LEVs Explained

LEVs Explained: Local Exhaust Ventilation in Labs

Extraction Arms

What Are Local Exhaust Ventilation (LEV) Systems — and Why Every UK Laboratory Needs One

When it comes to laboratory safety and air quality, one term matters most: Local Exhaust Ventilation (LEV). These systems play a critical role in COSHH compliance, safeguarding staff from hazardous substances in the workplace.

Whether you’re fitting out a new lab, upgrading fume extraction, or conducting a COSHH review, an effective LEV system is your first line of defence.

What Is a Local Exhaust Ventilation (LEV) System?

An LEV system is an engineered solution designed to capture airborne contaminants — including fumes, vapours, aerosols, and dust — at their source.

Each system typically includes:

  • A capture hood

  • Ductwork to transport air

  • Filtration units

  • A fan to move air

  • A discharge point (external or recirculated)

These systems are essential for:

  • Reducing airborne exposure

  • Ensuring COSHH Regulation compliance

  • Improving indoor air quality

  • Protecting laboratory personnel from long-term health risks

Types of LEV Systems in UK Laboratories

Fume Cupboards (Fume Hoods)

The most recognisable LEV system — essential in chemistry labs, universities, and pharmaceutical research.

✔ Pros: High containment, protects users, ideal for volatile chemicals
✘ Cons: Fixed location, higher cost than mobile alternatives

Read our full guide to UK Fume Cupboards

Articulated Extraction Arms (LEV Arms)

Flexible systems ideal for soldering, small-scale benchtop work, and light-duty use.

✔ Pros: Easy to retrofit, adjustable, affordable
✘ Cons: Requires precise positioning, less effective on dense vapours

For HSE’s guidance on choosing LEV, see HSG258 Controlling Airborne Contaminants.

Glove Boxes and Isolators

Fully enclosed LEV units used for hazardous drug handling, biohazards, or sterile work.

✔ Pros: Max containment, highest operator protection
✘ Cons: High cost, limited adaptability

Downdraught Benches and Slot Hoods

Perfect for sample weighing, dust control, or histology tasks.

✔ Pros: Great for balance work, low-profile
✘ Cons: Ineffective with rising or volatile fumes, limited scope

Why LEV Systems Beat General Ventilation

General lab ventilation is designed for comfort — not contamination control. Only LEV systems ensure:

  • Contaminants are captured before dispersion

  • Lower exposure levels at breathing zones

  • Targeted, efficient extraction

If you want to meet COSHH guidelines, LEV is non-negotiable.

COSHH, HSG258, and LEV Maintenance: What You Need to Know

LEV systems are not “fit and forget”. Under the COSHH Regulations, LEV systems must be Thoroughly Examined and Tested (TExT) at least every 14 months.

Your LEV maintenance checklist:
✔ Regular user training
✔ Performance checks on filters and fans
✔ Record-keeping and servicing logs
✔ Follow HSG258 Guidance for system design, testing, and operation

Compliance with BS EN 14175 Standard is also key when specifying or upgrading fume cupboards.

Summary: Choosing the Right LEV System

If you’re a UK laboratory planner, safety officer, or procurement lead, understanding your LEV system options is essential.

At The Fume Cupboard Company Ltd, we supply and install fully compliant LEV systems — from fume cupboards to articulated arms — tailored to your workspace, budget, and compliance requirements.

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