CHF Chemistry WebQuest #5 The Great PVC Controversy < Back | Home | Teacher's Guide | Next >

Introduction Your Task The Process Resources Conclusion

Introduction

PVC is short for poly(vinyl chloride). This polymer is made by polymerizing the monomer vinyl chloride. PVC is a very strong and very rigid plastic, and it's a really useful one, too. People use it to make pipes, the kind used for plumbing in most newer houses. PVC is also used to make the "vinyl" siding on the outside of houses. PVC is flame-resistant because it contains chlorine. Compounds that contain chlorine often are. Because of this, PVC is useful for making fixtures for the interiors of airplanes, where a fire could be especially dangerous.

PVC also can be made into a soft and flexible plastic by mixing it with small-molecule compounds called plasticizers. The "new car" smell that motorists love so much comes in part from plasticizers evaporating from PVC in the seats and dashboards. Plasticized PVC can be used for a lot of things. It's waterproof, so it can make things like tarps and raincoats. It's also good for making clear flexible tubing.

But there is a problem: Those plasticizers that make PVC soft and flexible can be toxic and carcinogenic. The PVC itself isn't toxic or carcinogenic, but the plasticizers can cause health problems. As if that weren't enough, the monomer used to make PVC, vinyl chloride, is carcinogenic and can be harmful to people who work in the factories where PVC is made.

Your Task

Coming up with a solution won't be easy. Using PVC has risks, and some people would like to ban it. This may seem like a good idea, but alternatives to PVC aren't always easy to find. In this activity, you and a partner will set out on a quest to find solutions to the PVC dilemma.

The Process

As a team of two, one of you will research PVC and what its uses and benefits are. The other team member will research the risks of using PVC. Each of you will prepare a 1-2 page report of your findings.

Once you have written your reports on PVC risks, you are to prepare another written report, this time on your ideas for possible solutions. Please try to avoid simplistic solutions such as "stop using PVC." That only works if you have a good replacement for PVC in every possible use. Rather, your written report should answer the following questions:

1. What materials might be used in place of PVC for certain applications?

2. For what uses should people keep using PVC?

3. What is copolymerization and how could it be used to make PVC soft without using toxic plasticizers?

4. How can we protect workers who make PVC from the harmful effects of vinyl chloride?

5. In your research, what claims did you find that you could substantiate? What claims could not be substantiated?

Resources

To give you a head start, some online resources that you may find useful have been listed below.

For the uses and benefits of PVC:

Vinyl: One Material, Infinite Uses—from the Vinyl Institute, the Vinyl Council of Canada, and the European Council of Vinyl Manufacturers.

PVC-Toys.com—industry-based advocacy group.

Chlorophiles—an organization of workers in PVC-related industries, based in Belgium. The site contains an ample list of other PVC and chlorine-related sites.

For the risks of PVC:

It's Perfectly Clear: The Case Against PVC Packaging—from the Massachusetts Public Interest Resource Group.

Europe to ban PVC toys—report from BBC News.

New Concerns about Phthalates—explores the risks posed by plasticized PVC, from Science News.

Our Stolen Future—site on the risks of hormone-distrupting compounds, including phthalates used to plasticize PVC.

For additional information on PVC, plastics, and polymers:

The Macrogalleria—a comprehensive resource of polymer information from the Polymer Science Learning Center at the University of Southern Mississippi.

Simple treatment makes PVC safer—report from BBC News.

FDA Public Health Notification: PVC Devices Containing the Plasticizer DEHP—from the U.S. Food and Drug Administration.

Conclusion

After you and your partner have completed your final report, there will be a class discussion of the issues at hand and the solutions proposed by all the teams in the class.