In this exercise,
students define and explore the relationship between hazardous
substances and hazardous waste. The exercise allows them to
identify a number of commonly used toxic chemicals, describe
how these materials are used and disposed of, and sort them
into the various types of hazardous waste. Students then discuss
how the improper use and disposal of these materials can affect
people in their community and the environment.
Many familiar products contain
hazardous substances. Hazardous substance is a broad term that includes
many chemicals and materials, including poisonous or toxic chemicals.
Improper use and disposal of these products can result in the production
of hazardous waste that can pollute our environment. Becoming
more aware of the hazardous substances we encounter every day and of
the types of hazardous waste they produce is the first step in learning
how to properly handle and dispose of them, thereby protecting ourselves
and our environment.
Flash 1: Hazardous Substances and Hazardous Waste describes
these terms and their application. For more information on hazardous
substances, see the Suggested Reading list found at the end of the Haz-Ed
materials. Other Haz-Ed materials that are related to this topic include
Fact Flash 7: Pollution Prevention and
Activity 10: Pollution Prevention.
Gather the following materials:
- Read Fact
Flash 1 to prepare for the lesson.
- Distribute Fact
Flash 1 to the students and have them read it as homework.
- Ask students what a hazardous
substance is. Have them write their definitions on a sheet of
paper or share them with the class. Record them on the chalkboard.
Define hazardous substances
for the class:
are materials that present a threat or potential risk of injury
to people or the environment when they are produced, transported,
used, or disposed of.
of hazardous substances. To be hazardous, a substance must have one
or more of the following characteristics:
- Corrosive -
capable of chemically wearing substances away (corroding) or destroying
them. For example, most acids are corrosive. They can eat through
metal, burn human skin on contact, and give off vapors that burn
the eyes. Acids found in batteries are corrosive.
- Toxic - poisonous
to people and other organisms. Toxic substances can cause illness-ranging
from severe headaches to cancer-and even death if swallowed, and
many also can be absorbed through the skin. Pesticides, weed killers,
and many household cleaners are toxics.
- Ignitable -
capable of bursting into flames. Ignitable substances pose a fire
hazard and irritate the skin, eyes, and lungs. They also may give
off harmful vapors. Gasoline, paint, and furniture polish are
- Reactive -
capable of exploding or releasing poisonous gas when mixed with
another substance or chemical. For example, chlorine bleach and
ammonia are reactive. When they come into contact with each other
they produce a poisonous gas.
(NOTE: You may want
to bring to class examples, such as those mentioned above, of the
various types of household products that can become hazardous waste.
Use caution in handling these products.)
- Discuss with the class
some types of hazardous substances that may be found in their community.
- Divide the class into
4 or 5 small groups. Distribute Fact Flash
1: Hazardous Substances and Hazardous Waste and have the students
Write the questions below
on the board, or make copies for the students. Have each group discuss
the questions. Explain that each group should be prepared to participate
in a class-wide discussion later in the period. Allow about 20 minutes
for group discussion.
- What household chemicals
do people have in their homes or garages that are hazardous and
that could become hazardous waste?
- Do you think you
or your family contribute to the hazardous waste problem? If so,
- What problems could
you, your family, and the community face as a result of being
exposed to hazardous waste?
- What businesses in
your community do you think might use hazardous materials?
- What are some ways
hazardous waste problems can be prevented? Which of these things
can you do? (Give 1 or 2 examples, such as using vinegar
and water to clean windows and not using pesticides on plants.)
- After about 20 minutes,
have the class reassemble. Take each question in turn and have students
share the concerns, opinions, and questions raised in their groups.
You may want to have one or two students write unanswered questions
and suggestions for preventing hazardous waste problems on the chalkboard
for everyone to see.
- About 5 minutes prior
to the end of the period, summarize the discussion and identify subjects
students may want to explore more fully in subsequent classes.
- Introduce the concept
that there are simple steps the students, their families, and the
community can take to decrease and prevent pollution. Fact
Flash 7: Pollution Prevention provides additional information.
Activity 10: Pollution Prevention presents
some ideas for students to explore and contains a handout on nontoxic
alternatives that can be used around the house in place of cleaning
fluid, laundry detergent, pesticides, and so forth. You can copy and
distribute this handout to the class if desired.
- Have students list chemical
products in their homes and sort them into groups according to the
types of hazardous waste they could produce (for example, lawn and
garden pesticides belong in the "toxic" category, gasoline and lighter
fluid belong in the "ignitable" category). NOTE: Caution your students
not to touch any of these substances while they are making their lists.
- Have students contact
the local government environmental services office or sanitation department
and find out about recycling and other programs designed to minimize
hazardous waste. For example, have them find out how used paint thinner
and leftover paints should be disposed of in their community.
- Have students contact
local gasoline service stations, oil change and auto lubricating shops,
and nursery and garden supply companies and report on how these firms
are required to dispose of hazardous substances.
- Have students contact
your state environmental departments and ask if they have any posters
or materials that show how to dispose of hazardous substances and
hazardous waste, or that illustrate the use of alternatives to hazardous
substances. Get some of these materials to use in your school for
a display on Earth Day, Arbor Day, or other environmental event.