The US Congress has reached a compromise deal with Californian authorities over its plans for reducing emissions.

Californian legislators will be allowed to set new emissions standards for small off-road engines but will also have to follow a nationwide plan to lower emissions to be introduced for 2005.

The Californian law will require small engines used to power machines such as lawnmowers and chain saws to have catalytic converters.

Under the compromise, the US Environmental Protection Agency will consider safety issues of the Californian emissions reduction plan and also introduce a national strategy for off-road engines, which will apply to all states without their own emission standards.

The Canadian government has also moved to finalise regulations to limit pollutant emissions of off-road gasoline-powered engines.

The Off-Road Small Spark-Ignition Engine Emissions Regulations will harmonise Canadian rules with those of the US.

However, the rules will be less severe and also include a number of technical changes to exclude from the regulations engines such as those intended for the export market.

Environment Canada estimates that when fully enacted the legislation will reduce emissions of smog-forming pollutants from small off-road engines by roughly 44 per cent.