Laser hazards and safety

Lasers can be found in everyday consumer products. The most obvious and common laser products available are laser pointers. Lasers can also form the functional part of lighting systems such as indoor home lightshows or outdoor domestic lighting displays. They can also be found in common children’s toys such as:

• toy guns that incorporate a laser for aiming

  

• tops that project laser beams while they spin
• toy swords and 'lightsabers' that contain a hand held laser for lighting
• lasers intended to create optical effects in an open room.

Common trade tools including spirit levels and electric saws can incorporate lasers and they form an integral component of devices such as laser range finders.

What is the hazard?

It is a legal requirement in Australia for lasers to be labelled according to their particular hazard. This information includes the class of the laser, the power output and the wavelength.

All laser pointers that are available to the Australian public must have a radiant power output of less than 1 milliwatt. Lasers with an output below this are considered to be a low hazard.

Determining whether laser products available to the public are low hazard is based on the risk of injury to the eye. Protection from eye injuries occurs as a result of a human instinct called the 'aversion response'. This takes into account the blinking reflex when a laser beam shines onto the eye. However, when the beam is stared at directly, the potential for harm from the laser becomes much greater. Injuries resulting from staring into the laser beam include permanent damage to the eye and subsequent partial or total loss of vision.

Injuries from lasers can also occur when the beam is shone into the eyes of unsuspecting people. This can result in a 'dazzle effect' where the exposure leads to disorientation.

Unfortunately, Australian studies have shown that the labelling applied to laser products does not always reflect the hazard appropriately. In one study the majority of laser pointers tested failed to meet the output restriction of less than 1 milliwatt (Wheatley, 2013). For lasers with this higher output the aversion response is no longer sufficient to protect the eye from damage in the event of an exposure. Furthermore, a large number of the lasers tested fell within a hazard category where reflections of the beam had potential to cause eye injuries.

What should you do?

• Pay close attention to the hazard labels.
• Don’t point lasers at a person’s face or eyes.
• Don’t point lasers at aircraft, cars or other vehicles.
• Don’t point lasers at animals.
• Don’t give laser pointers to children.
• Make sure children playing with toys that contain lasers products are supervised.

References

Wheatley, T. 2013, Laser pointer Prohibition – improving Safety or Driving Misclassification, School of Engineering and Information Technology, UNSW Canberra, Australia. Paper 101.