'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.
More information on laser safety can be found here.