Updated Monday June 30, 2008

Firefighter Dictionary: S

The following is common terminology to structural fire firefighters. There are additional definitions for emergency medical terminology, building construction, arson investigation and hazardous materials and more. Please note that some definitions have more than one meaning but are spelled the same. Click on a letter to take you to that index.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 

S
SABA	Supplied air-breathing apparatus.
Sack mix	The amount of Portland cement in a cubic yard of concrete mix. Generally, 5 or 6 sack is required in a foundation wall.
Saddle	A small second roof built behind the back side of a fireplace chimney to divert water around the chimney. Also, the plate at the bottom of some—usually exterior—door openings. Sometimes called a threshold.
Safe Zone	A geographical region beyond the warm zone where there is no suspected product contamination; often referred to as the cold zone or the outermost zone.
Safety	The proper handling of a substance or carrying out of a task to eliminate its capacity to cause injury or do harm.
Safety belt	Device worn around the waist or as a harness for securing a person to a structure or within a vehicle.
Safety can	An approved container of not more than 5 gallons capacity, having a spring-closing lid and spout cover, and so designed that it will safely relieve pressure when subjected to fire exposure.
Safety Officer	A member of the Command Staff responsible for monitoring and assessing safety hazards or unsafe situations, and for developing measures for ensuring personnel safety. The Safety Officer may have Assistants.
Safety relief valve	A valve fitted on a pressure vessel or other containment under pressure to relieve overpressure.
Salamander	Portable type of furnace without grates that is used as a space heater in some work locations.
Salvage	The process of protecting the contents of a building from fire, smoke and water damage. Tools used include salvage covers (water proof tarps) that are placed over furniture, preventing damage from water and debris.
Salvage cover	A waterproof cover made of cotton duck, plastic, or other material and used by fire departments to protect unaffected furniture and building areas from heat, smoke, and water damage; a tarpaulin.
Salvage kit	An assortment of tools and appliances used for a specific purpose during salvage.
Sanitary sewer	A sewer system designed for the collection of waste water from the bathroom, kitchen and laundry drains, and is usually not designed to handle storm water.
SAR	Search and rescue
SARA	See Superfund Amendments and Reauthorization Act.
Sash	A single light frame containing one or more lights of glass. The frame that holds the glass in a window, often the movable part of the window.
Sash balance	A device, usually operated by a spring and designed to hold a single hung window vent up and in place
Saturated air	Air containing saturated water vapor with both the air and water vapor at the same dey-bulb temperature.
Saturated felt	A felt which is impregnated with tar or asphalt.
Saturated hydrocarbons	A hydrocarbon possessing only single covalent bonds. All of the carbon atoms are saturated with hydrogen. Examples include methane (CH4), propane (C3H8), and butane (C4H10)
Saturated steam	Steam at the boiling temperature corresponding to the pressure at which it exists.
SCBA	Self-contained breathing apparatus. It is a device consisting of an air filled cylinder, facemask and regulator and worn by rescue workers, firefighters, and others to provide breathable air in a hostile environment. It is often referred to as an air pack.
Scientific Method	The systematic pursuit of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of a hypothesis.
Scratch coat	The first coat of plaster, which is scratched to form a bond for a second coat
Screed, concrete	To level off concrete to the correct elevation during a concrete pour.
Screed, plaster	A small strip of wood, usually the thickness of the plaster coat, used as a guide for plastering.
SCUBA	Self-contained underwater breathing apparatus.
Click here to return to top of this page
Scupper	(1) An opening for drainage in a wall, curb or parapet. (2) The drain in a downspout or flat roof, usually connected to the downspout.
SDO	Standards Development Organizations
Sealer	A finishing material, either clear or pigmented, that is usually applied directly over raw wood for the purpose of sealing the wood surface.
Seasoning	Drying and removing moisture from green wood in order to improve its usability.
Seat of Explosion	A crater-like indentation created at the point of origin of an explosion.
