Article Synopsis
This article looks at the new British Standard which has been introduced for all new fume cupboards in the UK – and how it is designed to make the classification of various products and filtration systems clearer, while also improving overall lab safety.
There’s also a look at the services offered by Tecomak Environmental Services in this area.
It will take around three minutes to read.
A major change has been introduced for all laboratories which use recirculating and filtered fume cupboards. Here, Tecomak Environmental Services, who offer fume cupboard testing and a range of other related services, explain what the new standard is and how it will affect the sector going forward.
The Old Standard
Previously, BS 7989 was the British Standard for all fume cupboards and cabinets before the introduction of EN 14175 superseded it (for fume cupboards) in 2001. BS 7989 remained in force until November 2025.
The New Standard
In November 2025, the British and European Standards Committees for laboratory furniture and equipment published an important new standard: BS EN 17242.
The new standard applies only to new recirculating fume cupboards installed after November 2025, but it delivers a new benchmark for best practice across the sector.
The Finer Points of BS EN 17242 – Clearer Information and Definitions
The new standard requires clearer information on which chemicals are compatible with the filter installed in the fume cabinet. This information is provided by the filter supplier and must be updated if the filter is replaced. It must also be clearly displayed on the front of the cabinet.
The new standard also introduces a clearer distinction between fume cupboards and fume cabinets. In the UK, industrial recirculating units are now officially referred to as fume cabinets. This removes long-standing confusion between ducted fume cupboards (which extract air to the outside environment) and recirculating filtration systems (which filter the air and return it back into the laboratory).
That distinction matters because the safety of a recirculating system depends entirely on having the correct filtration in place. The filter system needs to be suitable for the chemicals being used in the fume cupboard, have been installed and maintained correctly, and continuously verified to ensure it’s still in good working order.
A New Classification System
To help laboratories select the correct filtration equipment, BS EN 17242 introduces a three-part fume cabinet classification system of X, Y and Z, with various sub-classes.
X relates to the filter arrangement; if it’s type A, then there are built-in filters in place, whereas type B has associated or external filters.
Y refers to the filtration type in use:
Y1 is for particulate filters (notably HEPA filters)
Y2 relates to gas and vapour filters (such as activated carbon)
Y3 is a mix of classes Y1 and Y2 (a system combines the use of particulate and gas/vapour filters)
And Y4 is for all other types of filtration devices.
Finally, Z refers to continuous monitoring: 0 means it is not fitted, while 1 means it is fitted.
So an A/1/0 fume cupboard would have a particulate filter built into the system, but without any continuous monitoring. This classification should improve clarity over which type of filters and filtration system are being used and should also help when it comes to carrying out any risk assessments.
More Continuous Monitoring
BS EN 17242 places a greater emphasis on the safety features of filter systems. So even if there isn’t any continuous monitoring system in place, the new standard says that sampling ports must be included on either side of the filter so that it’s easier to connect portable gas detection units to the filter to test its integrity.
Where continuous monitoring is installed, the systems should be able to detect any unwanted chemical contaminants at the outlet and trigger an alarm.
New Testing Approaches
The new standard separates out two testing approaches – filtration testing and containment testing. The former tests the filter under controlled conditions (by releasing a gas inside the cabinet at a specified rate). This will establish how efficient the filter is at a given point in time.
Traditionally, ducted fume cupboards were containment-tested using Sulfur Hexafluoride (SF₆) as a tracer gas. However, because recirculating cabinets return air to the room, releasing large amounts of SF₆ (a potent greenhouse gas) is problematic. The new standard promotes the use of Isopropyl Alcohol (IPA) or other approved tracer liquids for containment testing in recirculating units.
A fine mist or vapour is released inside the cabinet, and sensors placed at the opening or sash will detect if any of the vapour escapes into the user’s breathing zone.
Fume Cupboard Testing from Tecomak Environmental Services
When it comes to recirculating fume cupboards, we can supply and install the SafeHood variety in your laboratory. The various product specifications can be found on this page. However, our work doesn’t stop there – we also offer a comprehensive testing and validation service for fume cupboards as well, including HEPA filter testing facilities.
Along with making sure your fume cupboards are working safely and effectively, we pride ourselves on being up to date with all the latest legislation, so will be carrying out all our work to ensure that you are fully compliant with BS EN 17242. If you have any questions about the new standard, call us on 01732 852250 or follow this link and complete the online form.
