Every year, thousands of Australian welders develop serious, preventable lung disease. Welding fumes are classified as a Group 1 carcinogen — the same category as asbestos — yet many workplaces still lack formal assessment programs. If your business employs welders, fabricators, boilermakers or anyone who cuts or grinds metal, understanding your obligations under Australian WHS law is not optional. This guide covers everything you need to know about welding fumes assessment in Australia — the risks, the regulations, and how to protect your workers.
What Are Welding Fumes?
Welding fumes are a complex mixture of metallic oxides, silicates, and fluorides generated when base metals, coatings, and electrodes are heated beyond their vaporisation point. As these hot vapours cool and condense, they form ultra-fine particles — typically less than 1 micron in diameter — that remain suspended in workplace air for extended periods.
The exact composition of welding fumes depends on several variables:
- Base metal — mild steel, stainless steel, aluminium, galvanised steel, and cast iron each generate different hazardous components
- Welding process — MIG, TIG, stick (SMAW), flux-cored arc welding (FCAW), and oxy-fuel cutting produce varying fume concentrations and particle sizes
- Consumables — electrode coatings and wire flux formulations introduce additional chemical species including manganese, nickel, and chromium compounds
- Surface coatings — paint, primers, galvanising, and plating materials release their own hazardous decomposition products when heated
- Ventilation conditions — confined spaces and poorly ventilated workshops dramatically increase worker exposure
The most hazardous components routinely identified in welding fume assessments include: iron oxide (the primary component in mild steel welding), manganese and its compounds, hexavalent chromium (Cr(VI)) from stainless steel welding, nickel compounds, zinc oxide from galvanised metal, fluorides, and aluminium oxide.
Beyond the fume itself, welding processes also generate ozone and nitrogen oxides (NOx) from the interaction of the welding arc with atmospheric oxygen and nitrogen. These gases add respiratory and neurological hazards on top of the particulate risks.
The Health Hazards: Why Assessment Is Non-Negotiable
In 2017, the International Agency for Research on Cancer (IARC) reclassified welding fumes from Group 2A (probable carcinogen) to Group 1 (definite carcinogen) — the highest classification available. This decision was based on sufficient evidence that welding fumes cause lung cancer, and limited evidence linking them to kidney cancer.
The scale of the Australian problem is significant:
- Approximately 46,000 Australians are employed as welders, with many more working in adjacent trades exposed to welding fumes
- Studies show up to 91% of welders experience some level of welding fume exposure during their working life
- Research indicates that around 76% of welders regularly work at exposure levels above Australia’s new 1 mg/m³ Workplace Exposure Standard (WES) without adequate controls
- Welders face a 48% higher risk of developing lung cancer compared to unexposed workers, even after controlling for smoking
The documented health effects of chronic welding fume exposure extend well beyond lung cancer. Assessment programs must account for the full spectrum of health risks:
Respiratory diseases: Siderosis (iron deposits in the lung), pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), asthma, and metal fume fever — an acute flu-like syndrome caused by zinc oxide inhalation — are all established occupational diseases in welders.
Neurological effects: Manganese is a particular concern. Chronic manganese exposure causes manganism, a progressive neurological condition with symptoms resembling Parkinson’s disease including tremors, muscle rigidity, and cognitive impairment. High-manganese welding consumables (including some stainless steel electrodes) demand specific assessment and control strategies.
Kidney and urological effects: The 2017 IARC classification noted limited evidence of kidney cancer risk. Nickel and chromium compounds are also recognised nephrotoxins.
Cardiovascular effects: Emerging research suggests that ultra-fine particulate matter from welding may contribute to cardiovascular disease through systemic inflammatory pathways, though this remains an area of active investigation.
Reproductive hazards: Some welding fume components, including manganese and certain heavy metals, are reproductive toxins with potential effects on fertility and foetal development.
The latency period for occupational cancer is typically 15–40 years, meaning that welders who have not been monitored or who worked before tighter controls were introduced may develop disease decades after their primary exposure period. This underscores the importance of health monitoring and biological surveillance programs alongside air quality assessment.
Australian WHS Obligations for Welding Fume Control
In Australia, the management of welding fumes is governed by a comprehensive legislative framework operating at both Commonwealth and state/territory levels. Understanding your obligations is the first step in building an effective assessment program.
