42 U.S. Code § 7671f - Exchange authority
The Administrator shall, within 10 months after November 15, 1990, promulgate rules under this subchapter providing for the issuance of allowances for the production of class I and II substances in accordance with the requirements of this subchapter and governing the transfer of such allowances. Such rules shall insure that the transactions under the authority of this section will result in greater total reductions in the production in each year of class I and class II substances than would occur in that year in the absence of such transactions.
(b) Interpollutant transfers
(1) The rules under this section shall permit a production allowance for a substance for any year to be transferred for a production allowance for another substance for the same year on an ozone depletion weighted basis.
(2) Allowances for substances in each group of class I substances (as listed pursuant to section 7671a of this title) may only be transferred for allowances for other substances in the same Group.
(c) Trades with other persons
The rules under this section shall permit 2 or more persons to transfer production allowances (including interpollutant transfers which meet the requirements of subsections (a) and (b) of this section) if the transferor of such allowances will be subject, under such rules, to an enforceable and quantifiable reduction in annual production which—
The rules under this section shall also provide for the issuance of consumption allowances in accordance with the requirements of this subchapter and for the trading of such allowances in the same manner as is applicable under this section to the trading of production allowances under this section.