BESA TR40 Guide to Good Practice for Local Exhaust Ventilation

Updated April 2026 | Includes TR40 Online Awareness Training

The BESA TR40 Guide to Good Practice for Local Exhaust Ventilation has been comprehensively updated for 2026 and now includes access to the new BESA TR40 Online Awareness Course. Every full-price purchase includes two complimentary course places.

TR40 is a practical reference for all involved in designing, installing, commissioning, maintaining, or testing LEV systems. It offers employers and duty holders clear guidance on specifying, maintaining, and evidencing effective control.

Published Date: 22/04/2026
Number of Pages: 64
ISBN: 978-0-9957600-2-8
Publisher: Building Engineering Services Association (BESA)

Background

Local exhaust ventilation is a widely used engineering control for reducing exposure to airborne hazardous substances in the workplace. Under the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations, employers must prevent exposure where reasonably practicable, or adequately control it where that is not possible. In many cases, LEV is a key part of achieving that control.

TR40 provides a structured framework for managing LEV throughout its full lifecycle. It addresses strategic definition, design, specification, installation, commissioning, operation, maintenance, Thorough Examination and Test, and end-of-life decommissioning. TR40 also defines roles, responsibilities, and competency requirements, which support the wider HSE guidance in HSG258.

What's New In The 2026 Update?

• End-to-end LEV lifecycle coverage
  Clear requirements for LEV projects from concept and design, through installation and commissioning, to operation, review, and end-of-life.
• Aligned with the RIBA Plan of Work
  Reconfigured to follow the eight RIBA stages, providing a structured framework that defines tasks, responsibilities, and decision-making throughout the project lifecycle.
• New end-of-life stage
  An additional stage that addresses dismantling and disposal, completing the circular lifecycle of LEV systems and supporting responsible asset management.
• Enhanced inspection, testing, and competence guidance
  Expanded detail on ongoing inspection and testing, with stronger emphasis on competency and compliance requirements for all involved.
• Updated supporting documentation
  Revised example templates and forms included in the appendices, suitable for direct use or as best-practice guidance.

TR40 continues to deliver simple, accessible, and relevant advice to help you ensure LEV systems remain effective, compliant, and fit for purpose throughout their entire working life.

Included With The Purchase

To help you understand the updated guidance, every full-price purchase of TR40 includes two complimentary places on the new BESA TR40 Online Awareness Course, which you access through BESA Academy. We will email your discount code shortly after purchase.

Who Should Use This Guide

Essential for occupational hygienists, health and safety professionals, LEV designers, commissioning engineers, TExT assessors, mechanical and building services engineers, specialist LEV contractors, facilities managers, estates teams, and employer-appointed responsible persons. Also highly relevant to procurement leads, project managers, and anyone responsible for demonstrating compliance with COSHH and maintaining effective control of airborne hazardous substances in the workplace.

Key Topics Covered Include:

• Roles and responsibilities across the full LEV process, from employer to TExT assessor
• Competency requirements for designers, suppliers, commissioning engineers, maintenance engineers, and TExT assessors
• Employer brief and design parameters, including control benchmarks, process and hazard information, and discharge requirements
• System specification: hood types, ductwork, filtration, air movers, test points, alarms, and indicators
• Operating and maintenance manual requirements and log book obligations
• Commissioning requirements, what must be demonstrated, and what a valid commissioning report must contain
• Thorough Examination and Test: statutory intervals, procedure, and documentation
• End-of-life stage covering dismantling and disposal
• Updated example templates and forms in the appendices