Managing Welding Fumes in Australian Manufacturing

📋 Part of our complete series: Welding Fumes Assessment Australia: The Complete Guide

Managing Welding Fumes in Australian Manufacturing

Australia’s manufacturing sector employs thousands of welders across automotive, appliance, heavy engineering, and fabrication industries. Manufacturing welding is typically high-volume, occurring in fixed facilities with multiple simultaneous welding operations. This scale creates both challenges and opportunities: challenges in controlling cumulative exposure across large workforces, but opportunities for systematic engineering control, health monitoring programs, and process optimization. Unlike construction welding with its site-specific variability, manufacturing allows for standardized approaches to exposure assessment, control, and verification. This article outlines practical strategies for managing welding fume in Australian manufacturing facilities. For more information, see our guide to chemical hazards and workplace exposure standards.

Scale of Welding in Australian Manufacturing

Automotive Manufacturing: Although Australia’s automotive assembly industry has contracted significantly (with the closure of major OEM plants in recent years), automotive component suppliers and repair/maintenance operations continue substantial welding. Welding is used for chassis fabrication, suspension component assembly, and structural repairs.

Appliance Manufacturing: Steel and stainless steel appliances (washing machines, refrigerators, ovens) require extensive welding during assembly. While some welding has been replaced by mechanical fastening, welding remains critical for pressure vessels and structural components. Learn more about welding fumes risks on construction sites in our detailed guide.

Heavy Engineering: Manufacturing of mining equipment, construction machinery, industrial pressure vessels, and other heavy products involves substantial welding. These facilities often operate continuously with multiple welding workstations.

Fabrication and Metal Services: Dedicated structural steel fabrication shops, boiler making shops, and metal fabrication services perform bespoke and high-volume welding. These shops are geographically distributed across Australia, with facilities ranging from small operations (5–10 welders) to large multi-trade facilities (100+ welders). Learn more about welding fumes in shipbuilding operations in our detailed guide.

The common thread across all these sectors is that welding is a core manufacturing process with high-volume, routine activity. This allows for systematic implementation of control measures and continuous monitoring, unlike episodic construction welding.

Fixed vs. Mobile Welding Operations Within Manufacturing

Fixed Welding Operations: Most manufacturing facilities have fixed welding workstations where the welding work comes to the welder (e.g., assembly line stations, fixed fabrication bays). Fixed operations allow for permanent engineering controls (overhead extraction systems, booth ventilation, extraction arms at each workstation). These are ideal for implementing comprehensive LEV systems. Learn more about welding fumes exposure in mining in our detailed guide.

Mobile Welding Operations: Some manufacturing facilities include maintenance welding (repair of equipment and machinery) or mobile welding of large items where the welder moves to the workpiece rather than vice versa. Mobile operations may require portable LEV (fume guns, temporary extraction arms) similar to construction site approaches.

Most large manufacturing facilities have a mix of fixed and mobile welding. The fixed operations should be prioritized for permanent engineering control installation; mobile operations can rely on portable extraction supported by air monitoring.

Similar Exposure Groups (SEG) Methodology for Large Facilities

A large manufacturing facility may employ hundreds of workers in various welding and non-welding roles. Conducting individual air monitoring for every worker is impractical and costly. Instead, occupational hygiene practice uses the Similar Exposure Group (SEG) methodology to stratify workers by exposure probability.

What Is an SEG?
An SEG is a group of workers who share similar job tasks, work locations, equipment, and exposure patterns, and therefore are expected to have similar exposure to welding fume. By grouping workers into SEGs, a facility can conduct representative air monitoring for one worker per SEG, rather than monitoring every individual.

