What about soil resistant finishes like Scotchgard, GoreTex, NanoTex and GreenShield – are they safe?

10 02 2010

Last week I promised to take a look at soil and stain repellant finishes to see how each is applied and/or formulated.  Some of these trademarked finishes claim impeccable green credentials, so it’s important that we are able to evaluate their claims – or at least know the jargon!  The chemistry here, as I said in last week’s post, is dense.  The important thing to remember about all these finishes is that they all depend on flurocarbon based chemistry to be effective.

The oldest water repellant finishes for fabrics were simply coatings of paraffin or wax – and they generally washed out eventually.  Perfluorochemicals (PFC’s) are the only chemicals capable of repelling water, oil and other liquids that cause stains. Fabrics finished with PFCs have nonstick properties; this family of chemicals is used in almost all the stain repellant finishes on the market today.  Other materials can be made to perform some of these functions but suffer when subjected to oil and are considerably less durable.

The earliest type of stain resistant finish (using these PFCs)  prevented the soil from penetrating the fiber by coating  the fiber. For use on a textile, the chemicals are joined onto binders (polyurethane or acrylic) that acts as a glue to stick them to the surface of the fabric.  Gore Tex is one of these early coatings – a thin film was laminated onto the fabric; another, manufactured by 3M Corporation for nearly 50 years,  is Scotchgard.   Scotchgard was so popular and became so ubiquitous that “Scotchgard” entered the language as a verb.  

The chemical originally used to make Scotchgard and Gore Tex breaks down into perfluorooctane sulfonate, or PFOS, a man-made substance that is part of the family of perfluorochemicals.   PFOS and PFOA have chains of eight carbon atoms; the group of materials related to PFOA and PFOS is called C8 –  this is often referred to as “C8 chemistry”.

An aside on C8 chemistry:

If you recall from last week’s post, the PFC family consists of molecules having a carbon backbone, fully surrounded by fluorine.  Various “cousins” have carbon backbones of different lengths:  PFOS or C8, for example,  has 8 carbon atoms, C7 has 7, and so on.  There is controversy today  about  the so-called  “bad” fluorocarbons (C8 ) and the “good” ones (C6) which I’ll address below.

C8  –  (the backbone  is made of a chain of 8 carbon atoms):  two methods are used to produce two slightly different products:

1)     electrofluorination:  uses electrolysis to replace hydrogen atoms in a molecule by fluorine atoms to create the 8 unit chain containing just carbon and fluorine.  A small amount of PFOS (perfluorooctane sulphonate) is created during this process.

2)     Telomerisation:  chemical equivalent of making a daisy chain: produces mini polymers by joining single units together in chains.  The usual aim is to produce chains that are an average of 8 units long, but the process is not perfect and a range of chain length will result – ranging from 4 units to 14 units in length. So you can have a C4, C6, C12, etc. In this method a small amount of byproduct called PFOA (perfluorooctanoic acid) is produced.

C6 – this chemistry produces a by-product called PFHA (perfluorohexanoic acid), which  is supposed to be 40 times less bioaccumulative than PFOA.  But it’s also less effective, so more of the chemical has to be used to achieve the same result.  Manufacturers are trying to find smaller and smaller perfluorocarbon segments in their products, and even C4 has been used.  The smaller the fluorocarbon, the more rapidly it breaks down in the environment.  Unfortunatley, the desired textile performance goes down as the size of the perfluorocarbon goes down. “C6 is closest chemically to C8, but it contains no PFOA. It breaks down in the environment – a positive trait – but it doesn’t stick as well to outerwear and it doesn’t repel water and oil as well as C8, which means it falls short of meeting a vague industry standard, as well as individual company standards for durability and repellency.”[1]

Back to Scotchgard:

Scientists noticed that PFOS (the C8 fluorocarbon) began showing up everywhere: in polar bears, dolphins, baby eagles, tap water and human blood. So did its C8 cousin PFOA.   These two man-made perfluorochemicals (PFOS and PFOA) don’t decompose in nature. They kill laboratory rats at higher doses, and there are potential links to tissue problems, developmental delays and some forms of cancer.  Below are tables of results which the U.S. Environmental Protection Agency released from data collected by 3M and DuPont; some humans have more PFOA in their blood than the estimated levels in animals in this study.  For a complete review of this study, see the Environmental Working Group’s website, http://www.ewg.org/node/21726.

