Nalge Nunc International Corporation

1

A Student, Chemical Engineer

Nalge Nunc International Corporation

Outdoor Products Division

75 Panorama Creek Drive

Rochester, NY 14625 U.S.A.

Nalge Nunc International Corporation
Outdoor Products Division
75 Panorama Creek Drive
Rochester, NY 14625 U.S.A.

Dear Mr. Mackinder,

We are pleased to inform you that our work on behalf of the company Nalgene has progressed and is coming to a close. We have obtained our data and research and have outlined our findings in the body of this report, which we hope meets with your approval.

Recently, our company,Nalgene, was ordered by the Food and Drug Administration to cease production of water bottles containing BPA due to the fact that BPA causes very serious health problems, especially in women. Over the course of the last three months, our team of chemical engineers has been researching the effects of Bisphenol-A (BPA) in the human body. The compound BPA is found in product packaging (such as in water bottles); it has been determined that at high temperatures, BPA “leaks” into the water and is then ingested into the human body. Within the body, BPA is recognized as the primary female sex hormone,estrogen, and can lead to extremely adverse effects such as breast and ovarian cancer.

The goal of our team was to determine how BPA interacts with the human body and leads to these deadly diseases. In addition to health research, we were asked to find a better alternative plastic to BPA with which water bottles can be manufactured. We also needed to determine if this new plastic would withstand various tests (high-pressure or high-temperature tests, strain tests, stress tests) to ensure its durability and harmless biodegradability. Cost and manufacturing analyses were considered so that Nalgene could determine if switching production from one plastic to another would be in the company’s best interest.

We have expounded on our findings in our report. Please let us know if you have any questions.

Sincerely,

A Student

FDA-Mandated Alternative to BPA in Water Bottles

Eric Johnson, FDA; Head of Food Packaging, Nalgene

Head of Research and Development, Nalgene; Head of Manufacturing, Nalgene

A Group of Students

Table of Contents

List of Illustrations4

Abstract5

Executive Summary6

BPA Effects on Human Physiology8

Alternative Polymers13

Manufacturing Analysis18

Conclusion23

Recommendation23

Appendix A: References24

Appendix B: Image Citations26

Appendix C: Copolyester MSDS27

List of Illustrations

Figure 19

Figure 211

Figure 313

Figure 414

Figure 515

Figure 616

Figure 717

Figure 818

Figure 918

Figure 1018

Figure 1119

Figure 1219

Figure 1321

Abstract

The chemical Bisphenol-A (BPA) is a compound found in many water and pop bottles. Studies have shown that upon heating the containers, BPA diffuses into the liquid and is therefore ingested by the body. When BPA enters the bloodstream, it has a similar effects as estrogen, which is the primary female sex hormone. Because of this, BPA is linked with diseases such as breast cancer and prostate cancer due to uncontrollable cell growth influenced by fluctuations in hormone levels. The purpose of this project is to determine how BPA interacts with the human physiology, what possible alternatives to BPA are available, and how the cost and manufacturing of the alternative plastics would compare with those for BPA.

Executive Summary

Background Information

Bisphenol-A (BPA) is the chief component in the plastic lining of water and pop bottles. When the plastic bottles containing BPA are heated (such as when they are left out in the sun), BPA “travels” from the lining of the bottle and into the liquid in a process called leeching. When this happens, BPA can be ingested into the body. The human body recognizes this chemical as the female sex hormone estrogen (Linda B. White, 2009).

Estrogen is primarily found in women. However, men do have trace amounts of estrogen in their bloodstreams, just as women have trace amounts of testosterone in their bloodstreams. Because of this, BPA in the bloodstream would not seem like an immediate cause for concern.

