Tetra Tech completed a site-wide DSEAR risk assessment and hazardous area classification for a UK manufacturing facility that had undergone major process changes.
A HGV manufacturer had an existing Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) risk assessment for their Lancashire site, but this had become out-dated due to significant changes to the equipment and processes.
This prompted a requirement to update the DSEAR assessment and Hazardous Area Classification (HAC), ensuring that the assessment reflects the current site practices and compliance with DSEAR.
Tetra Tech was appointed to support the facility by carrying out a site-wide DSEAR risk assessment and HAC of their systems, including paint spray booths, paint and solvent mixing areas, LPG bulk storage and electric battery charging areas.
Challenge
Introduced in 2002, DSEAR is designed to prevent or limit the harmful effects of fires, explosions and similar energy-releasing events and corrosion to metals. Operators must understand and manage their risk profile by identifying areas where an explosive atmosphere may exist and then introduce control measures to reduce those risks.
To comply with the DSEAR regulations, operators must have a detailed risk assessment which evaluates the risks and recommends appropriate safeguards to demonstrate tolerability, a HAC study to demarcate hazardous areas into zones, and management of equipment in the identified hazardous areas.
Additionally, to comply with DSEAR, employers shall regularly review risk assessments, particularly if there has been a significant change to the workplace or work processes. This presented a challenge; the current risk assessment and hazardous area classification was not reflective of the current processes on site and required an update.
Solution
Tetra Tech was appointed to conduct the update due to our extensive knowledge and experience of DSEAR requirements and experience in carrying out risk assessments and HAC.
Our pragmatic approach consisted of a careful examination of the dangerous substances and related processes on site, exploring ways in which people could be harmed.
We first analysed how the risk could be eliminated, and where this was not possible, we proposed how the risk could be reduced to As Low As Reasonably Practicable (ALARP), by applying the DSEAR hierarchy of control.
In environments where an explosive atmosphere may occur, hazardous zones were defined. Our approach determined the minimum zones allowed in industry, this ensured that the future maintenance, inspection and equipment replacement costs are minimised. The solution gave guidance on the selection and installation of equipment that is specifically designed for use in hazardous environments.
We also advised the customer of regular inspection and maintenance regimes required to uphold safety standards and maintain equipment certification.
The final package also included addressing other critical aspects of DSEAR. We advised on strategies for mitigation of a fire / explosion, emergency response plan, implementation of appropriate signage, pipeline identification and management of change procedures.
Tetra Tech’s tailored solution provided the facility with the much-needed update so that the risk assessment and HAC truly reflects the site in its current state. It ensured that the site remains compliant with DSEAR, has correctly defined hazardous zones, risks are minimised, and a safer working environment with a priority for employee’s safety is created.
At a glance
Client
Confidential
Location
Lancashire
Services
Site wide DSEAR Assessment
The project featured in this article was undertaken by RPS, A Tetra Tech Company and originally published on RPSgroup.com. In March 2026 RPS rebranded to Tetra Tech.