California air regulators may modify the state's strategy for the clean-up of emissions from diesel engines - including those in forklifts - and give owners and operators more time to comply.

The California Air Resources Board (ARB) recognises the impact of the economic slowdown and the resulting lower volume of emissions, according to Mary D Nichols, ARB chair.

"The direction by the board (on 22 April) will result in additional flexibility to affected companies and individuals while still continuing to achieve the significant air quality and health benefits these diesel controls will deliver," she says.

In 2007, ARB approved off-highway diesel rules that require engine replacement or retrofitting of forklifts, tractors, bulldozers and other types of equipment. Large fleet operators have until 2020 to comply, while fleets with fewer than 20 vehicles have until 2025.

ARB staff members intend to conduct workshops in May and June in Los Angeles, Sacramento and Fresno to obtain feedback from the proposed revisions to the regulations. Findings will be presented to the board in September.

Previously, ARB extended compliance deadlines for off-road equipment owners through legislation that was signed in February 2009. The provisions included delay in compliance requirements and credits for those reducing fleet size or operating hours in response to the recession.

California classifies diesel exhaust and more than 40 compounds within the exhaust as dangerous and toxic contaminants with potential cancer-causing elements.

Sacramento-based ARB is a department of the California Environmental Protection Agency.