How to buy a quality sofa – part 4: synthetic fibers

3 10 2012

So from last week’s post, you  know that you want a durable, colorfast fabric that will be lovely to look at and wonderful to live with.  What’s the best choice?  I’m so glad you asked.

You have basically two choices in fibers:  natural (cotton, linen, wool, hemp, silk)  or synthetic (polyester, acrylic, nylon, etc.).  Many fabrics today are made from blends of natural and synthetic fibers – it has been said that most sheet sets sold in the U.S. are cotton/poly blends.

Natural fibres breathe, wicking moisture from the skin, providing even warmth and body temperature;  they are renewable, and decay at end of life.  On the other hand, synthetics do not breathe,  trapping body heat and perspiration; they are based on crude oil, definitely a non-renewable resource and they do not decompose at end of life, but rather remain in our landfills, leaching their toxic monomers into our groundwater.  They are, however, cheap and durable.

I like to think that even without the health issues involved I’d choose to live with natural fibers, since they work so well with humans!  The fibers themselves present no health issues and they’re comfortable.  But they simply don’t last as long as synthetics. But I have begun to see the durability of synthetics as their Dorian Grey aspect, in other words they last so long that they’ve become a huge problem.  By not decomposing, they just break into smaller and smaller particles which leach their toxic monomers into our groundwater.

The impact on health (ours the the planet’s) is an issue that’s often overlooked when discussing the merits of natural vs. synthetic.   And it’s a complex issue, so this week we’ll explore synthetic fibers, and next week we’ll look at natural fibers.

The most popular synthetic fiber in use today is polyester.

At this point, I think it would be good to have a basic primer on polyester production, and I’ve unabashedly lifted a great discussion from Marc Pehkonen and Lori Taylor, writing in their website diaperpin.com:

Basic polymer chemistry isn’t too complicated, but for most people the manufacture of the plastics that surround us is a mystery, which no doubt suits the chemical producers very well. A working knowledge of the principles involved here will make us more informed users.

Polyester is only one compound in a class of petroleum-derived substances known as polymers. Thus, polyester (in common with most polymers) begins its life in our time as crude oil. Crude oil is a cocktail of components that can be separated by industrial distillation. Gasoline is one of these components, and the precursors of polymers such as polyethylene are also present.

Polymers are made by chemically reacting a lot of little molecules together to make one long molecule, like a string of beads. The little molecules are called monomers and the long molecules are called polymers.

Like this:

O + O + O + . . . makes OOOOOOOOOOOOOOOO

Depending on which polymer is required, different monomers are chosen. Ethylene, the monomer for polyethylene, is obtained directly from the distillation of crude oil; other monomers have to be synthesized from more complex petroleum derivatives, and the path to these monomers can be several steps long. The path for polyester, which is made by reacting ethylene glycol and terephthalic acid, is shown below. Key properties of the intermediate materials are also shown.

The polymers themselves are theoretically quite unreactive and therefore not particularly harmful, but this is most certainly not true of the monomers. Chemical companies usually make a big deal of how stable and unreactive the polymers are, but that’s not what we should be interested in. We need to ask, what about the monomers? How unreactive are they?

We need to ask these questions because a small proportion of the monomer will never be converted into polymer. It just gets trapped in between the polymer chains, like peas in spaghetti. Over time this unreacted monomer can escape, either by off-gassing into the atmosphere if the initial monomers were volatile, or by dissolving into water if the monomers were soluble. Because these monomers are so toxic, it takes very small quantities to be harmful to humans, so it is important to know about the monomers before you put the polymers next to your skin or in your home. Since your skin is usually moist, any water-borne monomers will find an easy route into your body.

Polyester is the terminal product in a chain of very reactive and toxic precursors. Most are carcinogens; all are poisonous. And even if none of these chemicals remain entrapped in the final polyester structure (which they most likely do), the manufacturing process requires workers and our environment to be exposed to some or all of the chemicals shown in the flowchart above. There is no doubt that the manufacture of polyester is an environmental and public health burden that we would be better off without.

