DSEAR for Meters and Commercial Boilers

DSEAR for Meters and Commercial Boilers

Our client built a brand-new factory in 2021, which included a new gas installation servicing multiple commercial properties to heat both offices, the manufacturing area and warehouse. Finch were engaged following an internal health and safety audit, which highlighted that no assessment under the Dangerous Substances and Explosive Atmosphere Regulations (DSEAR) had been undertaken, and that potentially this had not been considered during the build phase of the factory.

Project Summary





The factory itself was a fast-paced environment which had minimal opportunity for downtime with an external gas meter, which fed multiple commercial boilers ranging from 50 KW to 500KW, through a 4” gas riser.  There was also an ammonia refrigeration system located at the rear of the factory.


Finch attended the site and met with the health and safety advisor on site, to assess the equipment, building and procedures against the requirements of DSEAR. This involved calculating ventilation rates, flow rates and looking at various potential release sources of natural gas. IGEM/SR/25 was used to calculate any relevant zones for the meter housing and riser pipework, with IGEM/UP/16 being used to determine whether a safe area for the boilers was possible.

For the Ammonia system ISO 60079 was used to determine the extent of any zones, and the equipment was assessed to make sure that it was appropriately ATEX-rated (a scheme used to certify that equipment is safe for use in potentially explosive atmospheres). This involved analysing P&IDs, and the equipment on site to identify the potential release locations, and pressures so that the extent of the zones could be calculated.

Finch created an Explosion Protection Document (EPD) which included all of the aspects to demonstrate compliance for the client, which included a DSEAR Risk Assessment, Hazardous Area Classification and methodology, Drawings based on schematics provided, and a detailed asset register.


Finch identified areas of improvement which would assist in reducing severity of the hazardous area, saving the company thousands of pounds. This was done by increasing and optimising the ventilation allowing the area to be categorised as either a safe area of Negligible extent, which negated the requirement for expensive equipment which is safe to operate in potentially explosive atmospheres.

The development of the EPD (which is a live document) and training of the health and safety advisor during the site visit, allowed our client to ensure compliance going forward, and to identify changes to the process that would require a review. This helped to assure the business and reassure people that the use of natural gas and ammonia was as safe as possible.

If you need further information or advice, please contact Tristan Pulford: [email protected] : 01530412777 

Related case studies