DOE/EH-0393 --- Issue No. 94-10 --- 10/94

The Safe Use of Common Laser Pointers

Despite their size, availability, and the fact that most pen size laser pointers are powered by small, widely obtainable batteries, these pointing devices can cause eye damage if used improperly. The potential hazard is limited to looking directly into the laser beam with unprotected eyes. No hazard to the skin exists. Users of laser pointers should never aim the pointer into the audience. When storing pointers, remove the power source or unscrew the case/housing enough to disable the power source.

Pen size laser pointers have become common presentation aids in recent years. These battery powered laser pointers that produce a narrow, bright red beam are convenient to carry and use, relatively inexpensive, and readily available through mail-order catalogs and magazines.

ANSI Classification Addresses Possible Eye Hazard

Two types of these pointer devices are widely used in visual presentations--helium-neon (HeNe) and diode lasers. The American National Standards Institute (ANSI) has defined the HeNe technology as a Class 2 laser, indicating that momentary or accidental viewing of the direct beam will not cause eye injury. A "CAUTION" label for these Class 2 devices is appropriate. On the other hand, ANSI has classified most diode lasers as Class 3a lasers, indicating that direct viewing into the beam has the potential to cause eye injury.

Class 3a lasers may be labeled "CAUTION" if they present the same risk as a Class 2 laser to the naked eye. However, if a Class 3a diode laser has a very small beam diameter (less than 7 millimeter (mm)) and a power rating between 1 and 5 milliwatt (mW), it must have a "DANGER" label. It poses a risk if viewed at close distance where the beam is less than 7 mm.

HeNe laser pointers have been available for several years. On a relatively low power level (typically less than 1.0 mW, they produce a bright red (632.8 nanometer (nm)) spot that is easily noticeable on a bright screen. The more recently developed diode lasers are smaller in size and more rugged. The fact that they cost only about one-third as much as HeNe lasers makes them popular.

The diode lasers, however, produce a light that is darker (670 nm) than the HeNe lasers. To achieve the same effect as the HeNe lasers, the diode laser power levels are increased (typically to 5 mW). ANSI has assigned the safety classifications described above to these laser pointers in accordance with the level of danger to the eye.

Recommendations for Use

Because of safety considerations, laser pointers with a "CAUTION" label should be purchased as opposed to those with a "DANGER" label. In other words, Class 2 lasers are recommended. If a Class 3a laser is preferred, users should ensure that its use complies with all the safety requirements of ANSI Z136.1-1993, the draft Department of Energy (DOE) Industrial Hygiene Model Program for Nonionizing Radiation and Fields, and local site safety policies. Users should also be aware of the manufacturer"s safety precautions.

For more information, contact Carlos Coffman, Office of Health Physics and Industrial Hygiene, at (301) 903-6493, or Dr. John Leonowich, the DOE Physical Agents Program, at (509) 375-6849.

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