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Baffled by the Baby Bottle


Michael A. Jeannot
Department of Chemistry
St. Cloud State University


This case is based on an actual article entitled "Baby Alert" that appeared in Consumer Reports (May 1999). The article raises some concerns about the safety of polycarbonate baby bottles, and recommends that parents dispose of them as a precaution. However, the American Plastics Council and the Food and Drug Administration have raised concerns about the experimental methodology used as well as the recommendations made in this article. The case has been used to help develop students’ critical thinking skills in an introductory chemistry course for non-majors. It may be used to illustrate applications in polymer chemistry, quantitative chemical analysis, toxicology, endocrine disruption, and risk-benefit analysis.

  • Stimulate student interest in the sciences.
  • Develop critical thinking and reasoning skills.
  • Acquaint the students with the fundamentals of polymer chemistry.
  • Introduce the concepts of detection limits, quantitation, lowest observed adverse effect limit (LOAEL), and reference (safe) dose.
  • Develop an understanding of scientific judgment.
  • Create an awareness of the endocrine disruption issue.
Keywords: Polycarbonate baby bottle; bisphenol-a; BPA; plastic; polymer; polymer chemistry; endocrine disruption; toxicity
Topical Area: N/A
Educational Level: High school, Undergraduate lower division
Formats: PDF
Type/Method: Dilemma/Decision, Directed
Language: English
Subject Headings: Chemistry (General)   Toxicology   Materials Science  
Date Posted: 09/03/99
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

Teaching Notes

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The case was used in a small class of second semester chemistry for non-majors. Polymer chemistry was covered briefly before the assignment.

The student references were handed out in class. The class was split into groups of four with one group of five. Each person was assigned to a role: mother, consumer reports scientist, plastics industry rep., judge (moderator for the discussion), and in the group of five an outside scientist. Each student was to read the references and think about points which they would like to ask the other experts (in the form of five questions). In addition they were to prepare answers from their assigned perspective which they felt might be addressed. The judge was given the task of coming up with the method to present the case with the group.

On the next class period, the groups discussed the case. Occasionally, groups needed assistance in discovering what might be valid arguments in the consumer report. Once the discussions died down I presented highlights of the main points that one might want to consider. Then a vote was cast about who would use polycarbonate bottles. Surprisingly, only a small portion of the students would continue using the bottles even though they believed that the consumer report case was not supported by facts. The students then recieved a copy of the summary of the RTI report given in 2001 confirming the safety of polycarbonate bottles.

The case was well received and very engaging.

Kerry Breno
Chemistry Department
University of Puget Sound
Tacoma, WA

I plan to use this case study with my first-year high school students during their polymer unit. Not only will it be a great timely connection but it also involves another important concept in my course - levels of detection and risk factors. I read about your site in C&E News. What wonderful resources. I will share the knowledge of this site and this particular case study with my high school colleagues at our first educators' discussion group of my local ACS. My polymer unit looks at some physical/chemical properties which distinguish the six major plastics. I then have the students study modifications to the slime recipe to produce products of greater viscosity or bouncibility. They design their own testing methods and measurement protocols. We will then end with this case study. This part of the course happens during the second quarter.

Linda Hall
Science Department
Seven Hills School
Cincinnati, Ohio
I’m a sales manager for (among other glass products) baby bottles made of special glass (borosilicate glass with expansion factor 3.3). Although many Americans may not be aware of this, such bottles have been in use for generations (since the 1920s), especially in Germany. The company I work for still produces such bottles, as do certain other factories in France, the Czech Republic, Italy, China, etc. In fact, consumption of these bottles is still in the double digit range of millions. In my opinion, bottles made out of borosilicate glass are preferable to those made out of ordinary soda lime glass due to the bad thermal shock resistance of the latter which does not allow for optimal hygenic cleaning.

The case study highlights six points which, to my understanding, are related to chemistry. But the "development of critical thinking skills..." should also address political, commercial and general environmental aspects, too. Historically, these factors frequently have triggered more profound research. After Our Stolen Future was translated into Japanese, health authorities in Japan stopped use of PC (polycarbonate) dishes in schools. The baby bottle market in Japan, which formerly manufactured according to the ratio of 25% glass - 75% plastic, subsequently changed to 80% glass - 20% plastic. In Europe, however, the effect has not been the same; here the market is still 25% glass - 75% plastic.

Basic worries, as well as proved and unproved statements, are often juxtaposed with the power and persuasion of industry representatives. Such basic worries apparently linger even after evidence is examined, as witnessed by the final vote of students at the end of the case (see Comment 1: "Surprisingly, only a small portion of the students would continue using the bottles even though they believed that the consumer report case was not supported by facts").

The American Plastics Council, although encouraging inquiries into "the truth," continues to defend the image of the plastic industry. However, this is not an area for blind trust since there is a long list of industry "trust me’s" that have been heard before: nuclear power, agent orange, car exhaust, tobacco smoke.... In the end, who evaluates (and who should evaluate) what is most important for a given population? Administrators representing the public health? Members of the relevant business community? I think that the case discussion should be broadened to include such a range of issues, on both the "pro" and "con” sides" when analyzing health issues.

Dietrich Leutelt
Sales Manager



The links referred to below are listed in the References section of the Teaching Notes for the case. Unfortunately, the often transient nature of the Internet means that what was accessible online at the time a case was written, might be gone tomorrow. With over 500 cases in our collection, we are unable to check or update all of these links, especially in the References section of the Notes, which are there primarily to document the sources used by the case author(s) when the case was written. However, archived versions of these items as they appeared at the time of publication can still be retrieved by using the Wayback Machine at Simply go to the website for the Wayback Machine and copy-and-paste in the original URL as cited in the Teaching Notes.


The links in this case study appear to be defunct.

Terrah J. Goeden
Portland Community College
Portland, OR

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