What does all of that mean in terms of our health?  Just by looking at one type of cancer, we can see how our lives are being changed by plastic use:

  • The connection between plastic and breast cancer was first discovered in 1987 at Tufts Medical School in Boston by research scientists Dr. Ana Soto and Dr. Carlos Sonnenschein. In the midst of their experiments on cancer cell growth, endocrine-disrupting chemicals leached from plastic test tubes into the researcher’s laboratory experiment, causing a rampant proliferation of breast cancer cells. Their findings were published in Environmental Health Perspectives (1991)[1].
  • Spanish researchers, Fatima and Nicolas Olea, tested metal food cans that were lined with plastic. The cans were also found to be leaching hormone disrupting chemicals in 50% of the cans tested. The levels of contamination were twenty-seven times more than the amount a Stanford team reported was enough to make breast cancer cells proliferate. Reportedly, 85% of the food cans in the United States are lined with plastic. The Oleas reported their findings in Environmental Health Perspectives (1995).[2]
  • Commentary published in Environmental Health Perspectives in April 2010 suggested that PET might yield endocrine disruptors under conditions of common use and recommended research on this topic. [3]

These studies support claims that plastics are simply not good for us – prior to 1940, breast cancer was relatively rare; today it affects 1 in 11 women.  We’re not saying that plastics alone are responsible for this increase, but to think that they don’t contribute to it is, we think, willful denial.  After all, gravity existed before Newton’s father planted the apple tree and the world was just as round before Columbus was born.

Polyester fabric is soft, smooth, supple – yet still a plastic.  It contributes to our body burden in ways that we are just beginning to understand.  And because polyester is highly flammable, it is often treated with a flame retardant, increasing the toxic load.  So if you think that you’ve lived this long being exposed to these chemicals and haven’t had a problem, remember that the human body can only withstand so much toxic load – and that the endocrine disrupting chemicals which don’t seem to bother you may be affecting generations to come.

And then there is acrylic.  The key ingredient of acrylic fiber is acrylonitrile, (also called vinyl cyanide). It is a carcinogen (brain, lung and bowel cancers) and a mutagen, targeting the central nervous system.  According to the Centers for Disease Control and Prevention, acrylonitrile enters our bodies through skin absorption, as well as inhalation and ingestion.  So could the acrylic fibers in our acrylic fabrics be a contributing factor to these results?

Acrylic fibers are just not terrific to live with anyway.  Acrylic manufacturing involves highly toxic substances which require careful storage, handling, and disposal. The polymerization process can result in an explosion if not monitored properly. It also produces toxic fumes. Recent legislation requires that the polymerization process be carried out in a closed environment and that the fumes be cleaned, captured, or otherwise neutralized before discharge to the atmosphere.(4)

Acrylic is not easily recycled nor is it readily biodegradable. Some acrylic plastics are highly flammable and must be protected from sources of combustion.

Just in case you missed the recent report which was published in Occupational and Environmental Medicine [5], a Canadian study found that women who work with some common synthetic materials could treble their risk of developing breast cancer after menopause. The data included women working in textile factories which produce acrylic fabrics – those women have seven times the risk of developing breast cancer than the normal population, while those working with nylon fibers had double the risk.

What about nylon?  Well, in a nutshell, the production of nylon includes the precursors benzene (a known human carcinogen) and hydrogen cyanide gas (extremely poisonous); the manufacturing process releases VOCs, nitrogen oxides and ammonia.  And finally there is the addition of those organophosphate flame retardants and dyes.

[1] http://www.bu-eh.org/uploads/Main/Soto%20EDs%20as%20Carcinogens.pdf

[2] http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info:doi/10.1289/ehp.95103608

[3] Sax, Leonard, “Polyethylene Terephthalate may Yield Endocrine Disruptors”,
Environmental Health Perspectives, April 2010, 118 (4): 445-448

(4) ) http://www.madehow.com/Volume-2/Acrylic-Plastic.html

(5) Occupational and Environmental Medicine 2010, 67:263-269 doi: 10.1136/oem.2009.049817 (abstract: http://oem.bmj.com/content/67/4/263.abstract) SEE ALSO: http://www.breastcancer.org/risk/new_research/20100401b.jsp AND http://www.medpagetoday.com/Oncology/BreastCancer/19321





Bioplastics – are they the answer?

