Servicing & maintenance
Cleaning a Fume Cupboard: Best Practices and Tips
Cleaning is the part of fume cupboard upkeep that stays with the lab rather than the engineer. Done properly it keeps the enclosure safe to work at between annual examinations; done carelessly it is one of the quickest ways to lose containment.
Holliday Technical Services
A fume cupboard protects the person standing at it only while the enclosure is clear and the airflow through it is undisturbed. Residue on the work surface, clutter against the baffle and a film on the sash all work against that, and none of them are visible on a test certificate issued twelve months ago.
This guide covers what a laboratory can and should do itself: how to prepare before cleaning, what a weekly and a monthly routine should include, how to handle contaminant-specific residues and waste, and where cleaning stops and servicing begins.
It is written from what our engineers find on site. Nothing here replaces your own COSHH risk assessment or the safety data sheet for the substances in use — those decide the method in every case.
Pre-cleaning preparations
Safety guidelines
- —Consult the risk assessment. Check the COSHH assessment and the safety data sheet for every substance that has been used in the cupboard. The residue decides the cleaning method, not the other way round.
- —Wear the right protection. Chemically appropriate gloves, safety goggles and a fastened lab coat as a minimum, kept on for the whole procedure. Where the residue is unknown or the safety data sheet calls for it, add respiratory protection.
- —Clean with the extract running. Leave the fan on and the sash at its marked working height so anything you disturb is drawn away from your face rather than into the room.
Preparing the work area
- —Remove everything. Glassware, apparatus, reagent bottles and waste containers come out of the enclosure before cleaning starts, not part-way through.
- —Isolate the services. Gas taps closed, water off, and sockets isolated where the clean involves liquids anywhere near them.
- —Clear the airflow path. Check the baffle slots and the gap under the airfoil at the front of the work surface. Blocked baffles and an airfoil packed with stored items are among the most common reasons a cupboard fails a containment test.
Detailed cleaning procedures
Weekly routine
- —Work surface. Wipe down with warm water and a mild laboratory detergent, then dry. Match the cleaner to the liner: epoxy resin, ceramic and stainless steel all take detergent, while solvents and abrasives can dull or craze some surfaces permanently.
- —Interior panels and sash. Clean the side and rear panels and both faces of the sash glass. A streaked sash is a safety problem as much as a cosmetic one — the operator needs to see what is happening inside the enclosure.
- —Exterior. Front frame, sash handle, controls and the face of the airflow monitor. Check the monitor is still reading and still in date while you are there.
- —Waste. Wipes, gloves and rinsings go into the correct stream immediately, labelled. Nothing used for cleaning stays in the cupboard.
Monthly deep clean
- —Repeat the weekly routine, then work into the corners, the service fittings, the cup sink or drain and the underside of the airfoil, where residue collects unseen.
- —Behind the baffle. Where the design allows the baffle to be removed safely, clean behind it. Report corrosion, cracking or loose fixings rather than working around them — see repair.
- —Recirculating units. Check the pre-filter and the remaining life of the main filter. A filter is a replacement item, never a cleaning one — see filters.
Cleaning specific contaminants
Mercury, hydrofluoric and perchloric acid, radioisotopes and biological agents each have their own decontamination procedure. None of them should be treated as general residue, and none of them should be cleaned by someone working from a general guide.
- —Work from the safety data sheet. It states the compatible cleaning agents, the protection required and the disposal route for what you collect.
- —Neutralise before wiping. Acid and alkali residues are dealt with by the local neutralising procedure first, then cleaned as normal.
- —Biological work. Use a disinfectant validated for the agent in use and leave it for the full stated contact time. A quick wipe with the wrong product achieves nothing.
Post-cleaning actions
Disposal of waste
- —Non-hazardous solids. Wipes and gloves carrying no hazardous residue go to the normal laboratory waste stream.
- —Water-soluble, non-hazardous liquids. To drain with plenty of water, and only where your local rules and consent to discharge allow it.
- —Hazardous chemical waste. Into a labelled, compatible container for collection by a licensed contractor. Never to drain.
- —Biological waste. Autoclaved or routed as clinical waste according to your local procedure.
Leaving the cupboard ready
- —Return cleaning materials to their marked store. Bottles left standing in the enclosure become the next containment problem.
- —Sash down, surface clear, monitor reading. Leave the cupboard as the next user should find it, and record the clean alongside the annual test certificate.
Best practices and common mistakes
Do
- ✓Clean at the end of a session, while residues are fresh and identifiable.
- ✓Keep a written cleaning record, filed with the test certificate and the service history.
- ✓Work with the sash as low as the task allows, including while cleaning.
- ✓Report anything you cannot clean — staining that will not lift, corrosion, a rattling fan, a monitor that has stopped reading.
Don’t
- ✕Use the fume cupboard as storage. Clutter across the work surface disturbs the airflow the enclosure depends on.
- ✕Reach for abrasives or strong solvents on liners, sash glazing or monitor faces.
- ✕Clean while a reaction or process is running inside the cupboard.
- ✕Assume a clean cupboard is a working one. Containment is proven by measurement, not appearance.
Need assistance? Contact Holliday Technical Services
Cleaning keeps the enclosure usable. Everything beyond it — airflow measurement, containment testing, filter changes, fan and motor work, monitor calibration — is engineering work with a legal duty attached under COSHH Regulation 9.
We test, service, repair and remove fume cupboards across the UK. See testing, servicing and maintenance, or get in touch for a quotation.
FAQs
Clear the enclosure, put on the protection the safety data sheet requires, and clean with the extract running and the sash at its working height. Warm water and a mild laboratory detergent suit most liners, working from the back of the enclosure forward, then dry. Where a specific contaminant is involved, its own decontamination procedure comes first.
Work at least 150 mm inside the sash line, keep the sash as low as the task allows, raise apparatus off the work surface so air can pass beneath it, and keep the baffle and airfoil clear. Slow movements at the face — a cupboard is defeated more often by draughts and quick reaching than by anything chemical.
A wipe down after each session, a fuller clean weekly, and a deep clean monthly suits most laboratories. Frequency really follows use and hazard: a cupboard in constant use, or one handling anything that leaves a persistent residue, is cleaned more often and after every spill.
No. COSHH Regulation 9 requires local exhaust ventilation to be examined and tested at intervals of no more than 14 months by a competent person, with the results recorded. Cleaning keeps the cupboard fit to use between those visits; it does not substitute for one.
References
- Health and Safety Executive (HSE) — the regulator for COSHH and for the examination and testing of local exhaust ventilation. hse.gov.uk
- CLEAPSS — practical guidance on fume cupboards in school and college laboratories, including cleaning and decontamination. cleapss.org.uk
- British Occupational Hygiene Society (BOHS) — professional guidance on control of exposure and on the competent examination of controls. bohs.org
- BS EN 14175 — the fume cupboard performance standard, covering type testing, on-site commissioning and periodic testing.
- Safety data sheets — supplied by the manufacturer of each substance in use. The first place to look before cleaning anything unfamiliar.