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Handling Hazardous Materials
VI
EW AND
RE
F
ACTIVITY OVERVIEW
Students are challenged to think about what they would do if they found an unlabeled container filled with a potentially hazardous mixture. They watch a DVD segment that shows how a hazardous materials (called “hazmat”) team responds to an
abandoned barrel of unlabeled, potentially hazardous waste. Based on their observations of the hazmat team in action, students develop a list of ways to safely handle
unlabeled substances. This list forms the basis for a set of classroom safety guidelines
that will be used throughout the course.
KEY CONCEPTS AND PROCESS SKILLS
(with correlation to NSE 5–8 Content Standards)
1.
Substances have characteristic properties, such as density, that are independent
of the amount of the sample. (PhysSci: 1)
2.
People should understand the risks associated with chemical hazards. (Perspectives: 4)
3.
Safe living involves the development and use of safety precautions and the recognition of risk in personal decisions. (Perspectives: 1)
KEY VOCABULARY
evidence
hazardous material
mixture
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Activity 1 • Handling Hazardous Materials
MATERIALS AND ADVANCE PREPARATION
For the teacher
1
Issues and Physical Science DVD
2
screw-top jars each holding a sample of the unlabeled mixture
containing:
5 mL of 40,000 ppm iron nitrate solution
35 mL of water
20 mL mineral oil
6 black high-density polyethylene (HDPE) squares
6 red HDPE tubes
1 aluminum cylinder
1 zinc cylinder
1
Literacy Transparency 1, “Key to Analysis Icons”
1
transparency of Literacy Student Sheet 1, “Keeping a Science
Notebook”
1
transparency of Group Interaction Student Sheet 2, “Developing
Communication Skills”
*
1
DVD player
*
1
TV monitor
*
chart paper
*
markers
*
newspaper and magazine articles about a local hazardous
materials incident (optional)
For each student
1
Literacy Student Sheet 1, “Keeping a Science Notebook” (optional)
1
Group Interaction Student Sheet 2, “Developing Communication
Skills” (optional)
*Not supplied in kit
Masters for Literacy Transparency 1, “Key to Analysis Icons,” Group Interaction and
Literacy Student Sheets are in Teacher Resources II: Diverse Learners.
Cue the Issues and Physical Science DVD to the “Hazardous Materials” segment.
For Activity 1, prepare two screw-top jars of “unlabeled mixture” for demonstration
purposes.
To make the mixture, you must first prepare an approximately 40,000 ppm solution of
iron nitrate. To do this, fill the 240 mL bottle containing iron nitrate crystals with
water. Next put 5 mL of the 40,000 ppm iron nitrate solution into each of two screw-
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Handling Hazardous Materials • Activity 1
top jars. Set the remainder of the 40,000 ppm iron nitrate solution aside to use in
Activity 3. To each screw top jar add 35 mL of water to dilute the solution to approximately 5,000 ppm. To each of the jars containing 40 mL of 5,000 ppm iron nitrate
solution, add:
20 mL mineral oil
6
black high-density polyethylene (HDPE) squares
6
red HDPE tubes
1
aluminum cylinder
1
zinc cylinder
The two demonstration jars of the unlabeled mixture prepared here are to be passed
around the classroom. Fresh samples will be prepared for student groups in Activity 3,
“A Plan to Separate the Mixture.” This is because after three to four days the iron in
the iron nitrate solution will begin to react with the metal pieces, resulting in the corrosion of the metal and increasing the opacity of the iron nitrate solution. This will
affect both students’ observations and the results of the testing of the liquids.
In this introductory activity, students are presented with a scenario in which they find
a potentially hazardous container of unidentified substances at home. To connect this
to students’ lives and a broader social context, consider searching the Internet or local
newspapers for articles related to hazardous materials (accidents, spills or illegal
dumping) in your area. You might solicit the help of your school librarian to collect
articles about hazardous materials incidents that you can display around the classroom and integrate into future activities in this unit.
