Fume hood exhaust systems for laboratories

Fume hoods or fume cupboards are used to prevent people working in laboratories being exposed to harmful or unpleasant gases and dust particles. Fixed fume hoods are usually connected to extraction fans which vent to the outside air. Modern equipment uses filters to prevent the release of harmful material to the environment.

What you must do

Emissions to air

Research activities are exempt from the permitting and reporting requirements of the pollution prevention and control (PPC) regime. Emissions from fume cupboards are not likely to contain large amounts of chemicals.

If you use organic solvents you must check that the total quantity of solvents used across your site does not exceed certain thresholds. There are thresholds set for each activity. See our guidance on solvent emissions for further information.

Solvent emissions

Emissions from the venting of fume hoods are likely to involve small quantities of gases, fumes or dust. You must prevent emissions of noxious or offensive substances. You should render these substances harmless or inoffensive before you emit them.

If your emissions cause annoyance to the surrounding community you may have to deal with them as a statutory nuisance.

Noise, odour and other nuisances

Fume cupboard design and maintenance

Fume cupboards are classed as local exhaust ventilation (LEV) equipment and you must ensure that their design and fitting complies with British Standards. Depending on the age of your equipment, it should be built and fitted in compliance with BS 7258:1994 or BS EN 14175:2003. You must examine the equipment at least every 14 months. In practice, this is normally taken to mean annually. You must keep records for five years.

British Standards Institution: BS EN 14175:2003 Fume cupboards

British Standards Institution: BS EN 7258:1994 Laboratory fume cupboards

You must make sure that that the air being drawn into the fume cupboard has an average velocity of 5 m/s (metres per second). You must make sure that the minimum velocity at any point is 4m/s or greater.

If you use a fume cupboard for work involving radioactive substances you must fit it with a filter and label it as a Filtered Fume Cupboard.

If you use a fume cupboard for work involving reactive materials, such as hydrofluoric acid, which can damage pipework and the cupboard itself, then you should fit it with cascading water over the airflow outlet. You should label it as a Scrubbed Fume Cupboard.

You should treat used filters from fume cupboards as hazardous/special waste. You can identify contaminants from the Material Safety Data Sheet (MSDS) which is supplied with the chemicals you use.

Hazardous/special waste

Hazardous substances

You can find guidance on the steps you must take to comply with the Control of Substances Hazardous to Health Regulations (COSHH) from the Health and Safety Executive (HSE) or the Health and Safety Executive Northern Ireland (HSENI). These regulations have been amended to include work with biological organisms.

HSE: COSHH Basics

HSE: Control of substances hazardous to health (COSHH)

HSENI: A guide to the COSHH Regulations in Northern Ireland 

If you supply a potentially hazardous chemical, you may have to provide a safety data sheet (SDS). The SDS tells the user how to handle, store and dispose of hazardous chemicals.

For guidance about when to provide an SDS and what it should include, see the Health and Safety Executive (HSE) leaflet.

HSE: REACH and safety data sheets

If you don't receive an SDS with a chemical, you can contact the supplier and ask for one. Suppliers who do not provide adequate instructions for using their products safely may be breaking the law.

HSE: Classification, Labelling and Packaging (CLP) Regulations

HSE: Labelling and packaging

Good practice

• Always refer to the material safety data sheet (MSDS) before using a chemical.
• Try to find safer alternatives when working with dangerous materials.
• Careful planning can minimise the use of materials and reduce emissions. This will reduce the amount you use, release less to the atmosphere and save you money.
• Use microchemistry techniques where possible. This reduces the amount of materials you use and the waste you generate.
• Never use fume cupboards to store chemicals. This will help you avoid accidental spills and unplanned reactions.
• Always ensure that containers have lids securely fixed in place.
• Keep appropriate equipment on hand to deal with spills.
• Be aware that fume hoods do not provide complete containment. If you require complete containment you should use a glove box or glove bag.

Useful links

European Agency for Safety and Health at Work: Dangerous substances

European Agency for Safety and Health at Work: An introduction to dangerous substances in the workplace

European Agency for Safety and Health at Work: Elimination and substitution of dangerous substances

SEE ALSO: Life sciences, Education