# How many grams to toothpaste to kill a rat? One of the leading toothpaste brands advertises Fluoride (NaF) at 1400ppm. And the MSDS for Sodium Fluoride says that 52mg/kg is enough to kill a rat. How would I calculate this?

##### 1 Answer

You would need

So, let's start with what **PPM**, or parts per million, is used to express really small concentrations of a substance in a solution or a mixture. Mathematically, a 1-ppm concentration has

Every 1 kg of solution contains 1 mg, or **1400 mg** of

All you have to do now is set up a simple conversion factor to see how much toothpaste contains 52 mg of