Terms & Definitions in the Fire Retardant Coatings Industry

Afterglow: The smoldering combustion on a material when the heat source is removed

ASTM E 84 test procedure: In this test a 24 inch by 25 foot specimen is placed on the ledge at the tip of the tunnel and cover is set in place. A double gas burner at the front of the tunnel (sometimes called the ‘Steiner Tunnel’) provides a controlled heat source. The tunnel is calibrated using inorganic reinforced cement board and red oak. The cement board is assigned a flame spread rating and red oak 100. Smoke developed is also measured during this test. The E84 testing process has two methods: 10 minute test or 30 minute test, the procedure requires that coating intended for application to combustible surfaces be tested when applied to that specific surface. The one exception being that coating intended for application to any wood surface be tested when applied to Douglas fir. The tunnel test measures surface flammability of the specimen. The evaluation to the performance level of the surface flammability of building materials are: 0-25 (Class A or Type I), 26-75 (Type B or Class II) and 76-200 (Class C or Type III)

ASTM E119: Fire Tests of Building Materials: Hourly Ratings are assigned only to complete assemblies, of structural materials for buildings, including walls, floors, doors, ceilings, roofs, etc. It's vital to know that the hourly ratings have no reference whatsoever to real-time hours in an actual fire and they are NOT assigned to any one single component of a complete assembly such as a paint coating, wall covering or other single building material. Simply put, there is no such thing as a coating, additive or treatment that can be applied to and/or treated to any material which will give a 1, 2 or 3 hour rating.

Char length: The vertical distance of the specimen from the top of the test flame to the top of the charred area resulting from spread of flame and afterglow.

Combustible fibers: Includes readily ignitable and free burning fibers such as cotton, sisal, henequen, jute hem, tow, cocoa fiber, oakum, bled waste paper, kapok, hay, straw, Spanish moss, excelsior certain synthetic fibers and other like materials.

Conflagration: an extensive and destructive fire.

Decorative material: All materials such as curtains, draperies, streamers, surface coverings applied over the building finish for decorative, acoustical or other effect, and also cloth, cotton batting, straw, vines, leaves, trees and moss used for decorative effect.

Drip Burn: Any portion or residue of textiles or films which break or drip from the material and continue to flame after they reach the floor.

Fire Endurance: The period of resistance before failure a measure of the elapsed time during which a material or assemblage continues to exhibit fire resistance. The ability of building system, provide a degree of fire containment.

Fireproofing: Able to withstand fire or great heat, the term implies an absolute or unconditional property. Its use is inappropriate and misleading.

Fire Resistance: The property of material or their assemblies which prevents or retards the passage of excessive heat, hot gases or flames under conditions of use.

Fire resistance rating: The time in hours or fractions thereof that materials or their assemblies will resist fire exposure as determined by fire tests conducted in compliance with recognized standards.

Fire wall: a fire resistance rated wall, having protected opening, which restricts the spread of fire and extends continuously from the foundation to or through the roof.

Fire Resistant coating: A protection from a fire that extends the time that a structure can survive exposure to a fire.


A fluid applied surface covering on a combustible material which delays ignition and reduces flame spread when the covering is exposed to flame impingements; a substance or material applied to a combustible material to decrease its tendency to propagate flame across its surface. Reduces the rate of flame spread across the surface of a combustible material. Click on the link here for a full description of Fire Retardant.

Fire retardant paint: Intumesent surface coating that swells or chars when exposed to heat.

Fire Tetrahedron: An addition to the Fire Triangle, it adds the requirement for the presence of the chemical reaction which is the process of fire.

Fire Triangle: A simple model for understanding the ingredients necessary for most fires. The triangle illustrates a fire requires three elements: heat, fuel and oxygen. The fire is prevented or extinguished by removing any one of them. Without sufficient heat, a fire cannot begin, and it cannot continue. Without fuel, a fire will stop and without sufficient oxygen a fire cannon begin and it cannot continue. In the fire fighting and protection industry the fire triangle has been partially replaced by the Fire Tetrahedron.

Flameproofing: Able to withstand fire or great heat. The term implies an absolute or unconditional property. Its use is inappropriate and misleading.

Flame spread: The propagation of flame over a surface. Flame Spread Rating: The measurement of flame spread on the surface of materials or the assemblies as determined by tests conducted in compliance with recognized standards. Flame Resistant: The charring and decomposition when
exposed to flame or high temperatures. Flame Retardant: Chemical treatment utilized to reduce the flammability and tendency toward smoldering.

FR-S Rating: UL FR-S classified properties have a flame spread index of 25 or less and must not have progressed 10.5 feet beyond the center burners. Some companies say their treated lumber or plywood is FR-S rated with out UL Certified rating then it's just Class A rated.

Ignition Temperature: The lowest temperature to which a substance must be heated for it to continue burning without an outside source of heat. Some examples are listed below (The ignition temperature is only an approximation because of variables such as moisture content, mass, shape, conductivity and duration of exposure to heat.)

MATERIALSELF-IGNITION TEMPERATURE: Paper newsprint446°F, Cotton Batting446°F, Cotton Sheathing465°F, Woolen Blanket401°F, Viscose Rayon536°F, Wood fiberboard421°F - 444°F, Cane Fiberboard465°F.

UL Approved: "UL approved" is not a valid term used to refer to a UL Listed, UL Recognized or UL Classified product under any circumstances. There are a number of requirements and guidelines that should be followed to accurately communicate a product's UL certification.

UL Classified: LISTING SERVICE - A service whereby UL determines that a manufacturer has demonstrated the ability to produce a product that complies with UL requirements with respect to reasonably foreseeable risks associated with the product. As part of the service, UL authorizes the manufacturer to use the UL Listing Mark on products that comply with UL requirements and establishes Follow-Up Service conducted by UL as a check of the means the manufacturer exercises to determine compliance with UL requirements.

RECOGNITION SERVICE - A service whereby UL determines that a manufacturer has demonstrated the ability to produce a component for use in an end product that complies with UL requirements. It takes into account the performance and constructional characteristics of such end product insofar as this can be determined and the areas that require additional consideration for application of the component to the product. UL authorizes the manufacturer to use the UL Recognized Marking.

CLASSIFICATION SERVICE - A service whereby a manufacturer has demonstrated the ability to produce a product that complies with requirements for the purpose of classification or evaluation with respect to one or more of the following: (1) specific risks only, e.g., casualty, fire or shock, (2) performance under specified conditions, (3) regulatory codes, (4) other standards, including international standards, or (5) such other conditions that may be consider desirable.

Wood, in general, will ignite if subjected to the following temperatures for the stated periods of time.




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