Recently added item(s)
You have no items in your shopping cart.
Personalize your experience with Penn State Extension. Subscribe today!
Save For Later Print
The purpose of this demonstration is to illustrate how the level of toxicity isdetermined for a pesticide. Toxicity of pesticides is determined by the dose of the concentrated active ingredient that it takes to reach a 50% mortality rate with a test population of animals. As the Lethal Dose it takes to reach a 50% mortality rate it is expressed as the LD50 value of the chemical.
It doesn't matter how many participants that you have for this demonstration, as long as you have an even number.
Distribute the cups those participating in the demonstration, and have the participants stand.
Explain to the participants that they are the test population of "laboratory rats" for the experiment that will determine the toxicity of this "product" that is heading to the market. The only thing stopping from eating as much of the "product" that they want is that the level in their cup represents a fatal dose to them as a "laboratory rat".
Explain to the participants that they should eat their M&M's one at a time, but fairly quickly. When they have finished eating the M&M's in their cup they should sit down because they have reached the dose that was lethal to them. When the half of the "Laboratory Rats" (those that had the smaller amounts in their cups) are seated - the LD50 value has been reached.
Thank you for your submission!