Limiting oxygen index: Difference between revisions

Revision as of 08:28, 16 March 2009

Latest revision as of 12:52, 11 January 2019

(17 intermediate revisions by 13 users not shown)

Line 1:

The '''limiting oxygen index (LOI)''' is the minimum concentration of [[oxygen]], expressed as a percentage, that will support [[combustion]] of thea [[polymer]]. It is measured by passing a mixture of O₂oxygen and N₂[[nitrogen]] over a burning specimen, and reducing the O₂oxygen level until a critical level is reached. <ref>Definition taken from Principles of Polymer Engineering (2nd edition) by N.G. McCrum , C.P. Buckley, and C.B. Bucknall</ref>

{{Wikify|date=March 2009}}

LOI values for different plastics are determined by standardized tests, such as the ISO 4589 and ASTM D2863.<ref>[[ASTM]] D 2863, ''Standard Test Method for Measuring the Minimum Oxygen Concentration to Support Candle-Like Combustion of Plastics (Oxygen Index).''</ref>

{{deadend|date=March 2009}}

The LOI value is also dependent on the surrounding temperature of the sample. The percent of oxygen required for combustion reduces as the surrounding temperature is increased.

{{Orphan|date=February 2009}}

The '''limiting oxygen index (LOI)''' is the minimum concentration of oxygen, expressed as a percentage, that will support combustion of the polymer. It is measured by passing a mixture of O₂ and N₂ over a burning specimen, and reducing the O₂ level until a critical level is reached. <ref>Definition taken from Principles of Polymer Engineering (2nd edition) by N.G. McCrum , C.P. Buckley, and C.B. Bucknall</ref>

Plastics and cable material is tested for its LOI value at both ambient temperature and elevated temperature to understand its oxygen requirement under actual fire conditions.

<references />www.saassociates.com/pdf/criticaloxygen.pdf

Materials with an LOI greater than the atmospheric oxygen concentration are called fire retardant materials.<ref>{{Cite web|url=https://www.ias.ac.in/article/fulltext/boms/015/01/0067-0076|website=www.ias.ac.in|access-date=2019-01-11|title=Fire-retardant materials}}</ref>

==See also==

* [[Fire-resistance rating]]

==References==

<references />

[[Category:Passive fire protection]]