đź“‹ Part of our complete series: Welding Fumes Assessment Australia: The Complete Guide
Welding fumes air monitoring is the primary method Australian businesses use to demonstrate compliance with the Workplace Exposure Standard (WES) of 1 mg/m³. Without documented monitoring results, a PCBU cannot show that workers are protected — and with the January 2024 WES reduction, many workplaces that were previously compliant now need fresh data. This page explains how professional welding fumes air monitoring works, when it’s required, and what to expect from the process. For more information, see our guide to chemical hazards and workplace exposure standards.
What Is Welding Fumes Air Monitoring?
Air monitoring is the systematic measurement of airborne contaminants in a workplace to characterise worker exposure and assess the risk to health. For welding fumes, air monitoring quantifies the concentration of total inhalable fume — and specific hazardous components such as manganese, hexavalent chromium, and nickel — in the air that workers actually breathe during their working day.
Australian WHS Regulations require PCBUs to manage the risk of hazardous substance exposure, which means demonstrating that worker exposures are below relevant WES values. Air monitoring provides the objective, quantitative evidence needed to make that demonstration. Without monitoring data, a PCBU is relying on assumption rather than evidence — a position that is increasingly difficult to defend before WHS regulators, and one that leaves workers unprotected against preventable disease.
The fundamental principle of occupational air monitoring is to measure what a worker actually inhales, not just what is present in the ambient environment. This is why personal air monitoring — where a sampling device is worn directly on the worker in their breathing zone — is the gold standard for WES compliance assessment. Static or area monitoring can complement personal monitoring, but it cannot replace it as the basis for WES compliance decisions.
Types of Welding Fumes Air Monitoring
A comprehensive welding fumes air monitoring program may incorporate several complementary monitoring approaches, each providing different information:
Personal air monitoring uses a pump-and-filter sampler worn on the worker’s lapel, positioned within the breathing zone (within 30 cm of the nose and mouth). The pump draws workplace air at a calibrated flow rate through a pre-weighed filter for the duration of the work shift or a representative portion of it. After sampling, the filter is sent to a NATA-accredited laboratory for gravimetric analysis to determine total inhalable fume mass. For stainless steel or other high-risk welding operations, the filter is also subject to inductively coupled plasma mass spectrometry (ICP-MS) to quantify individual metal concentrations.
Static (area) air monitoring places samplers at fixed locations in the work environment rather than on workers. This approach characterises the ambient concentration at specific points — useful for mapping contamination zones, assessing the effectiveness of engineering controls such as local exhaust ventilation (LEV), and identifying areas where bystander exposure may occur. Area monitoring data informs LEV design and commissioning verification, but should not be used as a substitute for personal monitoring when assessing individual worker WES compliance.
Real-time (direct-reading) monitoring uses instruments such as laser photometers, optical particle counters, or photoionisation detectors to provide immediate, continuous readout of airborne particle or gas concentrations. Real-time monitors are valuable for rapid qualitative assessment, worker behaviour observation, and LEV troubleshooting, but they do not meet the analytical accuracy requirements for formal WES compliance assessment. They are best used alongside traditional gravimetric methods as part of a broader monitoring program. Learn more about stainless steel welding fumes hazards in our detailed guide.
Biological monitoring measures the internal dose of absorbed substances through analysis of blood or urine samples. For welding fumes, biological monitoring for manganese (blood) or chromium and nickel (urine) provides direct evidence of actual uptake into the body — accounting not just for inhalation but also for skin absorption and incidental ingestion. Biological monitoring is particularly useful for high-risk operations and as a cross-check on the effectiveness of RPE in controlling inhaled dose. It complements but does not replace air monitoring for WES compliance purposes.
The Personal Air Monitoring Process
A professionally conducted personal air monitoring assessment for welding fumes follows a structured sequence of steps designed to produce results that are statistically robust, technically defensible, and useful as the basis for control decisions.
Survey design: Before any sampling takes place, the occupational hygienist conducts a detailed review of welding operations on site. This involves identifying all welding and thermal cutting processes, the materials and consumables used, the duration and frequency of tasks, the number of workers in each similar exposure group (SEG), and the ventilation and workspace conditions. The survey design determines how many samples are needed, which workers will be sampled, which shifts and tasks represent worst-case conditions, and which analytes require specific laboratory analysis.
Equipment calibration: Sampling pumps must be calibrated before and after each sampling period using a NIST-traceable calibration device. Pre- and post-calibration flow rates are recorded and compared; if the difference exceeds 5%, the sample result must be qualified. Proper calibration is essential to the integrity of the monitoring result — a pump running at the wrong flow rate will yield an inaccurate exposure estimate.
Sampler attachment and shift monitoring: The occupational hygienist fits the lapel sampler to the worker and explains the sampling protocol, including that the worker should continue their normal work activities and not cover or obstruct the sampler. Full-shift sampling is strongly preferred over partial-shift sampling, as it captures the complete daily exposure profile including variability between different tasks and work positions.
Chain of custody: After sampling, filters are removed from the samplers, sealed in individual containers, and accompanied by a chain of custody (CoC) document that records every transfer of the samples from collection through laboratory analysis. The CoC ensures the integrity of the analytical results and is a required element of any monitoring report used for regulatory compliance purposes.
