Contents
- Why you should commission
- The commissioning report
- Before using LEV
- Core elements of commissioning
- LEV condition
- Commissioning results
- Training and information
- Self-employed
- What the law says
- Further guidance
Why you should commission
As an employer, you should commission your local exhaust ventilation (LEV) system to make sure it adequately protects people from breathing in harmful substances.
The law says that you must assess and control the risks from exposure.
Commissioning:
- ensures that there is adequate control from day one
- proves that the system is providing adequate control
- provides a benchmark for later regular examinations and tests
The commissioning report
The commissioning report should always include the:
- date of the test
- duty holder’s name and address
- commissioner’s name, job title and employer
Ensure the report has been signed appropriately.
You are responsible for ensuring your commissioner has demonstrated impartiality and competency.
Before using LEV
Before you start using your LEV system, ensure it has been checked and is suitable for the process when in use and compatible with the substances handled. The system should be installed correctly according to design, specification and any manufacturer's instructions, and meet specified technical performance.
For more information read chapter 5 of Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV) - HSG258[1].
Core elements of commissioning
Ensure that your LEV commissioner has:
- identified the LEV system and location – for example, LEV tester assigned a unique number
- assessed control and demonstrated whether the LEV system adequately controls exposure to the hazardous substances by:
- identifying the hazardous substances it is intended to control
- defining the process and how emissions occur
- defining the operating conditions
- detailing test methods and results
- defined benchmarks by providing performance targets such as flowrates and pressures, as reference for statutory examinations, maintenance and performance management
- ensured the LEV system is correctly balanced and achieving the performance required at every hood in a system
LEV condition
The commissioning report should detail the general condition of your LEV and the operating conditions at time of commissioning, including any external factors that might influence performance. It should also describe:
- the general configuration, components, fan specification, filter media, waste collection, make-up air supply and discharge arrangements, location, photographs of relevant parts and assign identification number
- any minor adjustments or repairs carried out to make the LEV system effective
- the methods used to judge performance, such as visual, smoke test, airflow measurements, pressure measurements, dust lamp, air sampling and filter testing
Commissioning results
You should be able to understand the information provided in the results. It should also give you enough information to update your user manual and logbooks after any defects have been resolved.
The commissioner should include a simple summary describing the effectiveness of the system. It should also include:
- quantitative assessment results such as volume flow rates, face velocities, duct velocities, static pressures, fan speed, motor speed and electrical power consumption and filter performance (where applicable)
- qualitative assessment results, including suitable observations
- the results of any airflow indicators and relevant air sampling
- a simple schematic with test points
- calibration certification
The commissioner should also provide information on the frequency of testing, if different from the statutory 14 months.
Training and information
Employees and operatives must be given suitable and sufficient information, instruction and training in the use of LEV.
Self-employed
If you’re self-employed, you have the same responsibilities as an employer and a worker to make sure people are not exposed to hazardous substances.
What the law says
Employers must assess and control the risks from exposure under the Control of Substances Hazardous to Health Regulations (COSHH) (as amended). They must provide appropriate information and training to workers, and LEV systems should be tested at least every 14 months.
LEV systems also present additional risks. Employers must control the risks to safety from fire, explosions and substances corrosive to metals under The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR). Employers must also consider compliance with The Control of Noise at Work Regulations 2005, to ensure that workers' hearing is protected from excessive noise.
Other regulations may also apply.
Further guidance
Publication ‘Controlling airborne contaminants at work: A guide to local exhaust ventilation (LEV)’[2] provides further guidance on:
- the roles and legal responsibilities of employers and suppliers
- competence
- principles of good design practice for effective LEV hoods and their classification
- ducts
- air movers
- air cleaners
- system documentation