Abstract

Propane-powered vehicles such as fork-lifts are one of the leading sources of exposure to carbon monoxide, an odourless, colourless, tasteless and non-irritating asphyxiant. To reduce workers' exposure to carbon monoxide, the IRSST has recommended that its concentration in vehicle exhaust not exceed 1%. However, this has not led to significant reductions in all situations, and reducing carbon monoxide emissions below 0.3% in fact increases the emission of nitrogen oxides (NOx). This study determines the maximum carbon monoxide concentration in vehicle exhaust that is not associated with an increase in the emission of nitrogen oxides. As engine maintenance and fuel adjustments (richness) influence all these emissions, the IRSST recommends that a preventive maintenance programme for fork-lifts be implemented and that general ventilation be provided.