Dry shampoo explosion: why heat and some aerosol cans are a dangerous mix

A woman in the US took to social media to share a tale of what happens when a dry shampoo bottle is left inside a hot car

On Thursday, September 19, a worried Missouri mum Christine Bader Debrecht shared a cautionary post on Facebook about a seemingly innocuous everyday product: dry shampoo.

She wrote about how the sunroof and console of her 19-year-old daughter’s Honda Civic were blown to smithereens when a can of Walmart’s Equate dry shampoo stored within exploded. Fortunately, her daughter was not in the vehicle at the time, but had parked it outdoors on a particularly hot and sunny day – the kind we are more than familiar with here in the UAE.

Also common in many women’s vanities are cans of dry shampoo, with some users on the Abu Dhabi Q&A group calling it “miraculous” and “a lifesaver”. Various brands of the product are available at nearly every supermarket and pharmacy across the Emirates.

What is dry shampoo?

It's useful for people with certain scalp types, who may not have the time to wash their greasy hair – say after a workout session – dry shampoo absorbs excess oil and leaves the hair looking fresher for up to 24 hours.

The product is typically made from a combination of starch (corn or rice) and laboratory alcohol, and is contained within an aerosol spray can. The powdery product requires no water, and need simply be sprayed on to the scalp.

Read the warning signs

It’s not uncommon for users to carry a bottle of dry shampoo – typically in spray can format – on their person or, indeed, in their cars. However, like most aerosol cans, dry shampoo, too, can contain traces of propellants such as propane, butane or isobutane, which can make up between 70 per and 90 per cent of the product.

These are also the gases found in LPG and cigarette lighters. And they may get reactive when they come in contact with certain other elements, including the harsh, hot rays of the sun. Hence the “store in a cool, dry place” warning that nearly every such product has imprinted on its packaging.

Other warnings include: flammable; keep away from fire; and do not attempt to puncture. And as Debrecht’s daughter discovered, you can never be too careful.

If you’re heading to the gym or out straight after work and feel the need to treat your greasy roots, ensure you keep your dry shampoo can in a place that’s, well, dry and cool – or simply rub some baby powder on your scalp instead.

Updated: September 24, 2019 12:39 PM


Editor's Picks
Sign up to:

* Please select one