Extrusion Expert: Countering plastophobiaExtrusion Expert: Countering plastophobia

Allan Griff, our Extrusion Expert, took on the growing phenomenon of "plastophobia" in his final Extrusion Expert webcast. Below are questions and answers taken from that session's live Q&A.

BPA is a building block in making PC but it is also a degradation product.

So we need to know the conditions of degradation , the end products and the amounts generated per unit time as a function of temperature Hydrolysis/chain breakage isn't the same as regeneration of BPA. A can lining is heated to 125°C for 20 minutes? How much of what is produced and transferred to contents? A baby bottle is sterilized for a few minutes at 100°C? How much of what? Room-temp uses such as water bottles aren't heated at all. How much of what? Paracelsus said " the dose makes the poison," and I agree. And if PC degrades to BPA, is there any phosgene recreated, too? Doubtful, as the chlorine is gone. How about H2C=O (formaldehyde)?

Have the BPA foes sought and based their claims on such numbers? I doubt it, but am ready to look at anything responsibly generated. Science is no place for guesswork or spin.

You say "BPA in polycarbonate should be zero" . How did the hullabaloo on BPA begin? Red herring?

Not quite. There is evidence that BPA affects humans (http://en.wikipedia.org/wiki/Bisphenol_A) but there is heated argument as to the extent and nature of this effect, and what to do about it. I consider it an example of chemical democracy, where laws and/or action follow public sentiment. As you may have deduced from my webinar, I don't like this distortion of science and I am trying to see where the "plastophobia" originates and why. I find it curious, for example, that the Wikipedia article, even though it tries to be scientific and to report what is done and known, virtually ignores the other building block for polycarbonates, phosgene, a very nasty stuff to humans (WWI poison gas!). It also seems unaware that the "polycarbonate" used for eyeglass lenses is chemically different from the thermoplastic polycarbonates, and has nothing to do with BPA at all. Wikipedia is technically correct there (see "uses"), but logically fallacious, as it implies that all polycarbonates are made with BPA, when in fact they aren't.

BPA is not a component nor ingredient in PC, but a building block (monomer), and a rather expensive one at that, so that there should be miniscule amounts left in the polycarbonate -- and even if some is there, it still has to transfer to foods and then to us before we need to be concerned.

It was pointed out by another webinarian that BPA is also re-produced when PC degrades -- but although degradation might theoretically produce some BPA, the primary results of the well-known water-catalyzed degradation are shorter polymer chains -- but they are still chains, not free BPA. I'd be very interested in knowing the amount of free BPA produced, if any, during the extrusion/blowmolding processes, and will now seek such information. The melt processing is the critical time, as later contact with food/drink is for much shorter time and much lower temperature.

You got the reference to Pink Floyd, "Teacher, leave those kids alone," a very important example of the need for youth to challenge authority as a form of cultural mutation to ensure adaptive change necessary for survival. As an "elder" it's my job to resist such challenges so that only the best ones survive and go on to color our lives. 

I'm concerned with genetic modification of foodstuff like corn, presumably to reduce the cost.  Do you think this is related to biomass plastics?

No, I am not concerned at all. Even if I was afraid of GM crops, the chemicals needed to make biobased plastic (such as ethanol) have no genetic material attached. Ethanol (ethyl alcohol) is a simple compound of two carbons, one oxygen and 6 hydrogens, no matter how it's produced.  As for fears of GM, the genetic material in a corn cell is already foreign to my own cells and no more/less likely to affect me whether it is modified or not.  Moreover, plant breeders and farmers have been managing plant genetics for millennia. Today's GM crops just do it faster, driven by the desire to supply a hungry world with limited money and too many people.

PVC has been dubiously linked to everything from cancer to birth defects and even potential terrorist risks; what can we do to defend it from junk science if the facts aren't enough? Do you have any anecdotes or go-to analogies?

The simple answer to your question of "what can we do" is: Not much. The popular negative view of plastics in general and PVC in particular is so deeply rooted that people will fight against logic and science to hold their views and thus not buck the popular "wisdom." History is full of instances where people were told something that was socially and personally dangerous to dis-believe. Iraq's "weapons of mass destruction" is the most recent example -- the foundations of race hatred are another. Fear is usually the driver -- with plastics there is fear of chemicals, corporations, and of changing our consumption-based life-style.  

What can we do? Speak out, backed with sound science where possible. And face the fears. At least you will follow Polonius' advice (in Hamlet): "to thine own self be true."

I can give you one anecdote: when I was getting an anti-PVC lecture (back in 1995), I asked the speakers if they knew what makes green leaves green. "Chlorophyll," they replied. "Well, then," I said, "why are you against chlorine?" BTW, there is no chlorine in chlorophyll -- the "chloro" is from the Greek word for the color green.

In the past, litter - glass and paper, tended to be degraded into non-recognizables while today, durable plastic product litter sticks around. I think the greater problem is the lack of concern for our environment by those that litter. Let's call the problem honestly and not blame plastics.

I agree, but I don't think we are going to make silk behavior from sows' heads.  These are people who see themselves as used by the powers that be, and they are not them. I would even expect a certain joy to be derived by one of these pigs who tosses something out and visible. And that goes for saving resources and energy, too, unless it costs them money, and even if it does, there is an abandon and freedom in not giving a damn what "Mommy" thinks. Conspicuous consumption isn't a new invention, but an old way to differentiate the consumer from the others, establish hierarchies and roles.