Seat of the fire	Area center where the main body of fire is located as determined by the outward movement of heat and gases and where the fire is most deep seated. Frequently, when the seat of the fire is extinguished, much of the heat is eliminated; and the mop-up stage follows.
Seated Explosion	An explosion with a high localized point of origin, such as a crater.
Secondary contamination	Contamination by emergency response personnel of medical or related personnel outside of the hot zone.
Secondary decontamination	Decontamination between the primary (gross) and tertiary stages. Used after gross decontamination removes the major portion of the product. Depending on the incident it may be the final stage prior to doffing outer clothing.
Secondary Explosion	Any subsequent explosion resulting from an initial explosion.
Secondary Search	Once the fire is under control a second search of the structure will be conducted. The searching companies should report, "Secondary Search, All Clear."
Section	The organizational level having responsibility for a major functional area of incident management, e.g., Operations, Planning, Logistics, Finance/Administration, and Intelligence (if established). The section is organizationally situated between the Branch and the Incident Command.
Sector	Is either a geographic or functional assignment. Sector may take the place of either the Division or Group or both.
Segment	A geographical area in which a Task Force/Strike Team Leader or Supervisor of a single resource is assigned authority and responsibility for the coordination of resources and implementation of planned tactics. A segment may be a portion of a division or an area inside or outside the perimeter of an incident. Segments are identified with Arabic numbers.
Seizure	Convulsion; fit; attack of violent muscle contractions.
Self contained respirator	One of three types of respiratory protective devices that is designed to provide breathing air to the wearer, independent of the surrounding atmosphere: open-circuit system, closed-circuit system with oxygen self-generating capability, and compressed air or oxygen closed-circuit device. Also classified as demand and pressure-demand units,
Self-heating	The result of exothermic reactions, occurring spontaneously in some materials under certain conditions, whereby heat is liberated at a rate sufficient to raise the temperature of the material.
Self-ignition	Ignition resulting from self-heating. Synonymous with spontaneous ignition.
Self-ignition temperature	The minimum temperature at which the self-heating properties of a material lead to ignition.
Self-sealing shingles	Shingles containing factory-applied strips or spots of self-sealing adhesive.
Sepsis	Infection of a wound or body tissues with bacteria, which leads to the formation of pus or to the multiplication of the bacteria in the blood.
Septic system	An on site waste water treatment system. It usually has a septic tank which promotes the biological digestion of the waste, and a drain field which is designed to let the left over liquid soak into the ground. Septic systems and permits are usually sized by the number of bedrooms in a house.
Series operation	An operation of a multistage centrifugal pump in which the first impeller provides its water volume and pressure to the second impeller, thus building pressure until the final impeller delivers the same volume of water at increased pressure to the discharge. See Pressure Operation.
Service branch	A Branch within the Logistics Section responsible for service activities at the incident. Includes the Communication, Medical, and Food Units.
Service Conductors	The supply conductors that extend from the street main or from the transformer to the service equipment.
Service drop	The overhead service conductors from the last pole or other aerial support to and including the splices, if any, connecting to the service entrance conductors at the building. The minimum size is #8 copper in cable.
Click here to return to top of this page
Service entrance panel	Main power cabinet where electricity enters a home wiring system.
Service equipment	Main control gear at the service entrance, such as circuit breakers, switches, and fuses.
Service lateral	Underground power supply line.
Service test	Series of tests performed on apparatus and equipment in order to ensure operational readiness of the unit; should be performed at least yearly or whenever a piece of apparatus or equipment has undergone extensive repair.
Service Vehicle	A general purpose vehicle used to carry everything from medical equipment to used hose and transporting fire personnel wherever they might need to go.
Setback thermostat	A thermostat with a clock which can be programmed to come on or go off at various temperatures and at different times of the day/week. Usually used as the heating or cooling system thermostat.
Sewage ejector	A pump used to 'lift' waste water to a gravity sanitary sewer line. Usually used in basements and other locations which are situated bellow the level of the side sewer.
