Textile chemicals – beginning with the one used the most

16 01 2013

saltLet’s begin our review of chemicals used in textile processing with the one chemical that is used most often and in far greater quantity than any other: salt. That’s right. Common table salt, the kind you probably use every day. But in the quantities used by this industry it becomes a monster – we’ll get to that in a minute.

Salt is used in the dye process. The way the dyestuff bonds to the fibers is very important – and the most permanent, colorfast dyes are the ones that are most tightly attached to the fiber molecules (called reactive dyes). Here’s how salt comes into the picture:

When fabrics made of cellulosic (i.e., cotton, linen, hemp or viscose) are dyed, they’re immersed in water which contains dyes which have been dissolved in the water. The surface of the fabric gets covered in negative ionic charges. The reactive dyes used most often to dye cellulosic fabrics also develop a negative charge, so the fibers actually repel the dye – like two magnets repelling each other. If we try to dye a cellulosic fabric without using salt, the dye molecules just roll off the surface of the fibers and the fabric does not show much color change. So these reactive dyes need the addition of salt to “push” the dyes out of solution and into the cloth by neutralizing the negative charge.

The salt acts like a glue to hold the dye molecules in place, and with the addition of alkali, a certain percentage of the dyestuff (called the “fixation rate”) will permanently grab hold of the fiber and become a part of the fiber molecule rather than remaining as an independent chemical entity. For conventional reactive dyes, the fixation rate is often less than 80%, resulting in waste of dyestuff, and also the need to remove that 20% (which is not fixed) from the fabric.(1) But this is incredibly difficult when the “unreacted” dyes are still “glued” onto the fabric by salt. So vast amounts of water are required to simply dilute the salt concentrations to a point where it no longer acts as glue.

That means the textile effluent contains both dyestuff and salt (lots of salt!) The concentrations of salt in the dye bath can be as high as 100 gm per liter. In the worst cases, equal weights of salt to fabric is used to apply reactive dye (i.e., if dyeing 10 lbs of fabric, you need 10 lbs of salt). Think of the billions of yards of fabric that’s produced each year: In Europe alone, 1 million tons of salt is discharged into waterways each year.(2) In areas where salt is discharged into the ecosystem, it takes a long, long time for affected areas to recover, especially in areas of sparse rainfall – such as Tirupur, India.

Tirupur is one of the world’s centers for clothing production , home of 765 dyeing and bleaching industries. These dyehouses had been dumping untreated effluent into the Noyyal River for years, rendering the water unsuitable or irrigation – or drinking. In 2005, the government shut down 571 dyehouses because of the effluent being discharged into the Noyyal. The mill owners said they simply couldn’t afford to put pollution measures into place. The industry is too important to India to keep the mills closed for long, so the government banned the discharge of salt and asked for an advance from the mills before allowing them to re-open. But … on February 4, 2011, the Madras high court ordered 700 dye plants to be shut down because of the damage the effluent was doing to the local environment. Sigh. (Read more about Tirupur here.)

Unfortunately, the salt in textile effluent is not made harmless by treatment plants and can pass straight through to our rivers even if it has been treated. The salt expelled into waterways (untreated) coupled with salt from roadway de-icing has led to the increase in salt in our waters in the United States – salt levels in Lake George have nearly tripled since 1980,(3) which mirrors many other parts of the U.S. Highest levels occur during the annual ice-out and snowmelt where high salt concentrations in streams flowing into Lake George have been linked to die offs of fish, and is known as “spring shock”. A study in Toronto found that half the wells tested exceeded the limit of 20mg of salt per liter of water, 20% exceeded 100mg/liter and 6% exceeded 250mg/liter. (4) It becomes a public health concern for people who drink this water, because it can exacerbate high blood pressure and hypertension in humans. This increase in our drinking water can also cause problems with water balance in the human body. Salt in water is also responsible for the release of mercury into the water system.

Recycling the salt used during the dye process is possible, and this has been used by many of the dyers in Tirupur, and elsewhere, who operate zero discharge facilities. The effluent is cleaned and then the salt is recovered using an energy intensive process to evaporate the water and leave the solid, re-useable salt. This sounds like a good idea – it reduces the pollution levels – but the carbon footprint goes through the roof, so salt recovery isn’t necessarily the best option. In fact, in some areas of the world where water is plentiful and the salt can be diluted in the rivers adequately, it may be better to simply discharge salt than to recover it.

There are some new “low salt” dyes that require only half the amount of “glue”: Ciba Specialty Chemicals, a Swiss manufacturer of textile dyes (now part of BASF) produces a dyestuff which requires less salt. As the company brochure puts it: “Textile companies using the new dyes are able to reduce their costs for salt by up to 2 percent of revenues, a significant drop in an industry with razor-thin profit margins” but these dyes are not widely used because they’re expensive – and manufacturers are following our lead in demanding ever cheaper costs. There are also new low-liquor-ratio (LLR) jet dyeing machines – but that doesn’t mean zero salt, so there is still salt infused effluent which must be treated. And these new ultra low liquor ratio machines are very expensive.

The best option is to avoid salt altogether. Though the salt itself is not expensive, using less salt delivers substantial benefits to the mill because the fabric requires less rinsing in hot water (and hence reductions in energy and water) as well as cost savings of up to 10% of the total process costs.(5) So what about using no salt at all?

There are two ways to dye fabrics without salt: “continuous dyeing” and “cold pad batch dyeing”. Continuous dyeing means that the dye is applied with alkali to activate the dye fixation; the fabric is then steamed for a few minutes to completely fix the dyestuff. Cold pad batch dyeing applies the dyestuff with alkali and the fabric is simply left at room temperature for 24 hours to fix the dye.

Both of these methods don’t use salt, so the unfixed dye chemicals are easier to remove because there is no salt acting as the “glue” – and therefore less water is used. An additional benefit is having a lower salt content in the effluent. So why don’t companies use this method? Continuous dyeing requires investment in big, expensive machines that only make environmental sense if they can be filled with large orders – because they use lots of energy even during downtime.

Cold pad batch machines are relatively inexpensive to buy and run, they are highly productive and can be used for a wide range of fabrics. Yet only 3% of knitted cotton fabric is dyed in Asia using cold pad batch machines.
Why on earth don’t these mills use cold pad batch dyeing? I would love to hear from any mill owners who might let us know more about the economics of dyeing operations.

