Organic Solvents: Workplace Fall & Toxic Exposure

1. It’s Organic, How Can That Be Bad? Robert Dayton Coordinating Chemistry Mentor New York State Biology-Chemistry Professional Development Network

2. Local Businessman Rushed to HospitalWORKPLACE 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.

3. 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?

4. 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?

5. Try This Directed Case Study Topics Addressed: Organic Chemistry, Solvents, Toxic Exposure, and Site Remediation

6. Case Study “nuts and bolts” Student-Centered Learning Activity Real-world context 4 class periods Contains a molecular modeling activity Chemistry content and skills Environmental health science content

7. 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.

8. Part 1: Questions Share and Discuss Answers to Questions: Define: solvents List the name and formula of the organic solvents related to automotive service. What is the human blood-alcohol level for an individual to be considered impaired?

9. Part 1: Questions Define: Threshold Limit Value Record the TLVs for the solvents [ http://msds.ehs.cornell.edu/ ] 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.

10. Part 1: Questions Draw the structural formulas of each of the solvents. Compare molecular formulas to structural formulas. What factors determine molecular polarity? (transition to Part 2)

11. Part 2: Molecular Modeling Activity Solvent Molecule Models

12. 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.

13. 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

14. Part 2:Molecular Modeling Activity Prerequisites: Bonding concepts Basic knowledge of organic chemical structures Experience with molecular models

15. 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…

16. Part 2:Molecular Modeling Activity Concepts Developed: Organic solvent molecules - Functional groups Molecular structure and polarity Dissolving and solubility Toxic exposure and effects

17. 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

18. Part 2:Molecular Modeling Activity Be a Facilitator: Check student work constantly Help students develop understandings and skills

19. 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.

20. 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.

21. 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.

22. 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.

23. 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.

24. Part 4: Presentations Evaluate the students during the presentation. Consider having the other students evaluate them too. And, each group can rate themselves.

25. Timeline Day 1: - Read and discuss the 1st article - Students answer and discuss Part 1 questions

26. Timeline Day 2: - Molecule Modeling - Read and discuss 2nd article

27. Timeline Day 3: - Answer and discuss Part 3 questions - Start work on Part 4

28. Timeline Day 4: - Complete preparation and present decontamination plans

29. 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.

30. A Note on Philosophy… Enjoy working with kids. Be patient. And… Be a facilitator.

31. Contact Me rdayton1@rochester.rr.com