Hazardous area zoning reduction is a common challenge for plant operators looking to control capital and operating costs while remaining compliant with ATEX and DSEAR requirements. Where flammable liquids, vapours or combustible dusts are present, zoning cannot always be avoided entirely, but in many cases it can be reduced or downgraded through practical design and operational measures.
A good starting point is to undertake a Hazardous Area Classification study. This establishes where zoned areas exist and provides an opportunity to identify improvements that could reduce their extent or designation.
Reducing Hazardous Area Zoning for Liquids and Vapours
For flammable liquids and vapours such as Zones 0, 1 and 2, several options may be considered.
Material substitution is always worth considering first. Replacing a flammable substance with a non flammable alternative may remove the need for zoning altogether, although this is often not practical.
Changing operating conditions can also influence zoning. For example, keeping a material below its flash point may reduce or downgrade hazardous zones, depending on how robust and reliable the temperature control is.
Ventilation is one of the most effective tools for hazardous area zoning reduction. Improving the availability and quality of ventilation can reduce how long vapours persist, allowing zones to be downgraded or, in some cases, treated as negligible extent in line with BS EN 60079 10 1.
Reducing the area where liquids can pool following a release can limit the size of a hazardous zone. Measures such as local bunding around containers can significantly reduce zone extent.
Reducing Hazardous Area Zoning for Dusts
Dust zoned areas are often designated as blanket Zone 22 due to the potential for dust layers. Improved housekeeping can remove this blanket zoning, leaving smaller localised zones that are easier to manage.
Material substitution and local extract ventilation can also help reduce dust zones. While BS EN 60079 10 2 provides less prescriptive guidance than for vapours, effective extraction can still support zoning reduction.
Segregation is another powerful tool for dust hazards. Physical barriers can limit the spread of dust zones, protecting nearby non ATEX equipment and avoiding unnecessary upgrades.
Getting the Right Advice
Not every zone can be removed, but many can be reduced with the right combination of design changes and operational controls. Independent hazardous area classification can help identify cost effective and compliant solutions.
If you are looking to reduce hazardous area zoning on your site, the OTECSA Consulting team can provide practical guidance tailored to your process and facilities. Contact Us.