Q: What is Local Exhaust Ventilation?
A: Local exhaust ventilation (’LEV’) is one of the main engineering controls used to reduce exposure to airborne hazardous substances in the workplace.[1] Contaminants are controlled at source and either thoroughly cleaned or expelled into the atmosphere, preventing them from spreading into the surrounding air.
Q: How serious a risk do hazardous substances pose?
A: Contaminants (including dust, mists, fumes and gases) can cause occupational lung diseases like cancer, COPD and asthma. An estimated 13,000 deaths each year are linked to past exposure at work to chemicals or dust, with lung disease from workplace exposure killing an estimated 12,000 people.[2]
Q: What are an employer’s legal duties to protect employees’ health and safety?
A: Workers (and others) are protected by a raft of health and safety regulations and guidance. The foundation is the Health and Safety at Work act 1974 which places a general duty on employers to ensure, so far as is reasonably practicable, the health, safety and wellbeing of their employees and others affected by their work. Sitting beneath the act are more specific regulations, one of which is the Control of Substances Hazardous to Health.
Q: What do the regulations say?
A: In summary, where substances can’t be eliminated or substituted, they must be controlled. Risk should be assessed and relevant controls agreed and implemented. Controls (including LEV systems) should be maintained, exposure monitored and emergencies planned for. Employers should establish procedures to ensure control measures are properly used and applied – and not made less effective by other work practices or improper use. The control measures implemented must be suitable and sufficient for the risk.
Regulation 9 stipulates that LEV systems must undergo a Thorough Examination and Test at least every 14 months (or sooner for certain processes) by a competent person.
Q: And the guidance?
A: HSG258, the HSE’s definitive technical guidance for LEV system operators, incorporates the design, installation, commissioning and maintenance, documentation and testing of LEV systems. Meeting its requirements is the benchmark for compliance with COSHH regulations.
Similarly, ‘TR40 Local Exhaust Ventilation: A Guide to Good Practice’ is a practical reference for those involved in designing, installing, commissioning, maintaining, or testing LEV systems. It provides guidance on how to specify, maintain and evidence effective control of local exhaust sources.
Q: What does an LEV monitor do?
A: An LEV monitor allows the system operator and duty holders to continually observe, check and record the operation of LEV systems to detect scenarios where control may be lost. Early detection can help mitigate the release of hazardous substances.
Q: Is monitoring required by the regulations?
A: Strictly speaking no. However, the requirement under law is to protect workers health, safety and wellbeing, so far as is reasonably practicable. It is this statement that needs to be defendable. If there is a perceived risk that a system may fail without detection, the duty holder must be able to defend that the cost of installing detection outweighs the benefit.
Q: So why install an LEV monitor?
A: There’s no downside to installing an LEV monitor and multiple benefits including :
1. Belt and braces compliance
Although there is no strict legal requirement for monitoring, failure to do so could contribute to a failure meet regulatory requirements. Conversely installing monitors can help ensure – and evidence – compliance. For example:
- Paragraph 182 of L5 (COSHH ACOP) recommends continuous airflow monitoring to support the requirements of risk assessments.
- Section 228 of HSG258 states that users of LEV systems, especially operators of LEV hoods, must be able to tell that the hood airflow remains adequate to control exposure. Real time monitoring enables operators to meet this requirement.
- The HSE and auditors often take the view that if appropriate airflow monitors aren’t in place, the system itself might not be deemed suitable.
2. Continuous protection
There is potentially a 14 month gap between each Thorough Examination and Test under COSHH regulations. During this time, problems can arise that may go undetected. Real time monitoring brings them to the systems operators’ attention so that swift corrective action can be taken. (Indeed, Regulation 9 (COSHH) states that LEV should be ‘maintained in an efficient state, in efficient working order, in good repair and in clean condition’ i.e. the requirement is continuous.)
3. Operator confidence
LEV monitoring gives operators a clear, visual indication that ‘the system is working’. It provides reassurance to workers, encourages workforce engagement and empowers workers to raise an alarm should a fault arise (also a strong route for compliance with COSHH Reg 8).
If you want the complete peace of mind that’s only possible with LEV monitoring, give our friendly team a call.
[1] https://publications.thebesa.com/products/local-exhaust-ventilation-guide-good-practice