(1) http://lifestylemonitor.cottoninc.com/Supply-Chain-Insights/Sustainable-Dyeing-Solutions-02-10/
(2) Dyeing for a change: Current Conventions and New Futures in the Textile Color Industry (2006, July) http://www.betterthinking.co.uk
(3) http://www.fundforlakegeorge.org/assets/pdf_files/Fact%20Sheet%2011%20Salt.pdf
(4) http://www.digitaltermpapers.com/a2206.htm
(5) “A Practical Guide For Responsible Sourcing”, The National Resources Defense Council (NRDC), February 2010.

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Is Ultrasuede® a “green” fabric?

8 09 2010

In 1970, Toray Industries colleagues Dr. Toyohiko Hikota and Dr. Miyoshi Okamoto created the world’s first micro fiber as well as the process to combine those fibers with a polyurethane foam into a non-woven structure – which the company trademarked as Ultrasuede®.

In April 2009,  Toray announced “a new  environmentally responsible line of products which are based on innovative recycling technology”, called EcoDesign™.    An EcoDesign™ product, according to the company press release, “captures industrial materials, such as scrap polyester films, from the Toray manufacturing processes and recycles them for use in building high-quality fibers and textiles.”

One of the first EcoDesign™ products to be introduced by Toray is a variety of their Ultrasuede®  fabrics.

So I thought we’d take a look at Ultrasuede® to see what we thought of their green claims.

The overriding reason Toray’s EcoDesign™ products are supposed to be environmentally “friendly” is because recycling postindustrial polyesters reduces both energy consumption and CO2 emissions by an average of 80% over the creation of virgin polyesters, according to Des McLaughlin, executive director of Toray Ultrasuede (America).   (Conventional recycling of polyesters generally state energy savings of between 33% – 53%.)

If that is the only advance in terms of environmental stewardship, we feel it falls far short of being considered an enlightened choice.  If we just look at the two claims made by the company:

  1. Re: energy reduction:  If we take the average energy needed to produce 1 KG of virgin polyester, 125 MJ[1], and reduce it by 80% (Toray’s claim), that means it takes 25 MJ to produce 1 KG of Ultrasuede® –  still far more energy than is needed to produce 1 KG of organic hemp (2 MJ), linen (10 MJ), or cotton (12 MJ).
  2. CO2 emissions are just one of the emissions issues – in addition to CO2, polyester production generates particulates, N2O, hydrocarbons, sulphur oxides and carbon monoxide,[2] acetaldehyde and 1,4-dioxane (also potentially carcinogenic).[3]

But in addition to these claims, the manufacture of this product creates many concerns which the company does not address, such as:

  1. Polyurethane, a component of Ultrasuede®, is the most toxic plastic known next to PVC; its manufacture creates numerous hazardous by-products, including phosgene (used as a lethal gas during WWII), isosyanates (known carcinogens), toluene (teratogenic and embryotoxic) and ozone depleting gases methylene chloride and CFC’s.
  2. Most polyester is produced using antimony as a catalyst.  Antimony is a carcinogen, and toxic to the heart, lungs, liver and skin.  Long term inhalation causes chronic bronchitis and emphysema.  So, recycled  – or not –  the antimony is still present.
  3. Ethylene glycol (EG) is a raw material used in the production of polyester.  In the United States alone, an estimated 1 billion lbs. of spent ethylene glycol is generated each year.  The EG distillation process creates 40 million pounds of still bottom sludge. When incinerated, the sludge produces 800,000 lbs of fly ash containing antimony, arsenic and other metals.[4] What does Toray do with it’s EG sludge?
  4. The major water-borne emissions from polyester production include dissolved solids, acids, iron and ammonia.  Does Toray treat its water before release?
  5. And remember, Ultrasuede®  is still  . . .plastic.  Burgeoning evidence about the disastrous consequences of using plastic in our environment continues to mount.  A new compilation of peer reviewed articles, representing over 60 scientists from around the world, aims to assess the impact of plastics on the environment and human health [5]and they found:
    1. Chemicals added to plastics are absorbed by human bodies.   Some of these compounds have been found to alter hormones or have other potential human health effects.
    2. Synthetics do not decompose:  in landfills they release heavy metals, including antimony, and other additives into soil and groundwater.  If they are burned for energy, the chemicals are released into the air.
  1. Nor does it take into consideration our alternative choices:  that using an organic fiber supports organic agriculture, which may be one of our most underestimated tools in the fight against climate change, because it:
    1. Acts as a carbon sink:   new research has shown that what is IN the soil itself (microbes and other soil organisms in healthy soil) is more important in sequestering carbon that what grows ON the soil.  And compared to forests, agricultural soils may be a more secure sink for atmospheric carbon, since they are not vulnerable to logging and wildfire. The Rodale Institute Farming Systems Trial (FST) soil carbon data (which covers 30 years)  demonstrates that improved global terrestrial stewardship–specifically including regenerative organic agricultural practices–can be the most effective currently available strategy for mitigating CO2 emissions. [6]
    2. eliminates the use of synthetic fertilizers, pesticides and genetically modified organisms (GMOs) which is  an improvement in human health and agrobiodiversity
    3. conserves water (making the soil more friable so rainwater is absorbed better – lessening irrigation requirements and erosion)
    4. ensures sustained biodiversity

Claiming that the reclamation and use of their own internally generated scrap is an action to be applauded may be a bit disingenuous.   It is simply the company doing what most companies should do as efficient operations:  cut costs by re-using their own scrap. They are creating a market for their otherwise un-useable scrap polyester from other operations such as the production of polyester film.  This is a good step by Toray, but to anoint it as the most sustainable choice or even as a true sustainable choice at all is  premature. Indeed we have pointed in prior blog posts that there are many who see giving “recycled polyester” a veneer of environmentalism by calling it a green option is one of the reasons plastic use has soared:     indeed plastic use has increased by a factor of 30 since the 1960s while recycling plastic has only increased by a factor of 2. [7] We cannot condone the use of this synthetic, made from an inherently non-renewable resource, as a green choice for the many reasons given above.

We’ve said it before and we’ll say it again:  The trend to eco consciousness in textiles represents major progress in reclaiming our stewardship of the earth, and in preventing preventable human misery.  You have the power to stem the toxic stream caused by the production of fabric. If you search for and buy an eco-textile, you are encouraging a shift to production methods that have the currently achievable minimum detrimental effects for either the planet or for your health. You, as a consumer, are very powerful. You have the power to change harmful production practices. Eco textiles do exist and they give you a greener, healthier, fair-trade alternative.

What will an eco-textile do for you? You and the frogs and the world’s flora and fauna could live longer, and be healthier – and in a more just, sufficiently diversified, more beautiful world.


