Nige, Here are the safety caps that are being talked about on this side of the pond, there is also another version of the high pressure cap that slides up and tilts to allow access to the valve: https://www.kimballmidwest.com/Catalog/CatalogIndex.aspx?p=6.628.591.4861 http://www.usasafety.com/lockable-c...ap-p-61.html?gclid=CNfBlvKe5L4CFQJqMgod5XcAsw Also, as I understand it, when the bottles are to be carried in a enclosed cabinet on a truck, that cabinet is supposed to be vented to allow air to circulate through and dissipate any gases that may leak out of a improperly closed valve.