When choosing Zone 1 or Zone 2 equipment – or Zone 0 equipment, if explosive vapours are present for long periods of time – it is best to err on the side of caution.
Hazardous area equipment exists to prevent incidents from occurring, and generally speaking, it can’t hurt to specify equipment that is ‘too safe’ rather than ‘not safe enough’.
Take a recent HSE incident report for example: in November 2013, a Northallerton engineering firm needed to transfer oxygen between two pressurised cylinders.
Rather than use equipment specifically designed for the task, the firm’s partners opted for a makeshift hose with an unsuitable fitting.
The hose became clogged by debris, which caused it to overheat – and this in turn ignited the oxygen, creating an explosion that severely injured an employee.
HSE inspector Geoff Fletcher said: “This was an accident that should never have happened. Their employee has to live with the permanent consequences of their failure to consider the risks of transferring oxygen with in-house manufactured components.”
In general, hazardous area equipment comes in Category 1, 2 or 3, equivalent to Zone 0, Zone 1 and Zone 2 equipment respectively.
But it can be used in less dangerous zones too – so Category 1 equipment can be used in Zones 1 and 2 as well – meaning that, to prevent incidents like the one described above, there is nothing to lose by opting for the safest equipment designed for the job in question