LEV for Dental Surgeries: High-Volume Suction, Aerosol Control and COSHH Duties

Dental practices generate aerosols constantly — from ultrasonic scalers, high-speed turbines, air-polishing units, and surgical cutting. Dental laboratories generate dust from grinding, polishing, and sectioning of acrylic, ceramic, and metal work. The question compliance-conscious practice managers ask is whether their extraction and suction systems count as local exhaust ventilation under COSHH, and whether the 14-month examination and test duty applies to them.

For many dental workplaces, the answer is yes — and the threshold test is simpler than many expect.

When Dental Suction and Extraction Becomes LEV

The Control of Substances Hazardous to Health Regulations 2002 apply whenever workers are liable to be exposed to a substance hazardous to health. In dental settings, the relevant hazardous substances include:

• Aerosol from dental turbines, ultrasonic scalers, and air polishers — containing blood, saliva, tooth structure, materials, and pathogens
• Acrylic dust and monomer vapour — generated during laboratory work on dentures, splints, and models. Methyl methacrylate (MMA) is a respiratory sensitiser.
• Silica and ceramic dust — from grinding and finishing porcelain crowns, veneers, and zirconia restorations
• Metal dust and fume — from grinding, sectioning, and polishing metal frameworks and implant components
• Chemical vapours — from impression materials, adhesives, cements, and cleaning agents

COSHH defines "local exhaust ventilation" by function, not by what a manufacturer calls it. Any system that captures one of these hazardous substances at or close to the source of generation, and removes it from the working environment, is functioning as LEV. What matters is what the system does, not what it is labelled.

High-volume suction (HVS) / high-volume evacuation (HVE) — the chairside suction tip held by the dental nurse — captures aerosol at source during operative procedures. When used specifically to control worker exposure to a hazardous aerosol (rather than purely for clinical aspiration of water and debris), it can function as LEV, and the COSHH LEV duties can apply.

Extraoral aerosol reduction devices (AARDs/extraoral suction) — units positioned near the patient's mouth to capture aerosol before it escapes into the surgery air — are more clearly LEV in character, being designed specifically to protect the dental team from aerosol exposure.

Dental laboratory extraction — the bench-mounted extraction arm or downdraught table used during grinding and polishing — is LEV for the purposes of COSHH in the same way that any workshop extraction arm is LEV. The substance being extracted (acrylic dust, silica dust, metal dust) is hazardous; the system captures it at source.

What COSHH Regulation 9 Requires

Where a dental extraction or suction system functions as LEV under COSHH, Regulation 9 creates three duties.

Maintenance

Under Regulation 9(1), the system must be "maintained in an efficient state, in efficient working order, in good repair and in a clean condition."

For dental suction units, this means:

• Traps and separator canisters emptied and cleaned at the frequency the manufacturer recommends (and before they reach capacity — an overfull trap restricts suction)
• Filters — particularly bacterial filters downstream of the separator — replaced according to the manufacturer's schedule, not when they look dirty
• Suction tubing and aspirators checked for blockages, cracks, and deteriorating seals
• Motor unit checked for noise, heat, and vibration that indicate bearing wear or impeller imbalance

For dental laboratory extraction arms and bench units:

• Filter media replaced before pressure drop affects airflow noticeably
• Ductwork checked for leaks and accumulation
• Fan and motor inspected

Thorough Examination and Test

Under Regulation 9(2), LEV must be thoroughly examined and tested by a competent person at least once every 14 months. This applies to dental laboratory extraction in the same way it applies to any workshop LEV. It applies to chairside suction and extraoral devices used as COSHH controls where the practice's COSHH assessment has identified them as LEV.

A competent person for LEV testing means someone who has the technical knowledge and practical experience to examine the system and produce a valid TExT report to the standard described in HSG258. In a dental laboratory setting, the testing contractor will typically be an occupational hygiene specialist or an LEV testing company familiar with laboratory extraction systems.

