Assessing Hazardous Substances Exposure in a Manufacturing Environment

The Challenge

A UK-based manufacturing facility operating multiple production areas required independent occupational hygiene support to assess employee exposure to a range of substances hazardous to health, including:

• Inhalable and respirable dust.
• Aluminium metal dust.
• Caprolactam vapour associated with printing processes.

While existing ventilation, PPE and training arrangements were in place, the organisation needed clear, defensible evidence to:

• Demonstrate compliance with COSHH Regulations and EH40 Workplace Exposure Limits (WELs).
• Understand exposure profiles across different work areas and tasks. 
• Confirm whether existing controls were effective.
• Identify opportunities to further reduce exposure in line with ALARP principles

The Approach

Sysco Environmental carried out a structured COSHH air monitoring assessment in accordance with:

• The Control of Substances Hazardous to Health Regulations 2002 (as amended).
• HSE guidance L5 and EH40/2005.
• BS EN 689:2018 exposure assessment strategy.
• Relevant MDHS and international sampling methodologies.

The assessment programme included:

• Personal exposure monitoring within operatives’ breathing zones.
• Monitoring across defined exposure groups, including fabrication and print room operatives.
• Assessment of aluminium dust, total inhalable and respirable dust, and caprolactam vapour.
• Observation of work practices, housekeeping methods, LEV systems and PPE use.
• Review of training, COSHH documentation and control measures.
• UKAS- and ISO-accredited laboratory analysis

Monitoring was undertaken during normal working operations, ensuring results reflected realistic, day-to-day exposure.

The Findings

The assessment confirmed that:

• All measured personal exposure results were below their relevant Workplace Exposure Limits.
• Aluminium inhalable and respirable dust concentrations were well controlled.
• General inhalable and respirable dust levels were low and not significant.
• Caprolactam concentrations in printing areas were below the limit of detection.
• LEV systems associated with fabrication equipment were functioning effectively and maintained in line with HSG258
• Housekeeping practices were generally good, although dry sweeping was identified as a potential source of avoidable dust re-suspension.

While no exceedances were identified, the results reinforced that ongoing management and good practice are essential, even where exposure levels are low.

The Recommendations

Sysco Environmental provided proportionate, preventative recommendations focused on maintaining control and supporting continuous improvement, including:

• Avoiding dry sweeping, favouring HEPA-filtered vacuuming or wet cleaning methods.
• Continuing regular LEV examination and testing at statutory intervals.
• Maintaining training and awareness around dust generation and control measures.
• Ensuring appropriate management and logging of Respiratory Protective Equipment (RPE) where used.
• Periodic review of COSHH assessments and exposure data.
• Repeating monitoring where processes, materials or work patterns change.

The Outcome

The assessment delivered:

• Clear, defensible evidence of COSHH compliance.
• Reassurance that exposure to dusts and chemicals was effectively controlled.
• Practical insight into minor behavioural and housekeeping improvements that further reduce risk.
• A documented, structured basis for ongoing occupational health protection.

Most importantly, it replaced assumption with measured reassurance, demonstrating that worker health was being actively protected and responsibly managed.

Why This Matters

Hazardous substance risks are not limited to high readings or regulatory exceedances. This case study highlights how proactive occupational hygiene monitoring validates controls, supports informed decision-making and helps organisations maintain safe, compliant workplaces — even where risks appear low.