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Page revision date - 4 September 2021
DSEAR relates to a particular area of Process Safety – that of flammable atmospheres. The principles of compliance with DSEAR are no different to compliance with any other aspect of process safety regulation. The benefit of the DSEAR regulations is that there is great deal of written “relevant good practice” guidance available guiding us all on how to comply.
In our webpage on risk assessment we identify the 5 steps that the HSE advocates for managing process risk. These 5 steps are also used to manage DSEAR hazards. The steps are described below with a DSEAR assessment focus:
|DSEAR Compliance Step and Description||How do we do this?|
Identify the hazards
|The hazard is your flammable substances. It might be a solid, dust, liquid, gas or vapour. Before you can assess the risk, you need to understand the substance: Flash point, auto ignition temperature, Kst, composition, particle size etc etc… It’s not complex; it is just laborious….we simply gather facts. |
We use the British Standard BSEN 60079 to guide us with this.
Who might be harmed and how?
|We Identify all the ways and locations where the flammable substances and/or flammable atmospheres can become ignited. Some ignition might occur in equipment, some might occur outside equipment (if there is a leak). If it ignites how bad will it be – injuries, fatalities, pollution?|
We use a variety of techniques to do this analysis depending upon the industry and how bad the consequence might be. A motor vehicle repair garage with 100 litres of petrol warrants a much lighter approach than a chemical plant with 70T of Acetylene. Our approach will range from using relevant good practice “templates” e.g UKLPG codes (LPG), INDG139 (batteries) through to HAZID or HAZOP. Judging the level of proportionality required is an important benefit of our experience.
Evaluate the risks and decide on precautions
Has relevant good practice been followed?
If the flammable atmosphere can’t be eliminated, then there is no option other than defining a hazardous area zone and to make sure that the equipment in that zone is suitable for it. For hazardous area classification we will draw upon a variety of written relevant good practice guidance sources depending on the application e.g. EI 15, BS EN 60079, HSG176, IGEMSR/25. All approaches require classification of zones as 0, 1 and 2 or, by default, “safe”
Record your findings
Typically, we would help you to produce a DSEAR Risk Assessment Report, Hazardous Area Calculations and Hazardous Area Drawings.
We would guide you on how to document the design, inspection, maintenance and testing records for the (“ATEX”) equipment located in hazardous zones.
Review your DSEAR assessment and update if necessary
|This is normally triggered by any changes to the plant or after a certain time period has elapsed. The review process should be determined on a case by case basis and we will help you develop the necessary protocols.|
COMAH Consulting Ltd is able to provide support with respect to DSEAR which can range from “hand holding” through to taking the lead and carrying out all aspects of assessment work for you. This would include providing recommendations for compliance and for beneficial improvements.
The full requirements of DSEAR are explained in the HSE Approved Code of Practice: “Dangerous substances and explosive atmospheres” L138. This is available for free at https://www.hse.gov.uk/pubns/books/l138.htm