Case Study: Welding fumes assessment in a specialist fabrication workshop with focus on fume reduction.
At Sysco Environmental Ltd, we set out to tackle the essential task of assessing welding fume exposure in a fabrication workshop in Northwich. Welding, whether done by small fabricators or large engineering firms, exposes individuals to a myriad of significant hazards. From burns and electric shocks to vision damage and harmful ultraviolet radiation, welders face daily risks that necessitate stringent safety measures.
Our mission was to ensure that the welding operations were safe and compliant with health regulations. Proper Personal Protective Equipment (PPE) is vital to protect welders and nearby workers from these dangers, and we were determined to ensure that everyone in the facility had the right gear and training.
The welding process itself is fascinating. It involves generating heat of around 3,500°C for most welding processes but can reach up to 20,000°C for TIG welding. This heat rapidly evaporates otherwise solid metals and disperses them into the working environment where they can be inhaled as metal fumes.
Welding fumes are a mixture of metallic oxides, silicates, and fluorides, formed when metal is heated above its boiling point. The composition of fumes varies based on the materials being welded. For instance, steel welding primarily produces iron fumes, while stainless steel welding generates chromium and nickel fumes. These fumes can include a range of hazardous substances, such as aluminium, cadmium, copper, and zinc.
The site comprised an office building and a separate fabrication workshop. During the survey, two out of six welding bays were active, and the plasma cutter was used intermittently. The workshop environment included tasks like welding, grinding, and plasma cutting of mild steel, carbon steel, and stainless steel.
The hazardous substances assessment revealed varying levels of airborne contaminants across different areas of the facility:
1. Welding Bays: The air monitoring indicated significant levels of inhalable dust and manganese, with personal exposure to weld fume suggesting the need for immediate training in the correct use of Local Exhaust Ventilation (LEV) systems. The inhalable dust levels were found to be 5.3 mg/m³, representing 53% of the applicable Occupational Exposure Limit (OEL). Manganese levels exceeded the OEL at 0.11 mg/m³, which is 227% of the limit, indicating a need for urgent action.
2. Office Area: Background monitoring showed notable levels of inhalable dust (5.1 mg/m³) and iron (0.14 mg/m³). These findings suggest that contaminants from the workshop were migrating to the office area, posing a risk to employees working there.
Health Effects of Hazardous Substances
Exposure to airborne contaminants such as welding fumes, dust, and specific metals can lead to various health issues, with the severity depending on the intensity and duration of exposure.
- Inhalable Dust: Can cause irritation of the respiratory tract, chronic bronchitis, and in severe cases, Chronic Obstructive Pulmonary Disease (COPD).
- Manganese: Acute exposure can irritate the eyes and respiratory tract, while chronic exposure can affect the central nervous system, leading to neuropsychiatric disorders.
- Welding Fumes: Can cause metal fume fever, occupational asthma, and are considered carcinogenic over long-term exposure.
Health Risks of Welding Fumes
Exposure to welding fumes and gases can be acute or prolonged. Acute exposure may cause eye, nose, and throat irritation, dizziness, and nausea. Prolonged exposure can lead to serious health issues, including lung damage, cancers, kidney damage, and nervous system disorders. Specific risks include:
- Zinc oxide: Can cause metal fume fever.
- Manganese fume: Can lead to Parkinson’s-like symptoms.
- Helium, argon & carbon dioxide: Risk of suffocation.
- Carbon monoxide: Can cause asphyxiation.
- Hexavalent chromium: Causes damage to eyes, skin, lungs, and cancer.
- Ozone: Causes headaches and lung damage.
Reducing Worker Exposure
Proper ventilation is key to reducing fume and gas levels in the workspace. Welding should not be performed in confined spaces without sufficient ventilation. Local exhaust ventilation systems can effectively remove toxic gases from the welder’s breathing zone. Additionally, using appropriate RPE and positioning workers to avoid direct exposure to fumes can further mitigate health risks.
Recommendations
Based on the assessment findings, several recommendations were made to mitigate the risks associated with exposure to hazardous substances:
1. Training and Use of LEV Systems: Ensure all welding operatives are thoroughly trained in the use of LEV systems, including proper positioning to maximise fume capture efficiency.
2. Health Surveillance: Implement an initial and ongoing health surveillance programme to monitor employees' health and detect any early signs of exposure-related conditions.
3. Dust Suppression and PPE: Regularly train employees on dust suppression techniques and the importance of using personal protective equipment. Ensure all respiratory protective equipment is maintained and used correctly.
4. Regular Monitoring and Maintenance: Conduct regular air monitoring to assess the effectiveness of control measures and maintain LEV systems to ensure they operate efficiently.
Protecting Welders' Health
Skilled welders must master the control of factors such as heat input, welding speed, and electrode angle to achieve proper penetration and fusion without causing defects like porosity or weld spatter. However, even the most adept welders must prioritise safety by wearing protective gear. Helmets, gloves, and flame-resistant clothing are essential to shield welders from hazards such as UV radiation, sparks, and hot metal splatter. Through precise execution and adherence to safety protocols, welding remains a critical process in fabricating structures, machinery, and infrastructure that are vital to modern society.
Practical Ways to Keep Your Welding Workspace Safe and Secure
Use Personal Protective Equipment (PPE)
Personal Protective Equipment (PPE) is crucial for safeguarding against welding hazards. Essential PPE includes safety glasses, welding gloves, helmets, respirators, face shields, and welding aprons. Wearing this gear reduces potential risks and protects welders from severe injuries.
Keep Your Workspace Tidy and Organised
Maintaining a clean and organised workstation is essential for minimising the risk of injuries and accidents. Ensure that your workspace is free of clutter and that all tools and equipment are appropriately arranged to avoid hazards.
Check Your Equipment Regularly
Regular inspection and maintenance of welding equipment are vital. Ensuring that your welding machine and tools are in good working condition reduces the risk of accidents caused by faulty equipment. If any faults are detected, promptly seek the assistance of a technician.
Avoid Welding Near Flammable Materials
Welding generates heat and sparks that can ignite flammable materials such as wood, cardboard, or other combustibles. It is crucial to keep these materials away from the welding area or remove them altogether. Always have a fire extinguisher accessible in case of a fire.
Ensure Proper Ventilation
Welding produces harmful fumes and gases that can be dangerous if inhaled. Proper ventilation is essential to protect welders from these hazards. Make sure that your welding area has adequate airflow and ventilation to maintain a safe and clean environment.
Welding is a demanding yet rewarding profession, and safety should always be the top priority. By following these practical safety measures, you can reduce potential risks and ensure the well-being of yourself and your colleagues. Whether you are a professional or a beginner welder, continuous education on safe welding practices is crucial. Beginner training typically covers various safety topics, including proper equipment handling, safe working techniques, and emergency procedures. Always prioritise safety to maintain a secure and efficient welding workspace.