[1]“Ecological Footprint and Water Analysis of Cotton, Hemp and Polyester”, by Cherrett et al, Stockholm Enviornemnt Institute

[2] “Ecological Footprint and Water Analysis of Cotton, Hemp and Polyester”, by Cherrett et al, Stockholm Environment Institute

[3] Gruttner, Henrik, Handbook of Sustainable Textile Purchasing, EcoForum, Denmark, August 2006.

[4] Sustainable Textile Development at Victor,  http://www.victor-innovatex.com/doc/sustainability.pdf

[5] “Plastics, the environment and human health”, Thompson, et al, Philosophical Transactions of the Royal Society, Biological Sciences, July 27, 2009

[6] http://www.rodaleinstitute.org/files/Rodale_Research_Paper-07_30_08.pdf

[7] http://www.edf.org/documents/1889_SomethingtoHide.pdf and http://discovermagazine.com/2009/oct/21-numbers-plastics-manufacturing-recycling-death-landfill





Optical brighteners

14 07 2010

I got a call awhile ago from Harmony Susalla, founder and chief designer for Harmony Art  (if you haven’t seen her glorious fabrics go right now to www.harmonyart.com).  She was wondering about optical brighteners, and I discovered I couldn’t tell her much except to say that some are derived from benzene, which is a chemical nobody wants to live with.  GOTS allows the use of optical brighteners – with caveats (see below) – but they are supposed to reevaluate them “in two years from date of adoption” of version 2.0, which puts the reevaluation right about now.

So let’s explore optical brighteners, which are used extensively in:

  • Laundry detergents (to replace whitening agents removed during washing and to make the clothes appear cleaner.) – detergents may contain up to 0.2% whitening agents,
  • Paper, especially high brightness papers, resulting in their strongly fluorescent appearance under UV illumination. Paper brightness is typically measured at 457nm, well within the fluorescent activity range of brighteners. Paper used for banknotes does not contain optical brighteners, so a common method for detecting counterfeit notes is to check for fluorescence.
  • Cosmetics: One application is in formulas for washing and conditioning grey or blonde hair, where the brightener can not only increase the luminance and sparkle of the hair, but can also correct dull, yellowish discoloration without darkening the hair).  Some advanced face and eye powders contain optical brightener microspheres that brighten shadowed or dark areas of the skin, such as “tired eyes”.
  • as well as fabrics, which may contain 0.5% OBAs. A side effect of textile optical whitening is to make the treated fabrics more visible with Night Vision Devices than non-treated ones (the fluorescence caused by optical brighteners can easily be seen with an ordinary black light). This may or may not be desirable for military or other applications

You can still buy “bluing” – which is advertised to “whiten whites and brighten colors”.  Bluing works by removing yellow light to lessen the yellow tinge.   Optical brighteners – also called optical brightening agents (OBAs), fluorescent brightening agents (FBAs), and/or fluorescent whitening agents (FWAs) or “synthetic fluorescent dyes” –  work a bit differently.  Optical brighteners are chemicals similar to dyes which absorb ultraviolet light and emit it back as visible blue light – in other words, they fluoresce the ultraviolet light into visible light. The blue light emitted by the brightener compensates for the diminished blue of the treated material and changes the hue away from yellow or brown and toward white.

They are designed to mask yellow or brown tones in the fibers and make the fabric look cleaner and brighter than it would otherwise appear to the naked eye.   In other words, the undesirable color is made invisible to the eye in an “optical manner”.  Optical brighteners are used both on natural fibers (cotton, linen, hemp, silk) as well as in polymer melts for polyester and other synthetic fiber production.

Optical brighteners aren’t effective unless they remain in the fabric, and persist after washing.  They only last so long, until the point when they actually burn out and no longer do anything. They are also subject to fading when exposed long term to UV.

Brighteners can be “boosted” by the addition of certain polyols like high molecular weight polyethylene glycol or polyvinyl alcohol. These additives increase the visible blue light emissions significantly. Brighteners can also be “quenched”. Too much use of brightener will often cause a greening effect as emissions start to show above the blue region in the visible spectrum.

Optical brighteners are synthesized from various chemicals.  The group of chemicals which are called “optical brighteners” consists of approximately 400 different types listed in the Color Index, but less than 90 are produced commercially. (To get more information about the Color Index click here .)

Basic classes of chemicals used in OBAs  include:

  • Triazine-stilbenes (di-, tetra- or hexa-sulfonated)
  • Coumarins
  • Imidazolines
  • Diazoles
  • Triazoles
  • Benzoxazolines
  • Biphenyl-stilbenes

Using these chemicals, many companies compose their own chemical versions of an optical brightener, and sell it under a branded name, such as:

  • Blankophar R
  • Calcofluor
  • Uvitex
  • Bluton
  • CBS
  • DMS E=416
  • Kolorcron 2B

To find out what is in the optical brightener in any fabric, you must know the name of the optical brightener, and also the C.I. number (such as Brightener 24 or 220).  Then you can look up the chemical composition of the substance – but  only if you’re a subscriber to the Color Index database.  So it’s pretty difficult to confirm what is actually in an optical brightener.

In exploring some of the chemicals used in formulating optical brighteners,  I found one called cyanuric chloride, a derivative of 1,3,5 triazine.  Cyanuric chloride is used as a precursor and crosslinking agent in sulfonated triazine-stilbene based optical brighterners.   It is also classified as “very toxic”, “harmful” and “corrosive” by the EU and has several risk phrases identified with it – including R26 (“very toxic by inhalation”).  R26 is a substance which is specifically prohibited by GOTS.  So how can optical brighteners be allowed under GOTS?

The short answer is:  some are allowed, some are not – it depends on the chemical composition of each individual optical brightener.   Like dyestuffs, GOTS allows optical brighteners if they “meet all criteria for the selection of dyes and auxiliaries as defined in chapter 2.4.6, Dyeing.”  Those criteria include the prohibition of all chemicals listed in 2.3.1 and substances which are assigned certain risk phrases “or combinations thereof”.   But in order to know if a particular optical brightener meets these criteria, it’s necessary to know the chemical formula for that brightener.   And that takes a bit of detective work – and even so you might not be able to get final answers.  Don’t you begin to feel like a hamster in one of those wheels going round and round?

What are the problems associated with optical brighteners?
Some brighteners have been proven to cause allergic skin reactions or eye irritation in sensitive people.   The German Textiles Working Group conducted a health assessment of various optical brightening agents  following concerns of potential health risks to the public. It was found that there is a general lack of information on toxicity and a need for studies into dermal  absorption and the release of these substances from clothes.  While it has not been shown to negatively affect health, it has also not been proven safe.

