Local Exhaust Ventilation (or LEVs) are engineering control systems designed to reduce airborne contaminant exposure of personnel / employees. They can range from simple single capturing hoods (e.g. welding) to large or complex systems such as paint spray booth enclosures. They often have the following components, hood, ducting, filter, fan & discharge.
Under CoSHH reg 9, it is statutory for employers / LEV owners to ensure all controls are maintained in an efficient state, an efficient working order, good repair & in a clean condition. Furthermore the employer / LEV owner must ensure that thorough examination & testing is carried out at least once every 14 months (or more frequently dependent upon process).
In 2009, it was estimated there was an approximate respiratory risk of 10% in businesses with ~60% of LEV systems not being tested and >60% not being checked or maintained. It was found that often employers did not fully appreciate the risk of exposure from processes and that both employers and employees were often over-optimistic about LEV capabilities. In addition there was no guidance on the purchase of LEV leading to the worst case scenario of the installation of ineffective and expensive LEV systems.
HSG 258 “controlling airborne contaminants at work. A guide to LEV” outlines the roles and responsibilities concerning LEV. Thorough examination and testing must be carried out by competent persons.
Thorough Examination & Test
- Elan Environmental Ltd can provide LEV testing services & deliver reports to the criteria laid out in HSG258, LEV testing involves through visual and structural examination (LEV components), Technical measurement of performance (face velocities, static pressures etc.) & assessment of the control effectiveness (observations of employee / LEV interactions, smoke testing, dust lamp scans etc.).
In addition to routine testing as outlined above Elan Environmental Ltd can deliver the following LEV related Services
Specification & Exposure Benchmarking
- For new (particularly complex) LEV systems HSG258 recommends that a LEV specification and quotation is prepared including selection of an appropriate exposure benchmark (exposure that would result with the control in place).
LEV Awareness Training
- Basic awareness training to outline the client’s full statutory requirements concerning LEV. E.g. on-going maintenance, routine checks etc. Can be tailored for the client’s specific needs and level of knowledge. clients who may not know their full roles & responsibility concerning LEV.
- HSG258 recommends that each LEV has a logbook & user manual. Often these are neglected or missing altogether. Elan Environmental can assist in producing these documents and formulating a full management plan.
Smoke Clearance Testing
- Use of smoke is standard during LEV testing however enclosure type systems may require the establishment of a smoke clearance time (minimum time for the enclosure to actually clear the contaminant). This test involves the use of a thermal generator and compressed CO2. The smoke produced is non-hazardous and provides a powerful visual test. Among other things, it can be used to study air eddies, containment effectiveness and test prototype systems.
Elan Environmental Ltd has experience working with industrial clients with large numbers of varying complexity systems and can project manage to any degree required by the client to fit their own unique structure. Our LEV Surveyors have full harness & MEWP licenses & LEV design issues are handled by a P602 qualified consultant.