PFOA and PFOS, according to the U.S. EPA:

  • Are very persistent in the environment.
  • Are found at very low levels both in the environment and in the blood of the U.S. population.
  • Remain in people for a very long time.
  • Cause developmental and other adverse effects in laboratory animals.

Eventually 3M discontinued Scotchgard production.  Yet accounts differ as to whether 3M voluntarily phased out the problematic C8 chemistry or was pressured into it by the EPA after the company shared its data in late 1999.  Either way, the phase-out was begun in December 2000, although 3M still makes small amounts of PFOA for its own use in Germany. 3M, which still monitors chemical plants in Cottage Grove, Decatur, and Antwerp, Belgium, insists there are no risks for employees who handled or were exposed to the chemicals.  Minnesota Public Radio published a timeline for milestones in 3M’s Scotchgard, which can be accessed here.

The phase-out went unnoticed by most consumers as 3M rapidly substituted another, less-effective spray for consumers, and began looking for a reformulated Scotchgard for carpet mills, apparel and upholstery manufacturers.   For its substitute, 3M settled on perfluorobutane sulfonate, or PFBS, a four-carbon cousin of the chemical in the old Scotchgard, as the building block for Scotchgard’s new generation. This new C4-based Scotchgard is completely safe, 3M says. The company adds that it has worked closely with the EPA and has performed more than 40 studies, which are confidential. Neither 3M nor the EPA will release them.

According to 3M, the results show that under federal EPA guidelines, PFBS isn’t toxic and doesn’t accumulate the way the old chemical did. It does persist in the environment, but 3M concluded that isn’t a problem if it isn’t accumulating or toxic. PFBS can enter the bloodstream of people and animals but “it’s eliminated very quickly” and does no harm at typical very low levels, said Michael Santoro, 3M’s director of Environmental Health, Safety & Regulatory Affairs. 3M limits sales to applications where emissions are low.

3M says convincing consumers Scotchgard is safe is not its No. 1 challenge; rather it’s simply getting the new, new Scotchgard out. The brand, 3M maintains, is untarnished. “This issue of safety, oddly enough, never registered on the customers’ radar screen,” said Michael Harnetty, vice president of 3M’s protective-materials division.

Scotchgard remains a powerful brand:  “We still get really good requests like, ‘Will you Scotchgard this fabric with Teflon?’ ” said Robert Beaty, V.P. of Sales for The Synthetic Group, a large finishing house.[2]

Another early soil resistant finish is Teflon, which was produced by DuPont.  Teflon is based on C8 chemistry, and PFOA is a byproduct of the manufacturing of fluorotelomers used in the Teflon chemistry.

There has been a lot of information on 3M, DuPont and these two products, Scotchgard and Teflon, on the web.  The Environmental Working Group  http://www.ewg.org/ has detailed descriptions of what these chemicals do to us, as well as the information on the many suits, countersuits, and research studies.  The companies say their new reformulated products are entirely safe – and other groups such as the Environmental Working Group, question this assumption.

By the way, both DuPont and 3M advertise their products as being “water based” – and they are, but that’s not the point and doesn’t address the critical issues.  In TerraChoice’s “Seven Sins of Greenwashing” this would be considered Sin #5: the sin of irrelevance, which is:  “An environmental claim that may be truthful but is unimportant or unhelpful for consumers seeking environmentally preferable products. ‘CFC-free’ is a common example, since it is a frequent claim despite the fact that CFCs are banned by law.”

In January 2006, the U.S. Environmental Protection Agency (EPA) approached the eight largest fluorocarbon producers and requested their participation in the 2010/15 PFOA Stewardship Program, and their commitment to reduce PFOA and related chemicals globally in both facility emissions and product content 95 percent by 2010, and 100 percent by 2015.

The fluoropolymer manufacturers are improving their processes and reducing their waste in order to reduce the amount of PFOA materials used. The amount  of PFOA in finishing formulations is greatly diminished and continues to go down, but even parts per trillion are detectable. Finishing formulators continue to evaluate new materials which can eliminate PFOA while maintaining performance but a solution is still over the horizon.  One critical piece in this puzzel is that PFOA is also produced indirectly through the gradual breakdown of fluorotelomers – so a stain resistant finish may be formulated with no detectable amounts of PFOA yet STILL produce PFOA when the chemicals begin to decompose.

