FOCUS
Current affairs
Figure 3: Explosive gas atmosphere zoning (taken from BS EN 60079-10-1: 2009)
Figure 4: Explosive dust atmosphere zoning (taken from BS EN 60079-10-2: 2009) Environmental impact
higher or lower category than usually required would only be present in special circumstances. Examples are: a. During maintenance operations where alternative effective precautions are provided to control the risk.
b. Where workers can be excluded from the hazardous area and will not be at risk from any ignition of an explosive atmosphere.
c. Where equipment of the required category is simply not available, but a lower category used with other protective measures will achieve purpose of these regulations.
In instances where employers intend to use the flexibility provided in DSEAR, their decision must be fully justified in their assessment of risk; otherwise the following apply: • category 1 equipment applies in Hazardous Area Zone 0/20
• category 2 equipment in zone 1/21 • category 3 equipment will suffice in zone 2/22
It is the employer’s responsibility to ensure that the strict categorisation of equipment is managed in hazardous areas. During the risk assessment process, equipment located in and in close proximity to zoned areas will be reviewed in order to confirm suitability of use. Equipment designed for use in hazardous areas should carry one of the markings, adapted to describe the groups and categories specific to the item (see Figure 5 on p51).
50 MAY 2020
www.frmjournal.com
As part of the risk assessment process, we do not only consider the effects of fire and explosion, but also factors such as the potential risks to the environment through release of hazardous materials. These considerations include large and small scale spillages, firefighting water runoff and release of gases heavier than air which may settle at ground level prior to entering low lying areas, rivers, streams and drainage systems. When reviewing the effects of a substance
on the environment, we analyse the existing drainage arrangements which may require an oil separator/interceptor as part of the containment strategy. BS EN 858 refers to two separator/ interceptor classes, based on performance under standard test conditions. 1. Class 1 separators/interceptors are designed to achieve a discharge concentration of less than 5mg/litre of oil under standard test conditions. These separators are required for discharges to surface water drains and the water environment. Many Class 1 separators/ interceptors contain coalescing devices, which draw the oil droplets together and facilitate the separation.
2. Class 2 separators/interceptors are designed to achieve a discharge concentration of less than 100mg/litre of oil under standard test conditions. They are suitable for dealing with discharges
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
