The following stationary engines are exempt from this division (relating to East Texas Combustion), except as specified in §117.3345(b) of this title (relating to Recordkeeping and Reporting Requirements):(1) engines with a maximum rated horsepower (hp) capacity of less than 240 hp;(2) engines used in research and testing;(3) engines used for purposes of performance verification and testing;(4) engines used solely to power other engines or gas turbines during startups;(5) engines operated exclusively in emergency situations, except that operation for testing or maintenance purposes is allowed for up to 100 hours per year, based on a rolling 12-month average;(6) engines used in response to and during the existence of any officially declared disaster or state of emergency;(7) engines used directly and exclusively by the owner or operator for agricultural operations necessary for the growing of crops or raising of fowl or animals;(8) diesel engines;(9) dual-fuel engines; and(10) gas-fired lean-burn engines.