P604 is an advanced proficiency module on the performance and management of LEV systems spanning four days. Its creation was requested by the Institute of Local Exhaust Ventilation Engineers and it was designed in conjunction with them.   You will develop a detailed understanding of the commissioning process to be undertaken to prove the effectiveness of LEV systems. The course incorporates validating control, RPE requirements to ensure safe maintenance, checking of systems, and setting parameters for future Thorough Examination and Tests (TExTs).

Booking must be made two weeks prior to the course date.

Gain knowledge and understanding of:

1. How, through industrial processes, airborne contaminants are generated and how this impacts on the strategy for controlling them. Alongside this, how the performance of control solutions can be evaluated and optimised.
2. Workplace, process and plant design considerations for lowering occupational exposures. How to identify the types of approach to risk reduction embodied in the hierarchy of control.
3. The primary elements and principles of an LEV system. This will include gaining a comprehension of the design features of LEV systems to enable adequate control of identified hazards.
4. The limitations of local exhaust hoods and enclosures and how to optimise their performance.
5. The measurements to determine whether an LEV system is functioning and performing to the design specification.
6. The methods of air sampling and interpretation and limitation of results.
7. How to work out either qualitatively or quantitatively whether an LEV system is capable and is achieving control of identified hazards.
8. How to identify the probable causes of system under performance and provide suitable remedies to any faults discovered.
9. The establishment of the operating requirements for ongoing performance to specification, and developing a testing checklist for routine maintenance checks. Know how to advise on suitable user pre-use checks and user training.
10. How to create commissioning reports, user manuals and system log books, to keep appropriate records of the results of examination and testing, in accordance with regulatory guidance and codes.


  • You must have some basic knowledge of the components of local exhaust ventilation systems and their purpose.
  • You must have taken the BOHS proficiency module P601, or P602 and have equivalent knowledge and experience.
  • You need to have a working knowledge of HSG258 Controlling airborne contaminants at work: A guide to local exhaust ventilation.

Course Who should attend:

You should consider this course if you are if you have responsibility for the specification, design, testing, contract management or occupational hygiene aspects of LEV systems. For example you may be one of the following:

  • An engineer
  • A manager
  • A supervisor
  • A health and safety professional
  • An LEV technician
  • An occupational hygienist


A practical assessment, a two-hour written exam (40 short answer questions) and the submission of two reports within 12 months of passing the exam.


We offer comprehensive post-LEV training delegate support and guidance. Our team is available by phone to answer one-off questions. We also offer a paid mentoring service for specific ongoing support. This one on one service will help if you have successfully passed your P604 exams, and would like guidance and tutoring on your report submission. Please contact us for costs.

Commitment to success:

We are committed to ensuring you complete the P604 course and have a high pass rate. If you do not pass, we will offer re-attendance of the course free of charge* as a show of our support to you.

*T&C’s apply

Resits can be arranged if necessary.


Email sadaf@vent-tech.co.uk for all training enquiries.