New air quality regulations issued by the California Environmental Protection Agency may lead to similar restrictions in other states, according to the National Air Transportation Association. The new rules were issued via the Air Resources Board and apply a fleet average emission level to off-road vehicles and equipment, which includes ground-services equipment (GSE) used at airports, with gasoline and liquefied-petroleum engines that produce more than 25 horsepower. An amendment to the rules might offer some relief by allowing airport GSE operators “to exclude gasoline-fueled GSE from the non-forklift fleet average calculation for determining compliance with the Jan. 1, 2009 fleet average emission level standard.” GSE built in 1990 or later for which no retrofit emission control systems are available are excluded from the fleet level standard until Jan. 1, 2011, according to the Air Resources Board. Diesel engines are covered by a separate rule, according to NATA.