They are known to be toxic to fish and other animal and plant life and have been found to cause mutations in bacteria.

Most OBAs are not readily biodegradable, so chemicals remain in wastewater for long periods of time, negatively affecting water quality and animal and plant life.  It is assumed that the substances accumulate in sediment or sludge, leading to high concentrations.
In wastewater, OBAs can also leach into groundwater, streams, and lakes. Since fluorescence is easy to detect,  optical brightener monitoring is an emerging technique to quickly and cost-effectivley detect the contamination of stormwater by sanitary wastewater.

REACH is the new European Union regulation which aims to  improve human health and the environment through better and earlier identification of the properties of chemical substances.  REACH stands for Registration, Evaluation, Authorisation and Restriction of Chemical substances.   REACH contains provisions to reduce the use of what are called “high volume production” chemicals.  These are defined as chemicals having annual production and/or importation volumes above 1 million pounds.  It is assumed that high volume production is a proxy for high exposure; in addition, large releases of low toxicity substances such as salts do cause environmental harm due to the sheer volume of the substance.
Much of the impact from optical brighteners comes in the form of large releases of low toxicity substances.  A number of these optical brighteners are listed as high and low production volume substances and so will be subject to REACH.   For example, C.I. Fluorescent Brightener 220 is listed as a high production volume chemical.





Wool

9 06 2010

When we talk about wool, we almost always mean the fiber from sheep, although the term “wool” can be applied to the hair of other mammals including cashmere and mohair from goats, vicuna, alpaca and camel from animals in the camel family and angora from rabbits.

As with many discoveries of early man, anthropologists believe the use of wool came out of the challenge to survive – Neolithic man used pelts from animals to keep warm.

Sheep (Ovis aries) were first domesticated 10 000 years ago.  The British sought to protect their own wool industry during the eighteenth century, and passed laws requiring native English wool be used – for example, judges, professors, and students were required to  wear robes made of English wool. Another law required that the dead be buried in native wool. When the American colonies began to compete with the motherland, the English passed a series of laws in an attempt to protect their “golden fleece.” One law even threatened the amputation of the hand of any colonist caught trying to improve the blood line of American sheep.

Today, wool is a global industry, with Australia, Argentina, the United States, and New Zealand serving as the major suppliers of raw wool – but wool is produced worldwide in about 100 countries on half a million farms.   Wool producers range from small farmers to large scale grazing operations.  While the United States is the largest consumer of wool fabric, Australia is the leading supplier. Australian wool accounts for approximately one-fourth of the world’s production.

The annual global output is now estimated at 2.2 billion pounds, yet wool represents less than 5 percent of the world consumption of fibers. Wool is an expensive fiber to produce and process.  Though cotton is the number one plant used for fabrics and the number one natural fiber overall, the number one source for animal fiber is still wool.

Two terms one often sees are Merino and worsted.  The main difference between them is that Merino pertains to the type of fiber while worsted pertains to the process the fibers go through:

Merino is a term used in the textile industry which has varied meanings:  originally it meant wool made from a specific breed of sheep:  the Merino.  Merino sheep are regarded as having some of the finest and softest wool of any sheep: it is finely crimped and soft, fibers are commonly 65 – 100 mm (2.5 – 4 inches) long and generally less than 24 microns in diameter.

But now the term has broader use and may pertain to an article which just contains some percentage of wool from Merino sheep – or even just a fine wool and cotton yarn!  The Australian Wool Testing Authority Ltd is trying to institute a definition for Merino wool, citing fiber diameter and comfort factors.

The essential feature of a worsted yarn is its long, straight fibers which lie parallel to each other, the result of having been both carded AND combed.

So yes, you can have Merino worsted wools!

THE FIBER:

In scientific terms, wool is considered to be a protein called keratin. Its length usually ranges from 1.5 to 15 inches (3.8 to 38 centimeters) depending on the breed of sheep. Fiber diameter ranges from 16 microns in superfine merino wool (similar to cashmere) to more than 40 microns in coarse hairy wools.  Wool has several qualities that distinguish it from hair or fur: it is crimped (meaning it has waves),  it has a different texture or handle, it is  elastic, and it grows in staples (clusters).

Each wool fiber is made up of three essential components: the cuticle, the cortex, and the medulla.

  • The cuticle is the outer layer. It is a protective layer of scales arranged like shingles or fish scales.   They are sometimes described as little “barbs” because it’s the points of the scales that give wool the reputation for being prickly.
    • When two fibers come in contact with each other, these scales tend to cling and stick to each other. It’s this physical clinging and sticking that allows wool fibers to be spun into thread so easily.  And it’s also what causes the fiber to interlock – or felt.   See below for more information on this.

    Scales on a wool fiber under electron microscope

  • The cortex is the inner structure made up of millions of cigar-shaped cortical cells. The arrangement of these cells is responsible for the natural crimp unique to wool fiber.  The amount of crimp corresponds to the fineness of the wool fibers.  A fine wool like Merino may have up to 100 crimps per inch, while the coarser wools may have as few as 1 to 2. Hair, by contrast, has little if any scales and no crimp, and little ability to bind into yarn.  Its wool’s scaling and crimp that make it easier to spin into yarn, because the individual fibers attach to each other, so they stay together.
  • Rarely found in fine wools, the medulla comprises a series of cells (similar to honeycombs) that provide air spaces, giving wool its thermal insulation value.

The Manufacturing Process

The major steps necessary to process wool from the sheep into yarns are:  shearing, cleaning and scouring, grading and sorting, carding.

SHEARING:

Sheep are usually sheared once a year—usually in the springtime. The fleece recovered from a sheep can weigh between 6 and 18 pounds (2.7 and 8.1 kilograms); as much as possible, the fleece is kept in one piece. While most sheep are still sheared by hand, new technologies have been developed that use computers and sensitive, robot-controlled arms to do the clipping.

GRADING AND SORTING:

Grading is the breaking up of the fleece based on overall quality. Wool fibers are judged not only on the basis of their strength but also by their fineness (diameter), length, crimp (waviness) and color.  In wool grading, high quality does not always mean high durability.

In sorting, the wool is broken up into sections of different quality fibers, from different parts of the body. The best quality of wool comes from the shoulders and sides of the sheep and is used for clothing; the lesser quality comes from the lower legs and is used to make rugs.

