The US DoT publishes a A Guidebook for First Responders During the Initial Phase of a Dangerous Goods/ Hazardous Materials Transportation Incident titled "Emergency Response Guidebook" It states that for a small LPG Tank (20 lbs/5 gal 9 kg/19 L ), the safe distance is 160ft/48 m--page 372 It also refers to guide 115 in the guidebook that is common for all Gases - Flammable (Including Refrigerated Liquids) on pages 167 & 168 that highlights for public safety to:- • As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. • Keep unauthorized personnel away. • Stay upwind. • Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). • Keep out of low areas. http://phmsa.dot.gov/sta...Files/Hazmat/ERG2012.pdf

Thanks, Chaps There's plenty there for me to get my teeth into. LB

Thanks, Frank Is that the same as the second document linked to above? LB

Interstingly, the Manuals of Firemanship - Hazmat Manual in Dept of Communities & Local Govt refers to the US DoT Emergency Response Guidebook as a key reference/information source on page 139! in Part C Technical considerations