Blacklight Uses

If you walked around all night with a portable black light, you would discover that there are phosphors all over the place. There are lots of natural phosphors, in your teeth and fingernails, among other things. There also a lot of phosphors in manmade material, including television screens and some paints, fabric and plastics. Most fluorescent colored things, such as highlighters, contain phosphors, and you'll find them in all glow-in-the-dark products. Clubs and amusement parks use special black light paint that glows different colors. You can also buy fluorescent black light bubbles, invisible black light ink, fluorescent black light carpet and even fluorescent black light hair gel.

Black light sources have many uses. They may be employed for decorative and artistic lighting effects, for diagnostic and therapeutic uses in medicine, for the eradication of microorganisms, for the observation or detection of substances tagged with other substances that exhibit a fluorescent effect, for the curing of plastic resins and for attracting insects. Strong sources of long-wave ultraviolet light are used in tanning beds. Black light lamps are used for the detection of counterfeit money. Most artificial ultraviolet sources are low power. Powerful ultraviolet sources present a hazard to eyes and skin; apparatus using these sources requires personal protective equipment.

Bug zapper" tubes

Some UV fluorescent bulbs are designed for use, particularly in kitchens, to attract insects for electrocution in bug zappers. These use the same near-UV emitting phosphor as normal black lights, but use plain glass instead of the more expensive Wood's glass or filter-coated glass

Authentication

Black lights are commonly used to authenticate antiques and banknotes. Black lights can be used to differentiate real currency from counterfeit notes because, in many countries, legal banknotes have fluorescent symbols on them that only show under a black light. In addition, the paper used for printing money does not contain any of the brightening agents which cause commercially available papers to fluoresce under black light. Both of these features make illegal notes easier to detect and more difficult to successfully counterfeit. The same security features can be applied to identification cards.

This application of Blacklight is sometimes used by store owners to check if returned goods are from their store or not or have been substituted for a defective unit from another store.

Security

security applications include the use of pens containing a fluorescent ink, generally with a soft tip, than can be used to "invisibly" mark items. If the objects that are so marked are subsequently stolen, a black light can be used to search for these security markings.

Hand Stamping

At some theme parks and at other, day-long (or night-long) events, a fluorescent mark is rubber stamped onto the wrist of a guest who can then exercise the option of leaving and being able to return again without paying another admission fee.

Forensics

Many body fluids contain fluorescent molecules, and as such forensic scientists can use ultraviolet lights at crime scenes to find blood, urine, or semen (all fluorescent).

Car Accidents

Manufacturers purposely include fluorescent additives in antifreeze fluid so that black lights can be used to find antifreeze splashes to help invesitagors reconstruct automobile accident scenes.

Tooth Whiteners

Whiteners and some enamels contain compounds that glow blue to keep teeth from appearing yellow.

White Paper

White paper is treated with fluorescent compounds to help it appear brighter and therefore whiter. Sometimes forgery of historical documents can be detected by placing them under a black light to see whether or not they fluoresce. White paper made post-1950 contains fluorescent chemicals while older paper doesn't.