Definitions Flashcards
Air reactivity (pyrophoricity)
A substance that ignite spontaneously in air at or below 54.5°C (130.19°F ) most pyrophoric should be extinguished with a class D extinguisher for burning metals
Aromatic hydrocarbon
A hydrocarbon containing the benzene “ring”, which is formed by six carbon atoms and contains resonant bonds. Examples include benzene (C6H6) and toluene( C7H8)
Biological agents and toxins
Biological threat agents consist of pathogens and toxins. Pathogens are disease producing organisms and include bacteria
(e.g. Anthrax, cholera, plague, e coli) and virus (e.g. small pox, viral hemorrhagic fever). Toxins are produced by a
biological source and include ricin, botulinum and mycotoxins.
Blood agents
Chemical agents consist of a cyanide compound, such as hydrogen cyanide (hydrocyanic acid) and cyanogens chloride. These agents are identical to the civilian counterparts used in industry.
Catalyst
Used to control the rate of chemical reaction by either speeding up or slowing it down. If used improperly catalyst, can speed up a reaction and cause container failure due to pressure or heat build up.
Caustic (Base, Alkaline)
Compound that forms hydroxides ion in water. These compounds have a pH of > 7, and caustic solutions will turn litmus
paper blue. Materials with a pH > 12 are considered a strong base. Also known as alkali, alkaline or base.
Chemical change
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. Some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions.
Chemical interaction
Reaction caused by mixing up two or more chemicals together. Chemical interaction of materials within a container may result in a buildup of heat and pressure, leading to a container failure. And other situation, the combine materials may be more corrosive than the container was originally designed to withstand and cause container to breach.
Compound, mixture
Chemical combination of two or more elements in the same element or different ones, that is electrically neutral. Compounds have a tendency to break down their component parts, sometimes explosively
Concentration
The percentage of an acid or base dissolved in water concentration is not the same as strength
Corrosive, corrosivity
The material that causes visible destruction or irreversible alteration to living tissues by chemical action at the point of contact
Cryogenic or liquid heat transfer process
There are three different ways that heat can transfer: conduction (through direct contact)
, convection (through fluid movement) or radiation (through electromagnetic waves). Heat transfer occurs when temperature of objects are not equal to each other and refers to how these differences change to an equilibrium state .
Dose
(1) concentration or amount of material to watch the body is exposed over a specific specific time. The amount of substance ingested, absorbed, and or inhale during exposure. (2) a quantity of radiation or energy, absorbed by the body, usually measured in millirems (mrem)
Dose response (relationship )
Basic principle of toxicology. The intensity of a response elicited by chemical within biologic mechanism is a function of the administered dose.
Endothermic
Characterized by or formed with absorption of heat
Evaporation rate
The speed at which a material changes from a liquid to vapor. As more heat is applied to liquid the evaporation rate increases.
Exothermic
Characterized by or formed with the evolution of heat
Expansion ratio
The amount of gas produced by the evaporation of one volume of liquid at a given temperature. Significant property when evaluating liquid and vapor release of liquefied gas is in cryogenic materials. The greater the expansion ratio, the more gas is produced and the larger the hazard area.
Firepoint
The minimum temperature at which a liquid goes off sufficient vapors that would ignite and sustain combustion. It is typically several degrees higher than the flashpoint. And assessing the risk close by flammable liquid release, greater emphasis placed on the flashpoint, since it is a lower temperature and to stay in combustion is not necessary for significant injuries or damage to occur
Flammable (explosive ) range (LEL & UEL)
The range of gas or vapor(percentage by volume) that will burn or explode if ignition source is present. Lemon in concentrations are commonly called the” lower flammable(explosive) limit” and the” upper flammable(explosive) limit. Below the lower flammable limit, the mixture is Tulane to burn above the upper flammable limit the mixtures too rich to burn. If the gas or vapor is released into oxygen, enriched atmosphere, the final range will expand. Likewise, if the vapors release into an oxygen deficient atmosphere, the flammable range will contract
Flashpoint
Minimum temperature at which a liquid gives off enough vapors that will ignite and flash over but will not burn without the addition of more heat. Significant in determining the temperature at which vapors from flammable liquid are readily available and may ignite.
