FAQs

A fume cupboard is a ventilated enclosure that protects users from hazardous fumes and vapours by extracting them safely from the workspace.

A fume cupboard — also known as a fume hood or laboratory fume hood — is a vital piece of safety equipment in laboratories. It works by drawing air away from the user and expelling it through an exhaust system, either externally (ducted) or via internal filters back into the lab (recirculating). This process helps minimise exposure to dangerous substances such as chemical fume and vapours, ensuring a safer working environment for laboratory staff and building occupants alike.

While they may appear similar, fume cupboards and MSCs are designed for entirely different tasks and types of protection in the lab.

A fume cupboard is primarily used for handling hazardous chemicals, protecting the user by drawing contaminated air away and either venting it outside or filtering it. It does not protect the product or environment.

In contrast, an MSC is designed for biological applications and offers triple protection — for the user, the sample or product, and the environment. It achieves this through HEPA filtration and controlled airflow to maintain a sterile workspace, making it ideal for microbiology, virology, and cell culture work.

Fume Cupboard – At a Glance:
• Protects the user
• Ideal for chemicals, solvents, acids, and vapours
• Does not protect the product
• Used in chemistry labs, schools, and industry

Microbiological Safety Cabinet – At a Glance:
• Protects the user, product, and environment
• Ideal for biological research
• Uses HEPA filters
• Common in bioscience labs, hospitals, and cleanrooms

A fume cupboard is vital for protecting users from hazardous substances and ensuring compliance with health and safety regulations.

Fume cupboards play a critical role in maintaining a safe laboratory environment. By effectively removing toxic fumes, gases, and vapours from the working area, they help protect staff and students from the risk of inhalation. They also prevent cross-contamination during experiments and support adherence to regulations such as COSHH (Control of Substances Hazardous to Health), making them essential in both research and teaching settings.

There are several types of fume cupboards, each suited to different lab applications and environments.

The main fume cupboard types include:

• Ducted laboratory fume cupboards – Extract fumes externally through ductwork.
• Ductless (recirculating) laboratory fume cupboards – Use filters (e.g. carbon or HEPA) to clean air before returning it to the lab.
• Walk-in laboratory fume cupboards – Ideal for handling large apparatus or bulk quantities of chemicals.
• Ducted school / educational fume cupboards – Designed for demonstrations and use with low volume / low risk chemicals.
• Ductless (recirculating) school / educational fume cupboards – Designed for demonstrations and low volume / low risk chemicals and for sharing between multiple classrooms.

Each type offers different benefits, depending on the chemicals used, the frequency of use, and whether portability or flexibility is a requirement.

Fume cupboards work by drawing contaminated air away from the user and either expelling it outside or filtering it before recirculation.

A ducted fume cupboard uses an external extract system and fan to pull air through the open sash and across the work area, removing harmful fumes which are then expelled safely above roof level. A recirculating (filtered) fume cupboard uses a built-in fan to draw air through filters that capture contaminants before releasing clean air back into the lab. Both designs ensure user protection but vary in suitability and how they handle and dispose of contaminants.

It depends on your application — ducted cupboards are best for heavy and high-risk use, while recirculating cupboards suit light-duty or mobile setups.

Ducted fume cupboards are ideal for handling a wide range of volatile or high-risk chemicals. They remove all airborne contaminants externally, offering high performance with lower maintenance demands, but require higher upfront installation, and fixed placement. Ducted fume cupboards have higher energy costs than recirculating models.

Recirculating fume cupboards are better suited to lighter use and lower-risk environments. They’re portable, cost-effective to install, and energy-efficient, but require regular and costly filter replacement and are only suitable for a relatively small range of substances.

Choose a ducted fume cupboard for:
• Hazardous chemicals
• Heavy or frequent use
• Research or industrial use
• Long-term installations
• Compliance with strict safety regulations

Choose a recirculating unit for:
• Educational use
• Temporary or mobile setups
• Locations where ductwork is very difficult to install
• Infrequent use
• Light-duty chemical handling

Place your fume cupboard away from draughts, doors, windows, and high-traffic areas to ensure safety and performance.

Correct positioning is crucial for effective fume extraction, safety and compliance and BS EN 14175. This standard outlines best practices for reducing airflow disturbances and ensuring the safe containment of hazardous fumes. Avoid placing fume cupboards near ventilation sources or busy walkways, and maintain a clear “free zone” in front of the unit.

A summary of the BSEN 14175 guidelines on installation can be downloaded here.

By law, all fume cupboards must be serviced at least every 14 months by a competent person.