However, studies have shown that an increased level of BPA inthe bloodstream may lead to breast and prostate cancer. Because BPA mimics estrogen, it is recognized by both breast cancer cells and prostate cancer cells. As a response to BPA, the tumor cells increase their growth and proliferation. BPA promotes two very common and deadly types of cancer. CITATION

Statement of the Problem

Because of the severe health problems caused by BPA, Eric Johnson, a representative for the Food and Drug Administration, has approached our company Nalgene, a manufacturer of plastic water bottles. The FDA has mandated that Nalgene switch from using BPA in their plastics to a less hazardous plastic. The interactions of BPA with the human body must be determined so that a proper alternative may be decided upon; a manufacturing analysis must also be conducted so that the feasibility of manufacturing the new plastic may be determined.

Statement of Task

The task for our team is to determine how BPA interacts with the human body (i.e., how it enters the bloodstream, what cell receptors it targets, how it leads to tumor growth). Once we have determined these interactions, we will be better equipped to determine a better alternative plastic to BPA-containing plastic that does not produce the same harmful effects. When we have gathered some alternatives, we need to research the plastics’ durability to high temperature, pressure, stress, and strain. After we have evaluated the properties of the alternative plastics, a manufacturing analysis needs to be conducted to better determine which new plastic should be implemented into the manufacturing of Nalgene’s water bottles.

Statement of Purpose

The purpose of this report is to discuss our research on the effects of BPA on the human body; the possible alternative plastics available and their properties; and the manufacturing techniques of each of the possible alternatives.

Statement of Conclusion

From the research we have gathered, we have discovered that previously determined amounts of BPA allowed to be ingested by the body were actually more harmful than expected. In fact, a dose 1000-fold less than the previous lowest effective dose is hazardous. Although BPA contains estrogen-like qualities, it behaves slightly differently than estrogen. It can bind to hormone-binding receptors; however, it is not recognized by the sex hormone regulation system in the bloodstream. If too much BPA is in the bloodstream, it will continue to build up and affect the body as if a build up of estrogen were taking place; the regulatory protein would not recognize it and would do nothing to curb the high BPA concentration.

The alternative plastics we have chosen to consider are polyethylene terephthalate (PETE), Eastman Tritan copolyester, and polystyrene. When considering the alternative plastics, many different material properties need to be taken into consideration. Some of these are thermal stability (durability against heating and cooling temperatures), tensile strength (durability against high pressure), and ultraviolet radiation stability (durability against dehydration at high temperatures). Considering only these properties, the choice plastic would be Eastman Tritan copolyester.

The manufacturing of each of these alternatives has to be taken into consideration as well. The manufacturing analysis is based upon safety (i.e., which alternatives are less flammable, do not cause runaway reactions, etc.), quality, and retooling (what new equipment needs to be implemented). Taking manufacturing into account, PETE would be the best plastic with which to replace BPA because PETE is safer and has better quality.

Statement of Recommendation

We recommend that all BPA-containing water bottles be replaced with PETE-containing water bottles. Although the Eastman Tritan copolyester has better material properties than PETE has, PETE is safer than the copolyester and is also of better quality. Because safety is the primary concern and quality is the secondary concern, our recommendation is to use PETE.

Discussion

When BPA is ingested into the body, it is recognized by the body as estrogen, the primary female sex hormone. This has caused concern for the public health because studies have shown that increased levels of estrogen in the body can lead to tumor growths (CITATION).

An important issue regarding the amount of BPA in plastic bottles is the fact that scientists have misjudged the appropriate level of BPA allowable in the human blood stream. Half of the allowable amount of BPA causes serious developmental problems.

Although BPA is similar to estrogen in the way it binds to hormone-binding receptors, it cannot be regulated by sex-hormone binding globulins (SHBGs). SHBGs allow the body to regulate the concentration of certain hormones in the bloodstream at any given time. If hormone concentration goes too high, the SHBGs are activated to reduce the concentration so as not to interfere with normal body functions. Because BPA does not respond to SHBGs, it will build up in the blood stream and impact the body’s functions.