Half Life
The time it takes for the activity of a radioactive material to decrease to 1/2 of its initial value through radioactive decay. The half life of knownmaterials can range from a fraction of a second to millions of years
Halogenated hydrocarbon
A hydrocarbon with halogen atom for example (chlorine fluorine bromine etc., ) substituted for a hydrogen atom. They are often more toxic than naturally occurring organic chemicals, and they decompose into a smaller, more harmful elements when exposed to high temperatures for a sustained period of time
Ignition (autoignition) temperature
Minimum temperature required to night gas or vapor without a spark or flame being present period significant in evaluating the ease at which a flammable material may ignite
Inhibitor
Added to product to Control their chemical reaction with other products. If the inhibitor is not added or escapes during an incident material would begin to polymerize, possibly resulting in a container failure.
Instability (Reactivity)
The ability of a material to undergo a chemical reaction with the release of energy. It could be initiated by mixing or reacting with other materials, application of heat, physical shock etcetera.
Irritants (Riot control Agents)
Usually solid materials that are dispersed in liquid spray and cause pain or burning on exposed mucous membranes in skin., examples include Mace (CN) and pepper spray (capsaicin)
Maximum safe storage temperature (MSST)
The maximum storage temperature that an organic peroxide may be maintained above which a reaction explosion may occur
Miscibility
Refers to the tendency or ability of two or more liquids to form a uniform blend, or to dissolve in each other. Liquids may be totally miscible, partially miscible or non-miscible
Mixture
Substance made from two or more compounds, physically mixed together. A mixture may also contain elements and compounds mixed together.
Nerve Agent
Nerve agents are a class of phosphorus containing organic chemicals (organophosphates) that disrupt the mechanism by which nerve transfer messages to organs.
Odor & Odor Threshold
Other threshold is the minimum concentration of a substance at which majority of test subjects can detect and identify the characteristic odor of a substance. While odor thresholds can serve as useful warning properties they must be use cautiously because olfactory perception varies among individuals.
Oxidation potential (ability)
The ability of a material to (1) either give up its oxygen molecule to stimulate the oxidation of organic materials EG chlorate, permanganate and nitrate compounds (EG chlorate comma permanganate and nitrate compounds) or (2) receives electrons being transferred from the substance undergoing oxidation (EG chlorine or fluorine). Result of either activity is release of activity is a release of energy.
Persistence
For longer than 24 hours and is non persistent if it evaporates within that time among the most persistent agents are VX, taubun, mustard and lewisite
pH( Power of hydrogen)
Acidic or base corrosives are measured by one another by their ability to dissociate in solution. Those that form the greatest number of hydrogen ions are the strongest acids, while those that form hydrogen ion air are the strongest bases. The measurement of hydrogen ion concentration and solution is called the pH (power of hydrogen) of the compound solution. The pH scale ranges from zero to 1, with strong assets having a low pH value and strong bases or alkaline materials having high page values and neutral substance would have a pH value of 7
physical change
Physical changes occur when objects or substances undergo a change that does not change their chemical composition in general a physical change reversible using physical means.
physical state (solid, liquid or gas)
The physical state or form (solid, liquid, gas) of the material at normal ambient temperatures 68 degrees Fahrenheit to 77 degrees Fahrenheit
Polymerization
A reaction during which a monomer is induced to polymerize by the addition of a catalyst or other unintended influences such as excess heat, friction, contamination etc. If the reaction is not controlled, is possible to have an excessive amount of energy release.
