Every term the ERG uses without defining inline: AEGL / ERPG toxicity levels, LC50, MAWP, TIH / PIH, Compatibility Groups, Packing Groups, protective-clothing levels, and dozens more. 93 entries transcribed verbatim from pp. 369-379.
A gas which sticks (adsorbs) to the surface of a solid and porous material (such as activated charcoal) contained within a metal cylinder. This results in an internal cylinder pressure of less than 101.3 kPa at 20 °C (14 psi at 68 °F) and less than 300 kPa at 50 °C (43 psi at 122 °F). These pressures are much lower than those of conventional cylinders containing compressed or liquefied gases.
Airborne concentration (ppm or mg/m³) above which the general population, including susceptible individuals, could experience notable discomfort, irritation, or certain asymptomatic, non-sensory effects. Effects are not disabling and are transient and reversible upon cessation of exposure.
Airborne concentration (ppm or mg/m³) above which the general population, including susceptible individuals, could experience irreversible or other serious, long-lasting adverse health effects or an impaired ability to escape.
Airborne concentration (ppm or mg/m³) above which the general population, including susceptible individuals, could experience life-threatening health effects or death.
Acute Exposure Guideline Level(s). Threshold exposure limits for the general public after a once-in-a-lifetime, or rare, exposure. Applicable to emergency exposure periods from 10 minutes to 8 hours. Three levels (AEGL-1, AEGL-2, AEGL-3) are developed for each of five exposure periods (10 and 30 minutes, 1, 4, and 8 hours), distinguished by increasing severity of toxic effects.
A sudden increase in fire intensity associated with the expulsion of burning flammable liquid caused by the boiling of water that has accumulated in the bottom of a tank car.
Refers to either a chemical or thermal burn — the former may be caused by corrosive substances, the latter by liquefied cryogenic gases, hot molten substances, or flames.
An infectious substance that poses a high risk to the health of individuals and/or animals or public health. These substances can cause serious disease and can lead to death. Effective treatment and preventative measures may not be available.
An infectious substance that poses a low to moderate risk to individuals and/or animals and/or public health. These substances are unlikely to cause serious disease. Effective treatment and preventative measures are available.
Area where the command post and support functions that are necessary to control the incident are located. Also called the clean zone, green zone, or support zone (EPA SOP Guidelines, OSHA 29 CFR 1910.120, NFPA 472).
Liquids which have a flash point greater than 60 °C (140 °F) and below 93 °C (200 °F). U.S. regulations permit a flammable liquid with a flash point between 38 °C (100 °F) and 60 °C (140 °F) to be reclassed as a combustible liquid.
Letters identify explosives that are deemed to be compatible. Class 1 materials are considered compatible if they can be transported together without significantly increasing the probability of an incident or the magnitude of the effects.
**A** — Substances expected to mass detonate very soon after fire reaches them.
**B** — Articles expected to mass detonate very soon after fire reaches them.
**C** — Substances or articles which may be readily ignited and burn violently without necessarily exploding.
**D** — Substances or articles which may mass detonate (with blast and/or fragment hazard) when exposed to fire.
**E, F** — Articles which may mass detonate in a fire.
**G** — Substances and articles which may mass explode and give off smoke or toxic gases.
**H** — Articles which in a fire may eject hazardous projectiles and dense white smoke.
**J** — Articles which may mass explode.
**K** — Articles which in a fire may eject hazardous projectiles and toxic gases.
**L** — Substances and articles which present a special risk and could be activated by exposure to air or water.
**N** — Articles which contain only extremely insensitive detonating substances and demonstrate a negligible probability of accidental ignition or propagation.
**S** — Packaged substances or articles which, if accidentally initiated, produce effects confined to the immediate vicinity.
The maximum temperature at which a temperature-controlled substance can be safely transported. Above this temperature, self-accelerating decomposition or polymerization may occur.
Designated areas at hazmat incidents, based on safety and the degree of hazard. In this guidebook: hot/exclusion/red/restricted zone, warm/contamination reduction/yellow/limited access zone, cold/support/green/clean zone (EPA SOP Guidelines, OSHA 29 CFR 1910.120, NFPA 472).
A refrigerated, liquefied gas that has a boiling point colder than -90 °C (-130 °F) at atmospheric pressure or is handled or transported at a temperature equal to or less than -100 °C (-148 °F).
The removal of hazardous materials from personnel and equipment to the extent necessary to prevent potential adverse health effects. See the Decontamination one-pager.
A preparation designed for fighting fires involving flammable liquids, pyrophoric substances, and electrical equipment. Common types contain sodium bicarbonate or potassium bicarbonate.
The accumulation of an excessive amount of watery fluid in cells and tissues. Pulmonary edema is an excessive buildup of water in the lungs — for instance, after inhalation of a gas that is corrosive to lung tissue.
The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing more than mild, transient adverse health effects or without perceiving a clearly defined objectionable odor.
The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing irreversible or other serious health effects or symptoms that could impair the ability to take protective action.
The maximum airborne concentration below which it is believed nearly all individuals could be exposed for up to 1 hour without experiencing life-threatening health effects.
Emergency Response Planning Guideline(s). Values intended to provide estimates of concentration ranges above which one could reasonably anticipate observing adverse health effects.
Evacuate aims to protect as many people as possible by removing persons from inside a zone safely. If removal is too risky, sheltering-in-place can also be considered.