Recently a new dimension was added to stain resistant formulations, and that is the use of nanotechnology.

Nanotechnology is defined as the precise manipulation of individual atoms and molecules to create layered structures. In the world of nanoscience, ordinary materials display unique properties at the nanoscale.  The basic premise is that properties can dramatically change when a substance’s size is reduced to the nanometer range. For example, ceramics which are normally brittle can be deformable when their size is reduced. In bulk form, gold is inert, however, once broken down into small clusters of atoms it becomes highly reactive.

Like any new technology, nanomaterials carry with them potential both for good and for harm. The most salient worries concern not apocalyptic visions,  but rather the more prosaic and likely possibility that some of these novel materials may turn out to be hazardous to our health or the environment.  As John D. Young and Jan Martel report in “The Rise and Fall of Nanobacteria,” even naturally occurring nanoparticulates can have an deleterious effect on the human body. If natural nanoparticulates can harm us, we would be wise to carefully consider the possible actions of engineered nanomaterials.  The size of nanoparticles also means that they can more readily escape into the environment and infiltrate deep into internal organs such as the lungs and liver. Adding to the concern, each nanomaterial is unique. Although researchers have conducted a number of studies on the health risks of individual materials, this scattershot approach cannot provide a comprehensive picture of the hazards—quantitative data on what materials, in what concentrations, affect the body over what timescales.

As a result of these concerns, in September, 2009,  the U.S. EPA  announced a study of the health and environmental effects of nanomaterials – a step many had been advocating for years.  And this isn’t happening any too soon:  more than 1,000 consumer products containing nanomaterials are available in the U.S. and more are added every day.

And nanotechnology has been used for textiles in many ways: at the fiber as well as the fabric level, providing an extraordinary array of nano-enabled textile products (most commonly nanofibers, nanocomposite fibers and nanocoated fibers)  – as well as in soil and stain resistance.

For scientists who were trying to apply nanotechnology to textile soil and stain repellency, they turned, as is often the case in science, to nature:  Studying the surface of lotus leaves, which have an incredible ability to repel water, scientists noticed that the surface of the lotus leaf appears smooth but is actually rough and naturally dirt and water repellent. The rough surface reduces the ability of water to spread out. Tiny crevices in the leaf’s surface trap air, preventing the water droplets from adhering to the service. As droplets roll off the surface they pick up particles of dirt lying in their path. Using this same concept, scientists developed a nanotechnology based finish that forms a similar structure on the fibers surface. Fabrics can be cleaned by simply rinsing with water.

Nano-Tex (www.nano-tex.com) was the first commercially available nanoparticle based soil repellant fabric finish.  It debuted in December of 2000.  Another nanotech based soil repellant is GreenShield (www.greenshieldfinish.com) which debuted in 2007. Both these finishes, although they use nanotechnology, also base their product on fluorocarbon chemistry.  Nano-Tex’s website does not give much information about their formulation – basically they only say that it’s a new technology that “fundamentally transforms each fiber through nanotechnology”.  You won’t get much more in the way of technical specifications out of Nano-Tex.   GreenShield is much more forthcoming with information about their process.

In the GreenShield finishes, the basic nanoparticle is amorphous silica, an inert material that has a well-established use in applications involving direct human consumption, and is generally recognized as safe and approved by the Food and Drug Administration (FDA) and Environmental Protection Agency for such applications.  The use of silica enables GreenShield to reduce the amount of flurocarbons by a factor of 8 or more from all other finishes and it reduces overall chemical load by a factor of three – making GreenShield the finish which uses the least amount of these flurocarbons.

The GreenShield finish gets mixed environmental ratings, however.   Victor Innovatix’s Eco Intelligent Polyester fabrics with GreenShield earned a Silver rating in the Cradle to Cradle program. However, the same textile without the GreenShield finish (or any finish) earned a higher Gold rating, reflecting the risk of toxicity introduced to the product by GreenShield. Information on product availability is at www.victor-innovatex.com.

