"Pyrophorus" redirects here. For the bioluminescent beetle genus, see Pyrophorus (beetle).
A substance is pyrophoric (from Greek: πυροφόρος, pyrophoros, 'fire-bearing') if it ignites spontaneously in air at or below 54 °C (129 °F) (for gases) or within 5 minutes after coming into contact with air (for liquids and solids).[1] Examples are organolithium compounds and triethylborane. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen. Class Dfire extinguishers are designated for use in fires involving pyrophoric materials. A related concept is hypergolicity, in which two compounds spontaneously ignite when mixed.
The creation of sparks from metals is based on the pyrophoricity of small metal particles, and pyrophoric alloys are made for this purpose.[2] Practical applications include the sparking mechanisms in lighters and various toys, using ferrocerium; starting fires without matches, using a firesteel; the flintlock mechanism in firearms; and spark testing ferrous metals.
Small amounts of pyrophoric liquids are often supplied in a glass bottle with a polytetrafluoroethylene-lined septum. Larger amounts are supplied in metal tanks similar to gas cylinders, designed so a needle can fit through the valve opening. A syringe, carefully dried and flushed of air with an inert gas, is used to extract the liquid from its container.
When working with pyrophoric solids, researchers often employ a sealed glove box flushed with inert gas. Since these specialized glove boxes are expensive and require specialized and frequent maintenance, many pyrophoric solids are sold as solutions, or dispersions in mineral oil or lighter hydrocarbon solvents, so they can be handled in the atmosphere of the laboratory, while still maintaining an oxygen- and moisture-free environment. Mildly pyrophoric solids such as lithium aluminium hydride and sodium hydride can be handled in the air for brief periods of time, but the containers must be flushed with inert gas before the material is returned to the container for storage.
Iron sulfide[disambiguation needed]: often encountered in oil and gas facilities, where corrosion products in steel plant equipment can ignite if exposed to air
Uranium, as shown in the disintegration of depleted uranium penetrator rounds into burning dust upon impact with their targets; in finely divided form it is readily ignitable, and uranium scrap from machining operations is subject to spontaneous ignition[7]
^N. Pradeep Sharma (September 1998), Dictionary Of Chemistry, ISBN9788121205931
^ abcAngelo & Subramanian (2008), Powder metallurgy: science, technology and applications, p. 48, Powders of aluminium, iron and magnesium are highly pyrophoric in nature
^C.W. Corti et al. / Applied Catalysis A: General 291 (2005) 257
^Pyrophoric lead composition and method of making it
^Charles J (1966). "The Reaction of Pyrophoric Lead with Oxygen". The Journal of Physical Chemistry. 70 (5): 1478–1482. doi:10.1021/j100877a023.
^DOE | Office of Health, Safety and Security | Nuclear Safety and Environment | Uranium 2015-02-21 at the Wayback Machine, retrieved 3 September 2013; on 24 August 2010.
^DOE | Office of Health, Safety and Security | Nuclear Safety and Environment | Plutonium 2015-02-21 at the Wayback Machine, retrieved 3 September 2013; on 28 September 2010.
External linksedit
(archived)
. Archived from the original on 2015-07-09.
(PDF). Environmental Health and Safety. University of Minnesota. Archived from the original (PDF) on 31 October 2014. Retrieved 27 March 2021.