Sewer lateral	The portion of the sanitary sewer which connects the interior waste water lines to the main sewer lines. The side sewer is usually buried in several feet of soil and runs from the house to the sewer line. It is usually 'owned' by the sewer utility, must be maintained by the owner and may only be serviced by utility approved contractors. Sometimes called side sewer.
Sexless couplings	Coupling with no distinct male or female components. Normally found on Large Diameter Hose (LDH). Also called Uni-sex or Storz Coupling.
Shake	A wood roofing material, normally cedar or redwood. Produced by splitting a block of the wood along the grain line. Modern shakes are sometimes machine sawn on one side. See shingle.
Shear block	Plywood that is face nailed to short (2 X 4's or 2 X 6's) wall studs (above a door or window, for example). This is done to prevent the wall from sliding and collapsing.
Sheathing, sheeting	The structural wood panel covering, usually OSB or plywood, used over studs, floor joists or rafters/trusses of a structure.
Sheaves	Grooved pulleys.
Shed roof	A roof containing only one sloping plane.
Sheet metal duct work	The heating system. Usually round or rectangular metal pipes and sheet metal (for Return Air) and installed for distributing warm (or cold) air from the furnace to rooms in the home.
Sheet metal work	All components of a house employing sheet metal, such as flashing, gutters, and downspouts.
Sheet rock- Drywall-Wall board or gypsum	A manufactured panel made out of gypsum plaster and encased in a thin cardboard. Usually 1/2" thick and 4' x 8' or 4' x 12' in size. The 'joint compound'. 'Green board' type drywall has a greater resistance to moisture than regular (white) plasterboard and is used in bathrooms and other "wet areas".
Shelter in place	To direct people to quickly go inside a building and remain inside until the danger passes.
Shim	A small piece of scrap lumber or shingle, usually wedge shaped, which when forced behind a furring strip or framing member forces it into position. Also used when installing doors and placed between the door jamb legs and 2 X 4 door trimmers. Metal shims are wafer  1 1/2" X 2" sheet metal of various thickness' used to fill gaps in wood framing members, especially at bearing point locations.
Shingles	Roof covering of asphalt. asbestos, wood, tile, slate, or other material cut to stock lengths, widths, and thickness'.
Shingles, siding	Various kinds of shingles, used over sheathing for exterior wall covering of a structure.
Shipper	A person, company, or agency offering material for transportation.
Shipping name	The proper shipping name or other common name for the material; also any synonyms for the material.
Shipping papers	A shipping order, bill of lading, manifest, or other shipping document issued by the carrier.
S-hooks	Metal hooks placed through the grommet holes of a salvage cover to secure the cover.
Shop	The fire department maintenance or repair area.
Click here to return to top of this page
Short circuit	A situation that occurs when hot and neutral wires come in contact with each other. Fuses and circuit breakers protect against fire that could result from a short. An abnormal connection of low resistance between normal circuit conductors where the resistance is normally much greater. This is an overcurrent situation but it is not an overload.
Short Section	A section of hose that is used when a normal 50 foot length would be too much and when the hose lay is less than 25 feet from a water source. A short section is much easier to handle and requires much less area than 50 feet of charged hose would need.
Short Term Exposure Limit [STEL]	A 15-minute, time-weighted average exposure to a substance that should not be exceeded at any time during a workday, even if the 8-hour exposure is within the TLV-TWA. Exposures up to the STEL value should not be for longer than I5 minutes, nor occur more than 4 times per day, and there should be at least 60 minutes between successive exposures in this range.
Shoulder carry	A procedure of carrying fire hose on the shoulder.
Shut off nozzle	A type of nozzle, the water supply to which can be controlled at the nozzle, rather than at the source of supply; type of nozzle that has a valve or other device for controlling the water supply, firefighters use it to control water supply at the nozzle rather than at the source of supply.
Siamese	A hose appliance that has two or more female inlets and one male outlet, two or more inlets for one outlet; connects two lines into one.
Sick Building Syndrome [SBS]	Situation in which building occupants experience acute health and/or discomfort effects that appear to be linked to time spent in the building, but in which no specific illness or cause can be identified.
