Position Paper: PVC

Tue, 11/10/2015 - 10:19 -- admin
Background

Worldwide, about 45 Mio tonnes of PVC are produced each year. PVC is used for many different applications, amongst others for toys, packaging and coated papers. PVC is associated with many issues, and therefore attacked from different sides, including EPEA. In the1980s, Michael Braungart headed the chemistry section of Greenpeace Germany and led its Anti-PVC campaign. It took decades but significant progress was made and is still ongoing in the market.

Some companies dealing with PVC - often visible ones - have taken the raised issues seriously and addressed them: Either PVC is substituted or PVC recipes are optimized by substituting phthalate plasticizers and heavy metal based stabilizers while take back systems for the safe and productive post-use management are established.

More Background and Consequences

Therefore, the way to think about and to deal with PVC needs to be specified today. In their book "The Upcycle", Michael Braungart and William McDonough stated: "In fact, ironically, PVC was initially put into mass production as a way to close loops in the manufacture of paper and hydrocarbons. Those processes created huge amounts of chlorine residue of sodium hydroxide and acetylene. Industry chose to put those byproducts into PVC, a choice that demonstrates how modeling manufacturing on a simplified version of a closed loop is often not sufficient. (...) Because hard PVC is manufactured without the problematic plasticizers or UV stabilizers found in soft PVC, we may have to consider sequestering these products in hard PVC piping deployed underground for the next thousand years or so." [1]

Historically, there was a good reason for the invention of PVC and its patenting on July 4th, 1913. It was to divert chlorine away from applications like chemical weapons or other very problematic routes of chlorine use. Chlorine gas is the toxic byproduct from the huge production volumes of some caustic chemicals, first of all caustic soda.

The magnitude of the issue can be illustrated by looking at the market: Caustic soda is one of the most demanded chemicals with a production volume exceeding 60 million tons/year [2], with increasing volumes. As a byproduct, almost the same amount of chlorine is produced annually.

Caustic soda is a consumable with no opportunity to be kept in technical cycles. The demand is difficult to meet with production routes other than the chloralkali process. In effect, likely more than 98% of caustic soda and 100% of chlorine are produced this way. [3, 4] As long as the demand for caustics prevails, a transitional chlorine management solution is obviously needed.

Against this background we believe that it is preferable to park chlorine in PVC applications with positively defined composition that can be managed after-use. Only those products for which a take back system and recycling system can be established and properly managed come into question for this sequestration. It is possible for durable products but not for packaging or other easily scattered applications like bags or toys.

Our proposal

The fact that PVC handling companies are starting to comprehensively deal with the management of PVC products opens the way to a distinction between “Non tolerable PVC still creating serious problems during and after-use” (like toys, packaging, coated paper) and “Tolerable PVC that provides a transitional solution”.

PVC is seen as tolerable provided that the following conditions are fulfilled:

  • Safe PVC production: Vinyl chloride isn’t produced with chlorine originating from mercury-based chloralkali processes. The residual Vinyl Chlorine Monomer (VCM) content is very low.
  • Safe additives: Optimized, non heavy metal based heat stabilizing systems are used. When plasticizers are needed, they don’t belong to phthalates but to modern products with much better safety profiles.
  • Applications: PVC is used for applications in the construction sector like pipes, tubes, doors, window frames, flooring, and siding. These products are predisposed for manageability after use because they are immobile during the use-phase and used in large quantities per functional unit. This makes them easily traceable and retrievable during building renovation and demolition.
  • Take back system and recycling: Effective commercial take-back systems are offered after use and recycling concepts maintain the integrity of the PVC molecule.    
  • Commitment and innovation: The company is reviewing its processes and commercial relationships for possibilities to substitute chlorinated organic chemistry and the demand for caustic products.

Published by EPEA Internationale Umweltforschung GmbH, December 2015

 

References

1. William McDonough, Michael Braungart: The Upcycle. Beyond Sustainability - Designing for Abundance. April 2013, North Point Press, p. 43/44
2. Cetin Kurt, Jürgen Bittner (2005), "Sodium Hydroxide", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a24_345.pub2
3. Dow Chemicals. Caustic soda. Process overview.
4. European IPPC Bureau. Best Available Techniques (BAT) Reference Document for the Production of Chloralkali. Industrial Emissions Directive 2010/75/EU (Integrated Pollution Prevention and Control). 2014.