Model WHS Act and Regulations: The model Work Health and Safety Act, adopted by most Australian jurisdictions, places a primary duty of care on persons conducting a business or undertaking (PCBUs) to ensure, so far as is reasonably practicable, that workers are not exposed to health and safety risks. For welding fume hazards, this duty is operationalised through the model WHS Regulations, which require PCBUs to:
- Identify all hazardous chemicals (including welding fumes) in the workplace
- Assess the risk of exposure using the hierarchy of controls
- Implement control measures that eliminate or minimise exposure
- Maintain and review controls to ensure ongoing effectiveness
- Provide information, training, instruction, and supervision to workers
- Monitor worker health where there is a risk of an occupational disease arising
SafeWork Australia Code of Practice — Welding Processes (2021): This Code provides practical guidance on managing risks from welding and allied processes. While a Code of Practice is not law, it represents an approved way of meeting WHS obligations. Compliance with the Code is the clearest demonstration that a PCBU has met the standard of “reasonably practicable” duty of care. The Code covers risk management, control measures, ventilation design, respiratory protective equipment (RPE) selection, and health monitoring requirements.
State and Territory Differences: While most jurisdictions have adopted the model WHS framework, Victoria and Western Australia maintain their own occupational health and safety legislation. Victorian employers operate under the Occupational Health and Safety Act 2004 and associated regulations. Despite these differences, the substantive requirements for hazardous chemical management — including welding fumes — are broadly consistent across all Australian jurisdictions.
The New 1 mg/m³ Workplace Exposure Standard
The single most significant regulatory change affecting Australian welding operations in a generation came into effect on 18 January 2024. SafeWork Australia reduced the Workplace Exposure Standard (WES) for inhalable welding fume from 5 mg/m³ to 1 mg/m³ — an 80% reduction in the permissible exposure limit.
This change directly reflected the IARC Group 1 carcinogen reclassification. A WES of 5 mg/m³ was simply not protective enough given the established cancer risk. The new 1 mg/m³ standard aligns Australia with comparable reductions already implemented or in progress in the UK, US (ACGIH TLV), and across the European Union.
The practical implications for Australian workplaces are substantial:
Many previously “compliant” workplaces are now non-compliant. Research conducted before the WES change found that a majority of welding workplaces that met the old 5 mg/m³ limit were operating above 1 mg/m³. This means that control measures which were previously adequate are now likely insufficient — a situation that demands immediate reassessment.
Existing air monitoring data must be re-evaluated. Historical air monitoring results above 1 mg/m³ (even if below 5 mg/m³) now indicate an exceedance situation requiring action. PCBUs relying on old monitoring data to demonstrate compliance face significant risk.
Engineering controls have taken on greater importance. Meeting 1 mg/m³ in many welding environments cannot be reliably achieved through administrative controls or RPE alone. Properly designed local exhaust ventilation (LEV) systems are now effectively mandatory in most enclosed welding areas.
Assessment frequency should increase. Given the tighter limit and the greater sensitivity required to demonstrate compliance, many organisations should revisit their assessment schedules and consider moving from periodic to continuous or real-time monitoring in high-exposure environments.
Individual component WES values remain important alongside the total inhalable fume limit. For stainless steel welding, the Cr(VI) WES of 0.01 mg/m³ (10 µg/m³) and the nickel compounds WES (0.1 mg/m³ for insoluble compounds) often drive the risk assessment independently of the total fume level. Stainless steel welding assessment requires a separate analytical approach.
Types of Welding Fumes Assessment
A comprehensive welding fumes management program draws on several distinct but complementary assessment methodologies. Understanding what each type involves helps PCBUs select the right approach for their specific circumstances.
