2,4,6-Trinitrotoluene

OVERVIEW

2,4,6-trinitrotoluene (two four six try-nye-troh-TOL-yoo-een), or TNT, is a yellow odorless solid that occurs in the form of crystalline needles. Its major use is in the manufacture of explosives. It may be used alone or in combination with other explosive chemicals. Although not as powerful as some other explosives, it has the advantage of being relatively insensitive to shock. Workers can handle the explosive without fear that it will suddenly explode if dropped or jarred. In fact, a blasting cap or detonator is needed to cause TNT to explode. Blasting caps and detonators are very sensitive explosives that can be attached to less sensitive explosives like TNT. Any small shock to the blasting cap or detonator will cause it to explode. That explosion, in turn, causes the less sensitive explosive, such as TNT, to blow up.

KEY FACTS

OTHER NAMES:

Methyltrinitrobenzene; TNT

FORMULA:

C₆H₂(CH₃)(NO₂)₃

ELEMENTS:

Carbon, hydrogen, nitrogen, oxygen

COMPOUND TYPE:

Substituted aromatic hydrocarbon (organic)

STATE:

Solid

MOLECULAR WEIGHT:

227.13 g/mol

MELTING POINT:

82°C (180°F)

BOILING POINT:

Decomposes explosively at 240°C (460°F)

SOLUBILITY:

Insoluble in water; soluble in alcohol, ether, acetone, and benzene

TNT was discovered by the German chemist Joseph Wilbrand (1811–1894) in 1863, although the compound was not recognized as an explosive until almost thirty years later. The compound was first produced commercially in Germany in 1901 and first used by Germany and its enemies during World War I. The explosive became so popular during the war that production of TNT could not keep up with demand by armies on both sides of the conflict.

HOW IT IS MADE

The method developed by Wilbrand for manufacturing TNT is simple, efficient, and inexpensive, and remains the primary process by which TNT is produced today. Wilbrand made TNT by adding nitric acid (HNO₃) and sulfuric acid (H₂SO₄) to toluene (C₆H₅CH₃).

COMMON USES AND POTENTIAL HAZARDS

Interesting Facts

• During World War I (1914–1918), people who made explosives for the military (usually women and girls) were sometimes called "canary girls." Their name came from the fact that their skin turned yellow when exposed to solid TNT. Women with red hair also found their hair turning an orangish or ginger color because of exposure to TNT.
• TNT has become the standard for explosive power in the world today. When someone talks about a "15 kiloton bomb" they are referring to a bomb with the explosive equivalent of 15 thousand ("kilo") tons of TNT. Nuclear weapons commonly have explosive powers rated in the kiloton or megaton (million tons of TNT) range.

By far the most common use of TNT is in the manufacture of explosives. Until the discovery of nuclear energy in the 1940s, TNT was the most powerful explosive known to humans. Today, TNT is often combined with other explosives to make even more powerful bombs. Some examples include the following:

• Torpex, a mixture of TNT, wax and aluminum used in underwater explosives, such as those found in torpedoes. Torpex is about 50 percent more powerful than pure TNT;
• Pentolite, a combination of TNT and pentaerythritol tetranitrate (PETN) used primarily in blasting caps and detonators;
• Military dynamite, which contains the explosive RDX, TNT, motor oil, and cornstarch, is less powerful than pure dynamite, but much safer to handle;

• Amatol, a combination of TNT and ammonium nitrate, is often substituted for TNT in ordnance (weapons);
• Minol, a variation of amatol that includes 20 percent aluminum to increase its explosive power; and
• Baratol, a mixture of TNT and barium nitrate that explodes more slowly than pure TNT.

In addition to its primary use in explosives, 2,4,6-trinitrotoluene is also used to produce a very attractive yellow tint in the manufacture of dyes and photographic chemicals.

2,4,6-trinitrotoluene is a hazardous chemical that can produce both short- and long-term health effects, such as respiratory problems, skin irritation, anemia, and lung damage. Some research shows the compound may be carcinogenic in laboratory animals, but not in humans. Since most people are never exposed to TNT, these hazards are primarily of concern to men and women engaged in the manufacture or use of TNT.

Words to Know

CARCINOGEN

A chemical that causes cancer in humans or other animals.

FOR FURTHER INFORMATION

Cooper, P. W., and S. R. Kurowski. Introduction to the Technology of Explosives. New York: Wiley-VCH, 1997.

"Public Health Statement for 2,4,6-Trinitrotoluene." Agency for Toxic Substances and Disease Registry. http://www.atsdr.cdc.gov/toxprofiles/phs81.html (accessed September 15, 2005).