C-4 (explosive)

[3] The original RDX-based material was developed by the British during World War II and redeveloped as Composition C when introduced to the U.S. military.

The toxicity of C-3 was reduced, the concentration of RDX was increased, giving it improved safety during usage and storage.

[4]: 125  C-4 was submitted for patent as "Solid Propellant and a Process for its Preparation" March 31, 1958, by the Phillips Petroleum Company.

to 2.2% lithium stearate and 8.8% mineral oil BP) as the binder; a taggant (2,3-dimethyl-2,3-dinitrobutane, DMDNB) is added at a minimum of 0.10% weight of the plastic explosive, typically at 1.0% mass.

The PE8 consists of 86.5% RDX, 1.0% DMDNB taggant and 12.5% of a binder composed of di(2-ethylhexyl) sebacate thickened with high molecular mass polyisobutylene.

The final material is a solid with a dirty white to light brown color, a putty-like texture similar to modeling clay, and a distinct smell of motor oil.

For example, a 1990 U.S. Army technical manual stipulated that Class IV composition C-4 consists of 89.9±1% RDX, 10±1% polyisobutylene, and 0.2±0.02% dye that is itself made up of 90% lead chromate and 10% lamp black.

[10] The manufacturing process for Composition C-4 specifies that wet RDX and plastic binder are added in a stainless steel mixing kettle.

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

For example, the complete severing of a 36-centimetre (14 in) deep I-beam takes between 680 and 910 g (1.50 and 2.01 lb) of C-4 when properly applied in thin sheets.

The gas exerts pressure in the form of a shock wave, which demolishes the target by cutting, breaching, or cratering.

[25] RDX has a high birefringence, and the other components commonly found in C-4 are generally 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 ng, each analysis must be individually handled using magnifying equipment.

The cross polarized light images obtained from microscopic analysis of the fingerprint are analyzed with gray-scale thresholding[26] to improve contrast for the particles.

Relative numbers and positions of RDX particles have been measured from a series of 50 fingerprints left after a single contact impression.

[6] U.S. soldiers during the Vietnam War era would sometimes use small amounts of C-4 as a fuel for heating rations, as it will burn unless detonated with a primary explosive.

[8] However, burning C-4 produces poisonous fumes, and soldiers are warned of the dangers of personal injury when using the plastic explosive.

[28] Among field troops in Vietnam it became common knowledge that ingestion of a small amount of C-4 would produce a "high" similar to that of ethanol.

[23][21] Others would ingest C-4, commonly obtained from a Claymore mine, to induce temporary illness in the hope of being sent on sick leave.

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