LPG is the abbreviation used to describe liquefied petroleum gas, a group of hydrocarbon gases typically containing three or four carbon atoms per molecule and often referred to as C3 or C4 . The normal constituents of LPG are propane (chemical formula C3 H8 ), propylene (C3 H6 ), butane (C4 H10) and butylenes (C4 H8 ).
Although there are many variations of LPG, it is primarily made up of propane (60%) and butane (40%) and it is compressed into liquid form for ease of transport, storage and handling.9 LPG is either produced as a by-product of the oil and gas refinery process or it is extracted “from oil or ‘wet’ natural gas streams as they emerge from the ground”.
It is normally stored in liquid form in pressurised tanks and transported by road in tanker trucks or in cylinders. LPG is a homogenous good, as the physical features and the quality of the product supplied by each supplier are the same. In South Africa, quality specifications for LPG are defined by South African National Standards (“SANS”) 1774:2007, outlining the requirements for LPG mixtures intended for use as fuel. LPG, as a liquid, is colourless, and as a vapour, cannot be seen. Pure LPG has no distinctive smell, but for safety reasons, a stenching agent is added prior to distribution to aid detection by the human nose at very low levels.