40 CFR 91.1306 - Trading.
(a) A marine engine manufacturer may exchange positive in-use emission credits with other marine engine manufacturers through trading.
(b) In-use credits for trading can be obtained from credits banked for model years prior to the model year of the engine family requiring in-use credits.
(c) Traded in-use credits can be used for averaging, banking, or further trading transactions.
(d) Unless otherwise approved by EPA, a manufacturer that generates positive in-use credits must wait 30 days after it has both completed in-use testing for the model year for which the credits were generated and submitted the report required by § 91.1309(a) before it may transfer credits to another manufacturer or broker.
(e) In the event of a negative credit balance resulting from a transaction, both the buyer and the seller are liable, except in cases involving fraud. Engine families participating in a negative trade may be subject to recall under subpart I of this part.