December 11, 2023
pyrophoricity, confused, with, porphyria, porphyriticity, pyrophorus, redirects, here, bioluminescent, beetle, genus, pyrophorus, beetle, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliab. Not to be confused with Porphyria or Porphyriticity Pyrophorus redirects here For the bioluminescent beetle genus see Pyrophorus beetle This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Pyrophoricity news newspapers books scholar JSTOR July 2019 Learn how and when to remove this template message A substance is pyrophoric from Greek pyroforos pyrophoros fire bearing if it ignites spontaneously in air at or below 54 C 129 F for gases or within 5 minutes after coming into contact with air for liquids and solids 1 Examples are organolithium compounds and triethylborane Pyrophoric materials are often water reactive as well and will ignite when they contact water or humid air They can be handled safely in atmospheres of argon or with a few exceptions nitrogen Class D fire extinguishers are designated for use in fires involving pyrophoric materials A related concept is hypergolicity in which two compounds spontaneously ignite when mixed Contents 1 Uses 2 Handling 3 Pyrophoric materials 3 1 Solids 3 2 Liquids 3 3 Gases 4 Explanatory notes 5 References 6 External linksUses editThe creation of sparks from metals is based on the pyrophoricity of small metal particles and pyrophoric alloys are made for this purpose 2 Practical applications include the sparking mechanisms in lighters and various toys using ferrocerium starting fires without matches using a firesteel the flintlock mechanism in firearms and spark testing ferrous metals Handling editSee also Air free technique Small amounts of pyrophoric liquids are often supplied in a glass bottle with a polytetrafluoroethylene lined septum Larger amounts are supplied in metal tanks similar to gas cylinders designed so a needle can fit through the valve opening A syringe carefully dried and flushed of air with an inert gas is used to extract the liquid from its container When working with pyrophoric solids researchers often employ a sealed glove box flushed with inert gas Since these specialized glove boxes are expensive and require specialized and frequent maintenance many pyrophoric solids are sold as solutions or dispersions in mineral oil or lighter hydrocarbon solvents so they can be handled in the atmosphere of the laboratory while still maintaining an oxygen and moisture free environment Mildly pyrophoric solids such as lithium aluminium hydride and sodium hydride can be handled in the air for brief periods of time but the containers must be flushed with inert gas before the material is returned to the container for storage Pyrophoric materials editSolids edit White phosphorus Alkali metals especially potassium rubidium caesium including the alloy NaK Finely divided metals iron 3 aluminium 3 magnesium 3 calcium zirconium citation needed uranium titanium tungsten bismuth hafnium thorium osmium neodymium Some metals and alloys in bulk form cerium plutonium Alkylated metal alkoxides or nonmetal halides diethylethoxyaluminium dichloro methyl silane Potassium graphite KC8 Metal hydrides sodium hydride lithium aluminium hydride uranium trihydride Partially or fully alkylated derivatives of metal and nonmetal hydrides diethylaluminium hydride trimethylaluminium triethylaluminium butyllithium with a few exceptions i e dimethylmercury and tetraethyllead Copper fuel cell catalysts zinc oxide aluminium oxide 4 Grignard reagents compounds of the form RMgX Used hydrogenation catalysts such as palladium on carbon or Raney nickel especially hazardous because of the adsorbed hydrogen Iron sulfide disambiguation needed often encountered in oil and gas facilities where corrosion products in steel plant equipment can ignite if exposed to air Lead and carbon powders produced from decomposition of lead citrate 5 6 Uranium as shown in the disintegration of depleted uranium penetrator rounds into burning dust upon impact with their targets in finely divided form it is readily ignitable and uranium scrap from machining operations is subject to spontaneous ignition 7 Neptunium Several compounds of plutonium are pyrophoric and they cause some of the most serious fires occurring in United States Department of Energy facilities 8 Petroleum hydrocarbon PHC sludgeLiquids edit Diphosphane Metalorganics of main group metals e g aluminium gallium indium zinc cadmium etc Triethylborane tert Butyllithium Diethylzinc Triethylaluminium Linseed oil rags soaked in linseed oil can self igniteHydrazine is hypergolic with oxidants like dinitrogen tetroxide or hydrogen peroxide but not truly pyrophoric Gases edit Nonmetal hydrides arsine phosphine i diborane germane silane Metal carbonyls dicobalt octacarbonyl nickel carbonyl Explanatory notes edit Phosphine PH3 is only pyrophoric if impure with P2H4 present References edit GHS seventh revised version https www unece org fileadmin DAM trans danger publi ghs ghs rev07 English ST SG AC10 30 Rev7e pdf N Pradeep Sharma September 1998 Dictionary Of Chemistry ISBN 9788121205931 a b c Angelo amp Subramanian 2008 Powder metallurgy science technology and applications p 48 Powders of aluminium iron and magnesium are highly pyrophoric in nature C W Corti et al Applied Catalysis A General 291 2005 257 Pyrophoric lead composition and method of making it Charles J 1966 The Reaction of Pyrophoric Lead with Oxygen The Journal of Physical Chemistry 70 5 1478 1482 doi 10 1021 j100877a023 DOE Office of Health Safety and Security Nuclear Safety and Environment Uranium Archived 2015 02 21 at the Wayback Machine retrieved 3 September 2013 archived on 24 August 2010 DOE Office of Health Safety and Security Nuclear Safety and Environment Plutonium Archived 2015 02 21 at the Wayback Machine retrieved 3 September 2013 archived on 28 September 2010 External links editUS Dept of Energy Handbook Primer on Spontaneous Heating and Pyrophoricity archived List of pyrophoric materials Archived from the original on 2015 07 09 Pyrophoric Chemicals Guide PDF Environmental Health and Safety University of Minnesota Archived from the original PDF on 31 October 2014 Retrieved 27 March 2021 Retrieved from https en wikipedia org w index php title Pyrophoricity amp oldid 1185067708, wikipedia, wiki, book, books, library,