Regular servicing is essential for maintaining safe airflow and effective filtration. Most labs opt for annual testing to align with best practices and ensure compliance with UK health and safety regulations. During a service, airflow is measured, components are inspected, and filters (where applicable) are checked or replaced to keep the system working efficiently and safely.

Please contact our service department if you would like your fume cupboard tested.

Always check airflow, keep the sash low, and avoid blocking airflow or storing chemicals inside.

To use a fume cupboard safely:
• Check airflow using a monitor or anemometer before each use.
• Keep the sash opening as low as possible.
• Avoid placing large equipment where it might block airflow.
• Keep materials at least 15 cm behind the sash.
• Never store chemicals long-term inside the cupboard.
• Avoid external draughts from fans, windows, or AC units.
• Maintain a clear area in front of the cupboard (the “free zone”).
• Keep the fume cupboard clean and tidy.

Following these steps helps ensure optimal containment and reduces exposure risks during lab work.

Yes — Fumair offers a wide range of bespoke fume cupboard options tailored to your laboratory’s needs.
Our fume cupboards can be fully customised in terms of size, material finishes, airflow performance, filtration systems, and more. Whether you’re designing a new lab or upgrading an existing facility, we can tailor a solution to meet your specific safety, compliance, and functional requirements.

In the UK, laboratory ducted fume cupboards must be designed, Type Tested, manufactured and installed to BS EN 14175, and recirculating (filtered) fume cupboards to BS 7989.

School fume cupboards must meet the requirements of CLEAPSS G9.
• BS EN 14175 – The main UK and European standard for fume cupboard design, performance, and testing.
• BS 7898 – The UK standard for ductless recirculating fume cupboards.
• HSG258 – Health and Safety Executive (HSE) guidance on local exhaust ventilation (LEV), applicable to fume cupboards.
• CLEAPSS G9 – Specific guidance for school fume cupboards to ensure pupil and teacher safety.

The best fume cupboard depends on your application, chemicals used, and whether ducting is available.
Choosing the right solution means considering safety requirements, the nature of your work, and installation constraints. Ducted units suit high-risk and high-volume usage. Recirculating units offer flexibility for lighter applications or temporary setups. The quickest way to make the right decision? Get in touch with Fumair — we’ll help you find the best option for your needs.

Fume cupboards can be energy-intensive, but there are ways to reduce their consumption.
Ducted fume cupboards constantly draw in and expel large volumes of air, which then needs to be heated or cooled to maintain room conditions. The good news is that energy use can be significantly reduced by:
• Turning off the fume cupboard when not in use.
• Fitting variable air volume (VAV) fume cupboard controls
• Consider lower average face velocities and/or a reduced maximum sash opening heights
• Lowering the sash whenever possible (applicable to VAV or 2-speed fume cupboards only)
• Fitting inverter driven extract fans

Contact Fumair for advice and guidance on how you can save energy.

A fume extract system is a ventilation solution that removes hazardous airborne contaminants from workplaces.

Also known as a fume extraction system, it captures fumes, vapours, dust, and smoke at source to protect worker health and maintain air quality. These systems form part of a local exhaust ventilation (LEV) setup and are essential in labs, workshops, and manufacturing environments.

Fume extract systems use hoods, ducting, filters, and fans to remove airborne hazards at source.

They work by capturing contaminants where they’re produced, transporting them through ductwork, and either filtering or expelling them safely. As part of a local exhaust ventilation (LEV) system, they help prevent inhalation and environmental contamination.

They are used in environments where fumes, vapours, or particulates are generated.

Common settings include laboratories, welding shops, pharmaceutical manufacturing, chemical processing plants, electronics assembly areas, and educational science labs.

Yes — a fume extract system is a type of local exhaust ventilation (LEV) system.

LEV is the broader category that includes systems targeting any airborne hazard (like dust, mist, or fumes). Fume extract systems are specifically designed to handle chemical fumes, vapours, and gases.

Yes, they must be tested at least every 14 months under UK COSHH regulations.

Regular testing ensures the system works effectively and remains compliant. It also helps identify any performance issues early to maintain a safe working environment.

: Yes, if air is being recirculated into the lab. If the fumes are being discharged to atmosphere, then filters are often not required.

Filters are essential for ensuring your system complies with COSHH regulations and protects users from exposure to hazardous substances. Whether you need a filter – and what type – depends on your process and whether the air is being recirculated or vented externally.

Common filter types include:
• HEPA filters – Capture fine particulates, dust, and biological agents. Ideal for cleanrooms, labs, and electronics.
• Activated carbon filters – Absorb chemical vapours, gases, and odours. Essential for solvent use or chemical handling.
• Combination filters – Handle mixed contaminants in multi-purpose environments.

