A fire-resistance rating typically means the duration for which a

passive fire protection Passive fire protection (PFP) is components or systems of a building or structure that slows or impedes the spread of the effects of fire or smoke without system activation, and usually without movement. Examples of passive systems include floor- ...

system A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its open system (systems theory), environment, is described by its boundaries, str ...

can withstand a standard fire resistance test. This can be quantified simply as a measure of time, or it may entail other criteria, involving evidence of functionality or fitness for purpose.

Common rating systems

The following depict the most commonly used international time/temperature curves: File:Din iso astm ul curves.JPG,

Time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

curves used for testing the fire-resistance rating of

s such as firestops, fire doors, wall and floor assemblies, etc., which are used in compartmentalisation in

building A building or edifice is an enclosed Structure#Load-bearing, structure with a roof, walls and window, windows, usually standing permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes, and functions, a ...

s and the petrochemical industry in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. File:Tunnel hc iso curves.jpg, Time/temperature curves used for testing the fire-resistance rating of passive fire protection systems in tunnels in

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

, the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

and

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

. File:Rws tunnel curve.jpg, Time/temperature curve used for testing the fire-resistance rating of passive fire protection systems in tunnels in the Netherlands. File:Eurocode 1 curve.jpg, Time/temperature curve used for testing the fire-resistance rating of passive fire protection systems in Europe. File:French hc curve 1.jpg, Time/temperature curve used for testing the fire-resistance rating of passive fire protection systems in tunnels in

. File:German tunnel curves.jpg, Time/temperature curve used for testing the fire-resistance rating of passive fire protection systems in tunnels in

. File:Euro furnace pressure.jpg, Furnace

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...

is also subject to standardised tolerances for testing to obtain fire-resistance ratings. This image shows European tolerances, subject to NEN- EN 1363-1. File:temp tolerance.jpg, Furnace temperatures for fire testing to obtain fire-resistance ratings are subject to certain tolerances. This graph shows the tolerance applicable to the European building elements / cellulosic curve. File:Moac_time_temperature_curve_astm_3134.png, MOAC: Mother of all curves, from ASTM International

International fire-resistance ratings

There are many international variations for nearly countless types of products and systems, some with multiple test requirements.

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

's Institute for Research in Construction (a part of the National Research Council and publisher of Canada's model building code – NBC) requires a special test regime for firestops for

plastic Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...

pipe penetrants. Fire endurance tests for this application must be run under 50Pa positive furnace pressure in order to adequately simulate the effect of potential temperature differences between indoor and outdoor temperatures in Canada's winters. Special hoods are applied here to provide suction on the top side of a test assembly in order to reach the 50Pa pressure differential. Afterwards, a 30PSI hose-stream test may be applied. Outdoor spray

fireproofing Fireproofing is rendering something (Building, structures, materials, etc.) resistant to fire, or incombustible; or material for use in making anything fire-proof. It is a passive fire protection measure. "Fireproof" or "fireproofing" can be u ...

methods that must be qualified to the

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...

curve may be required to pass a host of environmental tests before any burn takes place, to minimize the likelihood of ordinary operational environments rendering a vital system component useless before it ever encounters a

fire Fire is the rapid oxidation of a fuel in the exothermic chemical process of combustion, releasing heat, light, and various reaction Product (chemistry), products. Flames, the most visible portion of the fire, are produced in the combustion re ...

. If critical environmental conditions are not satisfied, an assembly may not be eligible for a fire-resistance rating.

Tests for fire resistance of record protection equipment

The following classifications may be attained when testing in accordance with UL 72.

Class 125 Rating

This rating is the requirement in data safes and vault structures for protecting digital information on magnetic media or hard drives. Temperatures inside the protected chamber must be held below for the time period specified, such as Class 125-2 Hour, with temperatures up to outside the vault. The temperature reading is taken on the inside surfaces of the protective structure. Maintaining the temperature below 125 °F is critical because data is lost above that temperature threshold, even if the media or hard drives appear to be intact.

Class 150 Rating

This is the rating required to protect microfilm, microfiche, and other film-based information storage media. Above 150 °F (65.5 °C) film is distorted by the heat and information is lost. A Class 150-2 Hour vault must keep the temperature below 150 °F. for at least two hours, with temperatures up to 2,000 °F. (1,093.3 °C) outside the vault.

Class 350 Rating

This rating is the requirement for protecting paper documents. Above 350 °F (176.7 °C) paper is distorted by the heat and information is lost. A Class 350-4 Hour vault must keep the temperature below 350 °F. for at least four hours, with temperatures up to 2,000 °F. (1,093.3 °C) outside the vault.

Different time/temperature curves

Typically, most countries use the building elements curve for residential and commercial spaces, which is nearly identical in most countries as that is what results by burning

wood Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...

. The building elements curve is characterized jointly by, including, but not limited to, DIN4102, BS476, ASTM E119, ULC-S101, etc. For industrial facilities in the hydrocarbon and petrochemical industries, a hydrocarbon curve (such as UL 1709) is used, reflecting a more rapid temperature rise. The only commonly used exposure beyond this, apart from the more recent tunnel curves shown above, would be the jet fire exposure standards such as ISO 22899, which are used where equipment may be subject to the extreme heat and momentum effects of jet fire exposure. During a fire in a tunnel, as well as in the petrochemical industry, temperatures exceed those of ordinary building (cellulosic) fires. This is because the fuel for the fire is

s, which burn hotter (compare hydrocarbon curve above to ASTM E119 curve), faster and typically run out of fuel faster as well, compared against timber. The added complication with tunnels is that heat cannot escape as well as it can in open area. Instead, the fire is confined to a narrow tube, where pressure and heat build up and spread rapidly, with little room for escape and little chance of compartmentalization.

Example of a fire stop test

Construction of a test sample consists of a mockup of a section of

concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...

floor, with typical mechanical and electrical utility components (pipes and cables) penetrating the floor assembly. A firestop mortar is applied around the penetrations. The completed test sample is inserted into a furnace such that one side is exposed to a fire. The test is terminated when the fire stops successfully meet the test criteria in minimizing the amount of heat and smoke allowed to pass through the assembly, when the fire penetrates the fire stops. This determines the fire stop F-Rating. The length of time required for a penetrant or sample on average to exceed a specified average heat rise above ambient at any single location determines the duration for the FT Rating (Fire and Temperature). If a hose-stream test is passed afterwards, the rating can then be expressed as an FTH Rating (Fire, Temperature and Hose-stream). The lowest of the three determines the overall rating.

References

External links

BAM Berlin

Institute for Research in Construction/NRC

iBMB TU Braunschweig
Technische Universität Braunschweig.
Gütegemeinschaft Brandschutz im Ausbau

Fire Retardant Glass
- UL9 Certified Fire Resistant glass in USA - 284 °F for 180 minutes {{Authority control Passive fire protection Rating systems