In addition to fluoride, some toothpastes also contain lime as a solid component. This serves to gently remove plaque from the teeth. You can find out whether a toothpaste contains lime with a simple experiment. Lime reacts with acids: if there is lime in the toothpaste, it will start to foam when mixed with vinegar. Does your toothpaste contain lime?
Does your toothpaste contain lime?
![cut out paper toothpaste tube attached to whiteboard](https://www.henkel-forscherwelt.de/resource/image/1150744/21x9/3000/1286/688dba9a8fa14c0a9eb389afa24550b0/59154396A7591BBF1E844FFD979AB864/components-toothpaste.webp)
You will need
- Eggshells
- Salt or sugar
- Citric acid (liquid)
- Toothpaste with and/or without lime (CaCO3)
- 3 glasses
- Measuring jug
- Freezer bag
- Rolling pin
Let’s get started!