Local Exhaust Ventilation (LEV) prevents employees from inhaling hazardous substances.
Local Exhaust Ventilation (LEV) & Statutory Requirements
Any employer who uses local exhaust ventilation to control hazardous chemical agents must ensure that it is operating effectively and is in good repair. There is a statutory requirement for a local exhaust ventilation system to be tested on a regular basis to ensure its effectiveness.
The Safety health and Welfare at Work (Chemical Agents) Regulations 2001 and the Safety health and Welfare at Work (General Application) Regulations 2007 requires that Local Exhaust Ventilation (LEV) systems are well maintained, thoroughly examined and tested at regular intervals.
Six month and twelve monthly tests are recommended.
OHSS Local Exhaust Ventilation (LEV) Testing Service
OHSS offers an LEV testing service which will help to determine whether your system is providing satisfactory control of the hazardous substance – our service is fully compliant with all current health and safety legislation.
Testing is carried out by a team of qualified Occupational Hygienists and Safety Practitioners with extensive experience in this area.
OHSS industrial hygienists follow the guidance given in HSE publication ‘Maintenance, examination and testing of local exhaust ventilation’ (HSG 54). A variety of test methods and equipment are used. These include vane and hot wire anemometers, pitot tubes and smoke visualisation tubes. The test results are compared to original design specifications (where available) and guidance given in HSE publication ‘An introduction to local exhaust ventilation’ (HSG 37) and (HSG258)‘Controlling airborne contaminants at work A guide to local exhaust ventilation’ (LEV).
A thorough visual examination to verify the LEV is in efficient working order, in good repair and in a clean condition.
Measuring and examining the technical performance to check conformity with commissioning data.
Assessment to check the control of worker exposure is adequate.
Local Exhaust Ventilation (LEV) Examination and Testing
Thorough visual and structural examination
This may include, as appropriate:
thorough external examination of all parts of the system for damage, wear and tear;
internal duct and hatch seal examinations;
checks that any filter cleaning devices (shake-down, reverse or pulsed jet) work correctly;
inspection of the filter fabric. Where filters have built-in pressure gauges, checks on their function (and that the operating pressure is correct);
checks of the water flow and sump condition in a wet scrubber;
checks that monitors and alerts/alarms, eg for returned air, are functioning;
inspection of the air mover drive mechanism, eg fan belt;
checks for indications of effectiveness. Are there significant deposits of settled dust in and around the LEV hood? Is any part of the system vibrating or noisy?
Local Exhaust Ventilation (LEV) Measure technical performance
This may include, as appropriate:
measuring the air velocities at suitable test points indicated in the system documentation. This includes hood faces, branch ducts and the main duct;
measuring static pressure at suitable test points indicated in the system documentation. This includes all hoods, ducting, across the air cleaner and fan;
checking the fan speed, motor speed and electrical power consumption;
checking the replacement or make-up air supply;
testing alarms, by simulating a failure, and the alarm’s ability to detect the failure;
measuring air temperatures;
Testing the air cleaner performance (eg a recirculating system).
Local Exhaust Ventilation (LEV) Reporting
We prepare a comprehensive report which evaluates the design and performance of the system and make recommendations for improvement, if required. We are also able to assist in the design and build of new extraction systems.
Your Legal Requirements Outlined - The Legislation
The Safety health and Welfare at Work (Chemical Agents) Regulations 2001 and the Safety health and Welfare at Work (General Application) Regulations 2007 requires that Local Exhaust Ventilation (LEV) systems are well maintained, thoroughly examined and tested at regular intervals.
Regulation 30: Inspection of work equipment
An employer shall ensure that—
(a) where the safety of work equipment depends on the installation conditions—
(i) an initial inspection is carried out after installation is completed and before it is first put into service, and
(ii) an inspection is carried out after assembly at any new site or in any new location, and that the work equipment is installed correctly and is operating properly,
(b) in the case of work equipment which is exposed to conditions causing deterioration liable to result in a danger to safety or health—
(i) periodic inspections and, where appropriate, testing is carried out,
(ii) special inspections are carried out when exceptional circumstances arise which are liable to make the work equipment unsafe, including modification work, accidents, natural phenomena or prolonged inactivity, and
(iii) deterioration is detected and remedied in good time,
(c) inspections carried out under paragraphs (a) and (b) are carried out by a competent person and are appropriate to the nature, location and use of the work equipment,
(d) the results of inspections carried out under paragraphs (a) and (b) are recorded and kept available for 5 years from the date of inspection, for inspection by an inspector, and access to these records is made available to users of the work equipment upon request, and
(e) when work equipment is used in another place of work, it is accompanied by evidence of the last inspection carried out under paragraphs (a) and (b).
Regulation 30 is far reaching in its scope and is not limited to any particular piece of equipment. It covers the requirements for inspection and the availability of inspection records.
It relates to both work equipment which is permanently installed at a location and to that which is moved from place to place requiring assembly each time. In either case equipment should not go into use until it has been inspected by a competent person to ensure that it has been properly installed and is safe for operation. Evidence of such inspections must be recorded and kept available for Health and Safety Authority inspection.
All work equipment is subject to varying levels of deterioration. Deterioration could be due to a range of factors, including corrosion, chemical attack, erosion, friction, fatigue, impact damage etc., which in turn can lead to erratic machine behaviour, structural failure, loss of containment of dangerous substances, failure to maintain adequate protection around dangerous parts and so on. Reference to equipment includes any associated monitoring and alarm systems.
Employers are required to set up programmes to maintain the integrity of work equipment by a system of ongoing monitoring which will detect deterioration in sufficient time to allow remedial measures to be taken. The inspection frequency should be based on how quickly the work equipment, or its parts, are likely to deteriorate and therefore give rise to unacceptable risk. In some cases, such as steam boilers in factories, there are statutory duties which determine the minimum level of inspection and Guide to the Safety, Health and Welfare at Work (General Application)
Where testing is required; this may be called for in the manufacturer’s instructions, specified in a Regulation or guidance document or required by the competent person.
Inspection results should be stored in a secure manner and be readily retrievable when required. While Regulation 30 does not prescribe the details to be examined or the format of the inspection results, these details may be prescribed under other Regulations for certain types of plant. Advice may also be found in relevant standards or codes of practice.
The scheme of inspections must take into account the known failure mechanisms of the work equipment.
In general, records should contain information on the:
• Type and model of equipment
• Means of identification
• Location
• Date of inspection
• Personnel who carried out the inspection
• Extent of inspection or test
• Faults found
• Remedial measures required, including deadlines for action
• Details of remedial action that has been taken.
The employees who use the equipment are entitled to see the inspection reports.
Evidence of the last inspection may take the form of a copy of the report for large items of plant and some form of labelling or tagging for smaller items.
The thorough testing and examination of LEV plants must be carried out at least every 14 months or more frequently for specific processes (in some cases every 6 months)
