History of plastic explosives starts in the time of the WW II, when special task units needed for destruction works easy to shape, high performance and water resistant explosives, resistant at high temperatures and, above all, safe to manipulate. The first types were mixtures of crystalline high explosives with oil, vaseline or natural rubber. Plastic properties of explosives were gradually improved by using synthetic binders and plasticizers.
Plastic explosive SEMTEX® was developed in the late 1950s, large scale production was launched in the 1960s. The name is a combination of SEMTín and EXplosive. Originally SEMTEX was designed primarily for the means of mine clearance, in the course of time, however, its use was extended also for commercial blasting, especially for boosting and special destruction works.
SEMTEX is by no means the only plastic explosive throughout the world, similar types of explosives are produced by a number of producers. Out of the most known producers it is possible to mention:
C 4 (Composition 4)
DEMEX, ROWANEX, PE 4
PE 4, PLASTRITE (FORMEX P 1)
Spreng Körper DM 12
PP – 01 (C 4 )
CHEMEX (C 4), TVAREX 4 A
At first SEMTEX was produced under trade mark B 1for military purposes. From 1964 it was produced under trade mark SEMTEX 1A, from 1967 as SEMTEX H and from 1987 as SEMTEX 10. SEMTEX 1A was used mainly in the Czechoslovak Republic. SEMTEX H was exported abroad, primarily to Vietnam for mine clearance and pyrotechnic works. In 1981 the export into risky territories was banned and SEMTEX was allowed to be exported into the Warsaw Treaty countries only. In 1989 the export of this explosive was temporarily banned at all.
In the early 1990s experts from the Research Institute of Industrial Chemistry, a part of Explosia a.s., actively participated in international negotiations on marking and detection of plastic explosives and contributed considerably to the conclusion of the "Convention on the Marking of Plastic Explosives for the Purpose of Detection", done at Montreal, (Canada) on March 1st, 1991. The Czechoslovak Republic was one of the first countries to ratify this Convention and Explosia a.s. as one of the first producers worldwide has been carrying out marking of all production of plastic explosives in a prescribed manner (DMNB). Since 1991 the export of marked explosive SEMTEX has been permitted again. The trade is subject to valid legislation and relevant control of state authorities.
The fact is, that new production of SEMTEX is minimal. Primarily rework and marking is carried out at present, or disposal of demilitarized plastic explosives from the Czech Army stock. Supplies of newly produced explosive are predominantly assigned to military purposes.
On talks with mass media Explosia a.s. put it many times that SEMTEX is neither the strongest explosive in the world nor the non-detectable explosive and last, but not least not the only explosive misused by terrorists. Simple and perhaps also understandable fact, that the producer cannot exclude a misuse of the product after its launching on the market , is not usually accepted in case of plastic explosive SEMTEX.
Interest and questions of the media concerning SEMTEX rise of course always, when a terrorist act is committed somewhere in the world, or on other occassions, when the name SEMTEX appears in media.
E.g. the interest following the establishing of "Semtex Girls" company.