Climate Summit for Local Government

Sept 6-8, 2023 | Melbourne

*This article was written by City of Yarra resident and transport consultant, Harry Barber. Harry has written two reports on this topic. For more information or links to the full reports, please email Harry on [email protected]

Today, most tradies in Australia have voluntarily switched to battery-powered tools. The trend has been accelerated by more-powerful and longer-lasting batteries. 

A similar but slower changeover to battery power is taking place with garden tools. Tool-sets for households and garden service companies offer blowers, trimmers, cutters, and chain saws all based off the same powerful battery. These tools are now powerful enough for municipal tasks. Council staff initiatives at Brighton Council in Tasmania and the City of Yarra in Melbourne have led to the electrification of many depot tools. 

In Australia, at the hardware store, some petrol-powered tools are no longer on sale. Imports to Australia of two-stroke engine tools and outboard motors were banned in 2018 and the sale of these products banned in 2020. These bans followed a long Commonwealth and COAG process that exposed the public health risks caused by the air pollution from these small motors.

The Commonwealth process concentrated on non-road, spark ignition engines. The definition of non-road excluded motorcycles but still captured the engine tasks responsible for most pollution: outboard motors and tools. However, the spotlight fell on two-stroke motors as they are more polluting and more numerous than four-stroke motors.

The pollution and health impact of these tools is substantial. The Commonwealth Regulatory Impact Statement says:

  • At peak times, non-road, spark ignition engines and equipment (NRSIEE) are estimated to contribute up to 10% of overall air pollutants in Australian urban environments. 
  • Emissions contribute to air pollution especially on summer weekends in urban centres when their use is high. On a summer weekend day, lawn-mowing and recreational boating activities together contribute on those days about 20% of total man-made carbon monoxide, 5 to 9% of total man-made particulate matter, and 20% of total man-made volatile organic compound emissions in these urban environments. 
  • One hour of operation of a 2-stroke leaf blower can produce around the same emissions of:
    • nitrogen oxides as a car operated over the same period and as much hydrocarbon as 150 cars operated over the same period. 
  • One hour of operation of a brush cutter produces around the same emissions of air pollutants as 10 cars operated over the same period. 
California accelerates tool electrification

In December 2021, California introduced an air pollution reduction regulation that will ban the manufacture and sale of most petrol-powered tools. The aim is to eliminate the use of these tools by 2035.

California has long been concerned about the smog or local air pollution that made the Los Angeles haze world famous. Efforts to reduce smog began in the late 40s and led in 1967 to the establishment of the California Air Resources Board or CARB. Thanks to their work, it is well known today that emissions of small particulates (PM 2.5) and other products of combustion harm healthy people and exacerbate chronic diseases such as asthma.

CARB has the power to make regulations that limit the air pollution including regulations that set minimum standards for motor vehicles. Given that the state has 30m cars – the largest fleet in the US – the CARB regulations set a de facto national standard for US motor vehicles. For example, it was a CARB regulation that first required catalytic converters on cars.

Smog caused by small motors

CARB has been concerned since the 1990s about the petrol-powered tools they call Small Off-Road Engines or SORE. The CARB definition of SORE includes hedge & string trimmers and edgers, blowers & mowers, pressure washers, and small chainsaws. 

CARB’s concern about petrol-powered tools has increased in recent years as these tools have now overtaken motor vehicles as the main cause of smog in California. Half of the SORE smog is caused by what CARB calls lawn and garden tools. 

The collective impact of the tool motors is large – there are a similar number of cars and tools in California. The following graphic from CARB (adapted to Australia) shows the individual impact of tool use.

The response 

The 2021 CARB regulation will mean that over time (probably by the end of 2025) there will be no new tools with small motors for sale. 

The latest electric tools are helping accelerate the transition. All major tool companies such as Stihl and Husqvarna offer electric tool sets with equivalent power, reduced noise, zero exhaust and lower running costs. 

Multiple benefits

CARB also supports efforts by local communities to switch to electric tools through incentives for households and landscape businesses and by loaning equipment for 3-week trials.

The regulatory and incentive effort by CARB to alert people to the risks from these small engines has provided a foundation for other related and complementary efforts.

Many jurisdictions across North America have introduced bans on the use of hand-held, petrol-powered tools such as blowers – usually to reduce neighbourhood noise. Washington DC is one example. (A high proportion of small-engine noise is at low frequencies which pass easily through windows into people’s homes.)


In Australia, there have been no formal reports on the OH&S impacts on the operators of these tools. The risks eliminated by electrification are many and substantive. For Council staff this includes eliminating fuel handling, eliminating injuries from pull starts, lowering noise levels from high risk levels and eliminating the inhalation of exhaust which includes carbon monoxide.

A Council might undertake an urgent and complete electrification program to comply with their OH&S duty. In Victoria an employer under the Occupational Health and Safety Act 2004 (OHS Act) has a duty to eliminate risks to health and safety, so far as is reasonably practicable. Similar requirements apply in other States and Territories. It would be difficult to argue in court that it is not reasonably practical to electrify most hand-held, petrol-powered tools.

Electrification could be undertaken out of fairness. It would be inconsistent to ensure all office workers had an ergonomic chair, but not spend a similar amount of money improving an outdoor workers ‘desk’.

Staff certainly appreciate the improvement electrification brings to their workplace including being able to converse or listen to music. In operation the tools are cooler and in the words of one: my wife is pleased I no longer come home smelling of two-stroke.

Climate investment

Finally, electrification of hand-held, petrol-powered tools is a low-cost and high impact climate investment. 

It is not possible to measure the global warming emissions generated by these small motors as emissions vary significantly from user to user and in different weather conditions. Broadly, we can assume that the global warming emissions in the exhaust (compounds such as nitrous oxides and volatile organic compounds) are of an equivalent scale to the particulates and other local pollution. 

It is of course much cheaper to purchase a battery blower with a backpack battery than buy an electric car. For half the cost of an electric car, the City of Yarra electrified 16 depot tools with their supporting chargers and batteries. Using the CARB estimate for blowers, if each of those tools were used for 10 hours each week then, each year, the emissions or smog reduction would be equivalent to avoiding 1.5 million kilometres of car travel – or the average annual travel of one thousand motor vehicles.

For Councils that have recognised the climate emergency, an investment in tool electrification at the depot and an electrification requirement in street maintenance contracts are necessary and relatively easy first steps.