Used to prevent contaminant spread.
Solution: A homogeneous mixture of two or more substances, usually liquid.
Solvent: A substance that dissolves another substance.
Sorption: Chemical and physical treatments that absorb or adsorb a substance, enabling its collection for disposal and in some cases (for example, in some oil spills), recovery.
Stafford Act Declaration: Disaster or emergency declaration invoked by the President of the United States in response to an incident either as requested by the states and/or by a federal agency requesting federal-to-federal assistance.
Stakeholder: Person who has a share or an interest in incident resolution and is representative of the affected public.
Stakeholder working group: A group that collectively works to represent and promote local interests, relating local preferences and concerns.
Strategic National Stockpile (SNS): Managed HHS ASPR, a stockpile composed of pharmaceuticals (e.g., medications, antibiotics, etc.) and medical supplies (e.g., equipment, surgical items, etc.) that may be required to control and/or respond to a public health emergency.
Surfactant: Often a detergent used to augment physical cleaning methods; surfactants work by reducing adhesion forces between contaminants and the surface being cleaned, and by preventing redeposit of the contaminants.
Supply chain: A system of organizations, people, activities, information, and resources involved in supplying a product or service to a consumer/end user.
Syndromic surveillance: Tracking of illness indicators that occur before clinical diagnosis confirmation, such as chief complaint data from urgent medical visits, over-the-counter medication purchases, school absenteeism rates, and key word (e.g., “fever”, “vomit”) presence on social media platforms. Syndromic surveillance is used for early detection of a health hazard incident and for trend monitoring.
Therapeutic: Product intended to diagnose, cure, mitigate, treat, or prevent illness, injury, disease or effects on the structures and functions of the body.
Toxic: Having the ability to harm the body, especially by chemical means.
Toxic Industrial Chemical (TIC): Any industrial chemical hazard that is toxic and/or lethal and not designed specifically for military purposes; however, a TIC may be employed as a chemical warfare agent.
Toxic Industrial Material (TIM): Substance (i.e., chemical, explosive, radiological) that when delivered in sufficient quantities may produce a toxic effect to humans, animals, and the environment. Although not designed specifically for military purposes, a TIM may be employed as a chemical warfare agent.
Toxidrome: A group of signs and symptoms constituting the basis for a diagnosis of poisoning.
Toxicity: Degree to which some agent is poisonous or harmful, often inversely related to the amount of the agent that causes the harmful or fatal effect(s).
Triage: The sorting of and allocation of treatment to patients, especially battle and disaster victims, according to a system of priorities designed to maximize the number of survivors. Also, the sorting of patients (as in an emergency room) according to the urgency of their need for care.
Uncertainty: Imperfect knowledge concerning the present or future state of the system under consideration; a component of risk resulting from imperfect knowledge of the degree of hazard or of its spatial and temporal distribution.
Unified Command (UC): Application of ICS used when there is more than one agency with incident jurisdiction or when incidents cross political jurisdictions. Agencies work together through the designated members of the UC to establish their designated IC at a single Incident Command Post and to establish a common set of objectives and strategies and a single Incident Action Plan (IAP).
Volatile: A substance that can be defined as evaporating readily at normal temperatures. Volatility describes how easily a substance will vaporize (turn into a gas or vapor).
Vapor density: Weight of a volume of pure vapor or gas (with no air present) compared to the weight of an equal volume of dry air at the same temperature and pressure. A vapor density less than 1 (one) indicates that the vapor is lighter than air and will tend to rise. A vapor density greater than 1 (one) indicates that the vapor is heavier than air and may travel along the ground.
Vapor pressure: Pressure at which a liquid and its vapor are in equilibrium at a given temperature. Liquids with high vapor pressures evaporate rapidly.
Vapor suppression: Chemical and physical treatments (i.e., sealing with foam) that suppress vapor generation by volatile substances.
Viscosity: Measure of a liquid’s internal resistance to flow. This property indicates how fast a material will leak out through holes in containers or tanks.
Voluntary agency liaison: Official that supports and works in collaboration with voluntary organizations.
Warm zone: At an incident site, the area that surrounds the hot zone and contains the area where victims and responding team members and their equipment are decontaminated (yellow zone, contamination reduction zone).
Whole community: Concept that includes persons, businesses, faith-based organizations, non-profit groups, schools and academia, and all levels of government.