16 04 2012

From Peak Energy blog; August 27, 2008

From last week’s blog post, we discussed how bio based plastics do indeed save energy during the production of the polymers, and produce fewer greenhouse gasses during the process.  Yet right off the bat, it could be argued that carbon footprints may be an irrelevant measurement,  because it has been established that plants grow more quickly and are more drought and heat resistant in a CO2 enriched atmosphere!   Many studies have shown that worldwide food production has risen, possibly by as much as 40%, due to the increase in atmospheric CO2 levels.[1] Therefore, it is both ironic and a significant potential problem for biopolymer production if the increased CO2 emissions from human activity were rolled back, causing worldwide plant growth to decline. This in turn would greatly increase the competition for biological sources of food and fuel – with biopolymers coming in last place.[2]  But that’s probably really stretching the point.

The development of bioplastics holds the potential of renewability, biodegradation, and a path away from harmful additives. They are not, however, an automatic panacea.  Although plant-based plastics appeal to green-minded consumers thanks to their renewable origins,  their production carries environmental costs that make them less green than they may seem.  It’s important to remember that bioplastics, just like regular plastics, are synthetic polymers; it’s just that plants are being used instead of oil to obtain the carbon and hydrogen needed for polymerization.

It’s good marketing, but bad honesty, as they say, because there are so many types of plastics and bioplastics that you don’t know what you’re getting in to;  bioplastics are much more complicated than biofuels.  There are about two dozen different ways to create a bioplastic, and each one has different properties and capabilities.

Actually the term “bioplastic” is pretty meaningless, because some bioplastics are actually made from oil – they’re called “bioplastics” because they are biodegradeable.  That causes much confusion because plastics made from oil can be biodegradeable whereas some plant-based  bioplastics are not. So the term bioplastics can refer either to the raw material (biomass) or, in the case of oil-based plastic, to its biodegradability.  The problem with biodegradability and compostability is that there is no agreement as to what that actually means either,  and under what circumstances

You might also see the term “oxo-degradable”.   Oxo-degradables look like plastic, but they are not. It is true that the material falls apart, but that is because it contains metal salts which cause it to disintegrate rapidly into tiny particles. Then you cannot see it anymore, but it is still there, in the ocean too. Just as with conventional plastics, these oxo-degradables release harmful substances when they are broken down.

Let’s re-visit  some of the reasons bioplastics are supposed to be an environmental benefit:

  • Because it’s made from plants, which are organic, they’re good for the planet.  Polymer bonds can be created from oil, gas or plant materials. The use of plant materials does not imply that the resulting polymer will be organic or more environmentally friendly. You could make non-biodegradable, toxic plastic out of organic corn!
  • Bioplastics are biodegradable. Although made from materials that can biodegrade, the way that material is turned into plastic  makes it difficult (if not impossible) for the materials to naturally break down.  There are bioplastics made from vegetable matter (maize or grass, for example) which are no more biodegradable than any other plastics, says Christiaan Bolck of Food & Biobased Research.[3]  Bioplastics do not universally biodegrade in normal conditions  –  some require special, rare conditions to decompose, such as high heat composting facilities, while others may simply take decades or longer to break down again, mitigating the supposed benefits of using so-called compostable plastics material. There are no independent standards for what even constitutes “biodegradable plastic.”  Sorona makes no claim to break down in the environment; Ingeo is called “compostable” (though it can only be done in industrial high heat composters). Close studies of so-called degradable plastics have shown that some only break down to plastic particles which are so small they can’t be seen  (“out of sight, out of mind”), which are more easily ingested by animals. Indeed, small plastic fragments of this type may also be better able to attract and concentrate pollutants such as DDT and PCB.[4]
  • Bioplastics are recyclable. Because bioplastics come in dozens of varieties, there’s no way to make sure you’re getting the right chemicals in the recycling vat – so although some bioplastics are recyclable, the recycling facilities won’t separate them out.  Cargill Natureworks insists that PLA  can in theory be recycled, but in reality it is likely to be confused with polyethylene terephthalate (PET).  In October 2004, a group of recyclers and recycling advocates issued a joint call for Natureworks to stop selling PLA for bottle applications until the recycling questions were addressed.[5]  But the company claims that levels of PLA in the recycling stream are too low to be considered a contaminant.  The process of recycling bioplastics is cumbersome and expensive – they present a real problem for recyclers because they cannot be handled using conventional processes. Special equipment and facilities are often needed. Moreover, if bioplastics commingle with traditional plastics, they contaminate all of the other plastics, which forces waste management companies to reject batches of otherwise recyclable materials.
  • Bioplastics are non-toxicBecause they’re not made from toxic inputs (as are oil based plastics), bioplastics have the reputation for being non toxic.  But we’re beginning to see the same old toxic chemicals produced from a different (plant-based) source of carbon. Example:  Solvay’s bio-based PVC uses phthalates,  requires chlorine during production, and produces dioxins during manufacture, recycling and disposal. As one research group commissioned by the European Bioplastics Association was forced to admit, with regard to PVC,  “The use of bio-based ethylene is …  unlikely to reduce the environmental impact of PVC with respect to its toxicity potential.[6]