The alternative plastics under consideration are polyethylene teraphthalate (PETE), polystyrene (PS), and Eastman Tritan copolyester. Each of these alternatives is tough and transparent, although polystyrene can be brittle. These new materials were subjected to various durability tests to determine if they were fit to be used in water bottle manufacturing. Some of the tests include thermal stability, ultraviolet radiation stability, liquid stability, toughness, and tensile strength. Based off these material properties only, Eastman Tritan copolyester would be the best plastic to use.

When comparing how these alternatives are manufactured, many other factors need to be considered such as safety, quality, and retooling. Based off these factors, PETE would be the best plastic to use because it is safer and of better quality.

BPA Effects on Human Physiology

Health Hazards of BPA

Corporate and health research groups have all extensively studied the toxicity of BPA. However, many of these groups have evaluated the toxicity of BPA incorrectly, and thus drawn incorrect conclusions about the effect BPA has on biological systems. Specifically, many scientists have incorrectly determined the lowest effective dose for BPA when ingested under toxicology studies. This section will review literature that discusses the new experiments used to determine the lowest amount of BPA required to produce an effect, by investigating BPA using principles of endocrinology.

Just like any other system that functions as a result of a multitude of organized processes, the human body relies on the cardiovascular system to circulate blood; the musculoskeletal system for mobility; the neurological system for control; and the endocrine system for growth and development. If one of these systems is not functioning correctly, the human body could develop serious complications, such as disease or improper growth. The goal of this section is to explain how the endocrine system functions and how BPA causes changes to the system. Moreover, the specific diseases caused by BPA ingestion over time will also be evaluated.

The endocrine system comprises the cellular signal systems that allow the cells within organ systems to communicate with one another. Similarly, the endocrine system regulates the types and amounts of hormones circulated throughout the human body. Hormones control many different bodily functions, and will even affect the growth and development of an organism(Welshons, Nagel, & Vom Saal, 2006). Moreover, the efficacy of certain hormones increases if an organism is exposed to relatively small fluctuating levels during fetal periods(Welshons, Nagel, & Vom Saal, 2006). Hormones have very specific functions, and an increase in the level of hormones in an organism, whether small or large, can change the way that organism develops over time. Fluctuations in hormones can even permanently change the size and function of organs in a developing organism.

Cancer has become a major concern for people of any level of health, due to its ubiquitous nature. Cancer is a general term that refers to uncontrollable cell growth, where the affected cells begin to form tumor masses. Incidences of cancer have increased in many parts of the developing world, and breast cancer specifically has increased by 40% in the quarter century in the United States(Markey, Luque, Munoz de Toro, Sonnenschein, & Soto, 2001). Medical professionals have known that unnatural fluctuations in hormones, specifically in estradiol and other estrogen hormones, can cause unnatural cell proliferation in some organs and thus induce cancer. Because an organism relies on its hormones to regulate its development, any change in hormone levels could lead to unnatural cell growth such as cancerous tumor growth.

How is BPA Ingested?

Many items encountered in everyday life are made from, or contain a component of, polycarbonate plastic manufactured from BPA. BPA is also used as a plasticizer, to introduce desirable physical properties to other types of plastics and polymers. It is no surprise then that Nalgene manufactures several food and beverage containers from materials containing BPA, and Nalgene customers are safe as long as BPA stays in its polymer form in the container and does not leech into the food or beverage. However, due to the chemical structure of BPA, shown in Figure 1, it is very possible for the polymer to undergo a chemical reaction that releases free BPA into the food or beverages.

Figure 1. The structure of BPA and the mechanisms by which it can be reduced to its monomeric form.

