Gore-tex: Time for alternatives. PART 1 | Part 2 | Part 3   

Gore-tex: High time for alternatives

Gore-tex, although generally praised as an indispensable component of outdoor garments, forms a threat for our environment and ourselves. This dirty side of Gore-tex (teflon) and similar membranes still seems to be largely unknown among the public, including outdoor fanatics. Therefore, in the first paragraphs I will explain what exactly the problem is, or why it would be better to avoid buying the products in question. After that, we will see that there is no reason to panic: banning Gore-tex in outdoor equipment does not have to be a step backwards at all. To the contrary, in many conditions the alternatives will even perform better.


An introduction to waterproof clothing

Imagine a rain jacket made from a big plastic bag. It could be perfectly waterproof, but it would not allow any sweat to vapour out. The jacket would not 'breath', and that could be a reason why waterproof clothes made from plastic are not very popular. Certain synthetic membranes have brought a solution: they are perforated with microscopic pores that allow vapour to pass, but not liquid water: sweat can evaporate out, but rain cannot come in. Most popular among membranes is probably Gore-tex. It is in fact a large molecule (polymer) called polytetrafluorethylene (PTFE). Although being dressed in a membrane might work for a while, these membranes are vulnerable and would tear or get damaged easily. Therefore, producers of outdoor clothing protect the membrane with some layers of synthetic fabric. That's why you can't easily see the membrane in clothes with a PTFE or other membrane. What you see on the outside is often nylon. At the inside, the membrane is usually protected with another lining.

Although no rain water can pass through the membrane, the water can still soak the outer layer of the clothing. Once soaked, the fabric will not allow vapour to pass any longer ('breath'). Although this outer fabric cannot be made really waterproof, it can be made water repellent, meaning that it will take a while before the fabric becomes wet. To make the outer fabric water repellent (often referred to as the Durable Water Repellent treatment), usually the chemical perfluorooctanoic acid (PFOA) is used.

You might never have heard about PTFE or PFOA, but you probably have been using it. PTFE is known under the market name 'teflon', and is used in scores of applications, such as frying pans, joint prostheses and bike chain lubricants. PFOA can be found in many sprays for making textile water repellent. PFOA is also a compound necessary for producing PTFE. No PTFE without PFOA.

If not heated, PTFE is chemically inert and non-toxic. Unfortunately, PFOA is needed to make PTFE. Like for many other organohalogens such as DDT, PCBs and brominated flame retardants, there is no known natural process that breaks down PFOA [1]. Being produced since the 1940s [2], PFOA can nowadays be found on all continents, in animals from albatrosses to polar bears and humans [3].

In animal studies, PFOA has been shown to cause among other things liver cancer, developmental problems, endocrine disruption and neonatal mortality [3]. In occupationally exposed humans biological effects have been demonstrated, such as increased incidence in bladder and kidney cancer, higher mortality rates for different types of cancer and diabetes, and changes in levels of the thyroid hormone triiodothyronine [4]. But also lower concentrations, such as found in the general population, cannot be considered safe. Although one study could not confirm this [5], two much larger studies on humans found an inverse correlation between blood serum levels of PFOA and birth weight [6,7]. Moreover a recent study from Denmark showed that levels of PFOA currently found in the general population are high enough to increase infertility with 60 to 154% [8]. To maintain that more evidence and hard prove is necessary before taking measures for reducing production of hazardous chemicals is a generally used tactic of big companies such as DuPont and 3M. Millions of dollars are spent to consultancy companies such as Exponent, Inc. that are specialized in defending harmful products, such as tobacco and asbestos in the past [9]. However, with the evidence available at this time and respecting the precautionary principle, no scientific panel is needed to conclude that it is high time to drastically reduce the production of PFOA.

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