Legacy Non-ATEX Equipment in DSEAR Hazardous Zones
A common issue experienced by sites across the UK is the continued use of equipment which was installed before the DSEAR was implemented in 2002.
Many people believe that “grandfathering rights” apply and that equipment which pre-dates DSEAR and the Equipment and Protective Systems for Use in Potentially Explosive Atmospheres Regulations (known as the EPS Regulations) - this is not the case.
Regulation 17 of DSEAR contains the transitional provisions and gave a deadline of 30th June 2006 for the requirements of Regulation 7 to be implemented. This includes using equipment suitable for the zones classified in the hazardous area classification and the dangerous substances which are present.
There is a caveat - equipment must be suitably ATEX rated unless a risk assessment finds otherwise. The risk assessment process for determining if equipment is suitable is essentially the same as the manufacturer of ATEX rated equipment would follow. It involves the following steps:
Determine where explosive atmospheres could form within the equipment, and classify a zone ( e.g. Zone 0/20, 1/21, 2/22)
Systematically assess the potential ignition sources - a process known as Ignition Hazard Assessment (IHA)
Determine the equivalent Equipment Protection Level (EPL) and any remedial actions required to achieve this
Implement the required changes to the equipment and maintain it as required
This risk assessment process is commonly conducted for non-electrical items of equipment (e.g. bulk solids handling equipment, such as conveyors, bucket elevators, mills, etc.) and is referred to as either a Mechanical Equipment Ignition Risk Assessment (MEIRA) or a Non-Electrical Equipment Ignition Hazard Assessment (NEEIHA). Electrical equipment typically needs to be replaced.
These risk assessments can allow non-ATEX equipment to continue to be used by demonstrating and documenting that it is safe to operate. Often remedial actions are identified as being required, such as installing condition monitoring, alignment sensors, or explosion protection.
The MEIRA / NEEIHA assessments should be conducted in line with recognised standards - the following are relevant for non-electrical equipment: EN 80089-36, EN 80079-37, and EN 1127-1.