Editing TNT (section)

== Energy content ==
{{See also|TNT equivalent}}
[[File:British 20 mm Oerlikon shell diagrams.jpg|thumb|Cross-sectional view of [[Oerlikon 20 mm cannon]] shells (dating from {{Circa|1945}}) showing color codes for TNT and [[pentolite]] fillings]]

The energy density of TNT is used as a reference point for many other explosives, including nuclear weapons, as their energy content is measured in equivalent tonnes (metric tons, t) of TNT. The energy used by [[NIST]] to define the equivalent is 4.184 [[gigajoule|GJ]]/t or exactly 1 [[kcal]]/g.<ref>{{Cite web |url=https://www.nist.gov/physical-measurement-laboratory/nist-guide-si-appendix-b8 |title=Guide for the Use of the International System of Units (SI) |work=NIST |date=2008 |access-date=2024-03-25 }}</ref>

For safety assessments, it has been stated that the detonation of TNT, depending on circumstances, can release 2.673–6.702 GJ/t.<ref>{{cite web |url=https://hal.archives-ouvertes.fr/hal-00629253/document |title=Blast effects of external explosions (Section 4.8 Limitations of the TNT equivalent method) |page=16 |year=2011 |archive-url=https://web.archive.org/web/20160810225249/http://hal.archives-ouvertes.fr/hal-00629253/document |archive-date=2016-08-10}}</ref>

The [[heat of combustion]] however is 14.5 GJ/t (14.5 MJ/kg or 4.027 kWh/kg), which requires that the carbon in TNT fully react with atmospheric oxygen, which does not occur in the initial event.<ref name=babrauskas>{{cite book |last1=Babrauskas |first1=Vytenis |title=Ignition Handbook |year=2003 |publisher=Fire Science Publishers/Society of Fire Protection Engineers |location=Issaquah, WA |isbn=978-0-9728111-3-2 |page=453}}</ref>

For comparison, [[gunpowder]] contains 3 MJ/kg, [[dynamite]] contains 7.5 MJ/kg, and [[gasoline]] contains 47.2 MJ/kg (though gasoline requires an [[oxidizing agent|oxidant]], so an optimized gasoline and O<sub>2</sub> mixture contains 10.4 MJ/kg).{{Cn|date=January 2021}}