Screening for Safer Chemicals using HMIS


elephant toothpaste

Elephant Toothpaste is a popular demonstration to introduce the concept of decomposition reactions.  The chemical reaction involved is the decomposition of hydrogen peroxide into oxygen gas and water.  The reaction is very slow at room temperature.  Consequently, it requires a catalyst.  Manganese dioxide is commonly used to catalyse the reaction.  However, bakers yeast works just as well, is easier to clean-up and is non-toxic. The key ingredient for this demo is hydrogen peroxide which is readily available in 6% and 30% solutions.  How can you tell whether or not these chemicals are safe to use? Fortunately, most chemicals used in schools come with a HMIS hazard rating. Continue reading