Why need to know your garments,leather product, food packaging, Flooring & wiring insulation are “PFOA” or fluorocarbons free?

Description:
PFOS and PFOA both fluorocarbons and are closely related substances, though PFOA is significantly different from PFOS in its physical, chemical and biological properties. However, both substances have together been identified widely in people and the environment.

PFOA – perfluorooctanoic acid (also known as C-8):
A synthetic (man-made) surfactant that does not occur naturally and is composed of mainly carbon and multiple fluorine atoms. It is an extremely stable compound resistant to heat, chemicals, water, oil and grease and is known as a perfluorinated chemical or fluorocarbon.

There are 2 main areas where it is used and found:
1) used as a processing aid in the industrial manufacture of PTFE (polytetrafluoroethylene)
2) found as an unintended reaction by product in the production of fluorocarbon / fluorochemical finishes.

PTFE (polytetrafluoroethylene) – a fluoropolymer:
PTFE is a long chain carbon polymer made from PFOA which can be used to make coatings with exceptional chemical, stain, water and heat restistance. These coatings can be applied to several different products such as i) as a membrane to textiles – i.e. Goretex ii) as a coating to pots and pans – i.e. Teflon.

N.B. The fluoropolymer PTFE should not be confused with fluorocarbon/fluorochemical finishes which have different chemistry (see below). PTFE is used as a membrane for bonding to textiles and is not applied as a topical finish for applying to textile fibres and fabric.

PFOA is present as a contaminant in PTFE and all the leading global manufacturers of PTFE have made a commitment to reduce the PFOA content in their PTFE products by 95% by 2020. DuPont has gone further than this and pledged publicly to no longer use, make or buy PFOA by 2010.

Fluorocarbon / Fluorochemical Finishes:
These finishes are used to give textile fibres and fabrics stain and soil resistant properties, they are based on either of the following 2 types of chemistry;

1) Fluorotelomer chemistry (DuPont, Asahi, Daikin, Clariant, Nanotex) which uses short chain fluorocarbons for making finishes
2) PFOS chemistry (3M) which uses PFOS (a specific type of fluorocarbon) for making finishes.
N.B. these are both different chemically from PTFE (see above).

In both fluorotelomer and PFOS chemistry, PFOA and PFOA precursors (chemicals that can form PFOA) are present as unintended reaction by products. Trace amounts of PFOA and PFOA precursors will be present in these finished products. The major manufactures are currently working to minimise these residual PFOA and PFOA precursors from their products.

Chemically
PFOA are fluorosurfactants, which posses a fluoroalkyl hydrophobic / lipophobic “tail” and what should be characterized as a solubilising “head”. These substances are effective to lower the surface tension of water in a higher degree than hydrocarbon surfactants.
pfoa

 

 

Possible application / Where they may be found:

Textiles & Leather – stain resistant and waterproof coatings and membranes on all fibre types. Used for clothing, ties, upholstery, carpets and leather.
Cookwear – non stick coatings used on pots, pans and baking equipments.
Non stick coatings – on various products e.g. Curling tongs.
Flooring – stone and tile protection.
Paper and food packaging – Oil and grease repellent paper and packaging for foods – used in popcorn bags, thought to be one of the major routes for contamination in Americans.
Fire Fighting Foams – and fire resistant materials in buildings and aircrafts.
Telecommunications and electronic wiring insulation.

PFOA can be found in water-, oil- and dirt-repellent treated textiles.
pfoa0

 

 

 

 

Effects / Reason for concern:
Concerns are centred on the persistence and biopersistence of PFOA. Although there are no proven adverse effects of PFOA, it is of concern that it has been detected in humans and animals on a global scale. Every effort is now being made to prevent more PFOA from being released into the environment and reduce the world wide presence of PFOA.

Humans – To date, no human health effects have been proven to be caused by PFOA even in workers who have significantly higher exposure levels than the general population. Recently published data indicates that levels in humans are declining, this is encouraging as manufacturers of PFOA have greatly reduced the amount of PFOA released into the environment.
There are some reports that PFOA is a suspected carcinogen and is toxic to animals, but levels of PFOA in these reports far exceed the levels of PFOA that have been detected in humans and animals. Current levels in the environment are too low to have any toxic or carcinogenic effects on humans or animals. PFOA has a 3-4 year half life in human blood.

Environment – Global pollutant, biopersistent and due to its highly soluble nature is found in water and animals worldwide. Though it is persistent in the environment, it does degrade when incinerated.
pfoa

 

 

 

 

 

Exposure:
Exposures comes from two main sources:

1) Manufacture of PTFE (fluoropolymer) – this is by far the largest source. PFOA has been found in high concentrations around PTFE production plants (in ground water) and higher levels of PFOA have been measured in production workers and residents living close to these plants. However, the mechanism of PFOA contamination is still not fully understood and several studies are underway looking into this. There have been no proven negative health effects on people of these high than normal levels of PFOA.

2) Application of both PTFE and Fluorocarbon finishes onto consumer products – as PFOA is only present in these products in trace amounts the exposure from this source is minimal. For fluorocarbon finishes on textiles, if correct manufacturing procedures are not followed and finishes are not fully exhausted onto the textile, trace amounts of PFOA will be present in the waste water effluent. However, as manufactures are working to eliminate these trace amounts of PFOA from their products, exposure from this route will be negligible.

It is worth noting that exposure does NOT come from the following sources;

3) The manufacture of fluorocarbon finishes.

4) The use of consumer products with PTFE coatings – the trace amounts of PFOA present in PTFE coatings are so small as to be negligible and pose not threat to human health and the environment. Research has shown that PFOA is not released from overheating cookwear products with PTFE coatings. However, other gases can be given off and it is these gases that can affect the sensitive respiratory systems of birds – as has been reported in some cases. If the manufacture of cookwear is carried out to industry standards all residual PFOA will have been driven off during the high temperature processes needed to apply the PTFE coating. It is therefore recommended that reputable branded products be used to ensure industry standards are being met.

5) The use of consumer products with fluorocarbon finishes – Studies have shown that trace amounts of PFOA found in fluorocarbon finishes are so small as to be negligible. They do not pose any threat to human health and the environment and do not result in quantifiably higher levels of PFOA in human blood.
Alternatives:
Since global contamination was discovered, the PFOA released from production plants has been greatly reduced and DuPont and other companies are working on finding replacements for PFOA (C-8), although PFOA has specific properties for which it is difficult to find alternative chemicals. Some companies are looking at products using C-6 or C-4 chemistry instead of C-8 chemistry.

Facebook0Google+0LinkedIn0Twitter0Email
(Visited 52 times, 2 visits today)

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *


× 6 = twenty four

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>