FHA Federal Housing Administration.

fiber (EPA-TEM Method) Structure greater than or equal to 0,5 micro with an aspect ratio of 5 : 1 or greater, and having substantially parallel sides

fiber (General) A panicle having a length to diam

fiber (PCM Method) Paniculate at least 5 micr (length to width ratio) of at least 3 : 1. A rodlike st of greater than 3 : Land ers in length with an aspect ratio re having a lenglh of at least three

fiber optics A system of flexible quartz or glass fibers can transmit light

fire The process of rapid oxidation that generally produces both heat and light. Also, referred to as combustion.

fire area An area of a building that is separated from the remainder of me building by construction, having a fire resistance of at least one hour and having all communicating openings properly protected by an assembly having a fire rating of at least one hour.

fire brigade An organized group of employees who are knowledgeable, trained, and skilled in at least basic firefighting operations.

fire classes See fires.

fire damper Device installed in ductwork in which (he duct passes through fire separations to aid in preventing the spread of a fire.

fire door Doors that building codes and the NFPA classify according to a rating system related to their fire resistance, such as 3-hour, 1 1/2-hour, 1-hour, etc.

fire extinguishers, classes (Portable Hand Held) Class A extinguishers rated for Class A fires may contain waier, aqueous-film-forming foam, dry chemical, or a halogen compound; Class B extinguishers for Class B fires may contain carbon dioxide, dry chemical, aqueous-film-fonning foam, or halogenated agents; Class C extinguishers for Class C fires may contain carbon dioxide, dry chemical, or a halogenated compound; and Class D extinguishers for use on Class D fires contain specially prepared materials, such as Met-L-X powder, T.E.C. powder, etc.

fire gases Gases that remain when products of combustion are cooled lo normal temperature.

fire partition A partition that serves to restrict the spread of a fire, but does not qualify as a fire wall.

fire point The minimum temperature to which a material musl be healed (o sustain combustion after ignition by an external source.

fire resistance rating The time period, in hours or fractions thereof, that a building member or assembly will resist a code-specified fire test without failure. For example, a 2-hour rating indicates that the assembly withstood the standard test for greater than two hours without failure by any of the failure criteria listed in the fire test protocol.

fire resistive The quality of a structure or material to provide a predetermined degree of fire resistance, usually rated in hours.

fire retardant Chemicals, paints, or coatings used for the treatment of combustible building materials that provide a lesser degree of protection than a fire-resistant material would have.

fire separation The distance in feet measured from the building face to the closest interior lot line, to the center of a street or public way, or to an imaginary line between two buildings on the same property.

fire triangle The three elements that must be present in the right proportion for a fire to exist: oxygen (or an oxidizing agent), fuel (or a reducing agent), and heat. Keeping the three elements of the fire triangle apart is the key to preventing fires, and removing one or more of these elements is the key to extinguishing fires that do start.

fire wall A fire-resistance-rated wall that is erected to restrict the spread of fire.

fire watch Individual provided with fire extinguishing equipment and training in its use who is posted (1) in the immediate area of welding or cutting operations when other than a minor fire might develop; (2) where there is an appreciable amount of combustible building material nearby; (3) where sparks could ignite nearby combustibles; or (4) where combustible materials are adjacent to the opposite side of metal partitions, walls, ceilings, or roofs and are likely lo be ignited by conduction or radiation.

firedamp A combustible gas, usually methane, occurring naturally in coal mines and form

firestopping The barriers for restricting the spread of fire in concealed spaces; the materials to fill gaps around penetrations in walls and ceilings.

fires Classes of fires: Class A fires are fires in ordinary combustible materials (e.g., paper, wood, cloth); Class B fires are those in combustible or flammable liquids, flammable gases, greases, and similar materials; Class C fires are those in electrical equipment; and Class D fires are those in combustible metals (e.g.. magnesium, sodium, potassium, etc.).

first aid (OSHA) Any one-time treatment and any follow-up visit for the purpose of observation of minor scratches, cuts, burns, splinters, and so forth that do not ordinarily require medical care.

first aid injury An injury requiring first aid treatment only, such as when only one treatment and only one subsequent observation of the injury is required.

