How often is LEV testing required?

The testing interval

The duty comes from the Control of Substances Hazardous to Health Regulations 2002 (COSHH). Regulation 9 requires local exhaust ventilation (LEV) used as a control measure to be thoroughly examined and tested at least once every 14 months, or at the shorter interval in Schedule 4 for the processes listed there. Employers should book before the applicable deadline to allow time for access problems, production changes or a tester needing to return.

The requirement concerns the extraction systems used to control exposure to hazardous substances at work. It is separate from routine maintenance. Check the process served by each installation, rather than assuming all LEV systems at the site follow the same calendar.

When the interval is shorter than 14 months

Schedule 4 is titled "FREQUENCY OF THOROUGH EXAMINATION AND TEST OF LOCAL EXHAUST VENTILATION PLANT USED IN CERTAIN PROCESSES". Its process descriptions and minimum frequencies are reproduced below. Regulation 9(2)(a) requires examination and testing at not more than the corresponding interval.

HSG258 also recommends more frequent examinations where wear could reduce effectiveness between visits. The process, the condition of the extraction and the available performance records matter when deciding on an earlier date.

• Processes in which blasting is carried out in or incidental to the cleaning of metal castings, in connection with their manufacture. Minimum frequency: 1 month.
• Processes, other than wet processes, in which metal articles (other than of gold, platinum or iridium) are ground, abraded or polished using mechanical power, in any room for more than 12 hours in any week. Minimum frequency: 6 months.
• Processes giving off dust or fume in which non-ferrous metal castings are produced. Minimum frequency: 6 months.
• Jute cloth manufacture. Minimum frequency: 1 month.

Count from the last test date

For a system on the general interval, count 14 calendar months from the date of the last thorough examination and test. For example, a test completed on 12 February 2026 reaches its 14-month deadline on 12 April 2027. The next test must be completed by that date. Allow enough time for the visit to take place.

The report and test label, if one was fitted, should show the last test date. Use the LevHQ LEV test due date calculator to check the deadline and set a reminder. If your risk assessment, manufacturer or previous report sets an earlier interval, use that earlier date instead of the general 14-month maximum.

Keep the records together

The employer must keep a suitable record of examinations, tests and repairs resulting from them. The record, or a suitable summary, must remain available for at least five years from the date it was made. Keep the full report rather than relying on a label. The report should identify the system, record its condition and measurements, compare performance with the intended standard and list any work needed.

Keep the commissioning report or other original performance data for the life of the equipment where possible. Store it with the user manual, later test reports and the log of routine checks, maintenance, replacements and repairs. This gives the next examiner a benchmark and shows what happened between statutory tests. It also makes a falling airflow or pressure reading easier to spot.

Booking LEV testing services

Book testing services from a competent person. Check that the tester works to published standards where these apply to the equipment. HSE describes checks against equipment-specific requirements as well as the original design information. Ask about relevant training and experience before booking. Agree any extra services and costs before the visit, such as a commissioning report if the original records are missing.

Plan safe access with the examiner. HSG258 identifies health risks from residues inside the system and safety risks from moving parts, electricity and work at height. Tell the examiner about these hazards and any protective equipment needed.

Checks between statutory tests

Employers must keep the extraction working between statutory tests. HSG258, Controlling airborne contaminants at work, explains in paragraph 106 how to check hoods while the work process is running. Options include an anemometer, dust lamp or smoke tracer. An airflow indicator is often the simplest way for an operator to see whether airflow at the hood is adequate.

HSG258 gives daily, weekly and monthly checks as examples for the system logbook. Typical checks cover damage or blockages in hoods, duct condition, airflow indicators, filters, unusual fan noise or vibration and whether operators are using the hood correctly.

A weekly visual check is not a substitute for the statutory test. Staff can look for damage, confirm indicators respond and record maintenance, but a competent examiner carries out the detailed visual and structural examination, performance measurements and assessment of control. Follow the manufacturer and risk assessment when setting check frequencies. Repair defects when found rather than waiting for the next test visit.

If the test is late

Book a competent examiner as soon as you discover the date has passed. Review the last report, the current condition of the system and the hazardous substance risk. An expired date does not show that the LEV has failed, but it does mean you no longer have the current examination required to confirm its performance.

Do not continue the process without effective exposure controls while waiting. If the LEV cannot be shown to provide adequate control, stop that work or use another control justified by the risk assessment until the system has been examined, any defects repaired and its control confirmed. Record the decision, the booking, any temporary controls and the work completed.