OSAC Lexicon
The OSAC Lexicon is a compendium of forensic science terms and definitions. This terminology tool was created to help bring consistency and understanding to the way terms are used by the various forensic science. Use of the OSAC Lexicon does not replace the need to reference the original published source.
The terms and definitions in the OSAC Lexicon come from the published literature, including documentary standards and technical reports. It is continually updated with the latest work from OSAC units, as well as terms from newly published documentary standards and standards elevated to the OSAC Registry.
Gradually terms are evaluated and harmonized by the OSAC to a single term. This process results in an OSAC Preferred Term. An OSAC Preferred Term is a term, along with its definition, that has undergone review and evaluation by the FSSB Terminology Task Group and has been approved by the FSSB. The FSSB recommends that subcommittees use OSAC Preferred Terms when drafting standards.
The OSAC Lexicon should be the primary resource for terminology and used when drafting and editing forensic science standards and other OSAC work products.
A rapid oxidation process, which is an exothermic chemical reaction, resulting in the evolution of light and heat in varying intensities.
The process of determining the origin, cause, development, responsibility, and, when required, a failure analysis of a fire or explosion.
The process of determining the origin, cause, development, responsibility, and, when required, a failure analysis of a fire or explosion.
The boundary of fire effects within a scene in which the area of origin will be located. The fire area is characterized by identifying the border between damaged and undamaged areas, which are distinguishable by fire effects and patterns created by flame, heat, and smoke.
The circumstances, conditions, or agencies that bring together a fuel, ignition source, and oxidizer (such as air or oxygen) resulting in a fire or a combustion explosion.
The study of chemical processes that occur in fires including changes of state, decomposition, and combustion.
The study of chemical processes that occur in fires including changes in state, decomposition, and combustion.
material of interest at a fire scene that can be collected by an investigator as evidence to analyze.
the science related to the examination of fire debris samples performed to potentially detect and identify ignitable liquid residues (ILR).
The detailed study of how chemistry, fire science, and the engineering disciplines of fluid mechanics and heat transfer interact to influence fire behavior.
The detailed study of how chemistry, fire science, and the engineering disciplines of fluid mechanics and heat transfer interact to influence fire behavior.
The observable or measurable changes in or on a material as a result of a fire.
Any situation, process, material, or condition that can cause a fire or explosion or that can provide a ready fuel supply to augment the spread or intensity of a fire or explosion, all of which pose a threat to life or property.
The process of determining the origin, cause, and development of a fire or explosion.
The process of determining the origin, cause, and development of a fire or explosion
An individual who has demonstrated the skills and knowledge necessary to conduct, coordinate, and complete a fire investigation.
An individual who has demonstrated the skills and knowledge necessary to conduct, coordinate, and complete a fire investigation.
A structured approach to predicting one or more effects of a fire.
The physical changes, or identifiable shapes, formed by a fire effect or group of fire effects.
See fire spread.
Systems, devices, and equipment used to detect a fire and its by-products, actuate an alarm, or suppress or control a fire and its by-products, or any combination thereof.
The process of recreating the physical scene during fire scene analysis investigation or through the removal of debris and the placement of contents or structural elements in their pre-fire positions.
The body of knowledge concerning the study of fire and related subjects (such as combustion, flame, products of combustion, heat release, heat transfer, fire and explosion chemistry, fire and explosion dynamics, thermodynamics, kinetics, fluid mechanics, fire safety) and their interaction with people, structures, and the environment.
The body of knowledge concerning the study of fire and related subjects (such as combustion, flame, products of combustion, heat release, heat transfer, fire and explosion chemistry, fire and explosion dynamics, thermodynamics, kinetics, fluid mechanics, fire safety) and their interaction with people, structures, and the environment.
The movement of fire from one place to another.
see suppression.
see «suppression»
a symbol to describe the necessary requirements for fire to occur: fuel, heat, oxidizer, and an uninhibited chemical reaction.
A symbol used to describe the necessary requirements for fire to occur: fuel, heat, oxidizer, and an uninhibited chemical chain reaction.
A symbol used to describe the necessary requirements for fire to occur in which the three sides represent fuel, oxidizer, and a source of ignition. The connection of the sides to form a triangle symbolizes the chain of reaction.
The first fuel ignited is that which first sustains combustion beyond the ignition source.
The portion of an oral dose metabolized in the intestine, gut wall, or liver before reaching the systemic circulation.
A type of distortion, where central objects of the image erroneously appear closer than those at the edge typically resulting in what appear to be unusually large noses in the image
A process or reagent that helps secure the blood to the substrate or secures the substrate itself (e.g. snow, sand, etc.) so that it is not destroyed or degraded during chemical enhancement.
A process or reagent that helps secure the blood to the substrate or secures the substrate itself (e.g.,snow, sand, etc.) so that it is not destroyed or degraded during chemical enhancement.
A lens with a focal length that is not adjustable.
A lens with a focal length that is not adjustable
A schedule of reinforcement in which rewards for a correct response occur after a fixed period of time.
A schedule of reinforcement in which the subject is rewarded after a set number of unrewarded correct responses.
Clear plastic sheet with a pressure sensitive adhesive layer.
A body or stream of gaseous material involved in the combustion process and emitting radiant energy at specific wavelength bands determined by the combustion chemistry of the fuel. In most cases, some portion of the emitted radiant energy is visible to the human eye.
A hot, usually luminous zone of gas that is undergoing combustion.
The flaming leading edge of a propagating combustion reaction zone.
The condition where unburned fuel (pyrolysate) from the originating fire has accumulated in the upper layer to a sufficient concentration (i.e., at or above the lower flammable limit) that it ignites and burns. This can occur without ignition of, or prior to the ignition of, other fuels separate from the origin.
capable of burning with a flame
Capable of burning with a flame.
The upper or lower concentration limit at a specified temperature and pressure of a flammable gas or a vapor of an ignitible liquid and air, expressed as a percentage of fuel by volume that can be ignited.
see ignitable liquid
A liquid that has a closed-cup flash point that is below 37.8C (100F) and a maximum vapor pressure of 2068 mm Hg (40 psia) at 37.8C (100F). (See also 3.3.34, Combustible Liquid.)