fiscal year [FY] A 12-month period for which an organization plans the use of its funds.

fissile material Any material fissionable by thermal neutrons.

fission The splitting of a nucleus into at least two other nuclei with the release of a relatively large amount of energy.

fission gases Fission products, such as radon, krypton, and xenon, that exist in the gaseous state.

fission products The products produced as a result of the fissioning of heavy elements, plus the nuclides formed by the fission fragments' radioactive decay.

fissionable material A material that can be fissioned (split) into other nuclei by any process.

fit check (Respiratory Protection) Action by a respirator user to determine if the respirator is properly seated to the face. A positive or negative pressure check is made to ensure proper respirator facepiece seal. See user seal check.

fit factor (Respiratory Protection) A measure of how well a respirator fits as determined by a quantitative fit test. The ratio of the test agent concentration outside the respirator to the agent concentration inside the respirator.

fit test (Respiratory Protection) A protocol for determining an individual's ability to obtain a good fit with a particular size and style of respirator. Fit testing may be qualitative or quantitative.

fixed contamination (Radioactivity) Contamination that is unlikely to become airborne so that it may be inhaled or unlikely to adhere io the hands on being touched, so that it is not likely to be ingested.

fl.p. Flash point.

flame arrester Device used in gas vent lines and other similar locations to arrest or prevent the passage of flame into an enclosed space, such as a container or flammable liquid storage cabinet.

flame ionization detector A carbon detector that relies on the detection of ions formed when a carbon-containing material, such as a volatile or gaseous hydrocarbon, is burned in a hydrogen-rich flame. This detector is commonly used in a gas chromatograph to detect and quantitate organic compounds. It is also employed in some portable instruments.

flame photometric detector A detection system based on the luminescent emissions between 300 and 425 nanometers when sulfur compounds are introduced into a hydrogen-rich flame. An optical filter system is used to differentiate the sulfur compounds present from other materials. This detector finds application in gas chromatography.

flame propagation The spread of a flame throughout an entire volume of a vapor-air mixture from a single source of ignition.

flame retardant The use of chemicals, paints, or coatings for the treatment of materials to retard both the rate of burning and the rate at which fuel is contributed by the treated material.

flame spread The propagation of flarne over a surface

flame spread rating The surface burning characte in NFPA 101. spread. Capable of being ignited and of burning. Substance with a flash point below 100XF.

flameproofing material Chemicals that catalytically control the decomposition of cellulose material at flaming temperature.

flammable limits The percent by volume limits (i.e., upper and lower flammable limits) of flame propagation does not occur on contact with a source of ignition. See flammable range.

flammable liquid Liquid having a flash point below IOOXF and a vapor pressure not exceeding 40 pounds per square inch (absolute) at 100XF is a Class I flammable liquid. Class I flammable liquids are subdivided inio Class IA, which have a flash point below 73XF and a boiling point below 100XF; Class IB. which have a flash point below 73XF and a boiling point above 100XF; and Class 1C, which have a flash point at or above 73XF and below 100XF.

flammable range All concentrations of a mixture of a flammable vapor or gas in air in which a flash will occur or a flame will travel if the mixture is ignited. The lowest percentage at which this will occur is the lower explosive limit, and the highest percentage is the upper explosive limit. The difference between the lower and upper flammable limits. See flammable limits.

flammable solid A solid m rial that is easily ignited and thati burns rapidly.

flow meter Device for measuring the amount of fluid (air, gas, or liquid) flowing through it.

flow rate The volume per time unit (e.g., liters per minute, etc.) given to the flow of air or other fluid by the action of a pump, fan, etc.

fluid A substance that flows and yields to any force tending to change its shape.

fluidization A technique in which finely divided solids are caused to behave like a fluid by suspending them in a moving gas or liquid. An example is the fluid catalytic cracking process in petroleum refineries.

fluorescence The emission of electromagnetic radiation, especially that of visible light, as a result of the absorption of electromanetic radiation, and persisting only as long as the stimulating radiation is continued.

fluorescent screen A screen coated with a fluorescent substance so that it emits light when irradiated with X-rays.