Stefan Bertilsson loves destroying Ikea furniture.
Twenty-four hours a day, seven days a week, the grey-haired Swede is putting a sofa, chair or table through its paces.
As the deputy manager of Ikea's 36-person test lab, Mr Bertilsson's job is to burn, freeze, scratch, bend, crush and corrode products, expose them to humidity and extreme weather and otherwise do his best to make things break.
And if one of the roughly 2000 new products Ikea puts out each year fails — as they do up to half the time — it goes straight back to the designer.
While Ikea prides itself on being a sort of democratic socialist staff collective, Mr Bertilsson is close as it gets to a monarch at the Swedish furniture giant.
"A lot of designers, people up there want to create a lot of things, a lot of different ideas, but you have to pass the lab first — I'm the king," Mr Bertilsson says with a grin.
Dressed in no-nonsense double denim, the 55-year-old clearly enjoys upsetting the designers. "Sometimes they are very angry," he says. "They come down and we have a meeting. They always say, 'You are testing the wrong way'."
Inside the 4800 square metre warehouse, five minutes walk from the Ikea headquarters in Almhult, Sweden, a 130kg pair of robotic buttocks sits up and down on a wooden chair 50,000 times.
A grey two-person sofa receives the same treatment, while nearby a mattress is pummelled like pizza dough under a giant rolling pin.
Upstairs, computer-operated racks of light bulbs are put through tens of thousands of hours of usage.
In labs resembling high-school science rooms, textiles are scorched over Bunsen burners and gas flames or lit with burning cigarettes.
"It's our purpose to destroy the products every week," Mr Bertilsson says. "Sometimes they're successful the first time. Sometimes they have to come back four times, three times, five times."
Before they're tested, all furniture items spend 24 hours in a climate room at 23 degrees and 50 per cent humidity.
They later move to a climate chamber where they spend three weeks at 28 degrees and 85 per cent humidity, followed by another two weeks at 25 per cent humidity, all while under heavy weights.
"When we do that quick change, a lot of things happen with wood material, it splits up, the shelves bend, everything can happen," Mr Bertilsson says.
Similar tests for moisture resistance and mould growth are conducted in a climate-controlled bathroom chamber.
Elsewhere, a high-powered climate chamber puts outdoor products through extremely tough conditions — it can rapidly go from minus 150 to plus 150 degrees and from zero per cent to 100 per cent humidity.
"You can make snow or rain, you can even make pizza in this," he says.
Many items don't make it past the first safety assessment for things like stability, sharp edges, open holes, shear and squeeze points.
"That's the first focus because if it's not fulfilled there's no point to test it inside," he says.
"It's better to take it back again and do improvements, otherwise we will spend three, four weeks, and that makes the timeline for product development too long, and they will be very angry."
And after 15 years in the role, Mr Bertilsson can often tell a product will fail just by looking at it.
"Sometimes before we start to test things we can say, we don't need to test this," he says. "It's better for you to go back because it will break."
Ikea's in-house test lab, which is independently accredited by the Swedish Board for Accreditation and Conformity Assessment, performs nearly 20,000 tests a year for the world's biggest furniture retailer.
"From the small screws to wedge dowels to completed furniture, we are deeply involved in everything," Mr Bertilsson says.
Just inside the main doors there is what they call the "red carpet" — a roughly one-and-a-half by three-metre rectangle where members of the public are timed while assembling Ikea products.
Once a product passes Ikea's in-house lab, it goes out to global suppliers who then perform their own production-level testing, often at the much larger Shanghai-based Ikea test lab that employs around 200 people and performs up to 200,000 tests each year.
Globally, Ikea has partnerships with around 100 external test labs.
Product testing has been a focus of the company since it was founded by Ingvar Kamprad 75 years ago, and each report generated by the test lab is kept for at least 25 years.
"Because if something happens, we have to go back to see what happened from when we started to do the testing until the accident," Mr Bertilsson says.
"We are deeply involved in investigating the reason why."
New range to cut down accidents
Despite the rigorous testing regime, accidents and even deaths still happen.
At least eight children under the age of three have been killed by falling Ikea chests and dressers over the past three decades. The company announced a recall of more than 17 million Malm products in 2016 but re-announced the recall in 2017 after the eighth death.
That came after Ikea paid out more than $US50 million in compensation to the families of three toddlers who were crushed to death by the top-heavy dressers.
Other product recalls have included falling glass ceiling lights, children's beds with broken metal support rods, and a bat cape costume that sparked choking fears.
All up Ikea issues about six product recalls a year.
The issue looms large at the test lab — literally.
Outside the main entrance stands a giant dresser, blown up to appear to the average adult as it would to a two-year-old. Dangling just over the top, just out of arm's reach, is an oversized teddy bear.
It's a replica of one of the company's new Glesvar range of dressers and chests, set to go on sale later this year, that has been designed with safety features to prevent tip-overs.
The chest of five drawers, for example, will only allow one draw to be open at a time unless secured to a wall. Once secured, several drawers may be opened simultaneously.
A smaller chest of three drawers can only be unlocked when secured to the wall, while another has no back legs and must be secured to the wall to stand upright.
"Engineering is quite a simple discipline," says range and product engineering manager Vladimir Brajkovic. "You pay attention to what has happened, and you make it better."
The author travelled to Almhult as a guest of Ikea