Glow sticks are long, narrow tubes that produce a bright, glowing effect when bent. Not only are they used recreationally (it's not uncommon to see them on Halloween, at concerts or on the Fourth of July), but they have practical uses as well. The military, law enforcement and fire brigades are all large consumers of this product. Glow sticks produce light without the aid of electricity or gas, so they are nonflammable and can be used in confined spaces. Under normal conditions of use, they are not considered to be toxic, according to GlowProducts.com.
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The light glow sticks emit is "chemiluminescent." The American Heritage Science Dictionary defines "chemiluminescence" as "the emission of light by a substance as a result of undergoing a chemical reaction that does not involve an increase in its temperature." This is the same kind of light that is emitted by fireflies. In glow sticks, the chemical compound responsible for producing light is called "diphenyl oxalate."
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Diphenyl oxalate was first synthesised by Michael M. Rauhut in the 1960s. He was able to create an ester (a compound formed from acid and alcohol) that, when mixed with a dye and hydrogen peroxide, produced a chemiluminescent glow. The compound was patented as "Cyalume."
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The glow stick is a tube within a tube. The outer, flexible tube contains the phenyl oxalate compound and the glow stick dye. Inside, there is a more fragile tube which contains the hydrogen peroxide. When the glow stick is bent, the inner tube is broken, allowing the phenyl oxalate and the hydrogen peroxide to mix. This creates the chemiluminescent glow unique to glow sticks. The glow can last from 4 to 12 hours, depending on the product.
The chemical reaction in glow sticks is not considered harmful to humans. It is not flammable, and it is considered much safer than other forms of light production utilising oxygen and electricity. The product is non-toxic, according to Cyalume.com. The flexible outer tubes are unlikely to break, but in the event they do, the contents are not dangerous unless a significant amount of the substance is consumed. It is an irritant, and contact with the eyes and skin should be avoided, according to GlowProducts.com. There is the possibility of an allergic reaction.
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The American Association of Poison Control Centers defines "poison" as "any product or substance that can harm someone if it is used in the wrong way, by the wrong person, or in the wrong amount." Under this definition, glow sticks contain a poison and are not to be used by children under the age of three. In case of ingestion, call a poison control centre immediately.