[1]PFOA Puzzle – Textile Insights — http://www.textileinsight.com/articles.php?id=37

[2] Bjorhus, Jennifer, “Scotchgard is Attractive Again”, St. Paul Pioneer Press, May 27, 2003



30 responses

23 02 2010

Good article

13 03 2010

Thanks for this! Very helpful.

16 11 2010
Moisture Management

I have been visiting various blogs for my dissertation research. I have found your blog to be quite useful. Keep updating your blog with valuable information… Thanks for this post.Keep up the scepticism!

16 11 2010

Thanks so much. What is your research on?

26 01 2012

I’m curious why Crypton was not included in this article. It was mentioned in the previous article leading up to it.

26 01 2012

Hi Kim: I meant to get back to that! Basically, Crypton uses the same flurochemistry as does the other stain resist finishes. I looked into Crypton’s marketing, which says:
“Crypton does not contain any toxic chemicals, heavy metals or carcinogens that can be leached out with water or upholstery cleaners. Crypton Super Fabrics do not contain air polluting VOCs. Crypton uses no PFOAs (perfluorooctanoic acids) during its manufacturing process. Crypton uses no formaldehyde and does not contain vinyl.”
In discussing these claims, remember that Crypton is only a finish – it is NOT the fabric. Crypton receives payment from fabric manufacturers in order to use Crypton and market their fabrics as Crypton fabrics. So if the Crypton is applied to fabrics which have been produced conventionally, then they most assuredly contain a number of chemicals which have been proven to impact human health adversely. All natural fiber fabrics are, by weight, about 27% synthetic chemicals (dyestuffs, bleaches, finishes); synthetics are of course 100%. So it’s important that these synthetic chemicals are safe for our use. And remember that there is a synergy in these chemicals – individually they might not be horrible, but often they react with each other to create something that truly is horrible.
But back to Crypton: what is most important in the description is what is NOT discussed. I will discuss each point individually:
• “Crypton does not contain any toxic chemicals, heavy metals or carcinogens that can be leached out with water or upholstery cleaners” – we have to take their word on this because they will not tell us what IS used because it is proprietary, yet MBDC just rescinded the Crypton Cradle to Cradle certification because it does not meet their new guidelines. Our discussions with Crypton included one assertion by Crypton representatives that Crypton does not include any Substances of Very High Concern identified by Europe’s REACH program. Our response: The fact that Crypton is free of Substances of Very High Concern identified by Europe’s REACH program is not much comfort as fewer than thirty chemicals are on the list as the EU slowly assesses the over 270 early candidates for inclusion on its SIN (Substitute It Now) List. The SIN list does not yet even include endocrine disrupters, which REACH is only now considering for inclusion. So chemicals like Bisphenol-A (which Americans have heard about) are not even on the SIN list yet, but no doubt will be in time.
• “Crypton Super Fabrics do not contain air polluting VOCs.” First this refers to Crypton’s Gold certificate from Scientific Certification Systems as having ultra low emissions – not zero, as this claim states. But even so, this diverts attention from the real concern, because products may happen to outgas at ultra low levels, but still be a product of grave concern. The passionate debate within the US Green Building Council on whether to award green LEED points for the use of vinyl is one illustration. Vinyl could qualify for LEED points because it does not happen to outgas, but it is still the very top of the Greenpeace plastics pyramid for substances to avoid. The vinyl proponents finally lost that battle. A whole movement has emerged to address these deficiencies in LEED: look at http://www.pharosproject.net/ or http://cascadiagbc.org/living-future/11/program
• “Crypton uses no PFOAs (perfluorooctanoic acids) during its manufacturing process” – here’s the meat of the problem, and it’s a bit hard to understand without some chemistry background. Suffice it to say that there are so many varieties of perfluorochemicals that a company can truthfully say they do not use one kind – while using another. According to an email dated April, 2011 from Dr. Hardy Sullivan, Director of Research, “Crypton is not made from or using PFOA or PFOS. Crypton is made from perfluorochemicals that are persistent (long-lasting) but Crypton is not toxic or bioaccumulative.” So by their own admission they use perfluorochemicals; they just do not tell us which kind they use. Much research has been done on what is known as C6 chemistry, which is supposed to be less harmful than PFOA or PFOS, however it has been found that in order to achieve the same results much more of the finish has to be applied – and maybe they use this kind but they will not disclose what they use. We had two blog posts on stain repellant finishes where you can read a bit more about this, https://oecotextiles.wordpress.com/2010/02/03/soil-and-stain-resistant-finishes/ and https://oecotextiles.wordpress.com/2010/02/10/what-about-soil-resistant-finishes-like-scotchgard-goretex-nanotex-and-greenshield-are-they-safe/
• “Crypton uses no formaldehyde and does not contain vinyl” – again another red herring and beside the point.

