Bath bomb

[2] While her first attempts looked much like Alka-Seltzer tablets, Mo and her husband Mark Constantine quickly began experimenting with a range of molds and ingredients.“We were up and down the high street, buying different shaped jelly moulds, anything.

[7] These are unreactive when dry, but react vigorously when dissolved in water to produce their characteristic fizzing over a period of several minutes.

This is an acid–base reaction that involves conversion of citric acid and sodium bicarbonate to monosodium citrate and carbon dioxide: The other ingredients in bath bombs can vary considerably.

Common skin irritants and allergens found in bath bombs include limonene, linalool and sodium lauryl sulfate.

[8] The main ingredients—citric acid and sodium bicarbonate—are generally not considered as skin irritants when used as bath enhancers because of significant dilution in water.