According to 6.2.6.1.2 of the ADR in conjunction with section 6.1.1 of the ADN, the capacity of receptacles made of metal shall not exceed 1 000 ml; that of receptacles made of synthetic material or of glass shall not exceed 500 ml. RECEPTACLES, SMALL, CONTAINING GAS (GAS CARTRIDGES) without a release device, non-refillable with a volume greater than 1 000 ml are therefore not permitted.