CLEANING AND SCOURING:

Scouring in the true sense of the word in the textile industry means simply removing any foreign material from the fabric; the term scour grew up around the washing of cottons and linens.

Wool taken directly from the sheep is called “raw” or “greasy”  wool.  It contains a substantial amount of natural contaminants, such as  sand, dirt, grease, and dried sweat (called suint) as well as pesticide residues from the treatment of sheep to prevent disease; the weight of contaminants accounts for about 30 to 70%  of the total weight of the fleece.

To clean the wool, the fiber is washed in a series of alkaline baths containing water, soap, and soda ash or a similar alkali. The scouring effluent contains these impurities, which has high levels of COD (chemical oxygen demand) and BOD (biochemical oxygen demand), suspended solids, organic matter and sheep dip chemicals.  These levels represent a significant pollution load:   the organic effluent from a typical wool-scouring plant is approximately equal to the sewage from a town of 50,000 people.[1]

The effluent is separated into three categories:

  1. grease – when refined, this is known as lanolin, which is saved and sold for a variety of consumer products.
  2. liquor (water) – discharged to sewage works or open waters
  3. sludge – this needs to be disposed of too:   The sludge contains high levels of organic materials such as the potentially toxic sheep dip pesticides (such as organochlorines, organophosphates and synthetic prethroids).   In the EU, landfills will now only accept non-recoverable and inert waste.  Since the global production of wool sludge is over 930,000 tons, research is being done on the feasibility of disposing of scouring waste by composting, incineration and other methods.

The processing stages to this point cause the natural fiber alignment of the scales (or “barbs” as mentioned above) to be completely disrupted; the scales no longer line up “tip to base” as they would in the fleece. Those scales make raw wool itchy and also cause the fiber to shrink when wet.

In order to prevent this shrinkage (also called felting), and to make the wool more comfortable when worn next to the skin, many producers use chlorine to “burn” off the scales…this doesn’t entirely remove them, but it does lessen their profile, and then the fibers are coated with a synthetic polymer resin, which essentially glues down the scales. This allows the wool to be machine washed without felting, and gets rid of the shrinkage of the fabric associated with felting.  This is the chemistry behind Superwash wool.  The tradeoff, of course, is that this chlorination process is highly toxic.

See our blog post on Organic Wool to read about the environmental effects of wool scouring and chlorination.  It’s not pretty.

CARDING:

Next, the fibers are passed through a series of metal teeth.  The teeth untangle the fibers and arrange them into a flat sheet called a web. The web is then formed into narrow ropes known as silvers.   Carding  is one of the processes that untangles the wool fibers and lays them straight; it also removes residual dirt and other matter left in the fibers.  Combing is the next process, which removes shorter length fibers and helps to further straighten the fibers and lay them parallel.  Combing also helps to clean more debris from the fibers.

  • Carding only produces woolenyarn.   Woolen yarns:
    • Have a short staple (1-4 inch long fibers).
    • Are carded ONLY
    • Have a slack twist
    • Are weaker, softer and bulkier than worsted
  • Carding and Combing produces worsted yarn.Worsted yarns:
    • Have a long staple (4 inch and longer)
    • Have a tight twist in spinning
    • Are stronger, finer, smoother and harder than woolen yarns.

CHARACTERISTICS of WOOL:

Wool is highly regarded as one of the most lavish natural fibers in the world.  Lightweight, versatile, resistant to dirt and considered somewhat water repellant, non wrinkling, and durable, wool:

  • Can absorb almost 30% of its own weight in water – and it can also release it.  This makes it breathable and extremely comfortable next to the skin.  It can absorb sweat and release it as vapor, keeping you cool and dry.  It prevents the clammy, cold feeling you may experience when wearing some types of synthetic clothing and sweating.
  • Is resistant to static electricity,  because the moisture retained within the fabric conducts electricity. This is why wool garments are much less likely to spark or cling to the body. The use of wool car seat covers or carpets reduces the risk of a shock when a person touches a grounded object.
  • fabrics have a greater bulk than other textiles because of the crimp, and retain air, which is a great insulation.  It keeps you warm when you’re cold, but insulation also works both ways – Bedouins and Tuaregs use wool clothes to keep the heat out.  And it does not cling to the skin, allowing for air circulation next to the skin.
  • fibers can be bent 20,000 times without breaking (compared to cotton, which breaks after 3,000 bends or rayon, which can be bent only 75 times without breaking), and have the power to elongate (it can be stretched 25 – 30% before breaking), stretch and recover. This natural elasticity and memory  returns to its natural shape
  • doesn’t readily catch fire – its ignition point is higher than cotton and some synthetics.  Even if it does burn, it burns slowly (not melting or dripping as in synthetics) and self-extinguishes when the source of the flame is removed.  It contributes less to toxic gases and smoke than synthetics, and is therefore often specified for high safety environments such as trains and aircraft.
  • has a naturally high UV protection, which is much higher than most synthetics and cotton.
  • is considered by the medical profession to be hypoallergenic.
  • is hydrophilic—it has a strong affinity for water—and therefore is easily dyed.

[1] Christoe, Jock; The treatment of wool scouring effluents in Australia, China and India”,  project # AS1/1997/069; http://aciar.gov.au/system/files/node/9074/AS%2003-04%20AS1-1997-069.pdf





Fabric structures for the new millenium

10 03 2010

Here we are in  the 21st century, with its acute global issues of over-population, loss of natural habitat, carbon emissions and pollution of all kinds — in a nutshell the specter of diminishing resources and climate change.   What’s a good architect to do?  Some are saying that fabric structures – that ancient way of providing shelter – is in a unique position to contribute significantly to a more sustainable built environment.  Fabric structures  have a modest carbon footprint, minimal post-construction refuse, daylighting and water-harvesting capabilities,  and are relatively  easy and inexpensive to replace.     According to Thomas Fisher, Dean of the College of Design at the University of Minnestoa, “Living lightly on the land is a key principle of sustainability, and fabric allows for that more effectively than almost any other material.”

Architects are finding new and unique ways of using fabric because there is a not so new polymer in their tool kit:  ETFE (ethylene tetrafluoroethylene).  This – some say- is the building material of the future.  It’s a transparent plastic, related to Teflon, and is just 1% the weight of glass, but it transmits more light, is a better insulator and costs 24% to 70% less to install.  It’s also resilient (able to bear 400 times its own weight, with an estimated 50 year life span), is self cleaning (dirt slides off its nonstick surface) and it’s recyclable.

