DIN4102 Flammability Class B1 Vertical Shaft Furnace at Technische Universität Braunschweig, iBMB, Germany.
Sample Holder for DIN4102 Flammability Class B1 Vertical Shaft Furnace
750°C Furnace to test A1 and A2 Class Combustibility as per DIN4102 Part 1 at TU Braunschweig
Flammable liquid warning sign

Flammability is defined as how easily something will burn or ignite, causing fire or combustion. The degree of difficulty required to cause the combustion of a substance is quantified through fire testing. Internationally, a variety of test protocols exist to quantify flammability. The ratings achieved are used in building codes, insurance requirements, fire codes and other regulations governing the use of building materials as well as the storage and handling of highly flammable substances inside and outside of structures and in surface and air transportation. For instance, changing an occupancy by altering the flammability of the contents requires the owner of a building to apply for a building permit to make sure that the overall fire protection design basis of the facility can take the change into account.



A fire test can be conducted to determine the degree of flammability. Test standards used to make this determination but are not limited to the following:

Categorization of building materials

Materials can be tested for the degree of flammability and combustibility in accordance with the German DIN 4102. DIN 4102, as well as its British cousin BS 476 include for testing of passive fire protection systems, as well as some if its constituent materials.

The following are the categories in order of degree of combustibility as well as flammability:

Rating Degree of flammability Examples
A1 100% noncombustible (nichtbrennbar)
A2 ~98% noncombustible (nichtbrennbar)
B1 Difficult to ignite (schwer entflammbar) intumescents and some high end silicones
B2 Normal combustibility wood
B3 Easily ignited (leichtentflammbar)

A more recent norm is the European EN 13501-1 - Fire classification of construction products and building elements - which roughly replaces A2 with A2/B, B1 with C, B2 with D/E and B3 with F.

B3 or F rated materials may not be used in building unless combined with another material which reduces the flammability of those materials.

Important characteristics

Flash point

A material's flash point is a metric of how easy it is to ignite the vapor of the material as it evaporates into the atmosphere. A lower flash point indicates higher flammability. Materials with a flash points below 100 °F (38 °C) are regulated in the United States by OSHA as potential workplace hazards.

Vapor pressure

  • The vapor pressure of a liquid, which varies with its temperature, is a measure of how much the vapor of the liquid tends to concentrate in the surrounding atmosphere as the liquid evaporates. Vapor pressure is a major determinant of the flash point, with higher vapor pressures leading to lower flash points and higher flammability.

Examples of flammable liquids

Flammable liquids include, but are not limited to:

Examples of nonflammable liquids

Classification of flammability

The US Government uses the Hazardous Materials Identification System (HMIS) standard for flammability ratings, as do many US regulatory agencies, and also the US National Fire Protection Association (NFPA).

The ratings are as follows:

Rating Degree of flammability Examples
0 Materials that will not burn water
1 Materials that must be preheated before they will ignite lubricating oils, cooking oils
2 Materials that must be moderately heated or exposed to relatively high ambient temperatures before they will ignite diesel fuel
3 Liquids and solids that can ignite under almost all temperature conditions gasoline, acetone
4 Materials which will rapidly vaporize at atmospheric pressure and normal temperatures, or are readily dispersed in air and which burn readily natural gas, propane, butane



For existing buildings, fire codes focus on maintaining the occupancies as originally intended. In other words, if a portion of a building were designed as an apartment, one could not suddenly load it with flammable liquids and turn it into a gas storage facility, because the fire load and smoke development in that one apartment would be so immense as to overtax the active fire protection as well as the passive fire protection means for the building. The handling and use of flammable substances inside a building is subject to the local fire code, which is ordinarily enforced by the local fire prevention officer.

Linguistics: flammable vs. inflammable

Flammable and inflammable are synonyms and mean capable of burning. The word "inflammable" came from Latin inflammāre = "to set fire to," where the prefix "in-" means "in" as in "indoctrinate", rather than "not" as in "invisible" and "ineligible". Nonetheless, "inflammable" is often erroneously thought to mean "non-flammable". In the United States, this safety hazard is typically avoided by use of the back-formation flammable, despite its not being the proper Latin-derived term, on warning labels referring to physical combustibility.

The antonym of flammable/inflammable is non-inflammable, incombustible, or non-combustible.[1]

See also


  1. ^ http://www.wsu.edu/~brians/errors/inflammable.html

External links

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Flammability — Flam ma*bil ity, n. The quality of being flammable; inflammability. [Obs.] Sir T. Browne. [1913 Webster] …   The Collaborative International Dictionary of English

  • flammability — užsiliepsnojamumas statusas T sritis Standartizacija ir metrologija apibrėžtis Medžiagos savybė užsiliepsnoti. atitikmenys: angl. flammability vok. Brennbarkeit, f; Entflammbarkeit, f rus. воспламеняемость, f pranc. inflammabilité, f …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • flammability — degumas statusas T sritis chemija apibrėžtis Medžiagos gebėjimas degti normaliomis sąlygomis. atitikmenys: angl. combustibility; flammability; inflammability rus. горючесть …   Chemijos terminų aiškinamasis žodynas

  • flammability — liepsnumas statusas T sritis chemija apibrėžtis Medžiagos savybė užsiliepsnoti. atitikmenys: angl. flammability rus. воспламеняемость ryšiai: sinonimas – užsiliepsnojamumas …   Chemijos terminų aiškinamasis žodynas

  • flammability — užsiliepsnojamumas statusas T sritis fizika atitikmenys: angl. flammability vok. Brennbarkeit, f; Entflammbarkeit, f rus. воспламеняемость, f pranc. inflammabilité, f …   Fizikos terminų žodynas

  • flammability — flammable ► ADJECTIVE ▪ easily set on fire. DERIVATIVES flammability noun. USAGE The words flammable and inflammable have the same meaning. It is, however, safer to use flammable to avoid ambiguity, as the in prefix of inflammable can give the… …   English terms dictionary

  • flammability — noun Date: 1646 ability to support combustion; especially a high capacity for combustion …   New Collegiate Dictionary

  • flammability — See flammable. * * * …   Universalium

  • flammability — noun a) The condition of being flammable b) A measure of the extent to which something is flammable …   Wiktionary

  • flammability — n. quality of being flammable, combustibility, ability to catch fire easily …   English contemporary dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.