Editing C-4 (explosive) (section)

== Analysis ==
=== Toxicity ===
C-4 has toxic effects on humans when ingested. Within a few hours multiple generalized seizures, vomiting, and changes in mental activity occur.<ref name="trippy">{{Cite journal|title = Toxic Effects Following Ingestion of C4 Plastic Explosive|last1 = Stone|first1 = William J.|date = December 1969|journal = Arch Intern Med|doi = 10.1001/archinte.1969.00300220078015|pages = 726–730|last2 = Paletta|first2 = Theodore L.|last3 = Heiman|first3 = Elliott M.|last4 = Bruce|first4 = John I.|last5 = Knepshield|first5 = James H.|issue = 6|volume = 124|pmid = 5353482}}</ref> A strong link to [[Central nervous system|central nervous]] dysfunction is observed.<ref>{{Cite journal|title = The Neurotoxicity of Cyclotrimethylenetrinitramine (RDX) in a Child: A Clinical and Pharmacokinetic Evaluation|last1 = Woody|first1 = Robert C.|date = 1986|journal = Clinical Toxicology|doi = 10.3109/15563658608992595|pmid = 3746987|pages = 305–319|last2 = Kearns|first2 = Gregory L.|issue = 4|volume = 24|last3 = Brewster|first3 = Marge A.|last4 = Turley|last5 = Sharp|first4 = Charles P.|first5 = Gregory B.|last6 = Lake|first6 = Robert S.}}</ref> If ingested, patients may be administered a dose of [[active charcoal]] to [[adsorb]] some of the toxins, and [[haloperidol]] intramuscularly and [[diazepam]] intravenously to help the patient control seizures until it has passed. However, ingesting small amounts of C-4 is not known to cause any long-term impairment.<ref name="yummy">{{cite journal | author1=K Fichtner, MD | title=A plastic explosive by mouth | date=May 2002 | journal=Journal of the Royal Society of Medicine | volume=95 | issue=5 | location=U.S. Army Hospital, Camp Bondsteel, Kosovo | pages=251–252 | quote=C4 contains 90% cyclotrimethylenetrinitramine (RDX) | doi=10.1177/014107680209500510| pmc=1279680 | pmid=11983768}}</ref>

=== Investigation ===
If C-4 is marked with a [[taggant]], such as [[DMDNB|DMNB]], it can be detected with an explosive vapor detector before it has been detonated.<ref name="MaterialsCouncil1998">{{cite book|author1=((Committee on Marking, Rendering Inert, and Licensing of Explosive Materials))|author2=((National Research Council))|author3=((Division on Engineering and Physical Sciences))|author4=((Commission on Physical Sciences, Mathematics, and Applications))|title=Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors|url=https://books.google.com/books?id=hgSdAgAAQBAJ&pg=PA160|date=27 May 1998|publisher=National Academies Press|isbn=978-0-309-06126-1|page=46}}</ref> A variety of methods for explosive residue analysis may be used to identify C-4. These include optical microscope examination and [[Scanning electron microscope|scanning electron microscopy]] for unreacted explosive, chemical spot tests, [[thin-layer chromatography]], [[X-ray crystallography]], and [[infrared spectroscopy]] for products of the explosive chemical reaction. Small particles of C-4 may be easily identified by mixing with thymol crystals and a few drops of [[sulfuric acid]]. The mixture will become rose colored upon addition of a small quantity of ethyl alcohol.<ref>{{cite web|last1=Allman, Jr.|first1=Robert|title=Explosives|url=http://chemstone.net/Forensics/Expl.html|website=chemstone.net|access-date=19 July 2014|archive-date=23 July 2014|archive-url=https://web.archive.org/web/20140723190157/http://chemstone.net/Forensics/Expl.html|url-status=dead}}</ref>

RDX has a high [[birefringence]], and the other components commonly found in C-4 are generally [[Isotropy|isotropic]]; this makes it possible for [[forensic science]] teams to detect trace residue on fingertips of individuals who may have recently been in contact with the compound.  However, positive results are highly variable and the mass of RDX can range between 1.7 and 130&nbsp;[[Nanogram|ng]], each analysis must be individually handled using magnifying equipment.  The [[Polarized light microscopy|cross polarized light]] images obtained from microscopic analysis of the fingerprint are analyzed with gray-scale thresholding<ref>{{cite web|last1=Brown |first1=Lew |title=Thresholding in Imaging Particle Analysis (A four part series) |url=http://www.particleimaging.com/wordpress/wp-content/uploads/2013/01/Thresholding_Series.pdf |website=www.particleimaging.com |publisher=ParticleImaging.com |access-date=19 July 2014 |url-status=dead |archive-url=https://web.archive.org/web/20150403104803/http://www.particleimaging.com/wordpress/wp-content/uploads/2013/01/Thresholding_Series.pdf |archive-date=3 April 2015 }}</ref> to improve contrast for the particles. The contrast is then inverted in order to show dark RDX particles against a light background. Relative numbers and positions of RDX particles have been measured from a series of 50 fingerprints left after a single contact impression.<ref name="fingerprints3">{{cite journal|last1 = Verkouteren|first1 = Jennifer R.|last2 = Coleman|first2 = Jessica L.|last3 = Cho|first3 = Inho|title = Automated Mapping of Explosives Particles in Composition C-4 Fingerprints|journal = Journal of Forensic Sciences|volume = 55|issue = 2|pages = 334–340|doi = 10.1111/j.1556-4029.2009.01272.x|pmid = 20102455|url = https://www.nist.gov/customcf/get_pdf.cfm?pub_id=831440|format=PDF|year=2010|s2cid = 5640135}}
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Military and commercial C-4 are blended with different oils. It is possible to distinguish these sources by analyzing this oil by high-temperature [[gas chromatography–mass spectrometry]]. The oil and plasticizer must be separated from the C-4 sample, typically by using a non-polar organic solvent such as pentane followed by [[solid phase extraction]] of the plasticizer on silica. This method of analysis is limited by manufacturing variation and methods of distribution.<ref name="atf"/>