LEV testing

What LEV is

Local exhaust ventilation, or LEV, is extraction that captures harmful dust, fume, mist or vapour at the point where it’s made, before people breathe it in. It covers a wide range of systems: dust extraction on woodworking and cutting machines, welding fume extraction, spray booths, fume cupboards, and extraction over mixing, weighing or packing in food production and other industries. Each system usually has a hood or enclosure, ductwork, often an air cleaner or filter, a fan and a discharge.

If the system stops working well, nobody may notice until people are exposed. That’s why the law asks for it to be examined and tested regularly.

An LEV system is designed to control a particular substance from a particular process. Over time, processes change, hoods get moved, branches get added and filters clog. A system that worked well when it was installed can stop protecting people without anyone noticing, which is why regular examination matters.

What the law says

LEV comes under the Control of Substances Hazardous to Health Regulations (COSHH). HSE explains that employers who use LEV to control exposure must have it thoroughly examined and tested (TExT) by a competent person, at least every 14 months, with a few exceptions where processes call for more frequent testing (HSE: local exhaust ventilation). HSE’s pages on LEV also cover buying, commissioning and using LEV systems, and are worth reading if you’re responsible for one.

Our article on LEV testing explained puts it in plain English.

The employer is responsible for making sure the testing happens and that problems found are put right. Workers who use the system should also be shown how to use it properly and told how to report faults, because a hood in the wrong position or a fan that has been switched off gives no protection at all.

What a thorough examination and test involves

1. We look at what the system is meant to control, where people work and how the extraction is used day to day.
2. We examine the hoods, enclosures, ductwork, filters or air cleaners, the fan and the discharge for damage, wear and blockages.
3. We take measurements of how the system is performing and compare them with what it should achieve.
4. We check whether the hoods are capturing the contaminant where people work.
5. You get a report setting out what we found, whether the system is working as it should and anything that needs putting right.

Common problems

• Hoods moved, damaged or too far from the work to capture the contaminant.
• Ductwork partly blocked by dust or debris, or damaged and leaking.
• Filters clogged or not changed on time.
• Fans worn, slipping belts or running the wrong way.
• Extra branches added to a system that was never designed for them.

Where cleaning is the answer, we can clean the ductwork and fan. Where a fan needs work, see extract fan repair. Other repairs may need the system’s installer or a specialist, and we’ll say so.

Keeping your records

Keep each test report so you can show when the system was last examined and what was found. Comparing one report with the next shows whether performance is slipping. Set a reminder for the next TExT well before the 14 months are up, or put it on a maintenance contract and we’ll remind you.

If the report shows something needs fixing, record what was done and when. Faults found at a test should be put right promptly, and the system checked again once the work is complete. A full history makes it far easier to show the system has been looked after.

Working around your site

Some tests need the process running so we can see how the extraction performs in real use. Others are easier with the system stopped. We agree the timing with you so production isn’t held up any longer than it needs to be, and we follow your site rules and any permits you use.

In food production, extraction over ovens, fryers, mixers and dusty processes may be a mix of LEV and general ventilation. We’ll help you work out which systems are LEV and need a TExT, and which are better looked after under ventilation duct cleaning or a TR19® Grease clean.

What it costs

We don’t publish prices. It depends on how many systems and hoods there are, how complex they are and how easy they are to reach. Tell us about your systems and we’ll give you a fixed quote, usually within one working day.