The California Air Resources Board (CARB) proposed amendments to the certification requirements for new heavy-duty diesel engines (HDDE) sold in the state in 2005 and 2006. Following the discovery that seven HDDE manufacturers disabled emissions control devices required by the U.S. Environmental Protection Agency (EPA), an agreement was reached between the federal government and the offending companies to restrict emissions levels on engines produced between Oct. 1, 2002 and Oct. 1, 2004. Under that mandate, HDDEs could emit no more than 2.5 grams per brake horse-power (g/bph) of non-methane hydrocarbons plus oxides of nitrogen (NOx). Most of the settling manufacturers also agreed to meet limits set in other tests, including the European Union’s Euro III standard. Those same tests were the subject of an October 1999 notice of proposed rulemaking by the EPA that would make them a requirement for all HDDEs manufactured as of 2007. The amendments proposed by CARB continue the standards set by EPA in the agreement with manufacturers until the federal regulations come into effect in 2007. “Taking this action will prevent the con-sent decree manufacturers from producing 2005 and 2006 model year engines that will emit significantly greater NOx emissions … compared to engines produced from 2002 through 2004,” CARB said. The proposal would also extend the jurisdiction of regulation to all engine manufacturers, not just those originally penalized by EPA.