| Assessment Type | What It Measures | Method | When Required |
|---|---|---|---|
| Personal Air Monitoring | Individual worker exposure to total inhalable fume and specific components (Mn, Cr(VI), Ni) | IOM or 37mm cassette sampler on lapel, gravimetric + ICP-MS analysis | Baseline, after control changes, periodic review; mandatory for WES compliance demonstration |
| Static (Area) Air Monitoring | Fume concentration at fixed locations in the work environment | Fixed-position samplers or real-time particle monitors | Characterising contamination zones, evaluating LEV effectiveness, continuous monitoring |
| Risk Assessment | Qualitative or semi-quantitative hazard and exposure likelihood evaluation | COSHH Essentials, AIOH framework, site walk-through and process review | Initial hazard identification, prioritising monitoring resources, controlling lower-risk tasks |
| Biological Monitoring | Internal dose of absorbed substances (blood Mn, urinary Cr, urinary Ni) | Blood or urine sampling, laboratory analysis against biological monitoring guidance values | High-risk operations (stainless, confined space), confirming RPE adequacy, health surveillance programs |
| LEV/Ventilation Assessment | Capture velocity, face velocity, system static pressure, LEV hood design effectiveness | Anemometer measurements, smoke visualisation, system commissioning tests | New LEV installation, annual LEV examination, troubleshooting fume control failures |
| Health Surveillance | Early signs of respiratory, neurological, or systemic disease in exposed workers | Spirometry, questionnaire, targeted clinical examination per relevant Codes | Workers with significant ongoing exposure; required where there is a risk of occupational disease |
Personal Air Monitoring: The Core of WES Compliance
Personal air monitoring is the gold standard for demonstrating compliance with the welding fume WES. It directly measures the concentration of hazardous substance that a worker actually breathes — as opposed to static area monitoring, which characterises the ambient environment rather than individual exposure.
A properly conducted personal air monitoring program for welding fumes follows a structured methodology:
Survey design: An occupational hygienist develops a sampling strategy based on the types of welding performed, the materials involved, the duration of welding tasks, and the number of workers in similar exposure groups (SEGs). The goal is to characterise the worst-case exposures in each SEG with statistical confidence.
Sampler selection and placement: For inhalable welding fume, a cassette-type sampler (typically a 37 mm closed-face cassette or an IOM sampler) is attached to the worker’s lapel in the breathing zone — within 30 cm of the nose and mouth. The sampler draws air at a calibrated flow rate (typically 2 L/min) through a pre-weighed filter.
Analytical requirements: After sampling, filters are returned to an accredited laboratory (NATA-accredited for occupational hygiene) for gravimetric analysis to determine total inhalable fume mass. For stainless steel welding, additional ICP-MS (inductively coupled plasma mass spectrometry) analysis is performed to quantify Cr(VI), total chromium, and nickel concentrations. Manganese quantification is recommended for high-manganese processes including flux-cored arc welding.
Result interpretation: Results are expressed as time-weighted average (TWA) concentrations in mg/m³, normalised to an 8-hour working day. These are compared against the relevant WES values — 1 mg/m³ for total inhalable welding fume, 0.01 mg/m³ for Cr(VI), and other component limits as applicable.
Statistical treatment: A single sample is rarely sufficient to characterise exposure reliably. AIOH and AS/NZS 3580 guidance recommends a minimum of 6 full-shift samples per SEG to enable Bayesian or non-parametric statistical analysis of the exposure distribution. The air monitoring methodology applied by your hygienist should include a formal statistical interpretation alongside the raw results.
Documentation and reporting: Results must be documented in a register maintained by the PCBU and retained for at least 30 years (for health hazard substances with long-latency disease potential). The monitoring report should include the sampling strategy, analytical results, statistical interpretation, comparison with WES values, and recommended actions.
Welding Fumes Risk Assessment: A Four-Step Approach
Before committing to a full quantitative air monitoring program, and as a framework for ongoing hazard management, a systematic welding fumes risk assessment provides the structured foundation required by WHS legislation.
Step 1 — Identify the hazards: Document every welding and thermal cutting process in the workplace. For each process, identify: the base material, consumables used (with Safety Data Sheets), surface coatings or treatments present, the duration and frequency of tasks, the number of workers involved, and the workspace characteristics (open air, forced ventilation, enclosed, confined space). Special attention should be given to processes involving stainless steel, galvanised or zinc-coated metal, painted or treated surfaces, and non-ferrous alloys, as these carry hazard profiles beyond the standard mild steel welding scenario.
Step 2 — Assess the risks: For each identified hazard, evaluate both the likelihood and consequence of exposure exceeding safe levels. Relevant factors include: proximity of the worker’s breathing zone to the fume source, the welding duty cycle (percentage of time actively welding), ventilation adequacy, whether RPE is worn and its likely effectiveness, and the concentration of hazardous components in the fume based on process knowledge and published data (HSE’s COSHH Essentials Welding Supplement and the AIOH Welding Fumes Database are useful reference resources). Where qualitative assessment indicates significant risk, quantitative air monitoring is required.
