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Welding Health and Safety by the Numbers
Managing welding hazards with measurement: fume, exposure, extraction, respirators, radiation, electricity, fire and gases, noise, heat and health records
Welding safety with numbers: risk management, fume and its measurement, extraction and ventilation, respirators, eyes and radiation, electric shock, fire and confined spaces, noise, heat and records.
Start readingAbout this book
Welding is one of the most useful trades in industry and one of the most hazardous. A welder works with an electric arc or flame hot enough to melt steel, intense ultraviolet and visible light, fume containing metals and gases that harm the lungs and other organs, electrical circuits that can kill in wet or cramped places, compressed and flammable gases, sparks and spatter that start fires, noise, heat and awkward positions held for hours. Most of these hazards are invisible or delayed in their effects. Arc eye appears hours after exposure, lung disease and cancer years later, hearing loss so slowly that it is noticed only when it is permanent.
This book is for fabrication managers, supervisors, safety coordinators, welders and instructors who manage those hazards. It explains, with numbers, how each hazard arises and how big it is: how much fume a process makes and how exposure is measured, how much air an extraction hood needs, what a respirator does, how radiation falls with distance, how much current a body carries at a given voltage, how fast a gas leak empties the oxygen from a confined space, and how noise doses and injury rates are calculated. Numbers make the hazards real and the controls measurable.
Early manuals as a starting point
The welding manuals of a century ago took the welder’s eyes seriously. The Davis-Bournonville course of 1919 gave a whole lecture to the care of the eyes, requiring coloured spectacles or goggles for welders, cutters and their helpers, warning that glasses darker than needed handicapped the welder, and offering a rough test of whether a pair was dark enough. P. F. Willis, in 1917, warned that glasses too dark strained the eyes as badly as none. E. Wanamaker and H. R. Pennington, in 1921, explained that the arc’s ultraviolet and infrared rays were dangerous even though invisible, and that a helmet must cover the whole face because the arc blistered exposed skin.
The fume, the electrical and the long-term health hazards were less understood then. Each chapter takes up a hazard, begins where the early manuals were right or silent, and works it through with modern knowledge and measurement.
The running case
This is an illustration. A fabrication shop of about thirty people makes structural steel, trailers and general fabrication, with gas metal arc, flux-cored and manual metal arc welding, plasma and oxy-fuel cutting, and some stainless and galvanised work. Its new health and safety coordinator, a former welder, wants to replace a folder of generic procedures with a programme built on the shop’s own hazards and measurements, and to bring down a run of eye injuries, burns and strain injuries.
The shop, its people, measurements, incidents and results are invented for teaching. They are not KEVOS® work. Real workplaces must assess their own risks, measure their own exposures and follow the work health and safety laws of their jurisdiction.
How to use the book
Chapter 1 covers the hazards and the risk management process. Chapter 2 explains welding fume, Chapter 3 how exposure is measured, Chapter 4 extraction and ventilation, and Chapter 5 respiratory protection. Chapter 6 deals with eyes, skin and radiation, Chapter 7 with electrical safety, and Chapter 8 with fire, gases and confined spaces. Chapter 9 covers noise, heat and ergonomics, and Chapter 10 health monitoring, training and safety records. Every chapter ends with an exercise and its worked answer.
Limits and professional responsibility
This book is educational and does not replace the work health and safety laws, regulations, codes of practice and standards that apply, or the advice of competent occupational hygienists, engineers and medical practitioners. It quotes no exposure standards, protection factors or shade numbers; those come from the current editions of the regulator’s publications and the standards named. Its figures are illustrations for teaching, labelled as such.
An original treatment
READOS covers welding equipment in Arc Welding by the Numbers, shop layout in Setting Up a Welding Shop by the Numbers, and the training of welders in Welder Training by the Numbers; this book links to them rather than repeating them. The explanations, the shop case, the calculations, figures and exercises are original KEVOS® writing. The historical sources are public-domain works in the United States; their advice is summarised in new words, and none of their text, tables or illustrations is reproduced.
Who this book is for
Fabrication managers, supervisors, safety coordinators, welders and welding instructors who manage the hazards of welding and cutting, and want to understand them with numbers.
What you will learn
- Apply the risk management process and the hierarchy of control to welding hazards.
- Explain how welding fume forms, how exposure is measured and how it compares with exposure standards.
- Size local exhaust ventilation and judge respiratory protection for welding tasks.
- Calculate the effects of distance on arc radiation, of body resistance on shock current, and of gas leaks in confined spaces.
