(1) Exemption from tax (A) In general No tax shall be imposed by section 4681 on— (i) any use of any substance as a propellant in metered-dose inhalers, or (ii) any qualified sale by the manufacturer, producer, or importer of any substance. (B) Qualified sale For purposes of subparagraph (A), the term “qualified sale” means any sale by the manufacturer, producer, or importer of any substance— (i) for use by the purchaser as a propellant in metered dose inhalers, or (ii) for resale by the purchaser to a 2d purchaser for such use by the 2d purchaser. The preceding sentence shall apply only if the manufacturer, producer, and importer, and the 1st and 2d purchasers (if any) meet such registration requirements as may be prescribed by the Secretary.
26 USC § 4682(g)(1)
None identified, default scope is assumed to be the parent (subchapter D) of this section.