By workplace & process
A fume cupboard is LEV under COSHH, but proving it works asks more than a general capture check - face velocity, sash and containment all come into it.
The short answer
A laboratory fume cupboard is local exhaust ventilation under COSHH, so Regulation 9 requires it to be maintained and thoroughly examined and tested like any other LEV. But proving a fume cupboard works involves more than confirming it captures - it is judged against a dedicated standard, BS EN 14175 for ducted cupboards, and against measures of face velocity and containment that a general LEV check does not routinely cover.
The detail
COSHH sets the legal duty to test; BS EN 14175 sets how a ducted fume cupboard should perform and be assessed. The two work together - the regulation says you must test, the standard says what good looks like. For ductless, recirculating cupboards a different standard, BS 7989, applies, adding filter saturation, seal integrity and gaseous-phase filter capacity checks that a ducted unit does not need.
Face velocity - the speed of air drawn in across the sash opening - is the familiar measure, taken at multiple points across the face, with HSE guidance pointing to at least around 0.5 metres per second for vapours and a face velocity that does not vary too widely across the opening. But airflow alone does not guarantee safety, and the modern emphasis is on containment testing: releasing a tracer gas and confirming that contaminant is actually held inside the working area rather than escaping past the sash. The sash position matters too, because the marked maximum safe opening is the aperture at which the design face velocity is achieved, and working with the sash higher than needed undermines the control.
What it means for you
A thorough examination and test of a fume cupboard checks the physical condition, measures face velocity across the sash and its variation, assesses containment against the commissioning data, and confirms the ducts and fan are performing - at least every fourteen months, in line with HSG258 and the relevant British and European standard. In schools and colleges the CLEAPSS guidance adds its own framework on top.
The practical point for a lab manager is that a fume cupboard cannot be signed off on a quick visual or a single airflow reading. It needs the specialised regime, carried out by a competent person familiar with the standards, because the whole purpose of the cupboard is containment - and containment is precisely what the deeper test sets out to prove.
The service behind the guide
We test laboratory fume cupboards to COSHH and the relevant British and European standard, covering face velocity and containment, and report on any shortfall.
Questions
Yes. A fume cupboard is local exhaust ventilation under COSHH, so Regulation 9 requires it to be maintained and thoroughly examined and tested like any other LEV system.
It is the standard governing the design, performance and testing of ducted laboratory fume cupboards. COSHH sets the duty to test; BS EN 14175 sets what good performance looks like. Ductless cupboards fall under BS 7989.
Because airflow alone does not guarantee safety. Containment testing releases a tracer gas to confirm that contaminant is actually held inside the cupboard rather than escaping past the sash into the room.
The speed of air drawn in across the sash opening, measured at multiple points. HSE guidance points to at least around 0.5 metres per second for vapours, with limited variation across the face.
At least every fourteen months under COSHH, in line with HSG258 and the relevant British and European standard, by a competent person familiar with fume cupboard testing.
Phoenix Duct Clean · by the numbers
We examine laboratory fume cupboards to COSHH and BS EN 14175, covering face velocity and containment, and report clearly. Call or email to book.