How to Develop SEGs for a Manufacturing Facility:

Walk-through and Job Task Analysis: Conduct a facility walk-through with operations managers, identifying all locations where welding occurs and describing the tasks performed. Document the type of welding process (GMAW, SMAW, etc.), materials (mild steel, stainless steel), duration, and any exposure controls in place.
Initial Grouping: Group workers by job role:
- Primary welders (full-time welding).
- Multi-skilled trades (welding as part of broader role, e.g., fabricator, millwright).
- Supervisors/inspectors in welding areas.
- Material handlers/labourers in welding areas.
- Maintenance workers (mobile welding).
Refinement by Location and Process: Within each job role, further subdivide by location (welding bay, production line) and process (stainless vs. mild steel), as these factors significantly affect exposure.
Expected Exposure Assessment: For each SEG, estimate expected exposure based on:
- Duration of welding per day (hours).
- Number of simultaneous welders in the area.
- Ventilation and engineering controls in the area.
- Material composition (stainless steel generates more fume than mild steel).
Monitoring Strategy: Decide which SEGs require monitoring. Typically, all primary welder SEGs and higher-risk multi-skilled trade SEGs should be monitored. Lower-exposure SEGs (e.g., office staff with occasional site visits) may not require monitoring if exposure is expected to be negligible.
Documentation: Document the SEG structure in writing, with worker rosters assigned to each group. This facilitates turnover (new hires can be assigned to an appropriate SEG with known exposure profile) and future monitoring (results for SEG are compared year-on-year).

Example SEG Structure for a Fabrication Shop:

SEG ID	Role Description	Location	Material	Est. Exposure Level	Monitoring Required
SEG-1	Full-time welder, structural steel	Structural bay	Mild steel	High (6–8 hrs/day)	Yes (annual)
SEG-2	Full-time welder, pressure vessels	Vessel bay	Stainless steel	High (6–8 hrs/day)	Yes (annual)
SEG-3	Fabricator (welding + grinding)	General fab area	Mixed	Medium (2–4 hrs/day welding)	Yes (annual)
SEG-4	Supervisor in welding areas	Multiple areas	N/A (not welding)	Low (ambient exposure)	Optional (area sample)
SEG-5	Maintenance welder (mobile, repairs)	Various (throughout facility)	Mixed	Medium (variable, 2–5 hrs/day)	Yes (annual)

LEV System Design for Manufacturing Workshops

Manufacturing facilities benefit from permanent, centralized LEV system design. Key considerations:

Centralized vs. Decentralized Systems: Large facilities often install centralized systems where multiple capture points (at each welding workstation) connect to a central dust collection unit. Centralized systems are typically more efficient and cost-effective than separate small units at each workstation. However, they require adequate ductwork layout and regular maintenance.

Ductwork Design: Main ducts should be sized to maintain adequate velocity (typically 15 m/s for welding fume to prevent settling). Horizontal ducts should pitch downward slightly toward the main trunk to encourage fume movement. Bends should be gradual (long radius) to minimize pressure drop. Ductwork should be cleanable and should include inspection points for checking internal accumulation.

Filtration: Central filtration units (bag filters, cartridge filters, or media filters) should be sized for the total airflow. Filter design should allow for high-efficiency capture of fine welding fume particles. Filter pressure drop should be monitored (via a manometer or electronic sensor) to trigger filter changes before excessive drop occurs.

Fan Selection: Fans should be rated for continuous operation (24/7 if facility operates continuously). Fan speed can be controlled by VFD (variable frequency drive) to match demand: at higher speed during peak welding hours, lower speed during slow periods. However, fan speed should never be reduced below design specifications during active welding work.

Energy Efficiency: Modern LEV systems can incorporate energy recovery (heat recovery from exhaust) or can be designed with high efficiency to reduce operating costs. When upgrading or designing new LEV, energy efficiency should be considered as a long-term cost reduction measure.

Welding Bay Design and Layout for Fume Control

Workstation Layout: Welding bays should be designed with adequate spacing between workstations to minimize cross-contamination (fume from one workstation traveling to an adjacent workstation). General guidance is to space workstations at least 3–5 metres apart if possible.

Ventilation Flow Pattern: Ventilation should be designed so that air flows away from workers’ breathing zones and toward the extraction point. Avoid recirculation of fume. In a welding bay with multiple workstations, design ventilation to create a smooth sweep across the area toward an extract hood, rather than allowing turbulent air movement.