- Plan noise, heat and ergonomic controls, health monitoring and safety records for a welding shop.
Inside this book
Chapters
- 01Welding hazards and the risk processList the hazards of welding and cutting, separate the immediate from the delayed, apply the risk process and the hierarchy of control, and read a shop's injury record for where to start.
- 02Welding fume: what it is and how much is madeSee how welding fume forms from vaporised metal, what it contains and does to the body, compare how much fume each process makes, and calculate why general ventilation alone rarely dilutes it enough.
- 03Measuring exposure to fumeSample fume in the welder's breathing zone, calculate an eight-hour time-weighted average, compare it with the exposure standard as a ratio, and see why one sample proves little when exposures vary.
- 04Extraction and ventilationCapture fume at the arc with arms, on-torch extraction, benches and booths, calculate how airflow grows with distance from the hood, test that systems work, and count the heat exhaust air removes.
- 05Respiratory protectionChoose respirators for welding, from disposable masks to powered helmets and supplied air, see how a protection factor divides exposure, why fit matters, and how time without the respirator erodes it.
- 06Eyes, skin and radiationUnderstand the arc's radiation, why arc eye appears hours later, how exposure falls with the square of distance, how filters and screens protect welders and bystanders, and how to stop flying chips.
- 07Electrical safety in weldingCalculate the current a welding circuit drives through a body, dry and wet, see why open-circuit voltage and confined spaces matter, how voltage-reduction devices help, and why stray current burns.
- 08Fire, gases and confined spacesControl hot work fires with permits and fire watches, handle gas cylinders, calculate how a leak drains or enriches the oxygen in a confined space, and plan confined space welding and rescue.
- 09Noise, heat and ergonomicsCompare the noise of welding and its allied work, add decibels from several sources, manage heat stress under leathers in summer, and cut the strains of awkward postures, heavy torches and lifting.
- 10Health monitoring, training and recordsMonitor welders' hearing and lungs where the risk or the law requires, train for competence, calculate injury rates and why small shops' rates jump, choose leading indicators, and review each year.
References and source notes
The manuscript and worked examples are original KEVOS® writing. References inform particular concepts; their authors do not endorse this book. Web references were consulted on 25 October 2026.
- Davis-Bournonville Company, Jersey City. Davis-Bournonville Oxy-Acetylene Welding and Cutting Course of Instruction (1919). Historical source for its lecture on the care of the eyes and safety: coloured glasses for welders, cutters and helpers, the rule of shutting out no more light than necessary, a rough test of whether the glasses are dark enough, spectacles against goggles, and sterilising shared goggles. Summarised in new words; no text, tables or illustrations are reproduced.
- P. F. Willis. Practical Manual of Oxy-Acetylene Welding and Cutting (1917). Historical source for tinted goggles of lighter and darker shades for different work, and the warning that glasses too dark strain the eyes as much as none at all. Summarised in new words.
- E. Wanamaker and H. R. Pennington (Simmons-Boardman Publishing, New York and Chicago). Electric Arc Welding (1921). Historical source for eye and skin protection in arc welding: the ultraviolet and infrared rays of the arc, coloured glass combinations with a clear cover glass, uniform glass free of streaks, and helmets and hand shields large enough to cover the face because the arc's rays blister exposed skin. Summarised in new words.
- International Agency for Research on Cancer. Welding, Molybdenum Trioxide, and Indium Tin Oxide, IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 118 (2018). Named for its classification of welding fumes as carcinogenic to humans (Group 1) and of ultraviolet radiation from welding. No text is reproduced.
- Safe Work Australia. Model Code of Practice: Welding processes; Model Code of Practice: Confined spaces; Model Code of Practice: Hazardous manual tasks; Model Code of Practice: Managing noise and preventing hearing loss at work; Workplace exposure standards for airborne contaminants (current editions). Named for the duties and guidance on managing welding risks, confined spaces and airborne contaminants. This book quotes no exposure values from them; the current editions, as adopted in each jurisdiction, govern.
- Standards Australia and Standards New Zealand. AS/NZS 1715, Selection, use and maintenance of respiratory protective equipment; AS/NZS 1338.1, Filters for eye protectors: filters for protection against radiation generated in welding and allied operations; AS/NZS 1337.1, Personal eye protection: eye and face protectors for occupational applications; AS/NZS 3760, In-service safety inspection and testing of electrical equipment (current editions). Named for their scope only. No protection factors, shade numbers or other values are quoted from them.