The arguments against supporting bioplastics include the fact that they are corporate owned, they compete with food, they bolster industrial agriculture and lead us deeper into genetic engineering, synthetic biology and nanotechnology.  I am not with those who think we shouldn’t go there, because we sorely need scientific inquiry  and eventually we might even get it right.  But, for example, today’s industrial agriculture is not, in my opinion, sustainable, and the genetic engineering we’re doing is market driven with no altruistic motive. 

If properly designed, biodegradable plastics have the potential to become a much-preferred alternative to conventional plastics. The Sustainable Biomaterials Collaborative (SBC)[7] is a coalition of organizations that advances the introduction and use of biobased products. They seek to replace dependence on materials made from harmful fossil fuels with a new generation of materials made from plants – but the shift they propose is more than simply a change of materials.  They promote (according to their website): sustainability standards, practical tools, and effective policies to drive and shape the emerging markets for these products.  They also refer to “sustainable bioplastics” rather than simply “bioplastics”.  In order to be a better choice, these sustainable bioplastics must be:

  • Derived from non-food, non-GMO source materials – like algae rather than GMO corn, or from sustainably grown and harvested cropland or forests;
  • Safe for the environment during use;
  • Truly compostable and biodegradable;
  • Free of toxic chemicals during the manufacturing and recycling process;
  • Manufactured without hazardous inputs and impacts (water, land and chemical use are considerations);
  • Recyclable in a cradle-to-cradle cycle.

Currently, manufacturers are not responsible for the end-life of their products. Once an item leaves their factories, it’s no longer the company’s problem. Therefore, we don’t have a system by which adopters of these new bioplastics would be responsible for recovering, composting, recycling, or doing whatever needs to be done with them after use. Regarding toxicity, the same broken and ineffective regulatory system is in charge of approving bioplastics for food use, and there is no reason to assume that these won’t raise just as many health concerns as conventional plastics have. Yet again, it will be an uphill battle to ban those that turn out to be dangerous.

A study published in Environmental Science & Technology traces the full impact of plastic production all the way back to its source for several types of plastics.[8]   Study author Amy Landis of the University of Pittsburgh says, “The main concern for us is that these plant-derived products have a green stamp on them just because they’re derived from biomass.  It’s not true that they should be considered sustainable. Just because they’re plants doesn’t mean they’re green.”

The researchers found that while making bioplastics requires less fossil fuel and has a lower impact on global warming, they have higher impacts for eutrophication, eco-toxicity and production of human carcinogens.  These impacts came largely from fertilizer use, pesticide use and conversion of lands to agricultural fields, along with processing the bio-feedstocks into plastics, the authors reported.

