Bath bombs are little chemistry sets in action. Our exploration into bath bombs includes the chemistry of the fizz, the purpose of Epsom salt, and making our own. This would make an excellent science fair project. This post contains affiliate links, you can read my full disclosure here.

IN A HURRY>>>

The Chemistry of the Fizz. Exploring Bath Bomb Science.

Bath Bombs have lots of ingredients:

baking soda
citric acid (I use food grade so that I can use it in projects like popping candy later.)
Epsom salts
water
essential oil or fragrance
oil
food coloring (any color you want)

A chemical reaction caused the fizz. Think of an antacid tablet in water.

What makes bath bombs fizz?

Baking soda should always be in your science cabinet because it is cheap and can be used in so many ways. I buy large boxes for science. That is why I buy the large citric acid packages as well.

The citric acid and the sodium bicarbonate combine with water to form sodium citrate and carbon dioxide (and water).

C₆H₈O₇ + 3NaHCO₃—> Na₃C₆H₅O₇+ 3CO₂+ 3H₂O

What are the indications that a chemical reaction has occurred? (besides the bath bomb chemical equation)

The production of gas and change in temperature.

Make sure to test your mixture before giving it to others.

Grab this download to turn this into a bath bomb lab

How does Espom salt help?

The Epsom salt is MgSO4 and is broken down in the presence of water into its ionic components magnesium and sulfate (a polyatomic ion). These are thought to be absorbed by the body and may help with muscle fatigue, but there’s more to that story.

Dr Teal’s Therapeutic Solutions Pure Epsom Salt Soaking Solution 6 Lb Bag Milliard Citric Acid – 2 Pound – 100% Pure Food Grade NON-GMO (2 Pound)Arm & Hammer Baking Soda-4LB (01170)

Why would magnesium help with muscle fatigue?

By flushing out a substance known as lactic acid. When you exercise, the demand for energy increases. We make energy through processes that require oxygen (preferred) and process that don’t (not preferred). When the energy demands are really high we use both of these pathways to try to keep up with demand, unfortunately, this results in lactic acid.

Muscle soreness causes a slow down in training for athletes and is often associated with this lactic acid, however, lactic acid is not the cause of delayed onset muscle soreness.

Ok, that’s cool – BUT WAIT

The deal is that it isn’t true. While lactic acid is often associated with muscle fatigue and soreness in the days following heavy exercise it isn’t true. Lactic acid is responsible for the burning sensation that occurs during heavy exercise and serves as a warning that you are pushing the limits of your muscles and fitness levels.

Cellular muscle damage causes the muscle soreness that shows up 1-3 days after heavy training. This damage releases unknown substances into the surrounding tissue. It is possible that Epsom salts help to wash those toxins away or that the warm bath helps to relieve the muscles.

Recipes for Bath Bombs

There are thousands of recipes for making bath bombs. This is where experimenting can be beneficial.

The basic bath bomb is in a 2:1 ratio

2 baking soda
1 citric acid
1 Epsom salt

Then add anything additional for scent, color, or moisturizing (olive oil, coconut oil, grapeseed oil – endless options)

Caydo 6 Set DIY Metal Bath Bomb Mold with 3 Sizes 12 Pieces for Crafting Your Own Fizzles 14 Essential Oil Set (7 Synergies and 7 Singles) Includes 100% Pure, Therapeutic Grade of: Sensual , Energy, Germ Fighter, Relax, Immune-Aid, Tranquil, Invigor-Aid, Lavender, Peppermint, Eucalyptus, Tea Tree, Orange, Lemon & Cinnamon. 10 ml each.Grapeseed Oil by Sky Organics – 100% Pure, Natural & Cold-Pressed Grapeseed Oil – Ideal for Massage , Cooking and Aromatherapy- Rich in Vitamin A, E and K- Helps Reduce Wrinkles – 8oz

You can check out more directions for bath bombs at the epsomsaltcounil.org

Bath bombs are very popular and a great handmade gift. They’re also a perfect chance for a Christmas Science Experiment (check out the other Christmas Science Experiments HERE). Christmas Science Experiment #4 – Bath Bomb Science Experiment

Citations:

Roth, Stephen M. “Why Does Lactic Acid Build Up in Muscles? And Why Does It Cause Soreness?” Scientific American, 23 Jan. 2006, www.scientificamerican.com/article/why-does-lactic-acid-buil/.