C-4 (explosive)

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Inserting blasting caps into blocks of C-4 explosive

C-4 or Composition C-4 is a common variety of the plastic explosive known as Composition C.

C-4 is composed of explosives, plastic binder, plasticizer and usually a marker or odorizing taggant chemical.

Characteristics and uses[edit]

A detonation within a blast resistant trash receptacle using a large C-4 explosive charge.

When detonated, C-4 rapidly decomposes to release nitrogen and carbon oxides as well as other gasses.[1] The gasses expand at an explosive velocity of 8,092 m/s (26,550 ft/s).[2] After the initial explosion, gasses rush back toward the center of the explosion causing a second, inward wave of energy.[1]

Composition[edit]

The explosive in C-4 is RDX (cyclonite or cyclotrimethylene trinitramine), which makes up around 91% of C-4 by mass.[3] The plasticizer is diethylhexyl (5.3%)[3] or dioctyl sebacate and the binder is usually polyisobutylene (2.1%).[3] Another plasticizer used is dioctyl adipate (DOA). A small amount of SAE 10 non-detergent motor oil (1.6%) is also added.[3] A taggant chemical such as 2,3-dimethyl-2,3-dinitrobutane (DMDNB) may be added to help detect the explosive and identify its source.[3]

C-4 is manufactured by combining the noted ingredients with binder dissolved in a solvent.[1] The solvent is extracted though drying and filtering and the final material is a solid with a texture similar to modelling clay.[1]

Advantages[edit]

A major advantage of C-4 is that it can easily be moulded into any desired shape to change the direction of the resulting explosion.[4][1]

C-4 is very stable and insensitive to most physical shocks. C-4 cannot be detonated by a gunshot or by dropping it onto a hard surface. It does not explode when set on fire[5] or exposed to microwave radiation.[5] Detonation can only be initiated by a combination of extreme heat and a shockwave, such as when a detonator inserted into it is fired.[1]

Toxicity[edit]

If ingested C-4 has toxic effects in humans. Wichtin a few hours multiple generalized seizures, vomiting, an changes in mental activity. [6] A strong link to central nervous dysfunction is observed.[7]

History[edit]

Development[edit]

Use in the Vietnam War[edit]

When ignited with a flame rather than detonated with a primary explosive, C-4 just burns, so American soldiers during the Vietnam War era would sometimes use small amounts of it as a fuel for heating rations.[1] However, burning C-4 produces poisonous fumes and should be avoided.[8]

Michael Herr in Dispatches, his book about the Vietnam War, relates that a soldier would occasionally ingest C-4 from a Claymore mine in order to cause temporary illness so that he would be sent on sick leave. Although the ruse might work with an inexperienced commander, experienced officers were usually aware of the trick.[9]

Similar compounds[edit]

There are a number of explosives that are used in a similar fashion to C-4 and these include PE4[10] and Semtex.[11]

See also[edit]

References[edit]

  1. ^ a b c d e f g Harris, Tom. "How C-4 Works". How Stuff Works. HowStuffWorks. Retrieved 14 July 2014. 
  2. ^ "C4 product page". Ribbands Explosives. 
  3. ^ a b c d e "Explosives – Compounds". Global Security. 
  4. ^ Nordin, John. "Explosives and Terrorists". The First Responder. AristaTek. Retrieved 14 July 2014. 
  5. ^ a b Nagy, Brian. "Grosse Point Blank Microwave C4 Mercury Switch". Carnegie Mellon University. Retrieved 14 July 2014. 
  6. ^ William J. Stone, MC, USAR; Theodore L. Paletta, MC, USAR; Elliott M. Heiman, MC, USAR; John I. Bruce, PhD; James H. Knepshield, MC. 'Toxic Effects Following Ingestion of C-4 Plastic Explosive.' in: Arch Intern Med. 1969;124(6):726-730. doi:10.1001/archinte.1969.00300220078015
  7. ^ Robert C. Woody, Gregory L. Kearns, Marge A. Brewster, Charles P. Turley, Gregory B. Sharp and Robert S. Lake Departments of Pediatrics, Neurology, Pathology and Pharmaceutics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205 Scientific Associates, Inc., 6200 South Lindbergh St., Louis, Missouri, 63123 [The Neurotoxicity of Cyclotrimethylenetrinitramine (RDX) in a Child: A Clinical and Pharmacokinetic Evaluation http://informahealthcare.com/doi/abs/10.3109/15563658608992595] 1986, Vol. 24, No. 4 , Pages 305-319 (doi:10.3109/15563658608992595)
  8. ^ US Army Field Manual 5–250, Explosives and Demolitions includes this bold print, block warning: "WARNING Composition C4 explosive is poisonous and dangerous if chewed or ingested; its detonation or burning produces poisonous fumes."
  9. ^ Michael Herr, (1977). "Dispatches". Knopf. ISBN 0679735259.
  10. ^ "Explosives - Compositions". GlobalSecurity.org. Retrieved 14 July 2014. 
  11. ^ Dovkants, Keith. "Semtex-style C4 explosive 'widely used by al Qaeda'". London Evening Standard. Retrieved 14 July 2014. 

External links[edit]