Traffic Flow: Material handling and worker movement should be planned to avoid crossing welding plumes. Separate entry/exit routes and material flow paths from welding work areas where possible.

Lighting and Thermal Comfort: Adequate lighting is essential for welding quality and safety. In hot climates (common in Australia), cooling/ventilation should be designed to maintain acceptable thermal conditions (especially during summer) without compromising fume extraction.

Supervision Sightlines: Supervisors should have clear sightlines to all welding workstations for oversight and rapid response to problems (control failures, workers in distress).

Health Monitoring Programs for Large Manufacturing Workforces

Manufacturing facilities with dozens or hundreds of welding employees should establish comprehensive health monitoring programs:

Program Structure:

Pre-employment Health Assessment: All welders should undergo baseline spirometry and occupational health questionnaire before beginning work. This establishes respiratory baseline and identifies pre-existing disease.
Annual Monitoring: All welders and multi-skilled trades with regular welding exposure should undergo annual spirometry and biological monitoring (blood manganese, urinary chromium, etc.) as indicated by materials and processes used.
Abnormal Result Protocol: If a result is abnormal (significant FEV₁ decline, elevated metal levels), the worker should be referred for specialist review and control measures should be enhanced.
Exit Monitoring: When a welder leaves employment or transitions to a non-welding role, exit spirometry and biological monitoring should be conducted.

Occupational Health Provider Engagement: Large facilities should contract with an occupational health clinic or provider experienced in manufacturing health monitoring. The provider should be on-site or accessible for convenient scheduling of workers. Electronic health records should link workers to their SEG and allow trending of results over time.

Data Management: Health monitoring data must be managed securely and separately from personnel records. Only authorized occupational health professionals and senior management should have access to health data. Results should be kept confidential; workers should be informed of their own results, but individual results should not be shared with supervisors or colleagues.

Return-to-Work Protocols: If a health monitoring result suggests respiratory impairment (e.g., significant FEV₁ decline), the facility should work with occupational health professionals to determine whether continued welding work is appropriate or whether the worker should be redeployed to a non-welding role temporarily or permanently.

Managing Multiple Welding Processes in the Same Facility

Many manufacturing facilities use multiple welding processes (GMAW, SMAW, FCAW, TIG, submerged arc, etc.) and work with different materials (mild steel, stainless steel, aluminium). Each combination has different exposure characteristics:

Mild Steel Welding (GMAW, SMAW): Generates fume primarily of iron oxides and manganese. Moderate fume volume. Capture velocity of 10–15 m/s typically adequate.

Stainless Steel Welding: Generates higher-Cr and Ni fume, plus carcinogenic hexavalent chromium (Cr(VI)). Fine fume particles. Requires higher capture velocity (15–20 m/s) and efficient filtration. May require special handling of contaminated filters depending on state regulations.

Aluminium Welding: Light-weight fume, requires adequate duct velocity to prevent settling. TIG welding of aluminium generates less fume than GMAW.

Flux-Cored Arc Welding (FCAW): Can generate more fume than GMAW, depending on consumables. Fume composition varies (some products generate lower-Mn fume).

To manage exposure across multiple processes, a facility should:

Inventory welding processes and materials used.
Conduct SEG analysis, separating workers by process/material.
Conduct air monitoring for each major process/material combination.
Ensure LEV design accounts for the fume generation rate of each process (some processes may require higher capture velocity).
Provide health monitoring specific to exposure (e.g., biological monitoring for chromium/nickel in workers doing stainless steel welding, but not necessarily in workers doing mild steel only).

Regulatory Compliance Timeline for Manufacturing

The 1 mg/m³ WES change became effective on 18 January 2024. Manufacturing facilities should have completed the following by now or in the immediate short term:

Risk assessment identifying welding operations and exposure risks (completed by January 2024).
Baseline air monitoring for all primary welding SEGs (completed or in progress by March 2024).
Control strategy documented and LEV systems inspected/tested (completed by March 2024).
Any necessary LEV upgrades or modifications implemented (within 3–6 months of identification of need).
Post-control monitoring to verify WES compliance (completed by mid-2024).
Health monitoring program designed and baseline assessments initiated (ongoing).
Annual monitoring schedule established and implemented (ongoing).

