ECJ EUROPEAN Cleaning Journal

How do scrubber dryer manufacturers ensure that their machines are safe – both to operate and to be around? ECJ looks at the risks involved with scrubber drying and finds out about the latest safety features incorporated into today’s machines.

Scrubber dryers tend to be large and cumbersome. And like any sizeable machines they can be dangerous – both for the operator and for the bystander.

Daytime cleaning has become much more common in recent years so it is more important than ever that scrubber dryers can be safely used in areas that are occupied by the public. However, operator safety is also crucial – and so is the need to leave the floor as dry as possible to avoid the risks of slips and trips.

So how do manufacturers ensure safety both on the part of the user and for the wider public?
Scrubber dryers represent a number of safety risks according to global portfolio manager for Diversey’s Taski machines Martina Kraehenbuehl. “For the operator these include potential contact with chemicals when filling the tank,” she said. “There is also the risk of crushing the hands between the handle and the wall when cleaning close to vertical surfaces. And the vibration and noise levels of the machine could also be an issue.”

Longer-term effects of using a scrubber dryer could include aches and pains as a result of adopting a poor working posture, says Kraehenbuehl. “Also, a heavy machine without a wheel drive
will need physical power to move it – and this can be exhausting when working for long periods.”

Collisions involving scrubber dryers are another danger, she says. “If the operator has a restricted view around the machine, he or she could bump into obstacles or people – particularly when driving too fast or in high traffic areas,” she said. “This could cause injury to persons or damage the machine or the building.”

Risks to building users may also occur when water is left behind on the floor by a poorly maintained machine, says Kraehenbuehl. “It is important to leave the floor dry to avoid the risk of accidents in high-traffic areas, and to ensure that it is left in a perfectly clean condition,” she said. The suction system on Taski machines is claimed to leave the floor 99 per cent dry after scrubbing.

Safety features of Diversey’s scrubber dryers include a high level of visibility, warning lights and an alarm when the machine is moving backwards. “They also have an emergency button for quick shut-down if, for example, the operator were to feel unwell,” she said.

Diversey’s step-on and ride-on machines have a minimum weight requirement that is triggered by a built-in sensor. “This eliminates the risk of misuse by children if the key has been left in the machine,” says Kraehenbuehl. “And there is an optional “turtle mode” for slow and easy use of the machine in congested or high traffic areas.”

All customers are given training when a machine is delivered to their site and the company offers training videos and wallcharts. “However, our scrubber dryers have been developed to be easy to use and have self-explanatory pictograms which means that no in-depth training is required,” she added.

Risks for operator

Poor posture when using a scrubber dryer could lead to musculoskeletal disorders on the part of the operator says IPC communications director Gabriella Bianco. “A poor seat position or a badly-positioned steering system could pose a risk to the operator’s musculoskeletal health,” she said.

“There is also the risk that the operator might lose control of the machine. And if a scrubber dryer has not been properly maintained it might fail to remove all the water from the floor, resulting in a slipping hazard that would put both the operator and passers-by at risk.”

Adjustable handles, ergonomic features and easy-to-access internal components are among the safety features of IPC’s scrubber dryers. The company also provides training and support tools to ensure that its products are used correctly. “We offer a high level of assistance to customers to avoid operators being caught unprepared when using these machines for the first time,” she said.

Not so dangerous

Operating a scrubber dryer is no more dangerous than any other day-to-day activity according to Hako’s application technology trainer and consultant Klaus Serfezi.

“An automatic scrubber dryer has moving parts which could represent a danger - but the same could be said of opening a car door or looking under its bonnet,” he said. “It is important to distinguish between actual dangers and possible dangers as described by safety experts. The handling of a machine presupposes that the operator is mentally and physically capable of operating it and that he or she can be given the necessary responsibility.”