Step 3 — Control the risks: Apply the hierarchy of controls in order of effectiveness:
- Elimination — Can the welding operation be replaced entirely? For example, replacing on-site welding with prefabricated assemblies. This is often impractical but should always be considered first.
- Substitution — Can a lower-hazard process, material, or consumable be used? Switching from flux-cored arc welding (higher fume generation) to MIG (lower fume generation) for suitable applications reduces exposure at the source. Using low-manganese consumables where performance requirements permit is another substitution strategy.
- Isolation — Can the process be physically isolated from other workers? Dedicated welding bays with curtain barriers, separation zones, and restricted access minimise the number of workers exposed.
- Engineering controls — Local exhaust ventilation (LEV) is the primary engineering control for welding fumes. A correctly designed and maintained LEV system captures fumes at or near the source before they enter the worker’s breathing zone. This is the most reliably effective control for enclosed welding environments. General dilution ventilation can supplement LEV but should not replace it as the primary control.
- Administrative controls — Job rotation to reduce individual exposure duration, scheduling high-fume tasks during low-occupancy periods, and training and supervision to ensure workers maintain optimal positioning relative to fume plumes.
- Personal protective equipment — Respiratory protective equipment (RPE) is the last line of defence, not a substitute for engineering controls. For welding fumes, a minimum of a P2 half-face respirator is required where WES exceedances are possible; powered air-purifying respirators (PAPRs) or supplied-air respirators may be required for high-risk operations or where fit testing demonstrates inadequate seal with standard RPE.
Step 4 — Review and monitor: Risk assessments are not set-and-forget documents. They must be reviewed when processes change, when air monitoring results indicate controls are insufficient, after incidents or near-misses involving welding fume exposure, and on a periodic basis (at least every 5 years, or more frequently in high-risk environments). The review cycle should be integrated with the air monitoring program so that quantitative data drives the evidence base for control adequacy.
Health Monitoring and Biological Surveillance
Air monitoring tells you what workers could be breathing. Health monitoring and biological surveillance tell you whether those exposures are causing harm — or whether absorbed doses are approaching levels of clinical concern. Under Australian WHS Regulations, health monitoring is required for workers who are, or are likely to be, exposed to a substance that can cause an occupational disease identified in Schedule 14 of the model WHS Regulations.
For welding fumes, the relevant health monitoring requirements depend on the specific substances present. Key considerations include:
Spirometry (lung function testing): Baseline and periodic spirometry is recommended for all workers with significant ongoing welding fume exposure. Spirometry measures forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), enabling early detection of restrictive or obstructive ventilatory defects before they progress to clinically significant disease. Results should be interpreted by a physician with occupational medicine training, and significant decrements from baseline should trigger immediate review of exposure controls.
Biological monitoring for manganese: Blood manganese levels are the primary biological indicator for manganese exposure assessment. Biological monitoring guidance values for blood manganese in occupationally exposed workers are typically in the range of 15–18 µg/L. Workers engaged in flux-cored arc welding, high-manganese electrode work, or welding in confined spaces should have biological monitoring as part of their health surveillance program.
Biological monitoring for chromium and nickel (stainless steel welding): For workers involved in stainless steel welding, urinary chromium and urinary nickel provide useful biological exposure indicators. End-of-shift urinary Cr is particularly valuable given the IARC Group 1 classification of Cr(VI) as a human carcinogen. ACGIH biological exposure indices (BEIs) provide reference values, though Australian guidance from Safe Work Australia and the AIOH should be used as the primary reference.
Health monitoring records: Under WHS Regulations, the PCBU must ensure health monitoring results are provided to the worker and to the relevant WHS regulator if a registered medical practitioner advises that the results indicate work-related disease or exposure. Records must be kept for at least 30 years.
Engineering Controls: Getting LEV Right
For most indoor welding environments, local exhaust ventilation is the cornerstone of an effective exposure control strategy. Meeting the new 1 mg/m³ WES in enclosed or semi-enclosed spaces is extremely difficult without functional LEV — particularly for flux-cored, stick, or MIG welding processes that generate high fume volumes.
