In elementary school, one of the first ways that the teacher demonstrated a chemical reaction was by creating a volcano. You just need to build a miniature mountain with a hollow top out of clay. Then, you pour some baking soda out of the box into the hole. Pour some vinegar on it, and the volcano erupts. Kids like watching this, and both baking soda and vinegar are safe enough to use in the kitchen.

This reaction isn’t just useful for demonstrating chemistry. Many household cleaners include ammonia, bleach, and other chemicals that are fairly harsh. Baking soda, like ammonia and bleach, is also basic, which is why it reacts with vinegar. However, baking soda itself is a much weaker base than ammonia or bleach, and won’t damage skin or eyes if it spills. Vinegar is a relatively weak acid, and the bottles of vinegar sold for household use are usually 5 percent vinegar and 95 percent water, so they are even more diluted.

Vinegar by itself can clean off dirt and grime. It’s possible to demonstrate this by dropping pennies in Tabasco sauce, since the acidic vinegar will melt away the crud on the pennies, leaving them shiny and new once again. This can improve the condition of coins in a coin collection. Vinegar will also help clean up a stain on the counter, or a spill on the floor.

The combination of vinegar and baking soda is a much more effective household product. The foam this produces can scrub away dirt and stains. Just be careful to use small quantities, since the reaction can release more foam than you would expect. Vinegar and baking soda are much cheaper than many other household cleaning products, and cause less environmental damage.

Do not mix stronger cleaning products, such as bleach or ammonia, with each other or with acids such as vinegar. The baking soda and vinegar reaction is extremely weak compared to most acid and base reactions. Mixing strong bases and strong acids can cause a fire or an explosion. Mixing bleach and ammonia with each other releases the chlorine in the bleach as chlorine gas, which is poisonous. Chlorine gas has a distinctive smell that anyone who visits a public pool will recognize.