Side sewer	The portion of the sanitary sewer which connects the interior waste water lines to the main sewer lines. The side sewer is usually buried in several feet of soil and runs from the house to the sewer line. It is usually 'owned' by the sewer utility, must be maintained by the owner and may only be serviced by utility approved contractors. Sometimes called sewer lateral.
Sidelap	The distance asphalt shingles overlap horizontally. Also known as endlap.
Siding	The finished exterior covering of the outside walls of a frame building.
Siding, (lap siding)	Slightly wedge-shaped boards used as horizontal siding in a lapped pattern over the exterior sheathing. Varies in butt thickness from ½ to ¾ inch and in widths up to 12".
Sill	(1) The 2 X 4 or 2 X 6 wood plate framing member that lays flat against and bolted to the foundation wall (with anchor bolts) and upon which the floor joists are installed. Normally the sill plate is treated lumber. (2) The member forming the lower side of an opening, as a door sill or window sill.
Sill cock	An exterior water faucet (hose bib).
Sill plate (mudsill)	Bottom horizontal member of an exterior wall frame which rests on top a foundation, sometimes called mudsill. Also sole plate, bottom member of an interior wall frame.
Sill seal	Fiberglass or foam insulation installed between the foundation wall and sill (wood) plate. Designed to seal any cracks or gaps.
Simple asphyxiant	A material that replaces the amount of oxygen admitted into the body without further damage to tissues or poisoning. Examples are nitrogen and carbon dioxide.
Simulcasting	Any time the dispatch center simultaneously dispatches an alarm on more than one radio frequency.
Single hung window	A window with one vertically sliding sash or window vent.
Single phase	Single phase 120/240 volts is used primarily in residential structures. It is operated by 3 wires, consisting of two hot wires each carrying 120 volts and a neutral wire having no voltage. Items requiring 240 Volts are connected between the two hot wires, and loads requiring 120 Volts can be connected between either hot wire and the neutral.
Single Resource	An individual, a piece of equipment and its personnel complement, or a crew or team of individuals with an identified work Supervisor that can be used on an incident.
Single stage centrifugal pump	A centrifugal pump with only one impeller.
Siphon	Section of hard suction hose or piece of pipe used to maintain an equal level of water in two or more portable tanks.
Siren	A warning device that provides a high-pitched or an alternating high-pitched and low-pitched wailing sound, used by emergency vehicles.
Site safety plan	Written site-specific safety criteria that establish requirements for protecting the health and safety of responders during all activities conducted at an incident.
SITREP	Situation Report
Click here to return to top of this page
Situation Unit	Functional Unit within the Planning Section responsible for the collection, organization, and analysis of incident status information, and for analysis of the situation as it progresses. Reports to the Planning Section Chief.
Size-Up	A mental process of evaluating all of the influencing factors at a fire scene before committing personnel and equipment to a course of action. This usually includes hazards, life safety, fire involvement and plan of attack. The verbal appraisal via radio of conditions at the scene of an incident by the first-in company or officer. May be updated as command officers arrive on the scene. This is the procedure and the report of the situation. The first arriving officer on the scene will "give a size-up" over the radio. This will include a description of the structure and the initial plan of attack. It's been said that size-up starts even before you leave the station. The time of day, the weather conditions, the availability of water and what you may already know about this structure are examples of factors that go into size-up. Once you arrive you don't just look at the fire. Are there cars in the driveway? Are there toys in the yard? Are the newspapers piled up? Many things go into size-up.
Skid load	A system of loading fire hose such that the top layer can be pulled off at the fire.
Skilled support personnel	Personnel who are skilled in the operation of certain equipment, such as cranes and hoisting equipment, and who are needed temporarily to perform immediate emergency support work that cannot reasonably be performed in a timely fashion by emergency response personnel.
Skin dosage	This is equal to the time of exposure in minutes of an individual's unprotected skin multiplied by the concentration of the agent cloud.
