Laser Safety

The Laser Safety Officer (LSO) is the individual who has the authority and responsibility to evaluate laser hazards, monitor and enforce compliance with required standards and regulations and perform other specific duties and responsibilities for a given facility or institution utilizing a Class 3B or 4 laser. 

The Laser Safety Committee (LSC) is a safety and compliance committee whose mission is to recommend policy and establish procedures for the safe use of lasers and laser systems at the West Lafayette campus, regional campuses, university farms and related facilities and operations, and at temporary job sites. The LSO can make recommendations to the LSC.

Any Class 3B or Class 4 laser used at Purdue University must register in the laser safety program. Ownership of the laser has no bearing on the registration requirement.

• Locate the class label on the laser. This will tell you if it is Class 1, 1M, 2M, 3R, 3B or 4. If you have an older laser you may find the class label to indicate alternative laser classes, such as Class 2a, 3a or classes that have Roman numerals as opposed to the now-standardized Arabic numeration requirement. Old Class 2a is equivalent to the present Class 1, and old Class 3a is equivalent to the present Class 3R.
• Dangers of a Class 1, 2 or 3R laser are much less significant than those of a Class 3B or 4 laser. Class 1M or Class 2M lasers may require an evaluation by the LSO to determine if the hazards associated with the laser warrant enrollment into and monitoring by the laser safety program. Even for these low power class lasers, however, direct exposure of the eye to the output beam can be dangerous. In addition, many of these lasers, regardless of class, have high-voltage power supplies that can be hazardous.
• If you have a Class 3B or 4 laser, the hazards associated with the laser warrant greater safety measures and require enrollment into the Purdue University Laser Safety Program.
• Refer to the Purdue University Laser Safety Guidelines, appendix A, for information on laser classification.

• Class 3B and/or Class 4 laser beams have the potential to cause damage to the eye and skin. Both the eye and the skin could suffer thermal and photochemical damage from the beam, but the eye may also suffer photoacoustic damage from the expansion and contraction of gases within the eye. Lack of knowledge and training in laser safety is easily remedied and immensely valuable to helping you work safely. Risk depends on the type of laser, the wavelength, pulse energy (or power for a continuous wave laser), pulse duration (or exposure duration for a continuous wave laser) and the type of application.
• Non-beam hazards associated with lasers have the potential for causing a negative biological impact, including fatality.

• Physical Hazards: Electrical, collateral and plasma, fire, explosion, mechanical (associated with robotics), noise
• Chemical Hazards: Laser Generated Air Contaminants (LGACs), compressed gases, laser dyes and solvents, assist gases
• Biological Hazards: Infectious material (e.g. could be made airborne as beam interacts with target material)
• Human Factors: Ergonomics (e.g. area illumination, visual distractions, workstation layout), space issues (e.g. trip/fall, available work space), work patterns (e.g. long or unusual work hours)

• Unanticipated eye exposure during alignment
• Misaligned optics and upwardly directed beams
• Available eye protection not used
• Equipment malfunction
• Improper methods of handling high voltage
• Intentional exposure of unprotected personnel
• Operators unfamiliar with laser equipment
• Lack of protection for non-beam hazards
• Improper restoration of equipment following service
• Eyewear worn not appropriate for laser in use
• Unanticipated eye/skin exposure during laser usage
• Inhalation of laser generated air contaminants and/or viewing laser generated plasmas
• Fires resulting from the ignition of materials
• Eye or skin injury of photochemical origin
• Failure to follow Standard Operating Procedures (SOPs)

• Obtain authorization from your Laser Principal Investigator (LPI) through completion of the LU-2
• Obtain laser safety training through the EHS located in the Civil Engineering Building by calling 765-494-6371.
• Read and follow the Purdue University Laser Safety Guidelines.
• Use the EHS Laser Safety section of the web site for information and updates.

Laser Principal Investigators (LPIs) are permanent faculty or staff Purdue employee that oversee the use of the laser and its users. The LPI of a Class 3B or Class 4 laser shall:

• Ensure the following personnel obtain laser safety training:
  • LPI
  • Authorized users
  • Other personnel that are not working with the laser but may work within the laser’s nominal hazard zone (as determined by the LSO) when the laser is in operation.
• Issue appropriate laser-specific instruction to all authorized users of lasers that are operated within the LPI’s jurisdiction.
• Not permit the operation of a laser unless there is adequate control of laser hazards to employees, visitors and the general public (through LSO approval of the laser project application).
• Ensure all individuals working have submitted a completed LU-2 form, including the LPI, to the LSO.
• Ensure LU-1 is submitted to the LSO for the laser project. The LU-1 must list all authorized individuals, including the LPI. Subsequent users may be listed with all required information either as an LU-1 addendum, or by written documentation to the LSO.
• For any known or suspected accident relating to a laser under his/her authority, enact appropriate response plan, which includes notification of the LSO.
• If necessary, assist in obtaining appropriate medical attention for any employee involved in a laser accident.
• Not permit operation of a new or modified Class 3B or Class 4 laser under his/her authority without LSO approval.
• Shall submit plans for Class 3B and Class 4 laser installations/modifications of installations to the LSO for review.
• Shall be familiar with the Standard Operating Procedures (SOPs) for each Class 3B and Class 4 laser under his/her authority, and ensure that that they are provided to all users of such lasers.
• Shall contact the LSO prior to changing project components such as laser location, major operational changes, etc.

No. The laser can only have one LPI who will have the duties and responsibilities for safety and compliance for applicable rules and regulations. Other faculty, staff or other individuals may be authorized by the LPI to use the laser under the LPI’s project restrictions.

As LPI, it is your responsibility to be familiar with Purdue policy and procedures, as well as pertinent regulations that govern the use of the laser that you oversee.

• Follow the safety procedures for the laboratory. EHS can help to formulate such procedures if they do not exist or are outdated.
• Use the minimum power required for your operation.
• Use correct approved laser safety eyewear when appropriate. The lenses in eyewear are for a specific wavelength range, and do not protect the wearer outside of this range. Even with appropriate eyewear, consider direct exposure to a laser beam to be dangerous.
• Set the beam path at a level that will not be at eye level.
• Question practices which appear unsafe. Are they necessary or outdated? Can the same function be performed in a manner which is less dangerous? Can the unsafe practices be replaced by some other diagnosis or measurement? Are work practices designed for expediency at the expense of safety?

Laser safety information is available through the EHS web site in the Purdue University Laser Safety Guidelines, the Laser Standard Operating Procedures and through contacting EHS.