12 04 2012

Hi–great post. So much detail/information. I’m curious..what do you know about Guardsman Fabric Protector? We just bought a sofa and I don’t want it treated w/any harmful chemical but also want to make sure it’s protected. I can’t find much detail on Guardsman and what the product is made of.

13 04 2012
O Ecotextiles

I have never heard of Guardsman. Why don’t you ask them if the products for fabric contain flurocarbons or PERC? You can learn a lot just by the way they answer your questions. Is this an important issue with them? Do you feel comfortable using their products and feel sure that they wouldn’t sell you something that’s unsafe to use?

12 12 2012

Thank you for the valuable information. One thing that is not clear from your post is whether you would be willing to use any kind of fabric protection on a couch. Is there one that you would use in a family room with children? Thanks. Patty

13 12 2012
O Ecotextiles

Hi Patty: I’m glad you’re asking my opinion, because I try to write the posts so that you can make up your own mind as to the tradeoffs associated with a particular topic. Knowing what I do now, I wouldn’t have any kind of stain protection in a room where children live. ( For my reasoning, see our posts: https://oecotextiles.wordpress.com/2012/02/10/real-life-examples-of-the-effects-of-our-textile-choices/ and https://oecotextiles.wordpress.com/2010/02/10/what-about-soil-resistant-finishes-like-scotchgard-goretex-nanotex-and-greenshield-are-they-safe/ ). The use of PFC’s carries far too much risk to make me comfortable.
If you’re really worried about staining, buy a bit of extra cloth and tuck it into and around the bottom cusions of furniture so it can be whisked off when company comes (or make a full slipcover). You can also occasionally have your furniture professionally cleaned, which can do wonders. I know that’s much easier said than done, and I’ve tried to come up with reassurances (like the fact that my three boys and dogs didn’t really so much stain the furniture as simply make it dirty) but I think the change must come from within. Do your kids really spill lots of food on the furniture or is this just anticipatory on your part?

20 01 2013

Thanks for presenting such detailed information about the formulations and risks of using stain repellents! I found a number of less helpful, other online sources that were muddied by people using purely anecdotal evidence or immaturely name-calling each other “alarmist” or “paranoid” for being concerned in the first place.

Ever since the seemingly minor task of researching my options for a new purse, I’ve been learning about so many ethical, environmental, and toxicity-related problems in the textile industry (more problems than I was already aware of).

Keep up the informative posts!

20 01 2013
O Ecotextiles

Thanks Diana. We do try to keep to the facts, but it’s sometimes hard to keep our bias out of the mix!

10 03 2013

What do you think of Micro Seal? I was told by Ecosteam a cleaning company that it was non toxic and safe as a protectant for carpet and upholstery? They also wanted to use Microban to sanitize and deodorize.

11 03 2013
O Ecotextiles

I have never heard of Micro Seal so I can’t comment.

17 04 2013

very interesting. can you give me some sources to find more information about this?

17 04 2013
O Ecotextiles

Sure, you can start by Googling any of the topics covered. Here are some to get you started:
Regarding PFOA and PFOS: http://www.epa.gov/fedfac/pdf/emerging_contaminants_pfos_pfoa.pdf
Washington Toxics Coalition summary of toxicity of PFC compounds: http://pollutioninpeople.org/toxics/pfcs
Background of 3M and Scotchgard by The Environmental Working Group: http://pollutioninpeople.org/toxics/pfcs
Nanotechnology in general: http://www.orionmagazine.org/index.php/articles/article/7278

7 08 2013
Susan Ray


Have you heard of Green Guard by Triplex? or Lock out by AFM Safecoat?
After reading you info, I guess it’s best just to get a slip cover!!
Still trying to find that magic product that’s safe for my family!

