An explosion of grey foam that looks like charcoal toothpaste was created by an Australian teacher to poke fun at the trend.

The science experiment took place at a New South Wales school on Tuesday (March 19), where foam emerged from the tube due to a number of different chemicals mixing together.

The practice of using charcoal toothpaste to whiten teeth has gained popularity in recent years.

The science behind the foam works by mixing Manganese dioxide ( the black powder) with liquid detergent. Hydrogen Peroxide is then poured in which is turned into oxygen and water by the manganese dioxide. This causes bubbles which froth up the detergent.

To poke fun at the current trend of 'charcoal' toothpaste, this Science teacher from Australia combines a number of different chemicals to produce his own 'charcoal foam' toothpaste.