The structure of BPA plastics is basically composed of individual BPA monomers, linked to one another by an ester bond, to form the long molecular chains that constitute a polymer. When the ester bond binds each BPA monomer, that BPA is harmless. However, the ester bond linking the BPA monomers together is easily broken by a reaction with water molecules, called hydrolysis. The rate of hydrolysis increases as temperature increases (Welshons, Nagel, & Vom Saal, 2006), as well as when acidic or basic substances are applied to the polymer (Kanga, Kondo, & Katayama, 2006). The result is that the storage of acidic foods or beverages such as coffee, soda, or juices can greatly accelerate the rate of hydrolysis of the ester bond, which will accelerate the release of free BPA monomers into the food or beverage. Furthermore, repeated washing of the storage containers with a basic cleaning agent will also accelerate the release of BPA monomers.

The real question is not whether or not BPA is leeching into food or beverages, but how much BPA is leeching into food or beverages. Human immune systems and biological functions are bombarded with adverse chemical substances on a daily basis; but these “bombardments” are in such small amounts that it makes no difference. Studies have shown that BPA is primarily ingested orally through intake of food or beverages (Vandenberg, Hauser, Marcus, Olea, & Welshonse, 2007). Scientists also found that the amount of BPA ingested by the general public dietary sourceswas 52-74 ng/kg per day (Vandenberg, Hauser, Marcus, Olea, & Welshonse, 2007). This level of consumption is below the former predicted safe dose of 50,000 nanograms per kilogram per day found by some studies (Welshons, Nagel, & Vom Saal, 2006). However, in this report we review literature that contradicts the predicted safe dose of 50,000 nanograms per kilogram per day, stating that the true safe dose is far less than that predicted by some research groups, and that average environmental exposure levels to BPA are in fact dangerous. The dangers of exposure to BPA at average environmental levels will be discussed in later sections of this report.

BPA usage is fairly ubiquitous, especially concerning food and beverage containers produced by Nalgene. A review of the literature on BPA shows that it is possible for BPA to depolymerize into its monomer form, allowing the BPA monomers to leech into food or beverages contained within a polymer storage unit. Furthermore, studies have shown that people do ingest BPA, most likely from food or beverages stored in BPA polymer containers. Because BPA exposure is ubiquitous, and BPA is ingested regularly, the effects of BPA must be monitored to ensure that public health is protected.

Validity of FDA Claims against BPA

The endocrine system consists of the hormone secreting glands of an organism. The hormones secreted by these glands control many bodily functions, and play an important role in the development of young organisms. BPA is known as an endocrine-disrupting chemical (EDC), due to its similarity in molecular structure to the sex hormone estradiol, a member of the estrogen hormone family(Welshons, Nagel, & Vom Saal, 2006). Because of the structural similarity, BPA exhibits effects similar to estradiol when ingested and transported to specific sites in the human body. Thus, rather than being particularly toxic when ingested, the danger lies within BPA’s structural similarity to a hormone that regulates many bodily functions.

The main problem with past BPA research has been the amounts of BPA tested. In the past, possibly harmful substances under suspicion were tested using toxicology methods. Toxicology testing involves dosing relatively large quantities of the suspicious substance to test animals, observing the symptoms, and correlating that information to human immune systems. The problem with this sort of testing on substances that exhibit endocrine-like behavior is that the substances generally exhibit a large effect on the endocrine system when dosed in very small quantities. With BPA in particular, the research consisted of dosing BPA to test animals in large doses, observing the effects in the animals, and then extrapolating the data down to the reported daily exposure level of 50,000 nanograms per kilogram per day (Welshons, Nagel, & Vom Saal, 2006). The problem with this sort of testing is that the groups responsible for these tests never actually tested the 50,000 nanograms per kilogram per day in a biological model. Instead, the group simply made a prediction based on their data. The groups should have focused the research on whether or not BPA affects the cellular estrogen receptors in the test animals. Instead, the groups used doses of BPA that saturated the estrogen receptors with the lowest doses, a thousand-fold higher than a predicted safe dose (Welshons, Nagel, & Vom Saal, 2006). Saturation of the estrogen receptors prevented the scientists from observing any hormone disruption effects from BPA ingestion.