This gas may also be packed in capsules under the following conditions:

(a) The mass of gas shall not exceed 150 g per capsule;
(b) The capsules shall be free from faults liable to impair the strength;
(c) The leakproofness of the closure shall be ensured by an additional device (cap, crown, seal, binding, etc.) capable of preventing any leakage of the closure during carriage;
(d) The capsules shall be placed in an outer packaging of sufficient strength. A package shall not weigh more than 75 kg.