Skylight	A more or less horizontal window located on the roof of a building.
Slab on grade	A type of foundation with a concrete floor which is placed directly on the soil. The edge of the slab is usually thicker and acts as the footing for the walls.
Slab, concrete	Concrete pavement, i.e. driveways, garages, and basement floors.
Slab, door	A rectangular door without hinges or frame.
Sleeper	Usually, a wood member embedded in concrete, as in a floor, that serves to support and to fasten the subfloor or flooring.
Sleeve(s)	Pipe installed under the concrete driveway or sidewalk, and that will be used later to run sprinkler pipe or low voltage wire.
Sliding rope	A system used by firefighters for lowering themselves from the upper stories of a building to the ground or into a below ground area.
Slope	The incline angle of a roof surface, given as a ratio of the rise (in inches) to the run (in feet).  It is expressed sometimes as a fraction but typically as "X" in 12. For example, a roof that rises at the rate of 4 inches for each foot (12 inches) of run, is designated as having a 4 in 12 slope. See also pitch.
Slump	The "wetness" of concrete. A 3 inch slump is dryer and stiffer than a 5 inch slump.
Small Diameter Hoses (SDH)	Hose of 3/4 to 2 inches in diameter; used for fire fighting purposes.
Small line	Any fire hose from 1 1/2 or 1 3/4-inch and smaller. See Handline and Booster Line.
Smoke	A combination of airborne gases, carbon particles, vapors, or solid and liquid aerosols and other products of incomplete combustion hindering respiration and obscuring visibility and access to the seat of a fire. Coping with smoke is one of the tasks for which firefighters require special training and experience.
Smoke Condensate	The condensed residue of suspended vapors and liquid products of incomplete combustion.
Smoke Detector	An alarm device that automatically detects the presence of smoke. Also called a smoke alarm.
Smoke ejector	A mechanical device to force smoke from a building or to blow fresh air into a building; sometimes equipped with a flexible tube.
Smoke Explosion	An explosion of heated smoke and gases, which have been pent-up in a burning building, when air is admitted, completing the fire triangle of fuel-heat-oxygen. As the self-ignition temperature of many solids is in the 450 degrees F. to 800 degrees F. range and such temperatures may be present in buildings in which a fire has gained headway, all that is needed is introduction of air containing more oxygen to produce combustion so rapidly as to have the appearance of an explosion. Also called a "backdraft."
Smolder	Bum with little smoke and no flame.
Smoldering phase	The third stage of burning in which flames cease to exist because the area of confinement is air tight and lacks enough oxygen.
Smothering	The act of excluding the oxidizer from a fuel.
Click here to return to top of this page
Soffit	The area below the eaves and overhangs. The underside where the roof overhangs the walls. Usually the underside of an overhanging cornice.
Soft sleeve hose	Large diameter, collapsible piece of intake hose used to connect a fire pump to a pressurized water supply source; sometimes incorrectly referred to as "soft suction hose."
Soil pipe	A large pipe that carries liquid and solid wastes to a sewer or septic tank.
Soil stack	A plumbing vent pipe that penetrates the roof.
Sole plate	The bottom, horizontal framing member of a wall that's attached to the floor sheeting and vertical wall studs.
Solid bridging	A solid member placed between adjacent floor joists near the center of the span to prevent joists or rafters from twisting.
Solid stream	A hose stream that stays together as a solid mass as opposed to a fog or spray; a water stream produced from a smooth bore nozzle.
Solubility	The ability or tendency of one substance to blend uniformly with or dissolve into another; the ability of a material to dissolve in water or another liquid. The ability of a substance to form a solution with another substance.
Solution	Mixture of one or more substances in another in which all ingredients are completely dissolved.
Solvent	A liquid that will dissolve a substance to form a solution. Some examples of solvents are water, petroleum distillate, xylene, or methanol. A substance, usually a liquid, capable of absorbing another liquid, gas, or solid to form a homogeneous mixture.
Soot	Black particles of carbon produced in a flame.
SOP