According to Serfezi, the risk of collisions is no different to that of a car when driving in traffic. “Scrubber dryer operators need to adapt to the circumstances and drive carefully and considerately,” he said. And he believes that the greatest danger posed by a scrubber dryer is the risk of tipping it over. “However, this is highly unlikely to happen even if the machine is operated incorrectly provided that all the necessary parameters have been taken into account during the development stage,” he said.

Problems could arise if the operator were forced to sit in an uncomfortable position for long periods at a time, he adds. And like other manufacturers, he says water left behind on the floor could be a danger – and not only to people. “It can also be dangerous in industrial areas where trucks are used,” he said.

Hako scrubber dryers are claimed to offer suction systems that absorb the majority of the residual water. They also have an anti-tipping device to prevent the risk of accidents when cornering too fast.

Comfortable ergonomics

The company places great store by ergonomics, says Serfezi. “A member of staff going about their daily tasks on a cleaning machine is entitled to a comfortable ergonomic workplace in the same way as an office worker can expect to be provided with a comfortable chair,” he said. The company’s machines are said to allow for ergonomic operation for both male and female users.

No workplace is entirely without its safety risks says Kärcher’s product manager for scrubbers  Daniel Friz. “When using a scrubber dryer these risks include physical contact with chemicals and disposing of the dirty water,” he said.

“The machines also need to be engineered to reduce safety risks, such as potential squeezing points. And all components should be certified since, for example, the use of uncertified lithium batteries could represent a safety risk both for the user and for the work environment as a whole.”

Collisions are always possible when using a scrubber dryer, he says. “We do everything we can to avoid even the slightest risk of accidents such as incorporating seat-contact switches, drive pedals, emergency stops and certified electronics,” he said. “But while the manufacturer can try to make the machines as secure as possible, at the end of the day the operator plays an important role in averting risks.”

He says the machines should always be handled according to the operating instructions and should never be misused. “This means there should be no workarounds of the safety features, such as bypassing the seat-contact switch or blocking the pedal,” he said.

Driving a scrubber dryer too fast or using the wrong detergents could also be dangerous, he adds. And slips could occur if the machine leaves water behind on the floor. “A scrubber dryer has two main tasks: to clean the floor and to remove the water afterwards,” he said. “We are always implementing new generations of squeegees to improve performance.”

Kärcher machines offer automated dosing with a closed loop system or automatic tank-rinsing to avoid any contact between the operator and the used water. And all parts and components are fully tested for safety.

“Our latest machines have a gyro sensor that recognises curves or uphill driving and prevents the machine from tipping,” said Friz. “And our Kärcher Intelligent Key system allows pre-settings to be defined for the operator and can also be used to electronically block the drive-speed or stipulate that the warning beacon needs to be switched on.”

To avoid the risk of operator strain the machines’ steering wheels, seats and foot pedals are all adjustable, he says. And training is provided on delivery of a new machine either by Kärcher or by the distributor. “Training improves operational safety for the driver as well as for other people in the building.” he said. “It also improves the efficiency of the machine in use and helps prevent damage to the floor.”

So, how do safety features rank on the customer’s list of priorities when choosing a scrubber dryer?

Price priority

“Price often eclipses the topics of both safety and ergonomics for customers, unfortunately,” said Hako’s Klaus Serfezi.

Kärcher’s Daniel Friz concurs. “Safety is always important - but price is also a crucial buying criteria,” he said. “However, the purchase price is insignificant compared with the operational costs and the operator’s wages during the lifetime of a machine. So companies should focus on safety and rethink the importance of their investment.”

Today’s customers are becoming increasingly safety-oriented while choosing their cleaning machines, according to IPC’s Gabriella Bianco. “Cost and productivity are both highly important considerations, but factors such as ergonomics, ease of use and ease of maintenance are all gaining more traction than they did in the past,” she said.

And Diversey’s Martina Kraehenbuehl adds that safety and ergonomics are both key considerations for European customers, who tend to be particularly concerned that their staff stay healthy.

“Performance and time savings are also very important, but these considerations don’t have to compete with safety because a good machine will enable customers to achieve their tasks in a safe and efficient way,” she said.