That’s the claim in a meme shared on Facebook in South Africa in November 2018.
It warns: “Due to increase in temperature in the coming days, please don’t fill petrol to the maximum limit. It may cause explosion in the fuel tank. Please fill the tank about half and allow space for air.”
Is this true?
Couldn’t happen even at the hottest temperatures
Forbes magazine fact-checked the claim back in June 2018. They say two things would have to happen for a petrol tank to explode.
- Evaporating petrol would have to build up enough pressure to make a pressure bomb. (This is similar to the way evaporating dry ice can make a soft drink bottle explode.) This could blow a hole in the petrol tank and cause the release of fumes.
- The petrol would have to heat to a high enough temperature that it explodes spontaneously, without even a spark.
Fortunately, Forbes says, “neither one of them can occur at even the hottest temperatures ever achieved on Earth”.
A full petrol tank poses no danger, “but running out of gas in the heat can be deadly”, the article adds.
“So fill up with confidence.”
Safety measures in fuel tanks
Africa Check asked fuel company Shell South Africa about the claim.
“These types of ‘warnings’ have not been heard of and NO incidents have been noted in Europe/South Africa region,” Shell spokesperson Dineo Pooe told us.
Pooe said the manufacturers of car components “have safety measures in place to avoid such issues”. One measure is that the fuel tank “is not a closed system”.
The tank has a valve and active coal filter “to allow tank breathing and to deal with temperature dependent volume increase and decrease”, she said. “This helps avoid overpressure due to fuel evaporation at high temperatures.”
Strict vehicle safety standards
Vehicle design has strict safety standards that apply across the world, including in South Africa. That’s according to Stuart Rayner, chair of the Fuel and Emissions Committee of Naamsa, the National Association of Automobile Manufacturers of South Africa.
“I’ve never heard of anything like you suggest,” he told Africa Check. “What you are suggesting is extremely unlikely.” – Taryn Willows
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