PVC Should Not Be Demonised

The BPF responds to the cover article of the June 2023 issue of E&T about PVC. The article was misconceived and gave no indication of the levels of exposure that give rise to the stated effects:

The cover article of the June 2023 issue of E&T about PVC was misconceived. With respect to vinyl chloride itself, you correctly point out the carcinogenicity classification of vinyl chloride. However, the article gave no indication of the levels of exposure that give rise to the stated effects.

The acute toxicity of vinyl chloride, which can induce anaesthesia, is exceedingly low. An angiosarcoma register was developed in the 1970s in Europe. It shows that sites operating at the revised occupational exposure level of three parts per million (now one part per million) created no additional cancer risk to employees. The REACH dossier for vinyl chloride is publicly available and includes summaries of all the carcinogenicity studies and conclusions.

Whilst lead and cadmium were used to give thermal stability for demanding PVC applications in the past, they are no longer used. The article also claims phthalates are endocrine disruptors and this is not reflective of many in use today. Four phthalates are regulated in Europe as endocrine disruptors and these have been replaced by high molecular weight phthalates or alternatives that are not classified as hazardous. In addition, rubber ducks are frequently not made of PVC – but if they are, they are made without plasticisers like phthalates.

The PVC used in building material and water pipes involves rigid, immobile polymeric networks that cannot “leach” into anything, as the article suggests. If the writer was referring to PVC additives, rigid PVC is highly effective at retaining additives. Any substance of concern used in materials in contact with drinking water must be assessed under the EU Construction Products Regulation and pass a suite of migration tests.

Vinyl chloride is regulated in drinking water (under the EU Drinking Water Directive) as well as in the USA. It is one of many substances for which water companies must test, and levels must be below 0.5 parts per billion.

The article also makes no reference to the great progress made in Europe on the levels of PVC recycling: in 2022, 800,000 tonnes of PVC was recycled.

The transportation of hazardous chemicals by rail is a topic that is worthy of serious and detailed investigation but your article missed the opportunity to stoke serious debate.

- Director General of the British Plastics Federation, Philip Law

Further Information and References

Carcinogenicity of vinyl chloride monomer

It is worth pointing out that vinyl chloride was just one of several chemicals being transported on the train at the time of the accident. The decision to incinerate was, I am sure, not taken lightly by relevant experts on the ground. 

With respect to vinyl chloride itself, you correctly point out the carcinogenicity classification of vinyl chloride. You refer to a 2020 article in the journal Cancer Spectrums, and gave details of its properties. However, the article gave no indication of the levels of exposure that give rise to the stated effects. This is critical to the understanding of the properties of vinyl chloride. In fact, the acute toxicity of vinyl chloride, which can induce anaesthesia, is exceedingly low. Critically, the “rare form of liver cancer,” angiosarcoma, was first identified in 1974 and gave rise to a complete change in the way the substance is handled. An angiosarcoma register was devised in Europe and this has followed every PVC worker since. It shows that sites operating at the revised occupational exposure level of three parts per million (now one part per million) gave no additional cancer risk to employees. This is a sensitive and difficult subject and should require similarly sensitive and objective reporting.

The comment from Until Justice Data Partners, namely “in the US, we don’t typically test chemicals for safety before we put them on the market” does not correspond with experience. If this was the case, it would both not apply to Europe (including the UK) and certainly not apply to vinyl chloride. In the EU, the REACH dossier for vinyl chloride is publicly available, being published with REACH dossiers for all other substances in commerce on the European Chemicals Agency website[1]. This is equally available in the USA and includes summaries of all of the carcinogenicity studies and the conclusions that led to the above-mentioned occupation exposure levels. With regard to its presence in the environment, we also point out that vinyl chloride is regulated in drinking water (under the EU Drinking Water Directive[2], as well as in the USA. It is one of many substances for which water companies must test, and levels must be below 0.5 parts per billion.