Architects started working with ETFE about 15 years ago, but the material got a boost by being used in the 2008 Beijing Olympics, where it’s an integral part of the distinctive designs of both the Beijing National Stadium (called the Bird’s Nest – see photo on right)  and the Aquatics Center (the Watercube, at the left).

ETFE has been described as a sturdier version of plastic cling wrap.  It can be used in sheets or inflated into pillows.  The 750,000 square foot Watercube is the largest ETFE project ever.  It is clad entirely in blue ETFE cushions.  It’s interesting to note that the Watercube is the first time the Sydney, Australia based PTW Architects, who designed the building, had ever used the fabric.  They were that confident.  Some bubbles in the design span 30 feet without any internal framing – a distance that wouldn’t be possible with other materials.

On an aesthetic level, the cushions reinforce the building’s theme. Their pillowy shapes evoke a bubble’s roundness, and their triple-layered construction, which mixes layers of blue film with transparent film, gives the façade a sense of depth and shifting color. And there’s  the fun factor:  ETFE comes in different finishes and colors, and can be lit from within using LED lights or decorated with light projections like a giant movie screen as in the picture.   Once the Olympics  started officials were able to transform the Watercube walls into a giant TV screen showing simultaneous projections of the swimming activities taking place inside.  It can take myriad shapes too: strips can be heat-welded together like fabric squares in a quilt.

But what is ETFE – and what does it mean that it’s related to Teflon?

ETFE was developed by DuPont, working with NASA, as a thermo plastic version of Teflon.  It was designed to have high corrosion resistance and durability to hold up under oppressive cosmic radiation that NASA would expose it to.

But Dr. Stefan Lehnert, a mechanical engineering student at the time, was looking for better foils for the sails on  his sailboat.  He experimented with ETFE and found a transparent, self cleaning, durable and very flexible material with just 1% weight of glass.  It also expands to three times its normal length without losing elasticity and offers shade and insulation control. Dr. Lehnert founded Vector Foiltec in Germany in 1982, where they sold ETFE as the Texlon Foil System.

Today it’s being touted as the new green alternative.  Why?

Affiliates of Brunel University in Middlesex and Buro Happold Consulting Engineers in London did a study of the environmental effects of ETFE manufacture and use for building cladding (it’s primary use).  The study compares ETFE foil cushions to 6 mm glass and concluded the following:

“ETFE foils can improve the environmental performance of a building from two points of view:  there is the opportunity to reduce the overall environmental burden incurred by the construction process itself; and there is also the opportunity to reduce the burden of the building during its lifetime.  This is all dependent, however, on the ability of the architects and engineers to take advantage of both the flexibility and limitations of ETFE foil cushions.”

Using ETFE can accrue LEED points by giving you opportunities for daylighting a structure, reduction of steel for support structures, and it can save on transport costs because of its light weight.  If you reduce the tonnage of steel, and reduce the raw building materials you have a real capacity to lighten up a building.  The Texlon Foil System, according to the company, has low energy consumption during its manufacturing process ,  much of which includes recycled materials.  The film itself is recyclable – the recycling is aided by the absence of additives in the manufacturing process, requiring only the ETFE and heat.    It can also be a tensile structure for renewable energy sources such as photovoltaic panels and provide shade to keep buildings cool in hot climates.

Larry Medlin, professor and director of the School of architecture at the University of Arizona, says:  “Fabric’s multiple capabilities from catching water, trellising plants, daylighting, and providing shade for cooling, are being looked at seriously,” he says. “Fabric can contribute to a regenerative landscape. This is important. It can’t be overlooked.” Medlin also explains that using fabric structures is one way to bring the indoor outside, as in the Edith Ball Center (shown at right), a project that required re-conceptualizing with a more innovative approach. Instead of being enclosed, the Center’s three community pools — lap, therapy and swimming — are under a dynamic, open fabric system that can be adjusted to season and climate.

But what about the material itself?  And is it really recyclable?  There are no life cycle analyses of ETFE that I know of  (please let me know if you’re aware of one and I’ll post it here) so until we know the carbon footprint issues of this product I’m still a bit skeptical, although there seem to be many points in its favor.

ETFE – ethylene tetrafluoroethylene – is a fluorocarbon based polymer, aka “fluoropolymer” – a type of plastic.  We did a blog posting on flurocarbons a few weeks back which can be accessed here. So the material is of the chemical family consisting of a carbon backbone surrounded by fluorine – part of the “Teflon” family of chemicals.  These chemicals as a group are highly suspect, since PTFE (which is the building block for Teflon) has been found to produce PFOA as a by product.  From our blog post:  ” They (perflurocarbons) are the most persistent synthetic chemicals known to man. Once they are in the body, it takes decades to get them out – assuming you are exposed to no more. They are toxic in humans with health effects from  increased chloesterol to stroke and cancer. Alarmed by the findings from toxicity studies, the EPA announced on December 30, 2009, that PFC’s (long-chain perfluorinated chemicals)would be on a “chemicals of concern” list and action plans could prompt restrictions on PFC’s and the other three chemicals on the list.”  The Stockholm Convention on Persistent Organic Pollutants states that PFOS is used in some  ETFE production.

ETFE is not a derivative of a petrochemical.   It is  manufactured from fluorspar (CaF2), trichloromethane (CHCl3) – called chlorodifluoromethane (CHF2CL) –  and hydrogen sulfate (HSO4).  Chlorodifluoromethane is a raw material classified as a class II substance under the Montreal Treaty on ozone depleting substances.   Class II substances are scheduled to be phased out but have a later timeline than Class I substances.

The by products formed during ETFE manufacture  are calcium sulfate (CaSO4), hydrogen fluoride (HF) and hydrochloric acid (HCl).  The calcium sulfate and hydrogen fluoride are reused to produce more fluorspar which can be used again as in input into the manufacturing process.

The manufactured ETFE is sold as pellets, which are then heated and extruded into sheets 50 – 200 microns thick.

As one pundit has said: if this is a recyclable product, what chemicals are running off into our water supply?  Do we know what those ETFE chemicals do to humans – not to mention cows, tree frogs or trees –  if ingested?

One thing we DO know about ETFE is that fumes given off at 300 degrees Centigrade cause flu like symptoms in humans, and above 400 degrees C – they’re toxic.  (1)  I have seen articles which say it is combustible and others that say ETFE is considered self extinguishing.  What everyone agrees on is that in the event of a fire, the foil will then shrink  from the fire source, thereby self-venting,   and letting  smoke out of the building.

I can’t make up my mind on ETFE as a sustainable building material.  What do you think?