13 08 2013
O Ecotextiles

I have not heard of either of these products. But I’d make them convince me of their safety before committing my children as subjects – and I’d probably make them get some kind of independent third party certification. Since GOTS and Oeko Tex now exist for fabrics, a slip cover does tend to reduce anxiety.

25 03 2014
environmentally friendly cleaning products

The commission’s authority over oil and gas production was further bolstered in 1917 by a law that created
the oil and gas division within the OCC and granted it
exclusive jurisdiction over all aspects of oil and gas production.
The EPA also states that a 2003 Office of Management and Budget study says
the program benefits exceeded costs ‘by more than 40 to 1.
Dumping them down the drain or tossing them in the trash can cause environmentally hazardous waste.

11 05 2014
Scott Johnston

Hello – I found this article very helpful with respect to sorting out all of the different waterproof textiles. I have two questions:

1) What are the immediate concerns of these fabrics. It is clear to me that in the long term, and on the global scale, PFCs are dangerous and should be phased out as quickly as possible. Still, in the short term, I would like to buy a waterproof jacket! What potential risk of owning a jacket with C6 or C8 compounds?

2) After doing some more research, I found that Nikwax (a company that I know and with products that I have used with good success) is entirely PFC-free, and makes a variety of DWR after-product finishing options. But I was unable to find out anything about the chemicals that they use.

11 06 2014
Potty training your baby

These are truly enormous ideas in about blogging. You have touched some good factors here.

Any way keep up wrinting.

6 11 2014

I see that nanotex has a new product called Aquapel which contains no PFOAs and won’t degrade into any PFOAs. I wonder what you think of this?

8 11 2014
O Ecotextiles

I can’t evaluate it because Nanotex doesn’t let us know the chemistry of the product. Even if they use no PFOAs there are still many questions: for example, does the application break down into any of the other PFCs, like PFOS. Basically all they tell us is that their use of nanotechnology enables them to “fundamentally transform” fabrics. Do they have any third party certifications of any sort?

20 11 2014
Green Energy

I’m really impressed with your writing skills and also with the layout on youyr blog.
Is this a paud theme or ddid you modify it yourself? Anyway keep up the
nice quality writing, it is rare to see a nice blog
like this one nowadays.

20 11 2014
O Ecotextiles

You can fill book with what I don’t know about computers! We use WordPress, the basic template, nothing fancy! Thanks for your kind words, glad you like the blog.

11 03 2015

the MSDS from Guardian says that Crypton fabric treatment is water, acetic acid and dipropylene glycol monomethyl ether. Does this make it more safe than a PFC based treatment?

11 03 2015
O Ecotextiles

Did you check to see what dipropylene glycol monomethyl ether (DPGME) was? The MSDS sheet also says, regarding Crypton, that “if exposure occurs, flush the affected area thoroughly with water for at least 15 minutes. Destroy contaminated clothing and shoes. Seek medical attention immediately.” DPGME is considered a hazardous substance according to OSHA 29 CFR 1910.1200, but there are no studies on humans. Acetic acid is rated “moderately toxic” by the US EPA, category II, “Warning”; it is not known whether acetic acid is a developmental or reproductive toxin, endocrine disruptor or carcinogen. PFCs, on the other hand, are known to disrupt normal endocrine activity; reduce immune function, and cause adverse effect on multiple organs. So perhaps your question should be whether you want to live with the devil you know or the devil you don’t know?

29 11 2015

can i wash scotchgard out of fabric?

30 11 2015
O Ecotextiles

Hi Francesca: well, think about how well Scotchgard would do in the market if it lost it’s stain fighting ability after a few washes? These finishes are designed to perform – and to perform well. If they could be washed out then they wouldn’t be around long. The answer is no, they cannot be washed out.

1 12 2015

Thank you so much for taking the time to respond to my question. I greatly appreciate it. The fabric I am using to make curtains has scotchgard. Will it always out-gas? I will only be touching it mostly as I sew then up on the widows they go only to touch briefly to open and close curtains. My concern is out-gassing.
Thanks for all you do.

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