Overlaid on this is the general plastophobia. The educated ones will not litter as much, but are just as antiplastic -- maybe more so -- as the pigs. The popular negative view of plastics is so deeply rooted that people will fight against logic and science to hold their views and thus not buck the popular "wisdom." History is full of instances where people were told something that was socially and personally dangerous to dis-believe. Iraq's "weapons of mass destruction" is the most recent example -- the foundations of race hatred are another. Fear is usually the driver -- with plastics there is fear of chemicals, corporations, and of changing our consumption-based life-style.  

What can we do? Speak out, backed with sound science where possible. And face the fears. At least you will follow Polonius' advice (in Hamlet): "to thine own self be true."

How do you feel biodegradable technologies affect the environmental impact?

Depends on what is degrading where, and the environmental impact of what the plastics replace. My own belief is that people are wanting plastics to "go away" and don't think much about comparative environmental impacts. There will always be a market for degradables as long as they are seen as "greener" in the public eye, but large-scale conversion to their use will be limited to consumer products and further by the cost. If the brand owners want to absorb the increased cost as the price to look green, this is like competitive advertising, and some of them will do this. They will also capitalize on the confusion between biobased and biodegradable -- example is the Coke plant-bottle I showed in the webinar. No degradation at all, yet green?

Is recycling effective? A recent study stated that that unless we can get over 50% recycle rates, it is better to landfill them. What are your thoughts?

Too general a statement. Depends on the resin, the location, the availability of landfill sites, the acceptability of incineration to power (more acceptable in some other more-crowded countries), and the cost to the environment of the actual recycling processes. My 2003 paper which I linked on one of the webinar slides deals with some of this, concludes the 2-l PET and aluminum cans are usually enviropositive, glass much less, but that's from an energy point of view, as that is something that can be measured and compared. Bring in the land availability and political inclination to do what the people think they want, and scientific measurement goes out the window,

PVC is one of the main Polymers that are demonized, but I don't think it is going to be banned or replaced for a very, very long time because of its great characteristics. We tried to replace PVC with PU and PE but the consumer market always comes back to PVC. What we do now is use safe ingredients in our PVC Formulas and we test them periodically to make sure we don't hurt people. We also try to educate customers about PVC.

I agree that your application will stay in PVC -- problem there is quality of offshore competition, not the base material. Some may be less resistant to UV damage, some may use plasticizers that migrate out and embrittle the product, some may even include heavy-metal pigments that are harmful (though you'd have to eat the product to ingest them).

Could you redefine ULS-FOS-TANA.

It stands for Use Less Stuff, Fix Old Stuff, and Throw Almost Nothing Away

If plastics have a good story to tell (and I believe they do), and educating consumers won't work, how do you suggest we defend this valuable and essential material?

By going deeper and trying to find out WHY people are so ready to resent/criticize/oppose plastics -- all plastics. This is a question of social psychology, not chemistry. Most people are afraid of chemistry as a science that impartially and impersonally takes away their conclusions and positions on which they rely for their perceived security. Plastics are on the front lines here, visible evidence of "man-made" invasion of their private lives.

What we can do about it will derive from what we find. I am not too optimistic, as I think people need such "demons" to give themselves a sense of power and importance in an increasingly technology-run world -- but that's only my opinion, and I think we need some serious study of this fear and resentment of plastics before we launch expensive efforts to convince people with facts when they have their minds already made up.

It's a tough row to hoe. I had the fantasy of a bunch of leaders -- Obama and/or Romney, Oprah, a movie star, a rock star, a sports hero, all eating a spoonful of PET pellets (maybe even PC) on national TV and then virally on you-tube -- but even that wouldn't work. People will say they did it for the money or the exposure (same as money to these people), rather than accept the harmlessness of their favorite chemical demon. Maybe we could start there, using resin company executives, doctors and professors.

I don't mean to trivialize the issue by these images. Rather, I want to show how deep-rooted the plastophobia is. It has already long passed the point of mass-image, where to show fear of plastics (BPA, leaching, PVC, don't microwave in it, bags kill fish) is socially OK, and to challenge these mass beliefs is socially dangerous. Any one who does so is just "doing it for the money." Not until we realize this, not until we realize that people can't always digest the information they are fed, but have their own needs for sanity and stability, that logic and science are fine at a distance, but not too close -- do we have a chance of reversing this status.

In one slide you say only PE & poly prop float, then in another slide say polystyrene floats.

Both are true, but for PS I was only referring to the foam (Styrofoam), such as hot cups, "peanuts" and foam blocks used to ship electronics.

The polyolefins (PE, PP) are lighter than water and float even in their solid (unfoamed) state. Solid PS and almost all other plastics sink in water.

Plastics that float are exposed to sunlight, which does deteriorate them and ultimately leads to smaller particles. Antiplastics people then say that these particles are eaten by fish (they are nontoxic, but may be nonexcretable). Sea mammals and larger fish may eat them, too, but should be able to process them harmlessly.  

This photodegradation breaks polymer chains but does not reduce the material to carbon dioxide and water, unlike combustion and some biodegradation. However, it does get them OOS-OOM (out of sight-out of mind) which is a major objective of the plastophobes.

Regarding energy potential - is this similar to the life cycle assessment LCA numbers being thrown around?"

Similar, but not the same. Life-cycle assessment is supposed to consider everything, but must be examined further to see what it is based on. For example -- how much importance is placed on carbon footprint (future effect on environment via global warming) vs resource conservation (recycling) vs energy costs from mine or well through disposal?

I have used energy needs in my own work because they can be quantified, but realize that is not the whole story. You should know who the storytellers are, and what are the factors they consider. That doesn't mean that everyone twists the facts to get the results they want, although there is certainly some of that on all sides. It's hard, though, to accept conclusions that are unfavorable to your technical, commercial and/or political points of view, or worse yet, if they conflict with what your customers think.