Laser Safety

"DANGER - Laser in Use" is a common poster in industry today. It has become common because devices that use laser light have so many practical uses. They guide blade alignments on portable cut-off saws, and set-up large rip saws in a timber mill. In construction, they are used in surveying equipment and assist with the layout of ceiling grids or interior walls. Lasers can be used for many operations that require laying a perfectly straight line over a long and/or uneven surface. Higher power devices can cut through steel with precision results. All-in-all, lasers are a valuable tool for improving productivity and accuracy. Yet, because they are so common in industry today, they are sometimes taken for granted. Lasers should always be treated with respect. They represent dangers to those who work with them, and those who work around them.

Lasers are generally divided into four basic classifications. These classifications are based upon a system of graded risk. The higher the class the greater potential for personal injury -- particularly to the eyes or skin. Classes of lasers and conditions of risk are as follows:

Class I: Under normal conditions, will not produce a personal injury hazard.
Class II: Low powered, visible laser beams normally present no hazard if viewed for short periods, Blinking or turning away is a normal human response.
Class IIIa: Do not produce a hazard if viewed for only momentary periods without
protection.

Class IIIb: Can produce a hazard if viewed directly.
Class IV: Hazardous to view with the naked-eye under all conditions. This class also has the potential for starting a fire and inflicting skin damage.

It is important to learn what class of laser you are working with, or working near, to determine safety precautions you should take. Laser manufacturers are required to record the appropriate classification on the laser. If it is missing, or if the laser has been modified, you should determine its class and safety requirements before activating the system. Some of the basic safety precautions for lasers are:

Every laser operator must be trained and qualified. Operators must have proof of this qualification and it must stay with them at all times.
All work areas where lasers are used must be posted with standard laser warning placards.
A laser must never be intentionally directed at another employee.
The laser must be turned off, capped or its beam shuttered when left unattended for a substantial period of time, such as at meal times, overnight, or during a work shift change.
Lasers must not be used when it is raining, snowing, foggy, or there is heavy dust in the air. Such conditions may deflect or scatter the radiation. If production cannot be postponed, then employees must be kept well out of range of the source and target of the laser.
The intensity of laser light can be harmful. The next time you find yourself working near a laser or laser-guided equipment, check the classification. What are the precautions? What PPE is required? Do posted signs warn of the lasers use?