The intent of the University’s Laser Safety Program is to ensure that appropriate procedures are in place to maintain a safe work place around our Class 3b and Class 4 lasers.  In cooperation with our Principle Investigators, Radiation Safety Staff will help to identify potential hazards and provide recommendations for hazard control.  The requirements and recommendations detailed in this program are applicable to all laser users employed by Washington University in St. Louis.  Requirements and recommendations will differ depending on the specific laser system and their application: research, instructional or clinical/medical.

Eye Protection

Eye protection devices which are specifically designed for protection against laser radiation from Class 4 laser systems shall be administratively required and their use enforced when engineering or other procedural and administrative controls are inadequate to eliminate potential exposure in excess of the applicable maximum permissible exposure (MPE). 

Many factors shall be considered to determine the appropriate eyewear, i.e., laser power, wavelength, exposure time, comfort, etc.   For more information, contact the laser manufacturer or the Radiation Safety Office at 314-362-3476.

Laser Hazard Evaluation Considerations

The following should be considered for a laser hazard evaluation.

  1. The laser system’s capability of injuring personnel or interfering with task performance.
  2. The environment in which the laser is used.
  3. The personnel who may use the laser or be exposed to radiation.
Lasers Other Than Class 3b And 4

Class 1 lasers should not be disassembled.   A class 1 laser may contain a powerful embedded laser capable of causing severe injury.   Maintenance of a class 1 laser should be performed only by trained technicians.   Class 2 and class 3a lasers are not capable of causing eye injuries when used properly.   You should avoid staring into the laser light.

Laser Registration

A LASER Registration form has been prepared to facilitate the collection of data concerning the University’s LASER inventory. Please use this form to submit inventory information to the Radiation Safety Office.

Laser Safety Audits

A LASER Safety Audit will be conducted annually for each Principle Investigator with class 3b or class 4 lasers. The audit will focus on the PI’s establishment of procedures incorporating the appropriate use of PPE, access control, training and warning signs.

Operating A Class 3b Or Class 4 Laser

Class 3b and Class 4 laser systems shall be operated at all times under the direct supervision or control of an experienced, trained operator who shall maintain visual surveillance of conditions for safe use and terminate laser emission in the event of equipment malfunction or any other condition of unsafe use.

Room Postings

For Class 3b and Class 4 lasers ANSI Z136.1 (2014) “Safe User of Lasers” addresses the posting of warning signs.  All signs shall be conspicuously displayed in locations where they best will serve to warn onlookers.  An area which contains a Class 3b or Class 4 laser or laser system shall be posted with the appropriate Laser Warning Sign.


Laser safety training programs shall be provided to the users of Class 3b and Class 4 laser systems.  In general, this training is provided by the principal investigator overseeing the laser system.   Please contact Radiation Safety at 314-362-3476 for more information.