A Missouri teenager saved money from her after-school job and small inheritance to buy a used Honda Civic.  The car was carefully selected - a 2018 with less than 5,000 miles.

Last week an aerosol can of dry shampoo left in the center console exploded - blowing out the sunroof and destroying the center console area.  

According to her family, the teenager hustles from school to work and is always on the go.  She kept a stash of beauty products in her car, including dry shampoo.  Dry shampoo is type of shampoo that reduces hair greasiness without the need for water.  It is typically in a powder form, often delivered through an aerosol can.  It is generally a mixture of corn starch and alcohol, which absorbs excess oil on the scalp and hair.  Many women celebrate it as a time-saving, miracle product.

But according to chemists who have studied this explosion, all dry shampoos are not equal.  The exploding bottle was an Equate brand, Walmart's in-house line of beauty products.  Interestingly, there was a second bottle of Dove brand dry shampoo in the same center console that did not explode.

Ingredients in the Equate bottle included propane and butane, flammable chemicals that become more dangerous under pressure.  The denatured alcohol, which forms the base of the dry shampoo, is also flammable.  Experts who commented suggest that the most likely explanation is that the car go too hot for the canister.  The propane and butane ignited in the pressure filled, hot canister and created a bomb-like situation that blew the sunroof off of the car.

The bottle did have a warning that said the product is flammable and "may explode if heated."  If you or someone you know keeps dry shampoo in their bag or in their car, be cautious.  That innocent looking bottle of shampoo may require a little extra care.