Laser Welding Safety, Class 4 Lasers, the LSO and Safety Booths

Industrial handheld laser welders use high-powered, highly focused laser beams capable of causing serious injury if used incorrectly. Unlike conventional MIG or TIG welding, several laser hazards are not immediately obvious — the beam is invisible to the eye yet intense enough to damage tissue in a fraction of a second.

The two primary hazards are to the eyes and skin. Direct or reflected laser radiation can cause serious eye injuries, and exposure can also burn or injure skin. There is a further, less obvious risk specific to welding: reflected beam hazards from metal. Some metals, particularly those with bright or reflective surfaces such as stainless steel and aluminium, can reflect laser energy in unpredictable directions. A beam that misses the operator directly may still reflect off the workpiece toward an unprotected person. Understanding these reflected-beam hazards is an essential part of safe laser operation and should be considered during every risk assessment. Class 4 lasers can also present fire hazards if not properly controlled.

A well-planned safety strategy protects not just the operator but nearby employees and visitors, and underpins safe day-to-day operation.

A Class 4 laser is the highest laser classification, and it includes all industrial laser welding systems — the HP Fiber and HPC handheld systems Weldability SIF supplies fall into this category. Class 4 lasers are capable of causing eye and skin injuries from both direct and reflected beams and may present fire hazards. Because of these risks, handheld laser welding systems should always be operated within a suitable safety management framework rather than treated like ordinary power tools.

A Laser Safety Officer (LSO) is a competent person responsible for advising on the safe use of laser equipment within an organisation. The role typically includes:

• supporting and reviewing laser risk assessments;
• developing safe working procedures and systems of work;
• advising on the correct PPE for the equipment;
• reviewing engineering controls and safety arrangements;
• promoting safe operating practices and good day-to-day discipline.

Weldability SIF employs a Certified Laser Safety Officer, which means customers do not have to navigate Class 4 laser safety alone. Our LSO can provide practical, real-world guidance when introducing handheld laser welding — from the initial assessment through to systems of work that support compliance and protect the workforce.

Yes. Before introducing handheld laser welding, the potential hazards should be assessed and appropriate control measures identified. A laser risk assessment typically considers the equipment itself, the working environment, the operator’s activities, access to the area, reflected-beam risks and emergency procedures. The outcome of the assessment determines which control measures — eyewear, signage, controlled areas, booths, extraction — are appropriate for your specific workplace. Every workshop is different, so the controls that suit one site may be inadequate or excessive for another.

PPE is a critical layer of protection, but it should complement, not replace other safety measures such as engineering controls and controlled access.

Laser safety eyewear is the single most important item of PPE. It must be matched to the wavelength and power of the laser system being used. This is the most important — and most misunderstood — point in laser safety:

• Ordinary safety glasses do NOT protect against laser radiation. Standard safety glasses are designed for mechanical hazards such as flying particles. They offer no protection against a laser beam.
• A standard welding helmet is not laser safety eyewear. The auto-darkening helmet that protects a MIG or TIG welder is designed for the visible and infrared light of the arc, not for laser radiation. It is not suitable for handheld laser welding unless specifically designed and rated for laser applications.
• Not all laser safety glasses suit every laser system. The eyewear must be rated for the specific wavelength and power of the equipment in use. Weldability SIF can advise customers on selecting suitable laser safety eyewear for HP Fiber systems.

Beyond the eyes, suitable protective clothing, gloves and appropriate footwear help guard the skin against burns from direct or reflected radiation and from the welding process itself. PPE should always be selected as part of the overall risk assessment.

A laser controlled area is a designated workspace where access is managed while laser equipment is in operation. Many handheld laser welding applications benefit from a clearly defined controlled area to prevent unauthorised people walking into an active laser process.

Control measures within a controlled area may include:

• Warning signs that alert employees and visitors when laser equipment is in operation — the type of signage depends on the installation and the risk assessment;
• restricted access so that only trained, protected operators are present during welding;
• barriers or screens to define the boundary of the laser area;
• enclosed laser welding booths for the highest level of containment (see below).

Visitors should always follow the site’s health and safety procedures. A clearly defined laser area — ideally an enclosed booth — reduces the likelihood of anyone entering an active laser work area unintentionally.

A laser safety booth is an enclosed workspace designed to contain laser radiation during processing. It provides one of the most effective engineering controls available, containing the laser process within a protected environment and separating it from the rest of the workshop.

Weldability SIF supplies Cepro Unisonic Class 1 laser safety booths.

What does Class 1 mean? A Class 1 laser enclosure is designed so that, during normal operation, laser radiation is contained within the enclosure — meaning the area outside the booth is effectively Class 1 (no access to harmful radiation under normal use). In practical terms, a Class 4 laser process is carried out inside a booth that keeps the radiation in, so people working elsewhere in the workshop are not exposed. Using a suitable enclosure simplifies access control and helps create a safer working environment.

Open workshop vs booth. Whether handheld laser welding can be carried out in an open workshop depends on the application, the workplace layout and — crucially — the findings of the risk assessment. Where laser welding is done in the open, robust control measures are essential to protect operators and anyone nearby. For many applications an enclosed booth is the more practical and reliable solution because it offers defined boundaries and controlled access that temporary screens cannot match. The Cepro Unisonic booth provides a dedicated, modular enclosed environment that separates laser operations from surrounding activity, allowing other employees to continue working nearby and adapting to different workshop layouts. Useful features to look for in any booth include reliable door interlocks (which stop the laser if a door opens unexpectedly), good operator visibility, practical access and integration with extraction.

Although laser welding generally produces less fume than conventional welding, metal vapours and airborne particles are still generated — and certain materials, such as galvanised (zinc-coated) steel, make effective fume control especially important. Suitable local exhaust ventilation (LEV) or fume extraction should always be used to protect operators, maintain air quality and help comply with COSHH requirements.

Extraction is also a key part of booth planning. Weldability SIF works closely with Extractability to recommend and integrate fume extraction solutions into laser booth installations, so the enclosure and the extraction are designed to work together rather than retro-fitted. See our fume extraction knowledge centre for wider guidance on LEV and COSHH compliance.

Even experienced welders should receive appropriate training before operating handheld laser welding equipment. Training should cover machine operation and setup, safe working practices, shielding gas selection, emergency procedures and — importantly — the specific hazards associated with Class 4 lasers. Many operators actually find laser welding easier to learn than TIG because it requires less manual coordination, but ease of welding must never be confused with ease of operating safely. Weldability SIF provides operator training with installations to help customers weld both safely and productively.

Finally, introducing laser welding should be reflected within your existing health and safety management procedures. This typically means updating risk assessments, training records, maintenance procedures and emergency arrangements so that laser welding is fully embedded — not bolted on. Safety should be treated as part of the investment, not an optional extra: a complete solution brings together machine selection, the LSO’s guidance, eyewear, controlled areas, booths, extraction and training from day one.

• Back to the laser welding hub
• How handheld laser welding works
• Materials and applications for laser welding
• Fume extraction knowledge centre

For wider guidance see our welding safety knowledge centre.