New 'clean-air' legislation being considered by the state Air Resources Board in California could see a variety of garden apparata require a catalytic converter.

Legislators are currently examining the effects of garden machinery on the environment with estimates suggesting such equipment generates about six per cent of the region's ozone-forming pollutants.

Equipment including lawn-mowers, leaf blowers and chain saws is now set to face stringent new laws in June, with many officials already offering discount price electric lawn mowers in a bid to cut pollution.

Jacline Lourenco, California's Air Resources Board manager of off-road engine controls, told the Los Angeles Daily News that lawn mowers can pollute more than a family car.

Most manufacturers would be forced to introduce catalytic converters if legislators go for a 50 per cent reduction in emissions, as many observers expect.

However, the move has already come in for criticism by local retailers who argue that the legislation will ultimately lead to unsafe products at a much higher cost.