If washed every day, they can live 1 to 2 weeks in the refrigerator. If worms are not available, you may substitute some other fresh water invertebrate, which can be obtained at tropical fish or pet stores. Brine shrimp, available at some pet stores, also may be substituted for fresh water invertebrates, but you will need to add table salt at a 5 percent solution in the water before adding the shrimp. Pour out the water and shake the containers dry. Shake or stir well.
Any substance can be toxic in a high enough concentration.
Contact your local sanitation or health department to request information on the proper disposal methods for antifreeze in your community. Using the information in the Background section, discuss how scientists conduct studies to get information on toxic substances. Divide the class into teams of two to four students each. Caution students to handle the antifreeze carefully. Provide each team with five clean plastic cups, tape, marker, one copy of the Student Handout , and five copies of the Student Worksheet .