SAFETY
The chemicals used in this unit may cause skin irritation. Wear goggles, and use caution when handling solutions. Instruct students to avoid contact with the components
of the “unlabeled mixture.” If contact does occur, students should rinse off any solution that touches skin or clothing with plenty of water. Have all students wash their
hands when they are finished with the investigation. It is highly recommended that
students wear aprons and gloves, if available, when working with chemicals to reduce
contact with skin and clothing.
Mineral oil leaves a residue. To remove the residue, wash with hot soapy water. For
further information on the proper handling chemicals used in this unit, see the Material Safety Data Sheets (MSDS) sheets included in the kit.
Disposal
It is imperative that with each solution used in an activity, you identify your local
guidelines for proper disposal. SEPUP recommends methods for disposal, but be cautious as local guidelines vary and may be more stringent than those listed in the
SEPUP Teacher’s Guide and information contained in the Materials Safety Data
Sheets (MSDS) contained in the kit.
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Activity 1 • Handling Hazardous Materials
At the end of the unit, the solids can be removed from the mixture, rinsed, and recycled, or placed in the garbage depending on your local recycling guidelines.
To dispose of the iron nitrate and mineral oil, pour them down the drain while diluting them with running water. For further information about handling and disposal of
individual liquids, see the MSDS sheets contained in the kit. Also refer to your local
disposal regulations. Given that one of the learning goals of this unit is proper care
and handling of hazardous substances, do not dispose of chemicals down the drain in
the presence of your students until the end of the unit when the components of the
“unlabeled mixture” have been identified and the hazards of the components (toxicity, flammability, and/or reactivity) have been established. This will reinforce the
proper disposal of liquids after their identify has been established.
TEACHING SUMMARY
Getting Started
1.
Introduce the unlabeled jar scenario.
Doing the Activity
2.
(LITERACY) Introduce the use of a science notebook.
3.
Students watch a DVD segment, “Hazardous Materials,” and observe how a hazmat team handles an unlabeled barrel.
4.
Student groups compare lists of safety precautions.
Follow-Up
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5.
Introduce the use of Analysis Questions and icons.
6.
The class constructs a list of classroom safety guidelines.if this works)
Handling Hazardous Materials • Activity 1
TEACHING SUGGESTIONS
GETTING STARTED
1.
Introduce the unlabeled jar scenario.
Read the introduction in the student book as a class
to introduce the scenario. Write the word “hazardous” on the board. Ask students, What does it
means when a substance is considered “hazardous?”
Students are likely to answer that a hazard is something that can cause harm. Ask students What hazardous substances can you name? After sharing
their responses challenge them to think about the
following, How do you know if a substance is hazardous? Their responses are likely to include that if
it is labeled, it will explain its hazards, and that if it
is not labeled it would take knowledge of the substance inside to determine its hazards.
Show the class the demonstration jars of the unlabeled mixture. As you pass those cups of mixture
around the room, ask, Do you think the substances
in this mixture are hazardous? Common responses
my include that it could not be hazardous if found
in a home or at school, but caution them to assume
something is hazardous to be on the safe side, until
knowing what the exact substance or mixture contains.
Focus students on the mixture by asking, How many
different substances do you think are in the jar?
What is your evidence? If necessary, review with students that evidence is information gained by observation or another source which can be used to
formulate an idea. Students will respond that they
see solids as well as liquids and that there appear to
be two different types of liquids, one that is orange
and one that is oily. Write the word “mixture” on
the board. Explain the definition of mixture, a
combination of more than one pure substance that
can be physically separated. Also explain that evidence is a fact or piece of information that helps
you come to a conclusion. Ask students, Based on
your observations, do you think this is a mixture or a
pure substance? What is your evidence? Responses
should indicate students think it is a mixture since
more than one substance is observed in the jar.
Explain that they will observe and model techniques similar to those used by hazardous materials
(hazmat) teams when they work with potentially
hazardous materials.
DOING THE ACTIVIT Y
2.
(LITERACY) Introduce the use of a science
notebook.
