Getting a Grip on Handheld Laser Safety

A handheld laser welding system can be a powerful tool when speed, precision, and productivity are critical to your project or operation. The welding industry is experiencing a surge in interest in this new technology, but many remain unfamiliar with its potential hazards.

For example, the diffusely reflected beams from a Class 4 laser can permanently damage eyes, burn skin, or ignite combustibles. The Class 4 hazard classification applies to lasers operating at 0.5 W or higher. Many industrial handheld lasers are available in the 1000- to 2000-W power range, exceeding the class threshold by several orders of magnitude.

“Having that level of power in the palm of your hand requires knowledge, planning, and proper safety protocols to mitigate risk and prevent injuries,” said Chris Agosti, an engineer and laser safety officer (LSO) for Lincoln Electric’s Laser Materials Processing Group. “Industry leaders need to inform the public about the safety requirements and best practices of handheld laser tools and their use.”    

Six Safety Steps

Agosti, a member of several subcommittees and industry panels on laser safety, outlined a series of preliminary action steps promoted by the American National Standards Institute (ANSI), International Electrotechnical Commission (IEC), Laser Institute of America, and AWS intended to help users maximize safety for handheld laser welding tools.

1. Understand the risks of Class 4 laser exposure. The three previously stated exposure risks — eye hazards, skin burns, and fire hazards — are associated not only with direct exposure but also with indirect, scattered reflections. Be aware of the nominal ocular hazard distance, which is the distance at which the laser energy, direct or reflected, is a hazard to the eyes.

2. Appoint an LSO and ensure they have proper training. Any operation using a Class 4 handheld laser system is required to designate an LSO. The LSO can either be a properly trained member of the existing staff or someone contracted from outside. Regardless of their affiliation, the LSO should undergo laser safety training requirements as defined by the ANSI Z136 series of standards.

   “The LSO must have ownership and authority over the safety measures that are being implemented,” Agosti said.

3. Train and educate all personnel affected (including those working nearby or who may require entry into the laser workspace). In addition to training the LSO, anyone potentially exposed to handheld laser radiation must also receive proper training in accordance with ANSI requirements. Agosti noted that, as with any workspace, safety in the laser environment should be a mindset, not just a procedural box to check off.

   “We have a lot of steps in place to keep individuals safe,” he said. “But training is one of the primary differentiators. Teaching users about the hazards and what they need to do to avoid them increases their awareness, and they are empowered to keep themselves safe. It’s no longer a matter of following rules at that point. It’s an owned awareness.”

4. Document a written laser safety program. Maintain a written safety plan and make sure the operator(s) and all other personnel are familiar with it. Typically, the LSO is the individual responsible for developing the written plan and ensuring that all personnel adhere to it.

   A written safety plan is essential for every user, regardless of the size or scope of your manufacturing operations. Class 4 handheld lasers are industrial equipment and should not be used recreationally or by home hobbyists. Ultimately, safety is paramount. If a user cannot ensure that the appropriate safety measures are in place, they should refrain from using a handheld laser.

5. Designate a laser-controlled area (LCA) or otherwise enclose the handheld laser workspace in a booth/box/surround. Identify the specific physical parameters of your LCA and ensure they are clearly marked and visible to the operator(s) and other personnel.

   The LCA should be an enclosure with noncombustible laser-blocking panels, an access door with an interlock switch, and a “Laser On” visible or audible warning indicator. Any barriers or windows used should be made of laser-rated material that can withstand direct and reflected beams. Aluminum and steel are effective, but ensure they are correctly rated for your specific laser application. Mirrorlike and reflective surfaces are undesirable in the LCA and must be excluded from the beam path. 

   “Understand the space in which you’re going to be operating the laser and where you’re directing the beam,” Agosti said. “Laser energy transmits through space, so the hazards persist over long distances — sometimes thousands of meters.” Unpro-tected individuals must not have access to direct line of sight with the laser.

6. Wear laser-rated personal protective equipment (PPE). Appropriate laser safety eyewear is critical, but PPE also includes a helmet, heat-resistant gloves, and flame-retardant clothing. The most serious hazard associated with Class 4 lasers is the risk of eye injury. Operators and exposed personnel must always use safety eyewear that’s specifically rated for the application, wavelength, and minimum optical density. In addition to PPE, a fume control system should be in place to manage laser-generated airborne contaminants (LGACs). Over time, unprotected exposure to LGACs may result in health issues.

   “Fumes generated from the laser are finer and may be less perceptible than arc welding fumes,” Agosti explained. “A reliable fume extraction system or an air purifying respirator (with filter media sized appropriately for the size of the fume particulate) should be used at all times during laser operation.”

Best Practices

Adhering to widely accepted best practices can also help enhance safety in your operation:

• Torch angle. The proper torch angle should always be between 30 and 70 deg in relation to the work surface. Avoid positioning the torch nozzle at either a right angle or an acute angle.
• Head and body position. At all times, the operator should be aware of the position of their head and other body parts in relation to the laser’s direct and reflected beam path.
• Proper hot work practices. Follow established laser welding safety protocols for hot work, including fire prevention measures, removing flammable materials from the work area, and ensuring that appropriate fire extinguishing equipment is readily available.

In addition to the requirements listed above, some handheld laser systems offer features and options that are not mandatory but could help add a layer of safety to your operation:

• Activation code required for initial start-up
• Shielding gas detection alarm
• Contact-based safety feedback circuit

Agosti recommends partnering with a reputable manufacturer or distributor rather than opting for an obscure brand that no one has heard of. When in doubt, consider a turnkey solution.

“If you’re not comfortable with all of the safety and compliance requirements, there are handheld laser manufacturers that also make laser booths and integrated fume extraction products,” he said. “Many also provide proper signage, door interlocks, and lighting to make compliance easy.”

For a comprehensive overview of all safety guidelines related to handheld laser tools, refer to the following:

• ANSI Z136.1, Safe Use of Lasers
• ANSI Z136.9, Safe Use of Lasers in Manufacturing Environments
• IEC 60825-1, Safety of laser products — Part 1: Equipment classification and requirements
• ISO 11553-1, Safety of machinery — Laser processing machines — Part 1: Laser safety requirements
• AWS Safety and Health Fact Sheet No. 46, Handheld Laser Welding Safety (aws.org/standards-and-publications/free-resources)

Safety without Fear

Maintaining safety with handheld laser operations can seem daunting. The requirements are rigorous because the potential hazards are significant, but that shouldn’t scare users from reaping the benefits of the technology. Get informed, get an LSO, and get trained.

“We want to make sure that users have proper respect for the tool,” Agosti said. “If they don’t, they can hurt themselves, or they can hurt others, and we don’t want that. It’s not good for the user, the laser manufacturer, or the laser industry overall. As long as we use [lasers] safely, effectively, and productively, we can ultimately transform the future of the industry.”

This article was written by the Lincoln Electric Laser Team for the American Welding Society.