According to the study, polypropylene topped the team’s list as having the least life-cycle impact, while PVC and PET (polyethylene terephthalate) were ranked as having the highest life-cycle impact.

But as the Plastic Pollution Coalition tells us, it’s not so much changing the material itself that needs changing – it’s our uses of the stuff itself.  We are the problem:   If we continue to buy single-use disposable objects such as plastic bottles and plastic bags, with almost 7 billion people on the planet, our throwaway culture will continue to harm the environment, no matter what it’s made of.

The Surfrider Foundation

The Surfrider Foundation has a list of ten easy things you can do to keep plastics out of our environment:

  1. Choose to reuse when it comes to  shopping bags and bottled water.  Cloth bags and metal or glass reusable  bottles are available locally at great prices.
  2. Refuse single-serving packaging, excess  packaging, straws and other ‘disposable’ plastics.  Carry reusable utensils in your purse, backpack or car to use at bbq’s, potlucks or take-out  restaurants.
  3. Reduce everyday plastics such as sandwich bags and juice cartons by replacing them with a reusable lunch bag/box that includes a thermos.
  4. Bring your to-go mug with you to the coffee shop, smoothie shop or restaurants that let you use them. A great  way to reduce lids, plastic cups and/or plastic-lined cups.
  5. Go digital! No need for plastic cds,  dvds and jewel cases when you can buy your music and videos online.
  6. Seek out alternatives to the plastic  items that you rely on.
  7. Recycle. If you must use plastic, try to choose #1 (PETE) or #2 (HDPE), which are the most commonly recycled      plastics. Avoid plastic bags and polystyrene foam as both typically have very low recycling rates.
  8. Volunteer at a beach cleanup. Surfrider Foundation Chapters often hold cleanups monthly or more frequently.
  9. Support plastic bag bans, polystyrene  foam bans and bottle recycling bills.
  10. Spread the word. Talk to your family and friends about why it is important to Rise Above Plastics!

[1] See for example: Idso, Craig, “Estimates of Global Food Production in the year 2050”, Center for the Study of Carbon dioxide and Global Change, 2011  AND  Wittwer, Sylvan, “Rising Carbon Dioxide is Great for Plants”, Policy Review, 1992  AND  http://www.ciesin.org/docs/004-038/004-038a.html

[2] D. B. Lobell and C. B. Field, Global scale climate-crop yield relationships and the impacts of recent warming, Env. Res. Letters 2, pp. 1–7, 2007 AND L. H. Ziska and J. A. Bunce, Predicting the impact of changing CO2 on crop yields: some thoughts on food, New Phytologist 175, pp. 607–618, 2007.

[3] Sikkema, Albert, “What we Don’t Know About Bioplastics”, Resource, December 2011; http://resource.wur.nl/en/wetenschap/detail/what_we_dont_know_about_bioplastics

[4] Chandler Slavin, “Bio-based resin report!” Recyclable Packaging Blog May 19, 2010 online at http://recyclablepackaging.wordpress.com/2010/05/19/bio-based-resin-report

[6] L. Shen, “Product Overview and Market Projection of Emerging Bio- Based Plastics,” PRO-BIP 2009, Final Report, June 2009





Bisphenol A in textile processing?

16 12 2011

If you’ve bought baby bottles or water bottles recently, I’m sure you’ve seen a prominent “BPA Free” sign on the container.

BPA stands for Bisphenol A, a chemical often used to make clear, polycarbonate plastics (like water and baby bottles and also eyeglass lenses, medical devices, CDs and DVDs, cell phones and computers).  And though it has been formally declared a hazard to human health in Canada and banned in baby bottles in both Canada as well as the EU,  U.S. watchdog agencies have wildly differing views of BPA:  The National Toxicology Program (NTP) reported “some concern” that BPA harms the brain and reproductive system, especially in babies and fetuses.  The Food and Drug Administration declared that “at current levels of exposure” BPA is safe.

