Welding safety

Risks of welding work

• Fumes and gases. Fine metallic particles and gases generated by the base metal, filler material, coatings and shielding gases; insoluble compounds of chromium (VI) and nickel, present in the welding of stainless and high-alloy steels, are recognized carcinogens.
• Optical radiation. Ultraviolet, visible and infrared radiation from the arc, causes keratoconjunctivitis, skin burns and long-term eye damage, both for the welder and for people nearby.
• Electrical contact. Open circuit voltage of arc equipment, deteriorated cables and clamps, work in humid environments or in contact with metallic masses.
• Burns and projections. Sparks, slag, splashes and hot pieces; flammable or oil-contaminated clothing.
• Fire and explosion. Sparks and projections onto combustible materials, work on containers that have held flammable substances, flashbacks and leaks in oxyacetylene installations, handling and storage of gas cylinders.
• Confined spaces. Accumulation of fumes and gases, displacement of oxygen by protective gases, and difficulty of evacuation.
• Noise, heat, and ergonomics. Noise from cutting and grinding processes, heat stress, awkward postures, and handling of parts.

Main preventive measures

The priority is to reduce exposure to fumes at the source: select processes, consumables, and parameters with lower emissions; remove coatings and contaminants from parts before welding; and use local exhaust ventilation (torches with integrated extraction, extraction arms, extraction tables) supplemented by general ventilation. Respiratory protection is reserved for residual exposures, work in confined spaces, or situations where effective extraction is not possible. Exposure assessments to chemical agents, and, when chromium (VI), nickel, or other carcinogens are involved, compliance with Royal Decree 665/1997 (reduction to the minimum technically possible, closed systems or extraction, registration of exposed persons, and health surveillance) are mandatory.

To protect against optical radiation, screens and goggles with filters appropriate to the process and intensity are used, along with leather clothing and gloves, welding screens and curtains to protect the surrounding area, and proper signage. Electrical safety requires CE-marked and maintained equipment, cables, clamps, and connections in good condition, no-load voltage reduction devices for high-risk work, and grounding of the workpiece. In oxyacetylene welding, non-return valves, suitable hoses and regulators, cylinders secured and separated by gas type, and leak checks are required. Hot work in areas with combustible materials or in containers requires a work permit, cleaning and atmospheric control, fire extinguishers, and subsequent monitoring.

Applicable regulatory framework

• Law 31/1995. Risk assessment of each welding task, planning of measures, training and information and health surveillance.
• Royal Decree 1215/1997. Welding and cutting equipment as work equipment: adaptation, maintenance, checks and training.
• Royal Decree 374/2001. Evaluation and control of exposure to chemical agents present in fumes and gases, with the environmental limit values ​​of the INSST.
• Royal Decree 665/1997. Protection against carcinogenic and mutagenic agents when compounds such as chromium (VI) or nickel are involved.
• Royal Decree 486/2010. Protection against artificial optical radiation, including that from the welding arc.
• Royal Decree 773/1997. Selection and use of screens, filters, gloves, protective clothing and respiratory protection.
• Technical Prevention Notes 494 and 495. Safety standards for electric arc welding and oxyacetylene welding and oxyfuel cutting.

Organizational application: how to manage safety in welding

1. Identify the welding and cutting processes, the base and filler materials, the coatings and the environmental conditions (workshop, construction site, confined space, areas with flammable materials).
2. Assess the risks of each task, including exposure to fumes and gases with measurements where appropriate, optical radiation, electrical and fire risks, and apply Royal Decree 665/1997 when carcinogens are involved.
3. Reduce emissions at the source (processes, consumables, cleaning of parts) and install and maintain localized extraction systems, with periodic verification of their effectiveness.
4. Define the personal protective equipment for each process (filters, screens, gloves, clothing, respiratory protection) and the criteria for use and replacement.
5. Establish work procedures, hot work permits, gas cylinder control and confined space entry procedures.
6. Train welders and nearby personnel, and integrate specific health surveillance with exposure records.
7. Maintain equipment, review assessments before changes in materials or processes, and investigate incidents, burns, and exposure episodes.

Preventive management software allows you to link each welding station with the evaluated agents, measurements and limit values, manage hot work permits, schedule the maintenance of extraction and equipment, control the delivery of protective equipment and maintain the record of people exposed to carcinogens as required by regulations.

Limits and common mistakes

1. Welding stainless steels or coated parts without local exhaust ventilation or assessment of exposure to chromium (VI), nickel or other agents.
2. Relying on general ventilation or unsuitable masks as the only protection against fumes.
3. Using insufficient filters or not protecting nearby people with screens and curtains.
4. Performing hot work without permission, without removing combustible materials, and without monitoring the area afterwards.
5. Welding in containers that have held flammable materials or in confined spaces without atmospheric control.
6. Neglecting the condition of cables, clamps, hoses, non-return valves and the securing of the bottles.

Specific measures depend on the process, materials, and environment; this sheet is for informational purposes only.

Regulatory and reference framework

• Law 31/1995, of November 8. Law on the Prevention of Occupational Risks.
• Royal Decree 1215/1997, of July 18. Use of work equipment; welding and cutting equipment.
• Royal Decree 374/2001, of April 6. Protection against risks related to chemical agents during work; welding fumes and gases.
• Royal Decree 665/1997, of May 12. Protection against exposure to carcinogenic agents during work; chromium (VI) and nickel.
• Royal Decree 486/2010, of April 23. Protection against risks related to exposure to artificial optical radiation.
• NTP 494. Electric arc welding: safety standards . Risks and measures of arc welding.
• NTP 495. Oxyacetylene welding and oxyfuel cutting: safety standards . Risks and measures of gas welding and oxyfuel cutting.

The INSST’s BASEQUIM database describes work situations involving exposure to metal fumes in welding stainless and high-alloy steels, and the INSST’s environmental limit values ​​are updated annually.