Working in an environment contaminated with dust, fumes, gases, mist, vapors and chemicals can put many stresses on a person’s health. Both employers and employees should make every effort to ensure the air in the workplace is comfortable and healthy to breathe. This may require a mixture of natural and artificial ventilation. Many employers install Local exhaust ventilation (LEV) or extraction systems. This should be efficient for workers to use and it should effectively ensure that harmful contaminants are not released into the workplace. Contaminated air should be filtered and discharged to a safe place. LEV may not always be necessary if the source of the contaminants can be eliminated by other means. However, if LEV is used, it must be installed correctly and working properly. Each year in the UK thousands of people die from occupational diseases such as asthma and lung cancer which could easily be prevented. According to the law, employers must adhere to the COSHH regulations (the Control of Substances Hazardous to Health). The Workplace (Health, Safety and Welfare) Regulations 1992 require that employers provide effective and suitable ventilation. This means that employers must ensure that exposures are kept below Workplace Exposure Limits (WELs) as identified in the work environment. The Health and Safety at Work etc Act 1974 places duties on anyone in control of a premises to take reasonable measures that there are no risks to health.
- Enclosed hazardous areas should have at least 12 air changes per hour.
- If working in a heated area, the ventilation may have to be increased so that the air doesn’t become too hot
- To protect against freezing and condensation, space heating may have to be installed
Apart from LEV, there are many other control methods that can be used. One control method is elimination and substitution. This involves eliminating or substituting a particular process or substance. For example anti-tack powders can be substituted by water based dispersions. Use of enclosed and automated processes are also cleaner. By changing the temperatures of materials in a process, fume levels may be reduced. Methods of handling materials at work can reduce dust and fume exposures. For example, sacks and bags that contain dust particles, should be handled under strict LEV. Segregating dusty processes at work can reduce the risk, for example, limiting the time spent close to dust and fumes. Relevant protective clothing can be worn, for example, goggles, gloves, aprons. Respirators should only be considered if other methods of dust and fume containment have been exhausted. Respirators should always be maintained and workers trained in their correct use.
Ventilation is not just there to remove fumes. It should also remove warm humid air. Fresh air should be drawn from outside the workplace. It should then be discharged from flues, chimneys or other processes. Movement of air through the workrooms should not cause a draught. Where possible natural ventilation, such as doors and windows, should be used.
Sources hse website