If your system discharges externally and the fumes are non-toxic, a filter may not always be required — but it’s still recommended for environmental protection. For recirculating systems, filtration is critical to maintain safe indoor air quality.

A professional assessment can help determine whether filtration is necessary and ensure the right filter type is installed for your application.

Typically, ducted fume cupboards are vented straight to atmosphere, without filters, relying on dilution and dispersal above the building to eliminate any risk of exposure.

Filters trap particles or vapours, while fume scrubbers chemically neutralise or wash harmful gases from the air.

Both are used in fume extraction systems but serve different purposes:
•Filters (like HEPA or carbon) physically capture contaminants from the air. HEPA filters trap fine particles, while activated carbon filters adsorb chemical vapours and odours. They are typically used in lab, pharma, and cleanroom settings.
• Fume scrubbers are wet systems that remove gases by passing contaminated air through a liquid (usually water or a chemical solution). They’re more common in industrial or high-volume chemical processes, especially when dealing with acidic, corrosive, or highly reactive fumes.

In short:
– Filters = trap solid or gaseous contaminants.
– Scrubbers = wash or neutralise harmful gases out of the airstream.

Choosing between them depends on the type of contaminants, airflow volume, and whether you’re recirculating or discharging to atmosphere. Fumair can help specify the right system for your needs.

A scrubber treats contaminated air before it is released; a baffle wash system removes settled contaminants from internal surfaces.

Both are used in fume cupboards and fume extraction systems but serve different purposes:
Scrubbers are designed to remove or neutralise harmful fumes, vapours or particles from the exhaust air stream — typically using water or chemical solutions — before it’s discharged to atmosphere. They will typically be used while the fume cupboard is in operation. Baffle wash systems, by contrast, rinse the inaccessible internal surfaces of the fume cupboard (behind the rear baffle) to remove settled contaminants and prevent potentially hazardous build-up. Baffle wash systems are typically only run for a few minutes at the end of the working day, when the extraction system is off.

Depending on the chemicals used, both a fume scrubber and a baffle wash system may be required.

You may need a fume scrubber if your process generates corrosive, acidic, or chemically hazardous gases.
Fume scrubbers are typically required when standard filtration alone can’t safely remove airborne contaminants. They’re especially important in chemical processing, acid etching, or plating operations where fumes like hydrochloric acid, ammonia, or sulphur dioxide are present.

You’ll likely need a fume scrubber if:
• You’re discharging hazardous gases to atmosphere and must meet environmental emissions regulations
• The process involves corrosive, soluble, or reactive vapours not suited to dry filtration
• You’re working in a high-volume or industrial chemical environment

Wet scrubbers work by washing contaminated air through a neutralising liquid (usually water or a specific reagent such as sodium hydroxide) to safely remove harmful gases.

Only if you have concerns that settled vapours or particulates may build-up and create a hazard.

Baffle wash systems are typically recommended for processes involving acids (particularly hydrofluoric and perchloric acid), corrosive chemicals, or particulate-laden fumes that may deposit on internal surfaces. Over time, this build-up can compromise the performance of the fume cupboard or even pose an explosive risk or health hazard. The baffle wash helps flush out these residues automatically, usually at the end of the working day. For general lab use or low-risk applications, a baffle wash is often unnecessary.

Base your choice on fume type, workspace layout, and safety requirements.

Consider the volume and type of fumes produced, space limitations, whether you need a mobile or fixed unit, and relevant legal standards. For expert advice, contact Fumair to ensure you select the most effective and compliant solution.

Fume extract systems must meet UK COSHH law and may need to follow specific British and European standards.

Key standards include:
• COSHH Regulations – Legal duty to control exposure to hazardous substances.
• HSE HSG258 – Government guidance on correct design, use, and maintenance of LEV systems.
• BS EN 14175 – The UK/European standard for laboratory fume cupboards.
• BS EN ISO 14644 / BS EN 12469 – For cleanrooms and microbiological safety cabinets.
• DSEAR/ATEX – For environments with flammable or explosive atmospheres.
• DW/154 – UK design and installation standards for plastic ductwork.
• DW/144 – UK benchmark for sheet metal ducting in extraction systems.

Meeting these standards ensures compliance, performance, and safety.

Your fume extract system should terminate vertically above roof level, away from windows or air intakes, to prevent re-entry of hazardous fumes and ensure sufficient dilution and dispersal.

Ideally, the termination point should be at least 3 metres above adjacent structures, with a high-velocity vertical discharge to aid safe dispersion. The outlet must be weather-protected, accessible for maintenance, and fully compliant with BS EN 14175 and COSHH regulations. Proper termination protects people, the environment, and your lab’s legal compliance.