49 CFR 173.307
Exceptions for compressed gases.
(a) The following materials are not subject to the requirements of this subchapter:
(1) Carbonated beverages.
(2) Except as provided in § 175.10(a)(2) of this subchapter, tires when inflated to pressures not greater than their rated inflation pressures.
(3) Balls used for sports.
(4) Refrigerating machines including dehumidifiers and air conditioners, and components thereof such as precharged tubing containing 25 pounds or less of nonflammable liquefied gas.
(b) [Reserved]
[Amdt. 173-94, 41 FR 16081, Apr. 15, 1976, as amended by Amdt. 173-135, 45 FR 13090, Feb. 28, 1980]