Do NOT heat your boules; they might explode!

A few petanque players in the USA brave the rigors of winter and continue to play with snow on the ground. Some of those players put their boules on some kind of device to warm them up. The moral of this post is that boules and heat do not mix.
Heating petanque boules on a stove


In 2009, a new, unsold set of leisure boules sitting on a shelf in a storeroom in a store in Switzerland spontaneouly exploded. Response to the incident was swift. The Swiss department store chain Coop, which sold the sets, immediately launched an aggressive recall campaign. A fews days later the German federal government issued a press release warning the public of the danger of cheap boules. The German Petanque Federation (DPA) recommended buying certified boules and shopping for boules in specialty stores rather than in supermarkets.

The Swiss Federal Laboratory for Materials Science and Technology (EMPA) analyzed the remaining boules in the set. They were cheap leisure boules manufactured by the Dutch company Nebus BV. Like all such boules, they had thin metal walls with poorly welded seams and were filled with a sand-like mixture (French news reports referred to it as “mortar”). EMPA found that the sand was damp and contaminated with iron filings. The moisture in the sand corroded the iron filings. That chemical reaction produced hydrogen gas, which caused high pressure inside the boule. The seam of the boule failed and the boule exploded. It literally blew its top.


The boules that exploded in Switzerland in 2009. The boules were stored in the black bag shown on the right. Note the top of the exploded boule on the left side of the shelf, the sand scattered about the shelf, and the dent in the shelf wall at the right. The black bag must have been standing upright against the wall when the boule exploded.


Closeup of the bottom half of the exploded leisure boule in its original packaging.


Cross-section of another boule in the set. In addition to the sand filling, note the thinness of the metal shell.

For an interesting short video showing EMPA testing cheap boules, see THIS. For EMPA diagrams comparing cheap leisure boules to competition boules, see THIS. The EMPA engineering failure analysis, “Investigation into the mechanisms leading to explosion of pétanque balls”, is available HERE.


On Saturday, September 4, 2016, in the German town of Nettetal, near Düsseldorf, during a neighborhood party, in the middle of a tent erected for the event, a petanque boule spontanously exploded. The explosion ripped a hole in the ceiling of the tent and left a small crater in the ground, but nobody was injured. A Düsseldorf bomb squad removed the remaining seven boules in the set and safely detonated them.


The first player to be seriously injured (killed, in fact) by an exploding leisure boule was a player in Thailand. Apparently some Thai players believe that soaking boules in water and then heating them can somehow improve a player’s ability to put spin on the boules. In preparation for an after-work game with his buddies, a firefighter named Decho Phetchnin had been heating his set of boules on an “Ang Lo” burner for about two hours when one of the boules exploded, blowing the burner apart and scattering debris in a 10-metre radius. The explosion occurred while Decho was bending over the burner stirring the boules. A metal fragment from the exploded boule struck Decho in the forehead, piercing his skull and killing him instantly. A photo of the boule shows what appears to be a cheap leisure boule. CLICK for a larger image


The second death due to an exploding boule occurred on April 19, 2018. A family was having an afternoon cookout in Boulou, a small village near Perpignan. The barbecue grill had been set up in the garden and a unnamed 31-year-old man was doing the cooking. Unknown to the man, a petanque boule had been left inside the grill and forgotten. The heat of the fire caused the boule to explode. Fragments of the exploding boule struck the man in the head— he was dead by the time a doctor arrived on the scene. Again, a photograph of the boule seems to show a cheap leisure boule.

The bottom line

Heat and boules do NOT play well together. Never put your boules directly on a source of heat such as a radiator, stove, or heater. If you just want to warm your boules up a bit, just put them in a large bowl of hot water for three minutes.

4 thoughts on “Do NOT heat your boules; they might explode!

    • Thanks for this information! Interesting! The story says that the man, a 60- to 70-year-old Frenchman, had refilled the petanque ball and was sealing it when it exploded. I wonder what he was doing with the boule and what he was refilling it with.


    • Valentijn, Thanks for this news. I’ve merged and translated several online news stories that I found, to produce this story.

      On Saturday, a 37-year-old man from Eindhoven was killed by an exploding petanque boule. The incident occurred during a bachelor party at a vacation home in Rivage, a small village in the Belgian Ardennes. According to bystanders, the group had lit a fire basket. There were several petanque balls around the basket, and the group decided to put a petanque ball in the fire pit. The ball heated up and around 9:30 it “exploded like a grenade.” Pieces of the ball struck the man in the head. He was taken to the hospital in Liege and kept in a coma, but died of his injuries on Thursday. Another man in the group suffered minor injuries.

      The neighbor of the vacation home told Belgian news channel VTM that it sounded like a gas cylinder had exploded. When he saw an ambulance and a trauma helicopter arriving, he knew it was serious. “We heard the ambulance workers saying to each other that the man’s whole face was burned,” he says. The police of Stravelot-Malmedy urged people to keep boules away from fire.

      This was not the first accident of this kind to cause injuries. About five years ago, another Dutch man, John de Jong, decided to put boules in a BBQ grill just “to see what would happen.” (I suspect that he was doing it as a Youtube stunt, because he made a video.)

      One of the balls exploded in his face. Luckily for De Jong, the two halves of the boule hit other balls instead of going straight for him. Shrapnel struck him in the face. “I had burn marks all over my face and about 30 splinters in my eye,” De Jong told the broadcaster. “Yes, of course, it wasn’t very smart. That experiment was actually a complete failure.” (Personally, I would say that he was lucky to have survived.)

      He provided video showing him placing several balls into the coals and using a hairdryer to make them even hotter.


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