The University of Iowa
Environmental Health and Safety

SAFETYmatters - When is a Laser a LASER?

Article published 07/01/19

Lasers have become commonplace items these days. They are found in a variety of consumer products such as pointers, scanners, CD/DVD players, and copiers. These laser systems pose virtually no risk to people around them because they are either low powered, fully enclosed, or both.

Laser use in research labs at the University of Iowa has been increasing in recent years, especially in the field of optogenetics. Many of these laser systems are Class 3B and Class 4, which means they can pose the risk of injury to people in and around their use areas. 

EHS has a laser safety program with the goal of minimizing the likelihood of such injuries. This program includes maintaining an inventory of all Class 3B and Class 4 laser systems, making recommendations for protective equipment, providing laser safety training, and performing periodic audits. EHS focuses on Class 3B and Class 4 laser systems because these are the lasers that are powerful enough to cause eye or skin damage. Some Class 4 lasers are even powerful enough to ignite combustible materials.

All Class 3B and Class 4 laser systems with accessible beam are required to be registered with EHS. Since there is sometimes confusion about this requirement, here are some guidelines to help decide if your laser needs to be registered with EHS:

  • Review the manufacturer literature that came with the equipment.
  • Confocal microscopes may have an enclosed beam or an open beam design. If the beam is fully enclosed, the system is classified as Class 1 and does not need to be registered. However, if the beam is open or accessible, this is a Class 3B or Class 4 and must be registered with EHS.
  • Optogenetics uses laser light to stimulate live cells or tissue in animals. The beam is delivered to the animal by a fiber that inserts into the animal. There is a possibility that the fiber could pull out of the animal exposing the open beam. These are treated as open beam lasers and must be registered with EHS.
  • A laser system with a fully enclosed beam that is interlocked to shut down the laser whenever the enclosure is breached would be normally be classified as Class 1 laser system. An example of this would be a CD or DVD player. These do not need to be registered with EHS.

Protective eyewear is required for the use of all Class 3B and Class 4 lasers systems. The laser eyewear must provide protection for the specific wavelength(s) of the laser being used, and have a minimum optical density (OD) rating of 3. The protective eyewear must be clearly marked by the manufacturer with this information. 

Be aware that some popular online retailers have made false claims about the protection provided by their eyewear. In these cases, the glasses will lack the required marking and documentation and should not be used. 

Following are links to a few reputable suppliers of laser protective glasses.

Contact the University's  Laser Safety Officer, Joey Michael at 335-8518 with any laser-related questions.