It’s Organic,
How Can That Be Bad?
Robert Dayton
Coordinating Chemistry Mentor
New York State Biology-Chemistry Professional
Development Network
Local Businessman Rushed to Hospital
WORKPLACE FALL CAUSES MINOR INJURIES
BY ELAINE BURNS
Lakeville Chronicle Staff Reporter
Yesterday Jack Castle, owner and operator of New Castle
Collision and Service in Lakeville was rushed to Westside
Hospital... he was working with contractors on the
expansion of the service center at his popular automotive
facility… they saw Mr. Castle walking erratically, then
stumble and fall…Castle has elevated levels of several
organic solvents… Daylight Environmental Services of
Pottstown has been hired to test the soil at the New Castle
construction site.
How Could This Happen?
• How was Jack Castle exposed to
organic solvents?
• Can solvents cause symptoms like
those from being drunk?
• How can solvents affect the human
body?
Is There More to This Problem?
• Where might you or your students be
exposed to toxic solvents?
• At what levels are solvents harmful
or lethal?
• If there is a solvent spill or leak, how
can the soil and groundwater be
cleaned up?
Try This Directed Case Study
Topics Addressed:
Organic Chemistry,
Solvents,
Toxic Exposure,
and
Site Remediation
Case Study “nuts and bolts”
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Student-Centered Learning Activity
Real-world context
4 class periods
Contains a molecular modeling activity
Chemistry content and skills
Environmental health science content
Part 1: Workplace Fall…
Students read a newspaper article and discuss
what they have read about Jack Castle.
Then, groups answer questions about
information in the article and questions that
lead from information in the article.
You monitor group work and provide student
resources.
Part 1: Questions
Share and Discuss Answers to Questions:
1. Define: solvents
2. List the name and formula of the organic
solvents related to automotive service.
3. What is the human blood-alcohol level for
an individual to be considered impaired?
Part 1: Questions
4. Define: Threshold Limit Value
5. Record the TLVs for the solvents
[ http://msds.ehs.cornell.edu/ ]
6. Convert the legal blood alcohol level to
parts per million. Compare this to the TLV
for ethanol. Which unit is best to express
this value? Explain.
Part 1: Questions
7. Draw the structural formulas of each of
the solvents.
8. Compare molecular formulas to structural
formulas.
9. What factors determine molecular
polarity? (transition to Part 2)
Part 2:
Molecular Modeling Activity
Solvent
Molecule
Models
Part 2:
Molecular Modeling Activity
Why?
A solvent’s ability to dissolve a given solute is
dependent in large part on the molecular polarity
of the solvent molecules.
Building and analyzing molecular models will
help students better understand solvents.
Part 2:
Molecular Modeling Activity
Success criteria
• Relate molecular bonding and shape to
molecular polarity and intermolecular forces
• Distinguish among various organic
solvents in terms of molecular structure
Part 2:
Molecular Modeling Activity
Prerequisites:
• Bonding concepts
• Basic knowledge of organic
chemical structures
• Experience with molecular models
Part 2:
Molecular Modeling Activity
Resources Needed
• Molecular Modeling Kits
• Chemistry textbook
• NYSED Reference Tables for Chemistry
• CRC Handbook
• Toxicology textbook and/or Internet
• Document: Solvent exposure and the risk of
slips, trips, and falls…
Part 2:
Molecular Modeling Activity
Concepts Developed:
Organic solvent molecules -
– Functional groups
– Molecular structure and polarity
– Dissolving and solubility
– Toxic exposure and effects
Part 2:
Molecular Modeling Activity
Modeling Solvent Molecules:
Monitor student group work building
and analyzing models
Ask questions; and ask more questions
Help with molecular geometry
descriptions
Part 2:
Molecular Modeling Activity
Be a Facilitator:
Check student work constantly
Help students develop understandings
and skills
Part 2:
Molecular Modeling Activity
Work with students while they answer the
Key Questions, Exercises, and Problems.
These three question types are designed to
scaffold in cognitive level.
Be a facilitator.
Part 3: …Leak Suspected
A follow-up article sheds more
light about the Castle site.
Students read this article,
discuss the new information,
and begin answering the Part
3 questions.
Part 3: …Leak Suspected
This section extends into the realm of
toxicology, and connects the solvents to
harm to humans.
Be sure you have done your homework.
Use information from the UR EHS site to
develop background information.
Part 4: Presentations
Students research methods to clean-up a
contaminated site.
In their group, they develop a plan to
decontaminate the Castle site.
They should include details as if they are an
environmental remediation company.
Part 4: Presentations
Students develop short presentations on
their plan to clean-up the Castle site in
Lakeville.
They should make a simple poster to use
with their presentation.
Give them the presentation rubric.
Part 4: Presentations
Evaluate the students during
the presentation.
Consider having the other students evaluate
them too.
And, each group can rate themselves.
Timeline
Day 1:
- Read and discuss the 1st article
- Students answer and discuss Part 1 questions
Timeline
Day 2:
- Molecule Modeling
- Read and discuss 2nd article
Timeline
Day 3:
- Answer and discuss Part 3 questions
- Start work on Part 4
Timeline
Day 4:
- Complete preparation and present
decontamination plans
Resources
Many resources are provided. Review
these and select which to use with
students.
Students can be given a resource sheet
with web links or printed documents.
A Note on Philosophy…
Enjoy working with kids.
Be patient.
And… Be a facilitator.
Contact Me
rdayton1@rochester.rr.com