LEV hood

What Does Local Exhaust Ventilation Mean?

September 17, 2021

Local Exhaust Ventilation commonly referred to as LEV, is an engineering control solution that captures and removes dangerous particles that contaminate the air including dust, mist, fumes, vapour and gas. 

Why Do We Need LEV?

Breathing in large quantities of contaminated air can cause health issues. Effective LEV helps to carry away airborne contaminants before they can be inhaled, minimising the risk of workers developing occupational asthma and other serious lung problems. 

As an employer, you have a legal responsibility to provide workers with an adequate supply of fresh air and, where necessary, powered ventilation and dust or fume extraction.  According to the HSE (Health and Safety Executive) in Great Britain, there are over 12,000 deaths per year from workplace exposure to chemicals and dust.

A properly designed  LEV system consists of the following: 

  • A Hood – this will be placed at the source of the contaminants to ensure they enter the LEV system
  • Ducting to help  the contaminant travel from the hood to the discharge point
  • An arrestor or air cleaner to filter the extracted air (some industries do not require filtering so this won’t be present in all LEV systems) 
  • An air mover –  usually a fan. This is essentially the engine that powers the extraction
  • A discharge point – releases the extracted air into a safe place where it won’t cause harm

Which Industries Need LEV?

LEV systems are important in a number of industries. If your workplace processes create harmful dust, fumes or vapours, LEV should be utilised and maintained. 

Bakery factories or mills are a particular health and safety hazard as flour dust can be harmful when breathed in. Likewise, timber manufacturing workplaces should also have LEV to extract sawdust and wood waste from the air – not only is sawdust and wood waste a risk to the respiratory system, but it is also a fire hazard. 

At Vent-Tech, we are experts in LEV installation and upkeep and have a wealth of experience across a multitude of industries.


How Does LEV Work?

Local Exhaust Ventilation systems work by extracting harmful particles from the air to prevent them from being inhaled. The contaminants are then contained and safely removed from the workplace. In some cases, air going through LEV can also be purified.

To ensure LEV systems are working at their best they should be designed with your workspace in mind. At Vent-Tech we offer airflow simulation as part of our design service. This simulation performs a flow analysis and will clearly show airflow through the system, or the whole room if necessary. These simulations can help you understand whether or not the system is working correctly or if there is any turbulence or dead air.

These airflow simulations can help with new LEV designs or improving old ones.

airflow simulation

Who is Responsible for LEV Installation and Upkeep?

In terms of selecting a competent installer and ensuring your LEV systems undergo routine checks and fixes, the responsibility lies with the employer. It is down to the employer to mitigate risks for their workforce as much as possible. However, responsibility for reporting malfunctions and issues with an LEV system lies with employees and once notified, employers must promptly rectify the issues.

When having LEV installed it is also good practice for the employer to ensure that people in the workplace understand what LEV is for and its importance to their health. It is also good to get people familiar with the systems so it’s easy for them to tell if something needs fixing. 


Local Exhaust Ventilation and the Law

Compliance with COSHH Regulation 9 is a legal requirement for businesses. COSHH Regulation 9 refers to maintenance, examination and testing of controls and it states, “Every employer shall prevent or, where this is not reasonably practicable, adequately control the exposure of their employees to substances hazardous to health.”

This means that there is a requirement for measures to be taken to provide and maintain dust and/or fume extraction equipment in settings where workers are at risk from hazardous airborne contaminants.

In terms of LEV COSHH Regulation 9 also details that any LEV test results and information about any repairs undertaken should be kept on record for at least 5 years.

There are also specific LEV regulations set out to prevent LEV system performance from diminishing over time; this is that LEV systems should be examined and tested every 14 months by a competent and experienced tester, at the very least.


Are there any downsides to LEV? 

LEV requires regular testing in order to remain in working order, it can be difficult to find someone competent in LEV testing, competency comes from a combination of training, knowledge, skills, and experience. 

At Vent-Tech, our engineers are competent in all aspects of LEV systems and all have ILEVE competency cards. We also offer training courses that  allow you to safely move your LEV testing in-house. 

Having a well maintained LEV system can save lives, but it’s important to evaluate where it’s going to go and the effects it may have on employees. For example, it may interfere with the employee and workplace by being too loud. The motor and fans may cause noise pollution in the workplace and this noise exposure should be taken into account when assessing this. 

Local Exhaust Ventilation is an effective way of minimising risk to those working in places with harmful airborne particles. Provided that systems are well tested and maintained they can prevent many occupational lung diseases which can cause death or permanent tissue damage. 

Whether you want to check your systems are working at their best, install new systems or access training and other helpful resources, speak to Vent-Tech today and we can assist.