Effective LEV design for welding fume control follows well-established principles:
Capture velocity: The LEV hood must generate sufficient air velocity at the fume source to overcome the thermal buoyancy of the fume plume. For welding fumes, a capture velocity of 0.5–1.0 m/s at the source is typically required, depending on hood type and cross-drafts. Receiving-type hoods placed close to the arc achieve this more efficiently than remote hoods.
Hood proximity and positioning: The effectiveness of LEV drops exponentially with distance from the source. As a rough guide, doubling the distance from the hood face requires approximately four times the airflow to maintain equivalent capture. Flexible extraction arms that can be positioned within 300–500 mm of the welding arc are highly effective for fixed-position work.
System design and commissioning: LEV systems must be designed by a competent person with appropriate consideration of duct velocity, fan sizing, filtration requirements (HEPA for fine metal particulates), and makeup air provision. A LEV examination and test at commissioning and annually thereafter is required under the SafeWork Australia Code of Practice on Welding Processes.
Maintenance: Blocked filters, damaged ducts, and fan deterioration all reduce LEV effectiveness without obvious visible signs. Regular maintenance checks, including static pressure measurements at commissioning reference points, are essential to confirm ongoing system performance.
Industries at Highest Risk
While any workplace where welding, cutting, or metal grinding occurs carries welding fume risk, certain industries warrant priority attention based on exposure intensity, worker numbers, and historical disease rates.
Construction and infrastructure: Structural steel erection, pipeline welding, and maintenance of construction plant involve extensive outdoor and semi-enclosed welding. Construction welders frequently work in confined or partially confined spaces and face the additional challenges of variable ventilation, multiple simultaneous trades, and work in positions that bring the breathing zone directly into the fume plume. The construction industry accounts for a significant proportion of Australian welding-related disease burden.
Manufacturing and fabrication: Metal fabrication workshops, automotive manufacturing, heavy engineering, and white goods manufacturing involve high-volume, sustained welding operations. Fixed LEV installations are more practicable in manufacturing environments, but the sheer volume and diversity of welding tasks means that comprehensive assessment across all work stations and SEGs is essential.
Shipbuilding and ship repair: Shipbuilding involves extensive confined space welding with multiple trades working simultaneously in enclosed hull sections. Fume accumulation in ship spaces can be extreme, and ventilation design for complex enclosed spaces is a specialist discipline. The shipbuilding industry has historically carried one of the highest welding fume disease burdens in Australia.
Mining and resources: Mobile equipment maintenance, structural welding, and pipeline construction in remote mining operations often involve welding in challenging environmental conditions. The distances involved, together with the prevalence of contract and FIFO workforces, can make consistent hygiene management difficult.
Small workshops and tradespersons: Small fabrication shops, panel beaters, plumbers, and maintenance tradespeople who weld as a secondary activity often receive disproportionately less attention in formal assessment programs. The sporadic nature of welding in these settings does not mean exposure is trivial — brief high-intensity exposures can generate significant short-term dose.
Choosing an Occupational Hygienist for Welding Fumes Assessment
A welding fumes assessment is a technical exercise requiring specialist knowledge of industrial hygiene sampling methodology, analytical chemistry, Australian WHS legislation, and exposure risk communication. Selecting a qualified, experienced occupational hygienist is critical to obtaining results that are defensible, actionable, and compliant.
Key qualifications to look for include:
- Certified Occupational Hygienist (COH) designation from the Australian Institute of Occupational Hygienists (AIOH) — the peak body for occupational hygiene practice in Australia
- NATA-accredited laboratory partnerships — ensure analytical results carry the weight of independent accreditation
- Industry-specific experience — a hygienist familiar with your sector will design more targeted assessment programs and make more relevant recommendations
- Comprehensive reporting — look for reports that include not just raw data but statistical interpretation, WES comparison, and prioritised recommendations with implementation guidance
- National coverage — for organisations operating across multiple states and territories, a hygiene consultancy with national reach ensures consistency in methodology and reporting
OccHygiene provides welding fumes assessment services across Australia, with experienced occupational hygienists covering all major industrial regions. Our assessments are designed to meet Australian WHS regulatory requirements and provide practical, actionable guidance for control implementation.
Frequently Asked Questions
How often does welding fumes monitoring need to be done?