(1)  .   http://www.buildnova.com/buildnovav3/buildingsystems/TensileFabric/tensilefabric.htm





Greenwashing and textiles

29 12 2009

I have been saying for years that fabric is the forgotten product.  People just don’t seem to care about what their fabric choices do to them or to the environment.  (Quick, what fiber is your shirt/blouse made of?  What kinds of fibers do you sleep on?)   They are too busy to do research, or they’re gullible – either way they decide to believe claims made by many product manufacturers.  And I can’t really blame them, because the issues are complex.

Green products are proliferating so quickly (the average number of “green” products per store almost doubled between 2007 and 2008, according to TerraChoice’s Greenwashing Report 2009) and adding so many new consumer claims that the term “greenwash” (verb: the act of misleading consumers regarding the environmental practices of a company or the environmental benefits of a product or service) has become part of most people’s vocabulary.    In the area of fabrics, the greenwashing going on has led the FTC to make the publication of its new Green Guide on textiles a priority.

Incidences of greenwashing are going up, and that means increased risk:

  • Consumers may be misled into purchases that do not deliver on their environmental promise.
  • Illigetimate environmental claims will take market share away from products that offer legitimate benefits, thereby slowing the spread of real environmental innovation.
  • Greenwashing will lead to cynicism and doubt about all environmental claims.  Consumers may just give up.
  • And perhaps worst of all – the sustainability movement will lose the power of the market to accelerate real progress towards sustainability.

The first step to cleaning up greenwashing is to identify it, and Kevin Tuerff (co-founder of the marketing consultancy EnviroMedia) and his partners have hit on an innovative way to spotlight particularly egregious examples. They’ve launched the Greenwashing Index,  a website that allows consumers to post ads that might be examples of greenwashing and rate them on a scale of 1 to 5–1 is a little green lie; 5 is an outright falsehood.  This hopefully teaches people to be a bit more cautious about the claims they hear.  Read more about greenwashing here.

TerraChoice published its six sins of greenwashing in 2007 but added a seventh sin in 2009.  Let’s look at these sins:

1)      The Sin of Worshiping False Labels:  a product that (through words or images) gives the impression of third-party endorsement or certification where none really exists; basically fake labels.  Examples:

  1. Using the company’s own in-house environmental program without further explanation.
  2. Using certification-like images with green jargon including “eco-safe”, “eco-preferred”.

I’ve begun to see examples of products which claim to be certified to the GOTS standard  (Global Organic Textile Standard) – but the reality is that the fiber is certified to the GOTS standard while the final fabric is not.  There is a big difference between the two.  And the GOTS-certifying agencies have begun to require retailers to be certified – to keep the supply chain transparent because there have been so many incidences of companies substituting non- GOTS products for those that actually received the certification.

2)      Sin of the Hidden Trade-off:  a claim suggesting that a product is “green” based on a narrow set of attributes without attention to other important environmental issues.  The most overused example of this is with recycled content of fabrics – a textile is advertised as “green” because it is made of x% recycled polyester.  Other important environmental issues such as heavy metal dyes used, whether the polyester is woven with other synthetics or even natural fibers  (thereby contributing to other environmental degredation), the fact that plastic is not biodegradeable and contains antimony or bisphenol A  may be equally important.  Cargill Dow introduced it’s new Ingeo fiber with much fanfare, saying that it is based on a renewable resource (rather than oil).  Missing entirely from Cargill Dow’s press materials is any acknowledgement of the fact that the source material for these products is genetically engineered corn, designed by one of Cargill Dow’s corporate parents, Cargill Inc., a world leader in genetic engineering.  (See our blog postings on genetic engineering dated 9.23 and 9.29.09) That’s a potentially huge problem, since millions of consumers around the world and several governments have rejected the use of genetically engineered (GE) products, because of the unforeseen consequences of unleashing genetically altered organisms into nature.

3)      Sin of No Proof:  An environmental claim that cannot be substantiated by easily accessible supporting information or by a reliable third-party certification.  Google organic fabric and you can find any number of companies offering “organic and natural fabrics” with no supporting documentation.   And the People for the Ethical Treatment of Animals really took exception to this claim:

4)      Sin of Vagueness:  a claim so poorly defined or broad that its real meaning is likely to be misunderstood by the consumer. ‘All-natural’ is an example. Arsenic,  mercury, and formaldehyde are all naturally occurring, used widely in textile processing,  and poisonous. ‘All natural’ isn’t necessarily ‘green’. Hemp is a fabric that has been expertly greenwashed, as most people have been led to focus on the fact that it grows in a manner that it is environmentally friendly. Few realize that hemp is naturally made into rope and that it requires a great deal of chemical softening to be suitable for clothing or bed linen.  Or this ad from Cotton Inc.:

5)      Sin of Irrelevance:  An environmental claim that may be truthful but is unimportant or unhelpful for consumers seeking environmentally preferable products.  The term “organic” is the most often used word in textile marketing – and what does it really mean?  Organic, by definition, means carbon-based, so unless the word “organic” is coupled with “certified” the term is meaningless.  But even “certified organic” fiber can cause untold harm during the processing and finishing of the fabric – think of turning organic apples into applesauce (adding Red Dye #2, stabalizers, preservatives, emulsifiers) where the final result cannot be considered organic APPLESAUCE even though the apples started out as organic. It is said that the amount of “organic cotton” supposedly coming out of India far outweighs the amount of organic cotton actually being grown. It is common practice for vendors to call a batch of cotton “organic”, if minimal or no chemicals have been used, even if no certification has been obtained for the fiber. It’s also generally understood that certification can be “acquired”, even if not earned.

6)      Sin of Lesser of Two Evils:  A claim that may be true within the product category, but that risks distracting the consumer from the greater environmental impacts of the category as a whole.  Again, the use of recycled polyester as a green claim distracts from the greater environmental impact that plastics have on the environment,  the much greater carbon footprint that any synthetic has compared to any natural fiber,  the antimony used in polyester production, the fact that polyesters are dependent on non renewable resources for feedstock…the list goes on.

7)      Sin of Fibbing:  just what it says – environmental claims that are simply false.

I’d like to add an additional sin which I think is specific to the textile industry: that of a large fabric company touting it’s green credentials because it has a “green” collection  (sometimes that “green” collection is anything but) – but if you look at the size of the green collection and compare it to conventional offerings, you’ll find that maybe only 10% of the company’s fabrics have any possible claim to “green”.  Is that company seriously trying to make a difference?





CPSIA, lead and textiles in your life

1 12 2009

What does it take to change human behavior?

