Gas Free 2 : A vessel, container, or area is considered to be gas-free when the concentration of flammable and/or toxic gases in it is within prescribed safe limits for persons to enter. (IOTTSG). Gas laws. See: Gas Equation
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}