Case Study Report
Application of DSEAR at Waste and Recycling Facilities
Integrated Learning for MRFs, Recycling Plants and SRF/RDF Operations
Executive Summary
This case study examines the application of the Dangerous Substances and Explosive
Atmospheres Regulations 2002 (DSEAR) across materials recovery and wider
waste-recycling operations, drawing on detailed assessments from two large UK
facilities:
• A Materials Recovery Facility (MRF) with hazardous waste transfer activities; and
• A multifunctional waste and recycling campus, including DMR, SRF, RDF, wood
processing and plasterboard recycling.
The integrated findings demonstrate that waste and recycling facilities operate with
multiple overlapping DSEAR hazards, including flammable liquids, gases, aerosols and
combustible dusts, often simultaneously. While fire detection and suppression
arrangements were strong, the residual risk remained medium to high, requiring further
governance, technical and behavioural controls.
The case study provides sector-specific learning that is directly transferable across
MRFs, recycling plants and fuel-from-waste operations.
Operational Context: Waste and Recycling Environments
Modern waste and recycling facilities differ from traditional industrial sites in that they:
• Handle unpredictable waste streams, often containing unexpected hazardous
items;
• Generate large volumes of combustible dust during shredding, grading and
processing;
• Rely heavily on mobile plant and vehicles within processing buildings;
• Combine operational processing with maintenance, welding and hot works;
• Store flammable fuels, aerosols and compressed gases to support plant, logistics
and site operations.
These factors create persistent and dynamic DSEAR exposures, rather than isolated
hazardous zones.
Dangerous Substances Typical of Waste and Recycling Sites
Across the assessed facilities, DSEAR-relevant substances included:
Liquids and Gases
• Diesel and petrol for mobile plant and fixed installations
• Oils, lubricants, thinners and cleaning solvents
• Flammable paints and aerosols
• LPG, propane, oxygen and argon used for welding and repairs
These substances were present not only in dedicated stores but distributed across
workshops, yards, spray areas and processing buildings, increasing the risk of
interaction with ignition sources.
Solids and Dusts
A defining feature of recycling operations was the presence of combustible dusts,
including:
• Wood dust and sawdust from shredding
• Plastic fines and particulate from SRF/RDF processing
• Plasterboard and gypsum dust
• Mixed recycling dust within DMR facilities
Dust hazards resulted in Zone 20, 21 and 22 classifications, particularly within:
• Bag filters and extraction units
• Ducting and collection hoppers
• Areas where settled dust was disturbed by plant or housekeeping activities
Hazardous Area Classification: Waste-Specific Findings
The assessments confirmed that many waste and recycling environments operate with
permanent or quasi-permanent hazardous zones, including:
• Zone 20 – dust continuously present (e.g. filters, enclosed LEV components)
• Zone 21 – dust clouds likely during normal operation (e.g. shredders, disturbed
stockpiles)
• Zone 22 – dust present intermittently or when disturbed
A key practical threshold identified was that 2–4 mm of settled dust, when disturbed, is
sufficient to:
• Create an explosive dust cloud;
• Trigger Zone 22 classification;
• Escalate DSEAR obligations even in otherwise “open” or naturally ventilated
buildings.
This provides a clear, measurable housekeeping standard for waste sites.
High-Risk Activities Unique to Waste and Recycling Operations
Dust Management and Housekeeping
The assessments demonstrated that:
• Dry sweeping significantly increases explosion risk by re-suspending dust;
• Poorly maintained LEV systems create both COSHH and DSEAR failures;
• Open-sided buildings do not remove zoning requirements where dust is routinely
disturbed.
Dust was therefore confirmed as a primary DSEAR hazard, not a secondary hygiene
concern.
Local Exhaust Ventilation (LEV) as a DSEAR Control
LEV systems were found to be critical explosion-prevention controls. Where
underperforming, risks included:
• Accumulation of dust within ductwork;
• Inadequate capture velocities;
• Undetected blockages and negative flow;
• Loss of designed containment.
This reinforces that LEV inspection reports must be reviewed through a DSEAR lens, not
solely occupational health compliance.
Mobile Plant and Vehicle Movements
A significant and often underestimated risk driver was vehicle movement within
hazardous zones, including:
• Diesel forklifts and loading shovels;
• Powered pallet trucks;
• Delivery vehicles entering processing buildings.
These introduce ignition risks from:
• Hot exhaust systems;
• Electrical faults;
• Overheating brakes;
• Fuel leaks.
The assessments highlighted the need for:
• Defined vehicle routes and exclusion zones;
• Clear site rules for zoned areas;
• Enhanced inspection and maintenance regimes.
Unexpected Dangerous Substances from Waste Streams
A hazard unique to waste facilities was the recovery of:
• Gas cylinders and aerosols within incoming waste loads.
Even temporary storage of recovered cylinders created hazardous zones and required:
• Segregated storage;
• Rapid removal protocols;
• Inclusion within DSEAR risk assessments.
This reinforces that DSEAR must account for unplanned substances, not just authorised
inventories.
Ignition Sources: Sector-Specific Risk Profile
Across waste and recycling operations, the dominant ignition sources included:
• Mobile plant and fixed machinery;
• Welding and hot work during maintenance;
• Electrical equipment and temporary supplies;
• Static electricity during dust handling and liquid transfer;
• Smoking, vapes and personal electrical devices;
• Lightning affecting external plant, extraction systems and fuel tanks.
Critically, the assessments confirmed that strong fire detection and suppression
systems do not replace explosion prevention, and cannot be relied upon as primary
DSEAR controls.
Governance and Management System Gaps
Despite technical controls, recurring weaknesses were identified at management level:
• Absence of a formally appointed DSEAR Coordinator;
• DSEAR not embedded into Health & Safety Policies;
• Incomplete ATEX equipment registers;
• Zoned areas lacking EX entry signage;
• Limited DSEAR-specific training for operators, supervisors and managers.
These gaps consistently presented the highest residual risk, even on well-resourced
sites.
Emergency Planning and Wider Impact
The findings explicitly link DSEAR scenarios to:
• Toxic fume release from burning plastics and polymers;
• Environmental contamination from melted containers or tank failure;
• Potential off-site impacts to neighbouring communities.
Recommendations included:
• Enhanced spill and fire-water containment planning;
• Consideration of gas dispersion modelling;
• Alignment of DSEAR emergency arrangements with major-incident response
plans.
This elevates DSEAR in waste and recycling facilities from an internal safety issue to a
broader resilience and environmental risk consideration.
Key Integrated Learning for Waste and Recycling Facilities
This integrated case study demonstrates that:
1. Combustible dust is a primary DSEAR hazard in recycling facilities
2. Quantified dust thickness limits (2–4 mm) are essential
3. Dry sweeping is incompatible with DSEAR compliance
4. LEV effectiveness is an explosion-prevention control, not just COSHH
5. Mobile plant is a major ignition source in zoned areas
6. Unexpected hazardous items in waste streams must be included in risk
assessments
7. Fire suppression ≠ explosion prevention
8. DSEAR failures most commonly occur at governance and system level
9. Waste-site DSEAR has off-site and environmental consequences
Conclusion
Waste and recycling facilities present complex, layered DSEAR risks driven by dust
generation, mobile plant, flammable substances and unpredictable waste inputs.
This integrated case study confirms that robust compliance requires:
• Strong technical controls;
• Disciplined housekeeping and dust management;
• Effective vehicle and contractor controls;
• Formal DSEAR governance, leadership and competence.
Embedding these principles at organisational level provides a sustained framework for
reducing fire and explosion risk across MRFs, recycling plants, SRF/RDF operations and
hazardous waste sites.