If you operate a potentially hazardous working environment, then it is up to you to ensure that workplace accidents are kept to an absolute minimum. Statistics on workplace accidents in South Africa suggest that while only 10% of all accidents are the result of unsafe working conditions, 88% of all incidents are the result of an employee’s actions, or lack thereof. This could be due to negligence or ill instruction, or it could be that hazardous zones were not clearly marked so that they could be easily avoided or navigated when need be.
A big part of ensuring workplace safety is to ensure that dangerous areas are clearly marked, and one of the most effective ways to do this is with lighting. However, when combustible materials are present in the area, the light fitting itself could pose a potential risk of ignition. For this reason, lighting plans should consider their environment carefully when having lighting installed.
More about Hazardous areas
As far as lighting is concerned, a hazardous zone is one in which a flammable substance is produced, handled or stored. In such areas, careful measures need to be taken to ensure that these substances are not accidently ignited. They can be divided up as follows:
Zones 1 and 2
Zone 1 hazardous areas are those with the presence of high risk gases and vapours that create a potentially explosive environment. There is always a risk of a flammable mixture contaminating the atmosphere of the area, in which case a spark or heat source from any nearby lighting could act as a catalyst to disaster.
Zone 2 areas are those with areas with medium to low risk vapours and gasses present in a form where they are unlikely to (but still could) combust, such as in store rooms.
Zones 21 and 22
Zone 21 materials are those that take the form of powder or dust, and present a relatively high risk of creating an explosive or flammable atmosphere even during normal operations. Processing areas where these materials are likely to be present, are extremely high-risk areas, and so require protected lighting that is safe to use without posing a risk of ignition.
Zone 22 materials are those that would not normally be in the position of creating an explosive environment, but could still do it under the right conditions.
Requirements for lighting in these areas
Protected light fittings that are suitable for high risk areas (particularly zones 1 and 21), should always be flame and explosion proof. That is to say that they should be sealed so as not to mix with gasses or fibres in the air. They should also be gas, dust or water resistant depending on their intended use, and they should be regularly inspected and maintained.