Posted By GavinR Hi, I looking through our processes and have come across an issue that i;m unsure about. Our pipework bringing acetylene, hydrogen and natural gas to our welding booths are seamless pipes and have a PM and inspection schedule. According to my understanding of DSEAR ACOP this would mean these pipes would be classified as no-hazardous and would not require zoning/signage. However at the welding booth itself there is the protective devices and connections which are potentially sources of a release of a dangerous substance that would lead to an explosive atmosphere. This would require zoning and signage. However it is a welding booth and and will have an ignition source present as part of the process so this cannot not eliminated. We have the protective device set up of WSoE under PSSR and operators have documented pre-use inspection for all equipment including leak testing. Is this enough to suffice under the DSEAR assessment? I have also started to investigate the possibility of installing a permanent gas monitoring system within the booths to detect any leakage and alarm to warn welders. In addition to this i have the same concerns over our heat treat furnaces. Again we have dangerous substances in endogas, natural gas all entering the furnace but the as part of the process there will be ignition sources and heat sources. We have multiple controls for furnace to prevent unburnt gas from accumulating and producing explosive atmospheres and mixture of endogas with air which would form a =n explosive atmosphere but its the requirement to identify and zone which is causing me some concerns. Any advice would be great