For the duration of this unit, students keep a science
notebook. Throughout activities in the Student
Book, they record data, observations, hypotheses,
conclusions, etc. in their notebooks. Keeping a science notebook helps students track data, record
questions as they investigate, process ideas, and
build scientific writing skills. Literacy Student Sheet
1, “Keeping a Science Notebook,” lists suggested
guidelines. For more information about Student Science Notebooks see the literacy section of Teacher
Resources II: Diverse Learners.
Science notebook can also be used to help students
learn to write lab reports. Formal laboratory
reports often include a title, purpose, introduction,
hypothesis, procedure, data, analysis, and conclusions. This unit develops students’ ability to record
observations, and collect and analyze data. In early
activities in the unit you may choose to focus your
teaching and assessment efforts on helping students develop strong skills in a few selected elements, such as designing and interpreting data
tables. As the year progresses your focus might turn
to helping them master additional elements of laboratory reports. Determine your approach based on
the needs of your students and your learning goals
for the unit.
3.
Students watch a DVD, “Hazardous
Materials,” and observe how a hazmat
team handles an unlabeled barrel.
Help students relate the DVD they are about to
watch to the unit scenario by asking, If you were
searching under the sink at home and found an old
jar filled with what appears to be rusty pieces of
metal and an oily liquid, what would you do with the
mixture? Elicit responses that will help students
think about how they will work with the mixture.
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Activity 1 • Handling Hazardous Materials
Responses may include putting on goggles or
gloves, taking the substance to someone else to
identify, trying to figure out where it came from and
how the mixture got to where it was stored, and trying to identify the parts of the mixture, which is the
focus of Unit A, “Studying Materials Scientifically.”
Tell the students they are about to view a short DVD
simulating the handling of an abandoned barrel of
hazardous waste. The DVD, “Hazardous Materials,”
is approximately eight minutes long. Let them know
that when they are finished watching it, they will
make a list in their notebooks recording the procedures and precautions the hazmat team took with
the barrel.
Start the DVD. Pause the segment when the question, “Why doesn’t the hazmat team go over to the
barrel right away?” is displayed on the screen.
Encourage students to discuss why the hazmat team
examines the barrel from a distance. Emphasize the
importance of not approaching or opening unidentified containers without taking protective precautions.
Show the DVD a second time, and encourage students to keep their notebooks open and add to their
lists as they view it again. Emphasize that hazardous materials are not limited to solids and liquids and include gases as well.
Some students may need guidance in connecting
the footage shown in the DVD to their personal
lives. If necessary, explain that hazardous materials is a catchall phrase that describes substances
that are harmful to human health or the environment if not handled with caution. They can be
found anywhere. In urban environments, abandoned waste may be discovered on unused lots or in
buildings, in garages, or around industrial areas
where waste had been dumped over the years. In
some places waste was left on undeveloped land or
buried, where it eventually might be unearthed
through erosion, flooding, or excavation of the
area. In the DVD, the barrel is shown in the side of a
lot. Students may have encountered similar barrels
in drainage gulches or local dumps. Draw on their
personal experiences to help them connect with the
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content of the DVD. When the movie is over, students record in their science notebooks the safety
precautions they saw in use.
4.
Student groups compare lists of safety
precautions.
In Procedure Step 4 students work with their group
of four to compare lists. Use this opportunity to set
the stage for group work. You may wish to explain
your expectations for working together as group, to
emphasize the strength of a group in working
together scientifically, and the benefits of conducting scientific investigations in groups. Before students begin to share their lists, model what
productive group interaction (both agreement and
constructive disagreement) look like and sound
like. The Group Interaction Student Sheet 2, “Developing Communication Skills,” provides sentence
starters you can model and students can use to facilitate discussion. For more information about the
use of this strategy, see the group interaction section
of Teacher Resources II: Diverse Learners.
FOLLOW-UP
5.
Introduce the use of Analysis Questions
and icons.
