Learning Outcomes

Students will:

• Understand that our world is composed of chemicals
• Understand the definition of toxic chemical
• Understand that it is not easy to know if a chemical is toxic
• Learn how to identify toxic chemicals by reading labels
• Identify toxic chemicals that are used in the home.

Grade Level: Middle school

Teacher Preparation

Time Required for Lesson: 30 minutes

Materials Needed:

Each group will need:

• Examples of warning signs and symbols and product labels
• Pictures of toxic chemicals or things that produce toxic chemicals such as frogs, spiders, plants, cleaning supplies, cigarettes, alcohol, car exhaust, incinerators, factories, etc.
• A Ziploc bag containing three (3) fruit flavored Tums
• A Ziploc bag containing three (3) Sweet Tarts
• A Ziploc bag containing three (3) Red Hots
• A Ziploc bag containing three (3) Advil
• A clear bottle containing Pine Sol
• A clear bottle containing apple juice

Activities:

1. Begin with asking the students if they know what a chemical is and ask them to brainstorm a list of chemicals or things that are made up of chemicals. This list might include chemicals like drugs they take when they are sick, bug spray that people put on themselves and on their gardens to get rid of bugs (e.g. pesticides), and cleaners that they use at home.

2. Ask students to think of some good uses of chemicals. Ask that class if they think some chemicals can harm them and if so, what kinds of chemicals can harm them and how. Explain to the class that when a chemical causes harm, it is called a toxic chemical. Have a student write the word “toxic” on the black board. Ask the students if they have ever heard the word toxic used before. Ask the students if they think all chemicals are toxic, including chemicals found in foods that are necessary for human life.

3. Explain to the class that all chemicals can be toxic or cause harm to people, animals, and plants if too much is taken in. Use an example of a child that eats too much candy – he feels sick afterwards. Explain to the class that many chemicals when used in the right amounts they can make you feel better, but if you take too much you can get even sicker.

4. Explain to students that some chemicals are more toxic than others. For example, if a person eats an entire bag of candy, s/he will feel sick. If a person eats a handful of mothballs, s/he could die. Show students photos or examples of the following and ask them which ones they think might be toxic. Some examples include: household chemicals, cleaning supplies; Pesticides, fertilizers, bug sprays; Pollution (air, water, soil, hazardous waste); Alcohol, cigarettes; Salt; Metals (iron, lead, etc); Poisonous plants like poison ivy or oak; A snake or spider. Tell the students that all of the things you showed them are examples of or contain toxic chemicals.

5. How can you tell its bad for you? Ask the students if they think toxic chemicals are easy or difficult to recognize. Show students the following:

a. a bottle containing apple juice next to one containing Pine Sol,

b. a jar of Tums next to a jar of Sweet Tarts,

c. a bag containing Red Hots next to a bag containing Advil.

Explain that one of each of the containers holds something that could make them sick if they ingested it. Ask if they can tell which jar contains something that might harm them if they ate or drank it. Ask to discuss ways that they can tell if something is toxic.

6. If students suggest taking the cap off of the bottle in order to smell the chemical to see if it smells toxic, explain to them that many toxic chemicals have no smell or taste. In some cases they can get sick just from smelling a toxic chemical, so it is never a good idea to smell or taste something to see if it is toxic.

7. Show students the skull and cross bones symbol and flammable, corrosive and explosive symbols. Ask them if they have ever seen these symbols before and if so where.

8. Ask the class what they think the symbols mean. Show students some of the following words and have them read them aloud. Caution, Warning, Poison, Toxic, Danger. Ask them if they recognize any of the words and what they mean. Explain what the symbols and words mean and how they can be helpful in recognizing whether or not something is a toxic or dangerous chemical. If you can find household product labels with these symbols on them, show them to the class as examples.