Diesel fork-lifts are often preferred over LPG due to lower costs and superior fire safety in in-door use but exhaust causes problems.Air quality was measured with standard and reformulated diesel fuel in a warehouse where diesel fork-lifts operated. Sulphur was 605 ppm for the standard and 7 ppm for the reformulated fuel. Aromatics were respectively 31 vol-% and 12 vol-% and 95-% distillation points 352 °C and 286 °C.Fuel reformulation reduced particulates in the ware-house air by 40 %, particulate SOF by 50 % and mutagenicity of SOF by 80 %. NO, NO2, SO2 and PAH concentrations were low. Irritation and the possibility of long-term health problems reduced.