HSE What is Local Exhaust Ventilation – Video

A Simple Introduction to How LEV Systems Protect Workers’ Health

 

LEVCentral Expert Commentary

This short HSE video is one of the best introductory resources available for anyone who is new to Local Exhaust Ventilation (LEV). Produced by HSE, it explains—in clear, non-technical language—what an LEV system is, why it is needed and how it protects workers from hazardous airborne contaminants. It introduces the four fundamental components of an LEV system and demonstrates how contaminants are captured at source before they reach the worker’s breathing zone.

Although the video lasts only a few minutes, it succeeds in explaining concepts that often prove difficult for newcomers to understand. Rather than concentrating on regulations or technical calculations, it focuses on the basic engineering principle of capturing contaminants close to where they are generated.

For employers, supervisors and employees, this makes the video an excellent awareness resource. For LEV professionals, it provides a useful introduction that can be shared with clients, managers and operators before discussing more advanced topics such as design, commissioning or Thorough Examination and Testing (TExT).

HSE Video

Key Learning Points

The video explains:

• What Local Exhaust Ventilation (LEV) is.
• Why hazardous airborne contaminants need to be controlled.
• The difference between capturing contaminants at source and allowing them to disperse.
• The four main components of an LEV system:
  • Hood
  • Ductwork
  • Air cleaner (filter)
  • Fan and discharge.
• How each component contributes to effective contaminant control.
• Why hood selection and positioning are critical.
• The importance of maintaining LEV systems.
• The employer’s responsibility to ensure LEV continues to perform effectively.

Source Information

Organisation: Health and Safety Executive (HSE)

Resource: What is Local Exhaust Ventilation (LEV)?

Resource Type: Educational Video

Primary Topics: Introduction to LEV, Source Capture, Hood Design, Airflow, Workplace Health Protection

Audience: Employers, Employees, Duty Holders, LEV Designers, LEV Engineers, Occupational Hygienists, Students and anyone new to Local Exhaust Ventilation.

LEVCentral Perspective

One of the strengths of this video is that it deliberately avoids unnecessary complexity.

Experienced LEV engineers may naturally think about duct velocities, static pressure, fan curves and commissioning data, but those concepts mean very little to someone seeing an LEV system for the first time. HSE instead concentrates on the one principle that matters most:

Hazardous substances should be captured before they enter the worker’s breathing zone.

The animation showing contaminants moving into the hood rather than into the workplace provides an excellent visual explanation of source capture and helps users understand why simply opening doors or relying on general ventilation is rarely sufficient.

The video also introduces the four main components of an LEV system. Whilst this is necessarily simplified, it provides an excellent foundation for understanding more advanced subjects such as hood design, transport velocities, filtration, commissioning and statutory Thorough Examination and Testing.

For organisations providing LEV training, this is an excellent resource to show at the beginning of an awareness session.

Further Resources

• HSG258 – Controlling Airborne Contaminants at Work
• INDG408 – Clearing the Air – A Simple Guide to Buying and Using LEV
• HSE LEV Web Pages
• BOHS P601 – Thorough Examination and Testing of LEV Systems
• BOHS P602 – Basic Design Principles of LEV Systems

Recommended Learning

• M200 Basic Principles in Occupational Hygiene
• M501 Measurement of Hazardous Substances
• M505 Control of Hazardous Substances
• M507 Health Effects of Hazardous Substances
• P304 Fundamentals of CoSHH Risk Assessment & Control
• P603 CoSHH PPE
• P600 Methods for Testing Performance of LEV
• P601 LEV Thorough Examination & Testing
• P602 LEV Basic Design Principles
• P604 LEV Commissioning & Performance Evaluation

Thought Leadership

Sometimes the simplest resources have the greatest impact.

One reason LEV systems are misunderstood is that many workers only see ductwork and a fan. They do not appreciate that every component—from the hood to the discharge stack—has been designed to achieve a single objective: preventing hazardous substances from reaching the worker.

This HSE video succeeds because it explains that principle without overwhelming the viewer with engineering detail. It provides an excellent introduction for those unfamiliar with LEV and creates a solid foundation upon which more advanced learning can be built.

At LEVCentral we often say that good LEV begins with understanding the hazard. Equally, effective training begins with understanding the basic principles of how an LEV system works.

This short video achieves exactly that, making it one of the best introductory resources available for employers, employees and anyone taking their first steps into the world of Local Exhaust Ventilation.