Point out to students that each activity in this book
includes Analysis Questions to help guide them in
their learning. You may wish to use Literacy Transparency 1, “Key to Analysis Icons,” or point out the
“Key to Analysis Icons” in the student book to
explain the meaning of the icons used with the
questions. The icons suggest which questions are
most appropriately answered as a class, but student
groups, by student pairs, or by each student individually. This helps manage the activity because it
identifies which questions are conducive to discussion and which are not. In general, it is not expected
that students will provide written responses to questions identified by group of four class icons. However, students should write responses to questions
identified with a “1-student” icon. Assessment questions are completed individually and are identified
with a “1-student” icon. Not all questions have
icons; in many instances, how these questions are
Handling Hazardous Materials • Activity 1
handled will depend on what aspect of the activity
is being emphasized.
SUGGESTED ANSWERS TO QUESTIONS
1.
If you plan to provide alternative instructions for
the icons suggested in the book, you can use Literacy Transparency 1 and incorporate your own set of
directions.
6.
Students’ responses will vary. Their answers
should include steps similar to those taken by
the hazmat team in the DVD, including: stop
before approaching the substance, and put on
protective gear; do not touch, inhale, or let the
substance come in contact with skin or clothing;
and, if there is contact, wash skin and clothes
immediately. And lastly, identifying the substance before determining the best way to dispose of it. They may also include suggestions
specific to their home scenario including such as
asking an adult for help.
The class constructs a list of classroom
safety guidelines.
Classroom safety is of primary importance in the
science classroom. During this unit, students will
establish and implement safe classroom conduct.
Analysis Question 2 provides an opportunity to connect what they observed in the DVD, with the unit
scenario and school safety procedures. Take this
opportunity to share student responses. Student
responses will likely include when working with
unknown chemicals assume they are dangerous
until their hazards are established, wear protective
eyewear, do not allow chemicals to come in contact
with skin, notify the teacher of any spills or accidents that occur, and be sure to wash and clean all
materials used in science class. Use students’
responses to establish classroom safety expectations. Construct the list on chart paper. This list of
guidelines will serve for the remainder of the
course. Just as hazmat teams are, students will be
required, in the classroom setting to demonstrate
their ability to safely handle and identify materials
before being allowed to work with potentially hazardous substances. For more information on developing guidelines for safety in the SEPUP Classroom
see Teacher Resources I: Lab Materials and Safety. If
your class develops its own list, you may wish to use
that or alter the provided safety guidelines. Consider reproducing and distributing the list to each
student as they will be required to demonstrate
their understanding of safety guidelines in Activity
2, “Types of Hazards.”
Based on what you observed on the DVD,
make a list of safety precautions you would take if
you found a jar of unidentified substances at home.
2. If you found a jar filled with unidentified substances
at school, would you handle it differently than you
would at home? Add to your list from Question 1
any additional safety precautions you would take.
Students’ answers should build on their answer
to Question 1 and incorporate specific guidelines you established for your science class. This
is an opportunity to reinforce safety regulations
that students should follow in science class.
3.
How could you identify the contents of an
unlabeled jar? Explain ways to identify the
jar’s contents.
Answers will vary but might include making
observations and conducting tests to identify the
components of the mixture. Students may not
know for certain how to proceed at this point.
This concept, identifying unknown substances
based on chemical and physical properties, will
be developed throughout the unit.
Analysis Questions 3 and 4 bring to light the need
for further testing that will take place throughout
Unit A, “Studying Materials Scientifically” of Issues
and Physical Science as students work to identify
unknowns based on identifying their unique chemical and physical properties.
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Activity 1 • Handling Hazardous Materials
4. Could you determine the contents of the unlabeled
jar through observation alone? Explain.
While it is possible to make an educated guess
about some of the contents, there is not enough
evidence to make an accurate identification.
Different substances may be similar in color or
appearance and can easily be misidentified. For
example, the silvery solid is most likely a metal.
However, without further testing, there is not
enough evidence to be absolutely certain that it
is a metal or to determine what type of metal it is.
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