We have known that lead is poisonous ever since the Romans began sprinkling it on their food as a sweetener.   Lead was used so extensively in Rome (for metal pots, wine urns, water pipes and plates)  that some Romans began to suspect a connection between the metal and the general befuddlement that was cropping up among the aristocracy – the very people who could afford these urns and plates.  But the culture’s habits never changed, and some historians believe that many among the Roman aristocracy suffered from lead poisoning. Julius Caesar, for example, managed to father only one child, even though he enjoyed women a much as he enjoyed wine.  His successor, Caesar Augustus, was reported to be completely sterile.  Some scholars go so far as to say that lead poisoning was a contributing factor to the fall of the Roman Empire.

Lead is a neurotoxin – it affects the human brain and cognitive development, as well as the reproductive system. Some of the kinds of neurological damage caused by lead are not reversible.

Specifically, it affects reading and reasoning abilities in children, and is also linked to hearing loss, speech delay, balance difficulties and violent tendencies. (1)   According to Ruth Ann Norton, executive director of the Coalition to End Childhood Lead Poisoning, “There are kids who are disruptive, then there are ‘lead’ kids – very disruptive, very low levels of concentration.”  Children with a lead concentration of less than 10 micrograms ( µ) per deciliter (dl = one tenth of a liter) of blood scored an average of 11.1 points lower than the mean on the Stanford-Binet IQ test. (2)   Consistent and reproducible behavioral effects have been seen with blood levels as low as 7 µ/dl (micrograms of lead per tenth liter of blood), which is below the Federal standard of 10 µ/dl.   Scientists are generally in agreement that there is no “safe” level of blood lead.  Lead is a uniquely cumulative poison:  the daily intake of lead is not as important a determinant of ultimate harm as is the duration of exposure and the total lead ingested over time.

A hundred years ago we were wearing lead right on our skin. I found this article funny and disturbing at the same time:

“Miss P. Belle Kessinger of Pennsylvania State College pulled a rat out of a warm, leaded-silk sack, noted that it had died of lead poisoning, and proceeded to Manhattan. There last week she told the American Home Economics Association that leaded silk garments seem to her potentially poisonous. Her report alarmed silk manufacturers who during the past decade have sold more than 100,000,000 yards of leaded silk without a single report of anyone’s being poisoned by their goods. Miss Kessinger’s report also embarrassed Professor Lawrence Turner Fairhall, Harvard chemist, who only two years ago said: ‘No absorption of lead occurs even under extreme conditions as a result of wearing this material in direct contact with the skin’. ”

This was published in Time magazine,  in 1934.  (Read the full article here. )



But lead has continued to be used in products, from dyestuffs made with lead (leading to lead poisoning in seamstresses at the turn of the century, who were in the habit of biting off their threads) (3), to lead in gasoline, which is widely credited for reduced IQ scores for all children born in industrialized countries between 1960 and 1980 (when lead in gasoline was banned).  Read more about this here.

Lead is used in the textile industry in a variety of ways and under a variety of names:

  • Lead acetate                 dyeing of textiles
  • Lead chloride               preparation of lead salts
  • Lead molybdate            pigments used in dyestuffs
  • Lead nitrate                  mordant in dyeing; oxidizer in dyeing(4)

Fabrics sold in the United States, which are used to make our clothing, bedding and many other products which come into intimate contact with our bodies, are totally unregulated – except in terms of required labeling of percentage of fiber content and country of manufacture.  There are NO laws which pertain to the chemicals used as dyestuffs, in processing, in printing,  or as finishes applied to textiles, except those that come under the Toxic Substances Control Act (TSCA) of 1976, which is woefully inadequate in terms of addressing the chemicals used by industry.  In fact, the Government Accounting Office (GAO) has announced that the 32 year old TSCA needs a complete overhaul (5), and the Environmental Protection Agency (EPA)  was quick to agree! (6).  Lisa Jackson, head of the EPA,  said on September 29, 2009 that the EPA lacks the tools it needs to protect people and the environment from dangerous chemicals.

And  fabrics are treated with a wide range of substances that have been proven not to be good for us.

The United States has new legislation which lowers the amount of lead allowed in children’s products – and only children’s products.   (This ignores the question of  how lead  in products used by pregnant  women may affect their fetus.  Research shows that as the brains of fetuses develop, lead exposure from the mother’s blood can result in significant learning disabilities.)  The new Consumer Product Safety Improvement Act (CPSIA) limits lead content in children’s products (to be phased in over three years) so that by August 14, 2011, lead content must be 100 ppm (parts per million) or less.  However there was an outcry from manufacturers of children’s bedding and clothing, who argued that the testing for lead in their products did not make sense, because:

  • it placed an unproductive burden on them, and
  • it required their already safe products to undergo costly or unnecessary testing.

The Consumer Product Safety Commission voted to exempt textiles from the lead testing and certification requirements of the CPSIA.

So let me repeat here: the daily intake of lead is not as important a determinant of ultimate harm as is the duration of exposure and the total lead ingested over time. Children are uniquely susceptible to lead exposure over time, and  neural damage occurring during the period from 1 to 3 years of age is not likely to be reversible.  It’s also important to be aware that lead available from tested products would not be the only source of exposure in a child’s environment.  Although substantial and very successful efforts have been made in the past twenty years to reduce environmental lead, children are still exposed to lead in products other than toys or fabrics. Even though it was eliminated from most gasoline in the United States starting in the 1970s, lead continues to be used in aviation and other specialty fuels. And from all those years of leaded gasoline, the stuff that came out of cars as fuel exhaust still pollutes soil along our roadways, becoming readily airborne and easily inhaled.   All lead exposure is cumulative – so it’s important to eliminate any source that’s within our power to do so.

Are the manufacturers of children’s bedding and clothing correct?  Are their products inherently safe?  I thought I’d do some exploration to find out what information I could find out about chemicals used in our fabrics – and I’ll have the results next week.

(1) “ ‘Safe’ levels of lead still harm IQ”, Associated Press, 2001

(2) Ibid.

(3) Thompson, William Gilmsn, The Occupational Diseases, 1914, Cornell University Library, p. 215

[4] “Pollution of Soil by Agricultural and Industrial Waste”, Centre for Soil and Agroclimate Research and Development, Bogor, Indonesia, 2002.   http://www.agnet.org/library/eb/521/

(4) http://www.atsdr.cdc.gov/toxprofiles/tp13-c5.pdf

(5) http://www.rsc.org/chemistryworld/News/2009/January/29010901.asp

(6) http://www.bdlaw.com/news-730.html