But consider this:  Of  the more than 100 independently funded experiments on BPA, about 90% have found evidence of adverse health effects at levels similar to human exposure. On the other hand, every single industry-funded study ever conducted — 14 in all — has found no such effects.  David Case made the argument in the February 1, 2009 issue of Fast Company that this is a story about protecting a multibillion-dollar market from deregulation.  But that’s beside the point  which is:    nobody disputes the fact that people are constantly exposed to BPAs and babies are most at risk.  It’s also undisputed that BPA mimics the female sex hormone estrogen, and that some synthetic estrogens can cause infertility and cancer.  If you’d like to read more about this click here.

Bisphenol A is now deeply imbedded in the products of modern consumer society.  This is important because it’s used in so many modern products (making it pretty much ubiquitous), and because it is extremely potent in disrupting fetal development. BPA contamination is also widespread in the environment. For example, BPA can be measured in rivers and estuaries at concentrations that range from under 5 to over 1900 nanograms/liter.(1)

What this all means is that most of  us live our lives in close proximity to bisphenol A.

Because it’s used to make plastic hard, I never thought it would have a place in the textile industry.  So it was with some concern that I came across articles which explain the use of bisphenol A in the manufacturing of synthetic fibers.

Producing synthetic fibers and yarns is almost impossible without applying a processing aid to the fibers during the extrusion and spinning processes.   The fibers and yarns are frequently in contact with hot surfaces, or they pass through hot ovens.  In order to withstand these extreme conditions, the yarns and fibers have processing aids or finishes applied.    This applied processing aid or ‘finish’, in addition to helping the yarns withstand extreme temperatures, also  reduces static electricity, fiber-fiber and metal-fiber friction, provides integrity to the filaments,  and altogether eases the manufacturing processes.

But because modern manufacturing equipment runs at higher speeds and subsequently at higher temperatures, the finish degrades in the high temperatures – yielding lower quality fibers –  and generates unwanted decomposition products.  These byproducts can be in the form of:

  1. Toxic and nontoxic gases which have environmental and safety issues;
  2. Liquids, which leave a sticky residue on the yarns,
  3. Or they may form a solid varnish on hot surfaces that is very difficult to remove; the presence of the varnish interferes with continuous, efficient production leading to economic losses due to equipment shutdown and product failure.

To overcome the problems caused by the degradation of finishes, several additives are introduced to prevent or delay the reactions of oxidation and degradation.  Several classes of antioxidants are typically used as these additives in these finishes.

In a study sponsored by the National Textile Center, a research consortium of eight universities, three North Carolina State University professors investigated the thermal stability of textiles, specifically with respect to the antioxidants used in the finishes.  They investigated four different antioxidants – one of which is based on Bisphenol A. (2)

So I got interested, and began a bit of poking around for other mentions of Bisphenol A in the textile industry. I found two scientific references to use of bisphenol A in the production of  polyester fabrics.  Both reported similar use of Bisphenol A as this quote,  which states:  “ a woven polyester fabric was … finished with an aqueous compound  containing 5% polyethylene glycol bisphenol A ether diacrylate for 30 min at 60° to give a hygroscopic, antistatic fabric with good washfastness.” (3)

I found that Bisphenol A is used  in the production of flame retardants, and as an intermediate in the manufacture of polymers, fungicides, antioxidants (mentioned above), and dyes.   Because it is often used as an intermediate it’s hard to pin down, and manufacturers keep their ingredients trade secrets so we often will not know – unless somebody funds a study which is published.

I have not seen any studies which report finding Bisphenol A in a finished fabric, so this may be a tempest in a teacup.  But isn’t it worth noting that this chemical, which has been found in the blood of 95% of all Americans, and which some say may be the “new lead”, can exist in products in which we previously never would have thought to look?

(1)  http://www.ourstolenfuture.org/newscience/oncompounds/bisphenola/bpauses.htm

(2) Grant, Christine; Hauser, Peter; Oxenham, William, “Improving the Thermal Stability of Textile Processing Aids”,  www.ntcresearch.org/pdf-rpts/AnRp04/C01-NS08-A4.pdf

(3)  http://www.lookchem.com/cas-644/64401-02-1.html?countryid=0