"Glass is nature's safest container" proclaims an ad that ran in my local newspaper, The Midland Daily News. Chicken with Broken Glass, one of our family recipes immediately sprang to mind. Broken glass clearly is a safety risk, certainly not suitable as an ingredient for a chicken dish, unless you are the Addams family. It is a family joke. Chicken with Broken Glass got that name the first time it was ever served to me. It was the night before I defended my dissertation. My wife, at that time my girlfriend, volunteered to make dinner. Her selection was a chicken dish that requires fruit jelly. She drop kicked a grocery bag on her approach to the apartment, breaking the glass jelly jar. My wife, at the time my girlfriend and not the beneficiary of my life insurance, decided that the jelly was still appropriate for use in the recipe.
The facts, up to this point, are not in dispute. The rest of the story has two versions, with one element of dispute. I recall seeing and picking a consequential piece of glass from the dish. The finding of the glass prompted her to tell me the story of the broken jar and the decision to use the jelly. My wife recalls I found no glass. She recalls telling me about the broken jar only after I had enjoyed the meal. The jar split along a single fracture, allowing safe salvage of the contents, according to her version. Truth cannot be determined almost 30 years after the event. The only two people present recall the events differently.
My wife and I are both well-educated. We are reasonably intelligent people. We also have been exposed to the concepts of "safe" and “safety” for our entire lives. We would, as most of you would, say that we know what safe and safety mean. I would not have used the jelly from the broken jar, judging it to be unsafe. Given exactly the same data and having very similar level of education, my wife saw the situation differently. In her view, the data support her interpretation: I did survive the meal unscathed. For her, that is proof that the dish was safe.
We discovered almost 30 years ago that we disagreed on what safe meant. That disagreement continues to this day. It shows that two people trained to let data inform their actions can interpret the same data in different ways, leading to different conclusions. Two similarly educated people confronted with the same circumstances act in different ways due to different interpretations of a word – a concept – we’ve both known our entire lives. A concept that everyone understands.
Based on the data I have and my interpretation of safe, the ad in The Midland Daily News is mistaken. Glass, due to its physical properties and tendency to break leaving sharp edges, is not "Nature's safest container". Others must agree with me. Glass bottles are a thing of the past at stadiums due to safety concerns, replaced by unbreakable plastic and metal containers. The ad in The Midland Daily News goes on to say glass is the most sustainable container too.
The Midland Daily News is the newspaper in the home town of the corporate headquarters of one of the largest plastics companies in the world. Dow Chemical is headquartered there and is one of the largest polyethylene producers globally. Linear low-density polyethylene makes up a large part of the Dow portfolio, containing both conventional Ziegler-Natta resins and the modern single-site metallocene and post-metallocene polymers. LLDPE is a prime resin for films, making exceptionally strong, puncture resistant films. Most people don't ponder things like plastic bags, whether for bread, trash or newspaper delivery. If you do take a moment to recall these bags from your youth, you must be impressed with how thin and strong the bags of today are relative to those of memory. The resins in today's films allow more to be done with less, reducing the amount of plastic used for each bag while offering superior performance. This is certainly one of the reasons that plastic packaging has become such a large part of our lives. More and more, bags are replacing boxes, jars, bottles and cans. The grocery shelves are being transformed.
Plastic has a compelling value proposition. It does the same job while consuming fewer resources in a safer way. Plastic does not fracture like glass. It does not yield sharp fragments when it fails. Safety and sustainability form the value proposition. Fewer resources are used across the life cycle in production, transportation, use, and disposal, whether in landfill, incineration or recycle. Plastic packaging is not an evil plot hatched on the world, it is a result of the market being driven to provide materials in the safest and most resource efficient way. It provides the lowest cost to serve, the direct result of resource efficiency.
Chicken with Broken Glass illustrates that reasonably intelligent folks can disagree on safety, a concept they have known since childhood. Sustainability and sustainable are relatively new concepts. They are also concepts that require more work to understand. Safety is frequently about a moment in time, like when a desperado breaks a bottle to make a weapon in an old western movie. We can see the sharp edges and based on that moment in time determine that the broken glass is not safe. We don’t have to know anything about how the bottle was made or how it was used prior to being broken to determine it is not safe.
Sustainability is harder. Sustainability requires understanding the life cycle. We have to know where something came from, how it was manufactured, how it was used and where it goes at end-of-life in order to understand the sustainability. It is not easy. It is no wonder that the discourse on sustainability can be so fractious. Ambiguous meanings and a requirement that life cycles be examined make for great difficulties. Safety should be much easier and we don't even agree on that.
Mark Jones is Executive External Strategy and Communications Fellow at Dow Chemical since September 2011. He spent most of his career developing catalytic processes after joining Dow in 1990. He received his Ph.D. in Physical Chemistry at the University of Colorado-Boulder doing research unlikely to lead to an industrial career and totally unrelated to his current responsibilities.