Facilities that have not yet completed these steps should prioritize them now, as regulators are conducting compliance audits at manufacturing sites.

Integration with Broader Industrial Hygiene Programs

Welding fume control should be integrated with broader occupational hygiene programs addressing other hazards:

Grinding and Metal Working Fluid Exposure: Metal fabrication facilities often involve both welding and grinding. Combined exposure to welding fume and grinding dust must be assessed. Similarly, machining with metal working fluids (potential respiratory irritants or allergens) co-occurs with welding in some facilities.
Noise: Welding generates noise (90–100 dB). Integrated noise and fume control may share ventilation infrastructure.
Thermal Stress: Welding areas can be hot, especially in Australian summer. Ventilation design should address both fume extraction and thermal comfort.
Hazardous Substances: Paint residues, cleaning solvents, and other substances may be present in welding areas. Comprehensive hazard assessment and chemical management should be part of the facility’s overall hygiene program.

Frequently Asked Questions

Q1: How often should air monitoring be conducted in manufacturing facilities?
A: At minimum, annual monitoring for each major SEG is required. If exposure is consistently below 0.5 mg/m³, monitoring frequency can potentially be reduced to every 2–3 years after control measures have been verified. If exposure is above 0.5 mg/m³ or approaches the 1 mg/m³ WES, more frequent monitoring (e.g., 6-monthly) should be conducted until controls are enhanced.

Q2: Can we combine air monitoring results from workers in the same SEG, or must each worker be sampled individually?
A: Once an SEG has been established and justified, representative monitoring can be conducted (typically 2–3 workers per SEG per year) rather than monitoring every individual. However, if significant heterogeneity exists within an SEG (some workers have higher exposure than others), this should be identified and the SEG may need to be subdivided.

Q3: What should we do if a health monitoring result shows significant decline in lung function?
A: Refer the worker to a respiratory physician for specialist assessment. Simultaneously, review LEV testing results and air monitoring data to determine whether controls are adequate. If controls are inadequate, enhance them immediately. Consider role modification (reduce welding hours, move to lower-exposure area, or redeploy if necessary). Increase monitoring frequency to 6-monthly to track trends. Document all actions in the worker’s health file.

Q4: How do we manage new hires or staff transfers into welding roles?
A: Assign the new worker to an appropriate SEG based on their role and location. Conduct baseline health assessment before they begin welding work. Provide induction training covering welding fume hazards, controls, and safe work practices. Assign a supervisor or experienced welder mentor for on-the-job training. Ensure the new worker understands LEV operation (e.g., how to position a fume gun, when to switch on extraction). Monitor the new worker closely in the first 1–2 weeks to ensure safe practice.

Q5: Is it necessary to monitor ambient air in non-welding areas of a manufacturing facility (e.g., office areas adjacent to welding bays)?
A: Not necessarily. If non-welding areas are sufficiently separated from welding work and have adequate ventilation, exposure in these areas is expected to be negligible (below background). However, if office areas are located adjacent to welding bays with poor separation, area monitoring may be prudent to verify that exposure is acceptable. Supervisors or office staff who spend some time in welding areas may warrant inclusion in SEG analysis and monitoring.

Q6: Can air monitoring be conducted during non-peak welding activity (e.g., low-production weeks), or should it always be during peak activity?
A: Monitoring should be conducted during typical/representative work periods. If welding volume is highly variable (e.g., peak season vs. low season), at least one round of monitoring should occur during peak activity to capture maximum exposure conditions. Monitoring during low-activity periods can be supplementary but should not be the sole basis for compliance assessment.

Moving Forward

Australian manufacturing has an opportunity to lead in welding fume control through systematic application of occupational hygiene principles. {{LINK_CONTACT}}Contact our team{{/LINK_CONTACT}} to assist with SEG development, air monitoring, LEV design and testing, and health monitoring program establishment for your manufacturing facility.

Request Manufacturing Welding Hygiene Services