Lowest temperature at which a liquid or solid gives off vapor in such a concentration that, when the vapor combines with air near the surface, a flammable mixture is formed. The lower the flash point, the more flammable the material.
Assigned by LC50, not distance.
**Zone A** — Gases: LC50 ≤ 200 ppm. Liquids: V ≥ 500 LC50 and LC50 ≤ 200 ppm.
**Zone B** — Gases: 200 ppm < LC50 ≤ 1000 ppm. Liquids: V ≥ 10 LC50; LC50 ≤ 1000 ppm and Zone A criteria not met.
**Zone C** — 1000 ppm < LC50 ≤ 3000 ppm.
**Zone D** — 3000 ppm < LC50 ≤ 5000 ppm.
Zones are not distances — they classify toxicity. Zone A is more toxic than Zone D.
Area immediately surrounding a hazmat incident which extends far enough to prevent adverse effects from the released product to personnel outside the zone. Also called the exclusion zone, red zone, or restricted zone.
Isolate indicates a zone of no entry that applies to the public and first responders who are not equipped, trained, and prepared to mitigate the incident.
Lethal Concentration 50. The concentration of a material administered by inhalation that is expected to cause the death of 50 % of an experimental animal population within a specified time. Concentration is reported in either ppm or mg/m³.
An agent giving rise to an increased occurrence of mutations in populations of cells and/or organisms. Mutation means a permanent change in the amount or structure of the genetic material in a cell.
"Not otherwise specified". Generic entries such as "Corrosive liquid, n.o.s." mean the actual chemical name is not individually listed in the regulations, so a generic name must be used on shipping papers.
A substance which acts as a central nervous system depressor producing effects such as drowsiness, narcosis, reduced alertness, loss of reflexes, lack of coordination, and vertigo. Can also present as severe headache, nausea, reduced judgment, dizziness, irritability, fatigue, impaired memory, deficit in perception and coordination, reaction time, or sleepiness.
An organic (carbon-containing) compound having two oxygen atoms joined together. Organic peroxides are thermally unstable and may be liable to explosive decomposition, burn rapidly, be sensitive to impact or friction, or react dangerously with other substances.
A value that represents the acidity or alkalinity of a water solution. Pure water has a pH of 7. Below 7 is acidic (1 is extremely acidic); above 7 is alkaline (14 is extremely alkaline). Acids and alkalies (bases) are commonly referred to as corrosive materials.
A chemical reaction that often produces heat and pressure. Once initiated, the reaction is accelerated by the heat it produces. Uncontrolled buildup can cause a fire or explosion or rupture closed containers. The letter (P) following a guide number in the yellow and blue sections marks a material that may polymerize violently under high temperature or contamination with other products, or that has strong potential for polymerization when an inhibitor is depleted.
Includes both respiratory and physical protection. Levels defined by U.S. Coast Guard, NIOSH, and U.S. EPA.
**Level A** — SCBA plus totally encapsulating chemical-resistant clothing (permeation resistant).
**Level B** — SCBA plus hooded chemical-resistant clothing (splash suit).
**Level C** — Full or half-face respirator plus hooded chemical-resistant clothing (splash suit).
**Level D** — Coverall including structural firefighters' protective clothing (SFPC), with no respiratory protection.
**SCBA** — Self-contained breathing apparatus. See the Protective Clothing one-pager.
As referred to in GUIDES 161–166 for radioactive materials — a Federal or state/provincial agency or designated official who evaluates radiological hazard conditions during normal operations and emergencies. If identity and phone are not known locally, obtain them from the agencies listed on the inside back cover of the ERG.
People should seek shelter inside a building and remain inside until the danger passes. Used when evacuation would cause greater risk or cannot be performed. Direct people inside to close all doors and windows and shut off ventilation. Not the best option when vapors are flammable, when clearing will take a long time, or when buildings cannot be closed tightly. Vehicles offer some short-term protection but are not as effective as buildings.
A spill that involves quantities of 208 L (55 US gal) or less. Typically from a single small package (drum), a small cylinder, or a small leak from a large package.
Water applied under pressure from a hose end for penetration — approximately 90 % of the water passes through a 38 cm (15 in) circle at the breaking point. Frequently used to cool tanks and equipment or to wash burning spills away from danger points. May spread a spill fire if directed into open containers of flammable liquids.
A chain reaction that leads to a violent release of stored energy and flammable gas. Can spread to other batteries or nearby combustible materials, leading to a large-scale thermal event with severe consequences.
Toxic Inhalation Hazard. Term for gases and volatile liquids that are toxic when inhaled (same as PIH). Poses a known hazard to human health during transport or is presumed toxic based on animal studies.
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. < 1: vapor is lighter than air and tends to rise. > 1: heavier than air and may travel along the ground.
Area between Hot and Cold zones where personnel and equipment decontamination and hot-zone support take place. Also called contamination reduction corridor (CRC), contamination reduction zone (CRZ), yellow zone, or limited access zone.
Finely divided water for high heat absorption. Spray patterns range from ~10 to 90 degrees. Used to extinguish or control a fire or to absorb, knock down, or disperse vapors. Particularly effective on fires of flammable liquids and volatile solids with flash points above 37.8 °C (100 °F); can also be used on low-flash-point liquids with proper application. Direct spray, rather than a solid stream, into a vapor cloud.