There is no single prescribed frequency under Australian WHS legislation. The Code of Practice on Welding Processes recommends monitoring “at regular intervals” and whenever there is a change in process, materials, or control measures. As a practical guide, an initial baseline assessment should be conducted for all welding operations. For operations found to be at or near the WES, annual monitoring is appropriate. For operations well within the WES with stable processes, three-yearly monitoring may be sufficient. After any significant process change — new materials, new equipment, changes to LEV — monitoring should be repeated promptly.
Does air monitoring need to cover all workers, or just a representative sample?
The concept of similar exposure groups (SEGs) allows monitoring resources to be focused on groups of workers with similar tasks, materials, and environments rather than monitoring every individual. A statistically valid sample of workers within each SEG is sufficient to characterise the group’s exposure distribution. Your occupational hygienist will determine the appropriate number of samples per SEG based on AIOH and AS/NZS 3580 methodology.
What happens if monitoring results exceed the new 1 mg/m³ WES?
An exceedance result requires immediate action. The PCBU must review and improve control measures — typically by enhancing LEV, improving worker technique and positioning, reviewing consumables, and/or upgrading RPE. Following control implementation, monitoring should be repeated to confirm that the revised controls achieve compliance. Results must be communicated to affected workers. Repeated exceedances without action could constitute a WHS regulatory breach.
Is RPE sufficient on its own for welding fume compliance?
No. Under the hierarchy of controls, RPE is a last resort, not a primary control. The SafeWork Australia Code of Practice is clear that engineering controls — particularly LEV — should be the primary means of achieving compliance. RPE may be used as a supplementary measure where engineering controls cannot reduce exposure to below the WES, or as a transitional measure while engineering controls are being designed and installed. RPE programs must include appropriate selection (protection factor, approval status), fit testing, training, and maintenance to be effective.
Does the 1 mg/m³ WES apply to outdoor welding as well?
Yes. The WES applies to all workplaces regardless of whether welding is conducted indoors or outdoors. In practice, outdoor welding in good weather with adequate natural ventilation may achieve compliance more easily than indoor operations, but formal assessment is still required to demonstrate this. Wind direction and speed, shelter configurations, and proximity of other workers all affect outdoor exposure levels.
What records do I need to keep?
PCBUs must retain air monitoring records for at least 30 years (for substances that can cause long-latency occupational diseases). Health monitoring records must also be retained for 30 years. Retain the full monitoring report including sampling strategy, chain of custody documentation, laboratory certificates of analysis, and the hygienist’s interpretation and recommendations. These records form a critical part of your WHS due diligence documentation.
What is the difference between inhalable and respirable fume fractions?
Inhalable dust/fume refers to the fraction of airborne particles that can be inhaled through the nose and mouth, including particles that deposit in the upper airways, trachea, and bronchi. Respirable dust refers to the smaller fraction that penetrates to the gas exchange region of the lung (alveoli). The WES for welding fume (1 mg/m³) applies to the inhalable fraction. Some component-specific WES values (e.g., for silica) apply to the respirable fraction. Your monitoring report should clearly specify which fraction was sampled and how it relates to the applicable WES.
Do subcontractors need to be included in a welding fumes assessment?
Yes. A PCBU’s duty of care extends to all workers under their management or control, including contractors and subcontractors. If a subcontractor is performing welding work on your premises or under your direction, their exposure must be considered in your assessment program. Similarly, host PCBUs must ensure that contractor welding activities do not expose other workers on the site to welding fume concentrations above the WES. A site safety management plan should address contractor welding fume control requirements and verification.
Take the Next Step: Commission a Welding Fumes Assessment
The combination of the IARC Group 1 carcinogen classification, the new 1 mg/m³ WES, and the clear evidence that most uncontrolled welding environments exceed this limit means that the risk of regulatory action — and more importantly, of worker harm — has never been higher. A proactive, professionally conducted welding fumes assessment program is the most effective way to demonstrate your duty of care and protect your workforce.
OccHygiene’s experienced team of Certified Occupational Hygienists delivers welding fumes assessments across all Australian states and territories, including air monitoring programs, LEV assessments, health surveillance support, and practical control implementation guidance. We work with industries from construction and heavy manufacturing to shipbuilding, mining, and small fabrication workshops.