Laboratory analysis: NATA-accredited occupational hygiene laboratories analyse the collected filters using gravimetric methods (for total inhalable fume) and ICP-MS (for individual metal species including Mn, Cr(VI), Ni, Zn, and others as required). Turnaround time is typically 5–10 working days from receipt of samples. The laboratory issues a certificate of analysis (CoA) with results expressed in micrograms per filter, which the hygienist converts to mg/m³ TWA using the calibrated air volume.
Statistical interpretation: A single monitoring result provides only a snapshot of exposure. To characterise the exposure distribution for a SEG with statistical confidence, the AIOH and AS/NZS 3580 series recommend a minimum of six full-shift samples per SEG. Statistical methods — including lognormal probability plotting, Bayesian analysis, or non-parametric tolerance interval methods — are applied to estimate the 95th percentile of the exposure distribution. The 95th percentile is compared with the WES to determine whether the majority of the workforce is likely to be protected. The occupational hygienist’s report must clearly describe the statistical methodology applied and its implications for risk management decisions.
When Is Welding Fumes Air Monitoring Required?
Australian WHS Regulations do not prescribe a fixed monitoring frequency, instead placing the obligation on PCBUs to monitor “as necessary” to ensure compliance with WES values. In practice, the occupational hygiene profession and WHS regulators expect monitoring to occur in the following circumstances:
Initial baseline assessment: Any workplace where welding, cutting, or grinding of metal occurs should have a documented baseline air monitoring assessment. Without baseline data, a PCBU cannot demonstrate that exposures are below the WES, and cannot detect trends in exposure over time. For operations that have never been formally assessed, obtaining a baseline is an urgent priority given the January 2024 WES reduction.
Following process or material changes: Whenever a significant change occurs in welding processes, materials, consumables, or ventilation arrangements, previous monitoring results may no longer accurately represent current exposures. A new monitoring survey should be conducted following any such changes before relying on old data for compliance decisions.
After control measure implementation: When new engineering controls (LEV systems, welding enclosures) or other significant control measures are introduced, monitoring should be repeated to verify that the controls are achieving the intended exposure reductions. This is sometimes called “validation monitoring.”
Periodic review: For operations found to be at or near the WES, annual monitoring is appropriate. For operations with results well below the WES and stable processes, three-yearly monitoring may be sufficient, but only if a documented risk-based rationale is on file. The decision about monitoring frequency should be made by or in consultation with a qualified occupational hygienist.
In response to worker health concerns: If workers report symptoms consistent with welding fume exposure — respiratory symptoms, metal fume fever, neurological symptoms — or if health surveillance identifies abnormal results, air monitoring should be conducted promptly to characterise current exposure conditions.
Following a regulatory notice: If a WHS regulator issues an improvement notice, prohibition notice, or requests monitoring data, the PCBU must conduct monitoring as directed. Having an existing monitoring program in place avoids the need to respond reactively to regulatory action.
What the Report Contains
A professional welding fumes air monitoring report from OccHygiene covers all elements required by Australian WHS Regulations and the AIOH Code of Practice for Air Monitoring in the Workplace. A complete report includes:
A site and process description documenting the workplace, the welding operations assessed, the materials and consumables in use, the ventilation conditions, the work positions and durations observed, and any unusual factors that may affect the representativeness of the results.
A sampling methodology section detailing the sampler type and placement, pump model and serial numbers, calibration records, sampling periods and flow rates, and the identity of sampled workers (or codes if anonymised).
A results table listing each sample result in mg/m³ (or µg/m³ for trace components), the 8-hour normalised TWA, and comparison with the applicable WES value, with clear indication of any exceedances.
A statistical analysis applying the appropriate method to estimate the exposure distribution for each SEG, including the estimated 95th percentile and a qualitative assessment of exposure acceptability in accordance with AIOH guidance.
Recommendations for control improvements, additional monitoring, RPE specification, or health surveillance, prioritised by urgency and with sufficient practical detail to enable implementation.
Laboratory certificates of analysis from the NATA-accredited laboratory as an appendix, providing the primary analytical data underlying the exposure calculations.
What Happens If Results Exceed the WES?
An air monitoring result above the welding fume WES (1 mg/mÂł for total inhalable fume) requires prompt action. The process for responding to an exceedance involves several steps:
The PCBU must immediately review control measures and identify which factors are contributing to the elevated exposure. This typically involves a review of LEV performance, work positioning and technique, and whether RPE is being worn and used correctly. The occupational hygienist will provide specific recommendations based on the monitoring data and site observations.
Affected workers must be informed of the monitoring results and the actions being taken. WHS Regulations require workers to be provided with information about their exposure to hazardous substances, and workers have a right to know when their exposure may be exceeding safe levels.
Interim controls — enhanced RPE, modified work procedures, or temporary restrictions on certain operations — may be needed while longer-term engineering solutions are being designed and installed.
Follow-up monitoring after control improvements confirms whether the revised measures are sufficient to achieve compliance. This closing-the-loop step is essential to demonstrate that the PCBU has met its duty of care.
