Soil and stain resistant finishes

3 02 2010

I grew up with Scotchgard on sofas, Teflon on non-stick pans and GoreTex on my raincoat.  These trademarked items were all made possible through the vast PFC (perfluorocarbon) family of chemicals which has transformed our lives – and the textile industry.  When applied to fabrics, they provide water and stain resistance.  These perfluorocarbons – commonly known as fluorocarbons – are among the most politicized and least understood chemicals used in the textile industry.  Until recently, they were thought to be biologically inert.  No one thinks so now.

The multi-billion dollar “perfluorocarbon” (PFC) industry has emerged as a regulatory priority for scientists and officials at the U.S. Environmental Protection Agency (EPA) because of  a flood of disturbing scientific findings which have been  published  since the late 1990s.  These findings have elevated PFCs to the rogues gallery of highly toxic, extraordinarily persistent chemicals that pervasively contaminate human blood and wildlife the world over. Government scientists are especially concerned because unlike any other toxic chemicals, the most pervasive and toxic members of the PFC family never degrade in the environment.
Here’s a quick dictionary of perfluorochemicals from the Environmental Working Group to give you an overview:

  • Perfluorinated chemicals or Perfluorochemicals (PFC): A chemical family consisting of a carbon backbone fully surrounded by fluorine, which makes them impervious to heat, acid or other forces that typically break down chemical compounds. Sometimes referred to as ‘Teflon’ chemicals.
  • Fluorotelomer: Chemicals that become PFCs when they are released in the environment.  These are the chemicals applied to food packaging, stain resistant clothing, and carpet protection.
  • PFOA: Perfluorooctanoic acid. Breakdown product of fluorotelomers and backbone of many consumer products. Also used as a surfactant to produce PTFE, the Teflon in pans. Sometimes called C8.
  • PFOS: Perfluorooctanyl sulfate. Breakdown product of fluorotelomers that are based on 3M chemistry.
  • C8,  C6, et al: The range of chemicals that are identical to PFOA but with carbon backbones of varying length. PFOA/C8 has 8 carbons, C7 has 7, and so on. These are breakdown products of fluorotelomers.
  • PTFE: Polytetrafluoroetheylene. Polymer used for cookware and other non-stick applications. Brand names include Teflon and Silverstone. A physically expanded form of PTFE is used to make Gore-Tex. PFOA is an ingredient in the manufacture of PTFE.
  • Teflon: Teflon is a brand name, it is not a single chemical. Teflon can refer to PTFE or to a fluorotelomer or to any number of perfluorochemicals. Perfluorochemicals are often termed “Teflon” chemicals or as having “Teflon” chemistry.

Perfluorocarbons  break down within the body and in the environment to PFOA, PFOS and similar chemicals.  (Note: the chemistry here is quite dense; I’ve tried to differentiate between the groups.  Please let me know if I’ve made a mistake!)   They 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 other  three chemicals on the list are polybrominated diphenyl ethers (PBDEs), phthalates and short-chain chlorinated paraffins (SCCPs)  Three of these four chemicals are used in textile processing.)

Although little PFOA can be found in the finished product, the breakdown of the fluorotelomers used on paper products and fabric treatments might explain how more than 90% of all Americans have these hyper-persistent, toxic chemicals in their blood. A growing number of researchers believe that fabric-based, stain-resistant coatings, which are ubiquitous, may be the largest environmental source of this controversial chemical family of PFCs.

There are many finishes on the market that claim to provide soil and stain repellants for fabrics.   Among the more well known are:

  • Scotchguard
  • Teflon
  • Zepel
  • NanoTex
  • GreenShield
  • Crypton Green

Each one of these finishes uses fluorocarbon chemistry to achieve their results; but they all go about it a bit differently.  And therein lies all the difference.

So when you ask for a treatment to make a sofa fabric soil and stain resistant, or a raincoat rain repellant, what does it mean for the environment?  Well, it sorta depends.  I thought we could cover each one of these in one post, but it gets complicated.  So next week we’ll look at individual finishes.