Monitoring Exposure to Welding Fume
Exposure monitoring can help you understand how much welding fume workers are exposed to and whether your control measures are working effectively.
Monitoring may form part of your COSHH assessment, help identify where better controls are needed and provide evidence about whether exposure is being adequately controlled.
Important: Monitoring is not a substitute for effective control of welding fume. The priority should always be to prevent or adequately control exposure.
Measures contaminants in the air around a worker's breathing zone and provides an estimate of their exposure during the work being carried out.
Best for: understanding personal exposure and assessing the effectiveness of controls.
Biological monitoring can complement air monitoring by measuring certain substances, or their breakdown products, in biological samples such as urine or blood.
It may be appropriate for exposure to particular metals associated with welding and can also help investigate exposure following a report of ill health.
When might biological monitoring be considered?
This will depend on the materials involved and the substances workers may be exposed to.
Examples can include exposure to:
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chromium
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nickel
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cadmium
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lead
Biological monitoring is a specialist activity and should be planned and interpreted by an appropriately competent professional.
Practical considerations
Biological monitoring requires worker consent. Depending on the programme, samples may be collected by an occupational health professional or occupational hygienist and analysed by an appropriate laboratory.
Fixed-site air samplers can be used to measure airborne concentrations at particular locations in the workplace.
Unlike personal monitoring, static sampling does not directly represent an individual worker's exposure, but it can help identify:
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sources of welding fume
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loss of effective fume control
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how far fume is spreading through the workplace.
Do I Need Air Monitoring
When might air monitoring be needed?
Consider air monitoring where:
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The level of exposure is uncertain
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Welding involves coated materials, such as galvanised steel
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The materials contain substances with low workplace exposure limits, such as nickel or chromium
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Visible fume is escaping into the workplace
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Existing extraction does not appear to be capturing the fume effectively
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There are concerns about the performance of existing controls
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You need information to help select or improve control measures
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You need to assess whether exposure is being adequately controlled
Not sure whether monitoring is necessary?
Exposure monitoring is a specialist activity. An occupational hygienist can help determine whether monitoring is needed, develop an appropriate monitoring strategy and interpret the results.
Why Monitor Exposure
Understand exposure
Identify the level of exposure associated with a task or process.
Check your controls
Assess whether LEV and other control measures are working effectively.
Identify improvements
Find out whether additional or improved controls may be needed.
Assess against exposure limits
Compare results with relevant workplace exposure limits where appropriate.
Select RPE
Help determine the level of respiratory protection required where RPE forms part of the control strategy.
Support health risk management
Provide information that can contribute to COSHH assessment and decisions about health surveillance.
How does air monitoring work?
Personal Air Monitoring
Personal air monitoring usually involves a worker wearing sampling equipment while carrying out their normal work.
The sampler collects contaminants from the worker's breathing zone. The sample is then analysed to help estimate exposure to relevant components of the welding fume.
What should a monitoring survey consider?
Results need to be interpreted in the context of the work taking place. Relevant factors can include:
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welding process
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material and consumables
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duration and frequency of welding
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production rate
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effectiveness of LEV and other controls
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use of RPE
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working environment
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other workers or processes contributing to exposure
This is why simply taking a sample is not enough, the monitoring strategy and interpretation are important.
Who should carry out monitoring?
Get competent advice, exposure monitoring is a specialist activity.
A competent occupational hygienist can help you:
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Decide whether monitoring is needed
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Design an appropriate monitoring strategy
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Carry out or oversee sampling
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Interpret the results
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Identify whether controls need improving
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Recommend appropriate next steps.
What do the results mean?
There is no single workplace exposure limit for welding fume as a whole.
Results may need to be assessed against the relevant workplace exposure limits for individual constituents of the fume, depending on the materials and processes involved. These can include substances such as:
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Iron oxide
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Chromium
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Nickel
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Manganese
Some constituents require particularly stringent control because of their health effects.
Monitoring results should therefore be interpreted by someone competent to understand both the sampling strategy and the substances involved.
What happens next?
The results may indicate that:
Controls are effective
Continue to maintain, check and review them.
Controls need improvement
Review the process and improve engineering controls or working methods.
Further investigation is needed
Additional monitoring or specialist assessment may be required.
Legal requirements
Under COSHH, employers must assess and adequately control risks to health from hazardous substances, including welding fume.
This includes requirements relating to:
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Assessing health risks
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Preventing or adequately controlling exposure
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Maintaining, examining and testing control measures
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Monitoring exposure where appropriate
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Providing health surveillance where appropriate
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Providing workers with appropriate information, instruction and training.
Additional requirements apply where welding activities involve substances covered by specific legislation, such as lead.
Link: Read HSE guidance on COSHH and welding fume →