If exceedances are persistent or severe, the occupational hygienist may recommend a more comprehensive welding fumes risk assessment to identify all contributing factors and develop a systematic control improvement plan.
Monitoring for Stainless Steel Welding
Stainless steel welding requires a more extensive monitoring program than standard mild steel operations. The primary additional hazards are hexavalent chromium (Cr(VI)) — an IARC Group 1 carcinogen with a WES of 0.01 mg/m³ — and nickel compounds (WES 0.1 mg/m³ for insoluble forms). These component-specific WES values are often more stringent than the total fume limit, meaning that stainless steel welding can be compliant with the total fume WES but non-compliant with the Cr(VI) or nickel WES.
For stainless steel welding, the monitoring program must include ICP-MS analysis of sampled filters for Cr(VI), total chromium, and nickel. This requires a more complex analytical procedure than standard gravimetric analysis and may increase laboratory turnaround times. The risk assessment for stainless steel welding should also consider the adequacy of RPE — P2 particulate filtration may not be sufficient for Cr(VI) control in high-intensity stainless welding; combination (P2 + A2) cartridges or higher-efficiency protection may be needed.
Detailed guidance on stainless steel welding fume monitoring and Cr(VI) control is provided in our specialist resource covering this higher-risk application.
Industries We Serve
OccHygiene provides welding fumes air monitoring services to organisations across all major Australian industries and states. Our hygienists have experience in:
Heavy manufacturing and engineering: Structural fabrication, pressure vessel manufacturing, boilermaking, and general metal fabrication facilities. We design sampling programs that account for the diversity of welding processes and materials in complex manufacturing environments.
Construction and civil infrastructure: Structural steel erection, pipeline welding, and maintenance activities. Our hygienists are experienced in monitoring on active construction sites with the associated logistical challenges of working environments.
Shipbuilding and ship repair: Hull welding, outfitting, and repair operations in dockyards and dry docks. Confined space welding presents particular challenges for both monitoring methodology and control effectiveness that we are well placed to address.
Mining and resources: Mobile plant maintenance workshops, processing facility maintenance, and construction activities at mining operations. We can conduct assessments at remote locations across Australia.
Small and medium fabrication workshops: Smaller operations often benefit most from a focused monitoring assessment, as they frequently lack the in-house resources to manage welding fume risks systematically. We scale our services to the size and complexity of the operation.
Frequently Asked Questions
How many samples are needed per worker?
A single sample result is generally not sufficient to reliably characterise a worker’s typical exposure. The AIOH recommends a minimum of six full-shift personal samples per similar exposure group (SEG) to enable statistically robust interpretation of the exposure distribution. In practice, fewer samples may be appropriate for preliminary screening, with a full six-sample program to follow if initial results suggest exposures near the WES. Your occupational hygienist will recommend the appropriate sampling strategy for your specific circumstances.
Can I use real-time monitoring devices instead of filter-based sampling?
Real-time particle monitors provide valuable supplementary information and are useful for qualitative assessment, LEV troubleshooting, and understanding variability in exposure over time. However, they do not meet the analytical requirements for formal WES compliance assessment. Real-time monitors are not calibrated to the specific particle size and density characteristics of welding fumes, and they cannot identify individual metal components. Filter-based personal monitoring with NATA-accredited laboratory analysis remains the required approach for compliance documentation.
What is a similar exposure group (SEG)?
A similar exposure group is a group of workers who perform the same or similar tasks with the same or similar materials in the same or similar conditions, and who therefore have comparable expected exposure profiles. Identifying SEGs allows monitoring resources to be directed efficiently — rather than monitoring every individual worker, a statistical sample within each SEG is sufficient to characterise the group’s exposure distribution. A well-defined SEG strategy is the foundation of an effective, cost-efficient monitoring program.
How long does a welding fumes monitoring assessment take?
A typical monitoring assessment involves a site visit of one to two days for sampler placement and shift monitoring, followed by laboratory analysis (5–10 working days) and report preparation (a further 3–5 working days). From initial engagement to receipt of the final report, allow approximately three to four weeks. If urgent results are required, expedited laboratory turnaround may be available at additional cost.
What qualifications should an air monitoring hygienist have?
Welding fumes air monitoring should be conducted by a Certified Occupational Hygienist (COH) or a hygienist working under COH supervision. The COH designation from the Australian Institute of Occupational Hygienists (AIOH) requires demonstrated competency in exposure assessment methodology, regulatory knowledge, and statistical interpretation. Partnering with a NATA-accredited laboratory for analysis ensures that results carry the weight of independent accreditation.
Get a Quote for Welding Fumes Air Monitoring
OccHygiene’s occupational hygienists are available across Australia to conduct welding fumes air monitoring assessments for organisations of all sizes. Whether you need a straightforward compliance check for a small workshop or a comprehensive multi-site sampling program for a large manufacturing facility, we provide the technical rigour and practical guidance needed to manage welding fume risks effectively.
Our monitoring reports are designed to meet Australian WHS regulatory requirements and provide clear, actionable guidance — not just raw data. We work with you to understand the results and implement the controls needed to protect your workforce.