Witches Brew

Again, your report is inaccurate here. Whilst lead and cadmium were used to give thermal stability for demanding PVC applications in the past, cadmium and lead are no longer used.[3] Any cursory visit to the website of any PVC manufacturer or fabricator will show this. Whilst the question of whether we can or should, in 2023, recycle materials manufactured in the 1970s containing these, is a valid one (and is very much a live question given the EU’s Circular Economy Action Plan) but this is not relevant for new manufacture.

Your comment “phthalates, which are endocrine disruptors” is not reflective of many of the phthalate esters in use today. Four phthalates are regulated in Europe as endocrine disruptors and, once again, these have been phased out of manufacture and replaced both by high molecular weight phthalates or alternatives that do not have these hazard classifications. This is all public information.[4] Additionally, rubber ducks are frequently not made of PVC, and if made of PVC would be made without plasticisers, since they are a rigid PVC application.

“PVC is used in building material and water pipes, so it can leach into your drinking water, but it is also in our credit cards.”

Typical PVC resins used in these applications have molecular weights in excess of 40,000 Daltons; they are rigid, immobile polymeric networks and hence cannot leach into anything. If the writer meant to refer to PVC additives, then again, rigid PVC is a highly effective material for retaining additives in the polymer matrix.[5] Any substance of concern used in materials in contact with drinking water is required to be assessed under the EU Construction Products Regulation and pass a suite of migration tests to demonstrate acceptability. So, the reality of PVC use and the image set in the article are poles apart. We also refer to the 0.1 ppb migration requirement in the EU Drinking Water Directive.

Disposal

The article makes a direct quotation of Toxic-Free Future and some claims relating to accidental building and landfill fires. Naturally, these do not constitute normal practice and it is well established that in well-run municipal incineration processes the presence or absence of PVC has no bearing on the levels of dioxin formation.[6] The article makes no reference to the great progress made in Europe on the levels of recycling. 2022 saw over 800,000 tonnes of PVC articles that would otherwise have been sent to landfill recycled back into new products.[7] Once again, this information is easily accessible and would have made a useful counterbalance to the claims in the article that your readers could use to make up their own minds.

Fence line communities

I would be concerned if pipes, packaging and toys were made from vinyl chloride monomer. However, they are not; they are made from PVC. Polymerisation is a chemical reaction: new bonds are formed as old ones are broken. There is no reason in chemistry for PVC to have similar properties to its monomer: after all, the polymer is a high molecular weight inert solid rather than a highly reactive and flammable gas. Implying that PVC is hazardous because its monomer is hazardous, is akin to implying that water will be flammable and explosive because it is made from hydrogen and oxygen.

The transportation of hazardous chemicals by rail is a topic that is worthy of serious and detailed investigation and comparison with both alternative modes of transportation and non-transportation and to generate a respective risk and socio-economic assessment of the consequences of not transporting (meaning companies not being able to manufacture polymers and the subsequent non-delivery of pipes, profiles and other articles that provide clean drinking water and insulation products linked to long lifetimes and low carbon footprints). Instead, you published a very small amount of a large and significant story. Publishing for a community of engineers that can make such assessments and understand them seems an opportunity missed.

Contact information

For further information about any of the above, please contact BPF Industrial & Public Affairs Manager Mohamed Elkhalifa at [email protected].

Sources

[1] Registration Dossier - ECHA (europa.eu)

2 DIRECTIVE (EU) 2020/2184 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 2020 on the quality of water intended for human consumption (Official Journal 23rd December 2020, L435/1)

3 Impact of lead restrictions on the recycling of PVC - VinylPlus

4 For example, see dossier for di-isodecyl phthalate (DIDP): Registration Dossier - ECHA (europa.eu)

5 See, for example, C. Howick, C. Mollett, J. Leadbitter and A. O’Brien: Plastics, Rubbers and Composites 2005 VOL 34 (No 3) page 121-126)

6 Prof Christophe Rappe: Conference Proceedings PVC90 (Institute of Materials, United Kingdom)

7 See www.vinylplus.eu