The examination should confirm:

• That airflow meets the design specification for the system
• That all components are functioning and in good condition
• That the system still achieves adequate control of exposure at the point it is used

The output is a written report that you keep as a record under Regulation 9(4).

Records

Examination and test reports, and records of repairs and maintenance, must be kept for at least five years under Regulation 9(4). For a dental practice, this means keeping TExT reports for laboratory extraction systems, and documenting servicing of any extraction unit that has been identified as a COSHH control measure, for at least five years from each record date.

Practical Guidance for Dental Practices

Step 1: COSHH assessment. The starting point is a COSHH assessment for each area of the practice — clinical surgeries, decontamination room, and laboratory (if applicable). The assessment identifies what hazardous substances workers are exposed to and what controls are in place to limit that exposure. Where a suction or extraction system is identified as a control measure for a hazardous substance, COSHH Regulation 9 applies to it.

Step 2: Identify which systems count as LEV. Dental suction systems primarily used for clinical aspiration — removing water and debris from the mouth — are not LEV in the COSHH sense if their primary function is clinical and the worker is not relying on them for personal protection from a hazardous substance. However, extraoral aerosol reduction devices, and laboratory extraction systems, are more straightforwardly LEV. If your practice operates a dental laboratory, the extraction units on bench grinders, acrylic polishing lathes, and model trimmers are LEV and the full Regulation 9 duties apply.

Step 3: Maintenance schedule. Document the maintenance requirements for each identified LEV system — filter change frequencies, cleaning intervals, and any manufacturer-recommended inspection tasks — and keep records of when these are carried out.

Step 4: Arrange TExT inspection. Identify a competent person to carry out the thorough examination and test. For dental laboratory extraction, you need someone experienced with workshop LEV who can measure airflow and produce a formal TExT report. Contact an occupational hygiene specialist or an LEV testing company. The examination must happen at least once every 14 months.

Step 5: Keep the records. TExT reports and maintenance records must be held for five years.

Dental Laboratories: The Clearest Case

The clearest example of LEV duties in a dental setting is the laboratory. Dental technicians work with materials that generate genuinely hazardous dust:

• Acrylic (polymethylmethacrylate) dust — generated when trimming, grinding, and polishing dentures and splints. Fine acrylic particles are a respiratory sensitiser. MMA monomer vapour, generated during mixing and curing, is also a sensitiser and can cause occupational asthma.
• Zirconia dust — generated during grinding and milling of zirconia (ZrO₂) restorations. Zirconia is a ceramic; fine respirable particles from dry grinding may pose long-term respiratory risk.
• Cobalt-chrome alloy dust and fume — generated during grinding and polishing of metal frameworks. Cobalt is classified as a probable human carcinogen.

MMA monomer, cobalt compounds, and zirconium compounds each have a substance-specific workplace exposure limit in the EH40 Workplace Exposure Limits table. Cured acrylic (PMMA) dust does not carry its own EH40 entry — it falls under the general inhalable and respirable dust limits — but it is still a respiratory hazard requiring adequate control. All of these substances require adequate control under COSHH Regulation 7. Bench extraction systems used to control these exposures are LEV, and the 14-month TExT requirement applies.

Many dental laboratories have had bench extraction in place for years without ever having it formally tested. A thorough examination confirms it is still working and producing airflow at the velocities for which it was designed. Without that confirmation, you cannot know whether the control is actually controlling anything.

Connecting to Your Compliance Tools

Our LEV testing due date calculator will help you track when your next TExT is due for each laboratory extraction unit. The LEV record-keeping requirements checker works through what documentation you need to maintain.

For more on how COSHH duties apply to LEV in general, our guides on COSHH Regulation 9 explained and COSHH and LEV legal obligations provide the full legal framework.

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This guide is for information only and does not constitute legal advice. The COSHH Regulations are at legislation.gov.uk. Specific questions about your practice's obligations should be addressed to a competent occupational hygiene adviser.