ECJ EUROPEAN Cleaning Journal

Safety is an important factor in any scrubber dryer – both for the person using the machine and any members of the public nearby. Ann Laffeaty asks scrubber dryer manufacturers how they make their machines safe.

Any machinery has its potential dangers and the scrubber dryer is no exception. Its very size means that a collision could cause significant injury. If the operator were to lose control of the machine it could cause problems both for the driver and for anyone else in the vicinity. And if a scrubber dryer fails to remove all the water from the floor it could create a slipping hazard.

But scrubber dryers are generally safe to use provided the operator follows the instructions according to Nilfisk’s group floorcare product manager Anders Sandstrom.

“Safety features are built in to all Nilfisk scrubbers but since the machine drives both forwards and backwards – and comprises a motor that turns a brush or pad - we do recommend some general product training before first use,” he said.

“The correct amount of detergent should be used since overdosing could create a slippery floor, even after it has been left completely dry. And cleaning speeds need to be adjusted according to the environment.”

He says accidents are rare and are usually the result of human error. “However, the possibility of mechanical or electronic errors should be considered,” he said.

Nilfisk models have a built-in switch that stop the machine if the user loses control while other safety features can include flashing beacons, front lights, a seat-belt and extra bumper protection.
“Our Ecoflex on-board detergent system also allows the operator to automatically adjust the amount of detergent being used,” said Sandstrom.

Hako’s application technology trainer Klaus Serfezi agrees that using a scrubber dryer should not pose any risks for the operator.  “As long as the manufacturer has complied with the appropriate guidelines when designing the machine and it is used appropriately there should be no moving parts that could cause injury to staff,” he said.

Runaway machine

“The machine ‘running away’ can only occur if the operator fails to release the driving signal lever. It is therefore crucial that the operator receives proper training before using the machine.”

He says any risks to the public are the operator’s responsibility. “For example, if the machine is used in a supermarket during opening hours the operator needs to show consideration for customers,” he said. “There should be no residual water left behind to cause slippery floors provided the machine is properly maintained.”

Operating a scrubber dryer can be compared with driving a car, he says. “All the safety features such as lane assistance, distance alert and speed alert systems are useless if they are not observed by the driver,” he said. “So it may be necessary to use additional warning signs or flashing beacons to draw people’s attention to the potential dangers.”

Flashing beacons and a back-up warning buzzer are available on Hako’s ride-on machines. “Our models may also be equipped with a seat contact switch and an overhead guard if required,” he said.

According to Serfezi, Hako is an industry pioneer in the field of machine safety. “Our engineers are meticulous in ensuring there are no safety hazards for the operator even when using the machine improperly,” he said. “But for most of our customers, safety is a secondary consideration and ergonomics are considered to be much more important.”

Diversey Care’s global marketing manager Anna Djurberg says accidents may occur when operators try to fix electrical problems by themselves. “This is of course against supplier policy,” she said.
“Other potential incidents include fingers being caught in the lid when closing the tank; injury to the fingers when changing blades on older models, and poor control of the traction mechanism.

“Any contact with the floor cleaning chemical could result in skin irritation or damage to the eyes. And longer-term body injuries can result if the machine is not set up in an ergonomic way.”

She says accidents among the public due to slippery floors are the most common of scrubber dryer-related injuries. “These can occur if the water suction is not optimal and the floor remains wet after use,” she said. “Some accidents – such as catching a finger between the tank and the lid - are fairly common despite the fact that we offer training when delivering all our machines.”

She says a less common scenario may arise when a machine falls down a flight of stairs. “I have personally recorded this twice in 15 years - and luckily there was no-one around to be injured by the falling machine,” said Djurberg.

First consideration

Safety is the customer’s first consideration when choosing a scrubber dryer, according to Djurberg. “After that they may be interested in factors such as productivity, connectivity or sustainability – but customers’ needs will vary according to the region, profile and challenges of the site.”

Standard safety features on Diversey Care’s Taski machines include flashing lights, push-button speed-limiting and an automatic slowing function when turning.

“All components are rounded so that there no crevices where fingers may be trapped,” said Djurberg. “And our Swingo 2100 machine has a patented offset brush that enables the user to move the brush mechanism outside of the machine. This allows them to work safely and concentrate on driving since the bumper will protect both the brush and the wall.”

Safety training can help to minimise the risk of accidents according to Truvox sales and marketing director Gordon McVean. “The main risks are from operators losing control of the machine and slip hazards from a damp floor,” he said. “If a scrubber dryer is not maintained or operated properly it may result in a dangerous residue being left behind.

