Respirable crystalline silica has a very low Workplace Exposure Limit of 0.1 mg/m3 as respirable dust. In fact, as the above chart shows, long term exposures to concentrations much lower than this can lead to some workers developing silicosis. There is also evidence that prolonged workplace exposure to crystalline silica can lead to an increased risk of lung cancer, although this is only likely to occur in those workers who have already developed silicosis. Given the nature of the risk exposures need to be reduced as low as practicable.
Local Exhaust Ventilation (LEV) is a machine that extracts air from a process as a way of controlling and reducing the exposure of workers to dust, fumes and vapor which could be hazardous to their health. It is a legal requirement, as set out in the Health and Safety at Work Act 1974, for any employer to maintain working conditions for employees. Any employer that uses LEV techniques in the workplace must have equipment examined and tested at least “every 14 months” to ensure it is working effectively and safely.
As LEV is a control measure under COSHH Regulations it must be regularly and thoroughly inspected and tested. As stated above, LEV regulations outline that any employer who uses local exhaust ventilation to control hazardous substances must ensure that it is operating effectively. Local Exhaust Ventilation Testing is a legal requirement in the UK. All equipment must be thoroughly examined and tested by a competent person at least every 14 months to ensure employees are safe.
All Companies and Employers using extraction equipment have legal requirements they must undertake. All equipment must be examined and tested in order to comply with Regulation 9 of the COSHH Regulations. The Employer must make sure that equipment is maintained and in efficient working order and of good repair. A thorough test should be undertaken once every 14 months and in some cases far more frequently. It is also a requirement of the employer to keep a suitable record of the test. All for a period of at least 5 years. This record should also include details of repairs carried out as a result of the test. Read more details at HSE LEV Testing.
The employer must consider other control options and use them where appropriate (see HSE leaflets Working with substances hazardous to health1 and Clearing the air2) before applying LEV. In some circumstances, LEV may not be a reasonably practicable control as there may be many sources or extensive contaminant clouds that are too large for LEV alone to control. LEV suppliers provide goods (an LEV system) and may then act as a service provider. Designers interpret the requirements of the employer and advise on an effective LEV system which is capable of delivering the required control.