The British Standards BS7989:2001 specifies the safety and performance requirements for general purpose fume cupboards and outlines the technical specifications required for design, manufacture, installation, and containment testing of fume cupboards.
While past guidance has relied on face velocity measurements (as a representative means of demonstrating fume cupboard performance) the current emphasis is to demonstrate containment - which is most reliably done by regular tracer gas containment testing.
Fume Cupboard Testing
All fume cupboards must be tested by a competent engineer every 14 months to ensure that they are performing as intended and to demonstrate that adequate control of exposure is achieved. Test methods should be similar to those employed at commissioning and include similar measurements to allow comparison. A variety of qualitative and quantitative methods may be employed, however HSE guidance for fume cupboard testing states the need to measure face velocity and carry out any further testing according to BS EN 14175 (HSG 258, 2011). Testing of Recirculatory fume cupboards must also include particular filter and seal integrity testing and gaseous phase filter capacity testing as outlined in BS 7989:2001.
Test equipment must be appropriately calibrated and maintained and individuals carrying out fume cupboard testing should ensure they have identified the type of unit to be tested and are clearly aware of the correct performance specifications to be met.
A visual inspection of the fume cupboards should be carried out as detailed in BS EN 14175-4:2004 and HSG 258 Controlling airborne contaminants at work, 2011.
Face Velocity measurements.
These tests measure the average rate at which air is drawn through the opening of the fume cupboard and is the conventional method for measuring fume cupboard performance. However, it is not a direct measure of the containment ability of a fume cupboard.
Containment testing uses tracer gas. This provides a quantitative measure of fume cupboard containment, under normal working conditions, by analysing the escape of a tracer gas (sulphur hexafluoride) from within the fume cupboard. It is advisable to carry out containment testing and robustness of containment testing on newly installed equipment and following any major repair work.
A routine test report should be completed and include the following:
• Fume Cupboard Identification number
• Date of test
• Reference to the type of test carried out
• General room conditions during the test
• Results of fume cupboard inspection
Test results must be kept for a minimum of five years.
To find out more about how ACF can help with the installation of filters and testing of fume cupboards, in order to keep within British Standards, contact us today!