“The failure to notice a dirty squeegee - which can reduce the pick-up of water - is the most common cause of leaving a floor wet after cleaning. This is easily avoided by checking and cleaning the squeegee regularly.”

Truvox machines are designed with all controls close to hand to make the operator’s job easy and provide an ergonomic design, says McVean. And while safety is important to customers, it is closely linked to productivity and efficiency he says.

“The better the pick-up of water, the safer the operation and the less likelihood that there will be of disruptions to productivity,” he explained.

Chemical risk

Like other commentators, IPC floorcare product manager Paolo Bassanini believes the possibility of operators coming into contact with cleaning chemicals is a risk.

“There are other risks associated with electrical components, the control panel and battery compartment if these are not operated with care,” he said. “And problems could arise if there is a build-up of germs in the waste dirt container.”

IPC machines offer flashing beacons and visual alarms plus squeegee blades that are designed to ensure a good drying performance to prevent trips and falls.

“Our ride-on machines also have a high level of manoeuvrability which gives the operator full control, even when unexpected events occur,” he said.

According to Bassanini, all maintenance operations should be performed in an adequately lit environment and only after disconnecting the machine from the power supply. “It is also recommended that any work on the electrical system and all maintenance and repair operations should be performed by qualified personnel,” he said.

Safety for operators and for the public is a key consideration for customers, he says. “This is particularly true in countries where legislation is sensitive to this issue and price is less of a concern – in Europe and the US, for example.”

Contact with cleaning chemicals, operator fatigue and microbial growth are among the chief risks associated with scrubber dryers according to Kärcher’s press officer David Wickel-Bajak.

“Acidic and alkaline cleaning agents may attack the eyes, skin and mucous membranes which means operators should wear protective equipment such as gloves and goggles,” he said. “Where flammable cleaning agents with a high solvent content are used it is important to provide good ventilation.

“Problems may also occur when too much solution is applied since it will form a slippery film. And if the machine’s suction unit is not maintained regularly some of the dirty water may be left behind.”He says Kärcher’s own dosing system eliminates this risk.

Working regularly for long periods using heavy machines may pose further health risks for the user, says Wickel-Bajak. “This has led to a trend for lightweight models plus machines that are equipped with a drive, since this reduces the physical effort required,” he said.

Machines that are not properly cleaned after use pose the risk of germs multiplying in the water tank, according to Wickel-Bajak. “Here tank-flushing systems can help to prevent contamination.”

He says the current trend towards daytime cleaning means that people are more likely to be present during cleaning operations. “More care needs to be taken as a result, but the risk can be reduced by adhering to a few basic rules,” he said.

“For example, the user must ensure all settings for suction, water quantity and cleaning agent are correct. And it is advisable to clean using the one-step method which involves water being applied and sucked up again in the same work step. This ensures that the floor is immediately dry and can be walked on straightaway.”

Safety features on Kärcher machines include a tank-flushing system, smooth surfaces for optimal cleaning and bespoke cleaning agents.

Speed limits

“Our large machines are fitted with work lights or flashing beacons that increase visibility for the user and enhance the visibility of the machine,” said Wickel-Bajak. “No effort is spared in the development of wheels and drive systems since it is crucial for the machine to start smoothly, have a short braking distance and offer wheels with good adhesion properties.

“And the Kärcher Intelligent Key enables various levels of authorised access which means the user could, for example, be limited to a certain driving speed.”

He believes safety is becoming increasingly important in today’s climate. “People are working longer hours which increases the risk of injury,” said Wickel-Bajak. “This means greater attention needs to be paid to safety since injuries to staff result in downtime for the cleaning company and therefore cost money.”

Diversey Care’s Anna Djurberg also feels that safety is coming increasingly under the spotlight. “Suppliers are differentiating themselves by their safety features,” she said.  “The launch of the Crash module of our telemetry system – Taski Intellitrail - will enable customers to track collision risks and identify those sites that require in-depth operator training to improve driving behaviour. This will allow us to play a leading role in combining connectivity with safety.”

And Nilfisk’s Anders Sandstrom concurs that the current focus on safety will only increase – particularly with the rise of autonomous machines. Nilfisk recently announced the launch of a new autonomous scrubber - the Nilfisk Liberty A50 – as part of its Horizon Program.

“When you combine an autonomous unit with heavy machinery the issues of personal safety and safety in the environment will naturally be a concern,” he said. “Throughout our development processes we test our products extensively to ensure that we consistently adhere to the applicable standards and security requirements.”