Radioactivity
The ability of a material to emit any form of radioactive energy
Reactivity
Reactivity is the tendency of a substance to undergo chemical reaction, either by itself or with other materials and to release energy
Relative density
Is the ratio of density mass of a unit volume of a substance to the density of a given reference material. Specific gravity usually means relative density with respect to water see definition. Vapor density usually means relative density with respect to air
self accelerating decomposition temperature (SADT
The temperature at which an organic peroxide or synthetic compound will react to heat, light or other chemicals and release oxygen, energy and fuel in the form of an explosion or rapid oxidation. When the temperature is reached by some portion of the mass of an organic peroxide, irreversible decomposition will begin
Slurry
Pourable mixture of a solid and a liquid
Solubility
The ability of a solid, liquid, gas or vapor to dissolve in water or other specified medium. The ability of one material to blend uniformly with another, as in a solid and liquid, liquid and liquid, gas and liquid or gas and gas. Significant property and evaluating the selection of controlled and extinguishing agents, including the use of water and firefighting foams
solution
A mixture in which all of the ingredients are completely dissolved. Solutions are composed of a solvent (water or another liquid) and a dissolved substance (known as the solute)
Specific Gravity
The weight of a material as compared to the weight of an equal volume of water. But the specific gravity is less than one, the material is lighter than water and will float. If the specific gravity is greater than one, the materials heavier than water it was sent. Most insoluble hydrocarbons are lighter than water it will float on the surface. Significant property for determining spill control and cleaning procedures from waterborne releases
strength
The degree to which a corrosive ionizes in water. Those that form the greatest number of hydrogen ions are the strongest acids (EG pH < 2) while those that formed the hydrogen ion are the strongest bases>while those that form the hydrogen ion are the strongest bases (pH>12
Temperature of Product
Influences the hazards present and the measures taken to control the incident that involved the product
Toxic products of combustion
The toxic byproducts of the combustion process. Depending upon the materials burning, higher levels of personal protective clothing and equipment may be required
Unsaturated hydrocarbon (straight & branched)
A hydrocarbon with at least one multiple bond between the two carbon atoms somewhere in the molecule. Generally, unsaturated hydrocarbons are more active chemically than saturated hydrocarbons, and are considered more hazardous. May also be referred to as the alkenes and alkynes. Example include ethylene(C2H4), butadiene(C4H6) and Acetylene (C2H2)
Vapor Density
The weight of a pure vapor or gas compared to the weight of an equal volume of dry air at the same temperature and pressure. The milex cular weight of air is 29. If the vapor density of a gas is less than one, the material is lighter than air and may rise. If the vapor density is heavier than air and will collect in low or in close places. Significant property for evaluating exposures and where hazmat gas or vapor will travel
vesicants (blister agents)
Chemical agents that pose both a liquid and vapor threat to all exposed skin and mucous membranes. These are exceptionally strong irritants capable of causing extreme pain and large blisters upon contact. Examples include mustard Lewisite and phosgene oxime
Viscosity
Measurement of the thickness of a liquid and its ability to flow. high viscosity liquids such as heavy oils, must first be heated to increase their fluidity. low is costly liquid spread more easily increase the size of the hazard of the area.
Water Reactivity (pyrophoric)
The ability of a material to react with water and release a flammable gas or present a health hazard
Roentgen Equivalent Man (REM)
chemical agents
Chemical agents are classified in military terms based upon their facts on the enemy. The intent of using chemical weapons is to incapacitate and kill.
P 199
What are the categories of chemical agent?
- Nerve agents (neurotoxins)
- Choking agents(respiratory irritants)
- Blood agents( asphyxiants)
- Vesicants or blister agents (skin irritants)
- Antipersonnel agents ( riot control agents)
Persistence of a chemical agent
Refers to the length of time a chemical agent remains as a liquid. A chemical agent is said to be persistent if it remains as a liquid for longer than 24 hours and nonpersistent if evaporates within that time. Among the most persistent chemical agents are VX, tabun(GA ) , mustard (H) and lewisite(L)
P199
LDL
lower detection limit. the lowest concentration to which a monitoring instrument will respond. the lower the LDL the quicker the contaminant concentrations can be evaluated
Toxicology
Is the study of chemical or physical agents to produce adverse responses in the biological systems in which they interact. Chemical agents include gases, vapors, fumes, dust, and so on wall physical agents include radiation, hot and cold environment, noise
Toxicity
Is defined as the ability of a substance to cause injury to a biological tissue
