Installing local exhaust ventilation is a massive step towards protecting workforce health on the factory floor. However, even top-tier extraction equipment relies heavily on proper daily operation by your staff to keep everyone safe from dangerous workplace emissions.
Many manufacturing businesses assume that once extraction hood units are fitted, workplace air quality is automatically guaranteed. Unfortunately, simple operational mistakes by daily workers can severely reduce system suction without anyone in management noticing the drop over time.
Under COSHH Regulation 8, employers are responsible for training staff on the correct use of LEV and keeping training records up to date, exploring these everyday errors is a practical starting point for that training. Working alongside specialists like Vent-Tech, an independent, design-led consultancy rather than an equipment manufacturer, helps you close that gap properly.
Mistake 1: Incorrect Hood Positioning and Distance During Daily Dust Extraction
One of the most frequent operator errors is placing capture hoods too far away from the active work area. Extraction strength drops off rapidly as distance increases, allowing toxic process dust and chemical fumes to escape easily into the wider room.
Welders and fabricators often move along a bench line without repositioning their flexible extraction arms as they move. This leaves significant portions of the cutting or joining process completely uncaptured across the duration of an entire working shift on site.
Training staff to keep hoods as close as possible to the emission point is vital for safety — effective capture distance depends on the hood’s design and airflow rather than a single fixed measurement, so positioning should follow the guidance in your system’s O&M manual rather than a rule of thumb. Correct placement ensures effective dust extraction and prevents hazardous microscopic particles from ever reaching a worker’s breathing zone during tasks.
Mistake 2: Mismanaging Airflow Dampers and Ignoring Basic LEV Maintenance
In multi-branch extraction setups, workers sometimes close dampers on unused arms to boost local suction, or alter settings without understanding system design. This completely disrupts overall airflow distribution across the rest of the factory floor.
Another common issue is blocking capture hoods with tools, storage boxes, or raw materials on workbench surfaces. Covering hood openings starves the main fan motor and causes heavy pressure drops throughout the entire ductwork network in the building.
Simple daily checks and staff awareness prevent these accidental airflow restrictions from happening in your workshop. Combining proper usage habits with routine LEV Maintenance keeps systems running smoothly across all active workstations every single day.
Mistake 3: Switching Off Systems Early and Skipping Routine LEV Testing
Employees often turn off extraction as soon as a grinding, cutting, or sanding task finishes. However, fine hazardous dust remains suspended in the air long after the noisy machinery stops running on the busy shop floor.
Leaving extraction systems running for a few extra minutes allows remaining airborne particles to be removed. This simple habit stops lingering fumes from spreading into the wider room and affecting other workers in adjacent areas.
Fitting modern LEV sensor technology helps monitor real-time airflow speeds and alerts operators the moment performance dips. COSHH ACoP L5 requires this kind of indicating device on many systems as standard, and pairing it with statutory LEV Testing, carried out at a maximum 14-month interval under COSHH Regulation 9, keeps your system’s performance on record rather than just assumed.
Mistake 4: Unauthorised Ductwork Modifications and Bypassing Engineered LEV Controls
Workshop staff sometimes attempt DIY fixes, such as taping extra flexible ducting onto hoods or altering collection shapes. These modifications can change internal air pressure, increase drag, and drastically lower overall capture efficiency across the entire building.
Staff sometimes also override automatic control settings, or leave variable-speed drives running at maximum when the system doesn’t need it, assuming more suction is always safer. In practice this just wastes energy and puts unnecessary strain on the fan and ductwork.
Teaching operators to respect engineered settings prevents unnecessary energy waste and dangerous suction drops. Maintaining strict operational guidelines protects staff health while keeping your facility running smoothly, safely, and cost-effectively at all times throughout the year.
Maximising Extraction Performance Across Your Workplace
Ensuring your local exhaust ventilation functions effectively requires both well-engineered hardware and properly trained operators. Even top-quality equipment fails to protect staff when simple daily usage rules are routinely ignored on the factory floor.
Addressing these four common mistakes through clear staff training and daily checks — the training COSHH Regulation 8 already requires you to provide and record — goes a long way to restoring extraction performance. Protecting your team requires continuous attention to both equipment care and worker habits across every single working shift on site.
If you want to review your system performance or improve staff usage habits across your facility, our BOHS-accredited engineers can help. Visit our contact page to discuss your specific site needs.