How ‘green’ is uPVC?

Trigger warning: the information I’m about to share with you challenges a common perception in the building industry about uPVC.

We've seen it before: "BPA-free" plastics replaced with equally harmful ingredients, "low VOC" labels masking the presence of semi-VOCs. Similarly, the absence of known harmful ingredients in a product doesn't automatically make it safe for our health or the environment.


The social, health and environmental impacts of ingredients that make up uPVC span the entire lifecycle of the material.

In the paper “The polyvinyl chloride debate: why PVC remains a problematic material”, Zero Waste Europe says “the initial regulatory response to concerns about PVC focussed mainly on substitution and phase-out of phthalates, but failed to address wider health and environmental issues associated with PVC manufacture and use” (June 2021).

Let’s clarify what it actually is: uPVC is PVC without the plasticisers (BPA and phthalates) but still contains the main components of Poly Vinyl Chloride:

  • Vinyl Chloride

  • Chlorine: PVC is nearly 60% chlorine by weight, (Healthy Building Network, 2018, as cited by Zero Waste Europe, 2021), with uPVC having a similar content according to Ningbo Baodi Plastic Valve Co.

  • Ethylene dichloride

  • Additives including light & heat stabilisers, fillers, & pigments: 370 additives were identified by the PLASI initiative, according to a report by the European Commission, The use of PVC in the context of a non-toxic environment, (2022), most of which were pigments. Metals (including mercury, lead, and cadmium) have traditionally been used in the production of PVC although have been phased out in many regions.

Vinyl Chloride

  • Classified a Group 1 carcinogen to humans’ agent by the International Agency for Research on Cancer (2018).

  • Vinyl Chloride can leach dioxin, a potent carcinogen and is widely recognised in scientific literature as the most toxic chemical known to man (Marinkovic et al. 2010 a).

  • Dioxin is thousands of times more powerful than most other chemicals that cause cancer in animals, according to CDC health scientist, Mark McClanahan. It’s also listed in the Environmental WorkingGroup’s Dirty Dozen Endocrine Disruptors (2013).

  • Acute (short-term) exposure to high levels of vinyl chloride in air has resulted in central nervous system effects (CNS), such as dizziness, drowsiness, and headaches in humans. Chronic (long-term) exposure to vinyl chloride through inhalation and oral exposure in humans has resulted in liver damage, (US EPA).

    The derailment of a train carrying vinyl chloride in the USA in 2023 caused significant devastation to the surrounding community, environment, and wildlife, as you can see from the below extracts from an article published in The Repository (17 February, 2023).

Chlorine

  • Significant electrical energy is required to produce chlorine, to split the salt into chlorine and sodium hydroxide), estimated to be 47.8 GJ per tonne of chlorine (Worrell, E. Phylipsen, D. Einstein, D. 2000)

  • Worldwide about 35-40 per cent of the chlorine manufactured is used to make PVC, making the PVC industry the single largest user of chlorine worldwide, according to Vinyl Council Australia.

  • Greenpeace have previously called for the phasing out of all synthetic chlorine.

  • Chlorine used for PVC production generates hazardous waste, which build up in the eco-system and are harmful to fish, humans, and wildlife and are toxic at low doses. Low level exposures are particularly harmful to developing foetuses and infants (No Harm, Europe, 2021).

  • Increased chlorine/chloride concentration in soil can be fatal to plant species if exposed (Parveen N, Chowdhury S, Goel S, 2022).

  • Low grade of pneumoconiosis and a small degree of lung function impairment is associated with PVC dust exposure (Ng TP, Lee HS, Low YM, Phoon WH, Ng YL, 1991).


    The United States Environmental Protection Agency shared the below observations about the impact of chlorine emissions on food crops at a nearby farm, as per the below extract from the paper: Environmental Effects of Chlorine (1975).

Ethylene dichloride

  • A Federal hazardous air pollutant according to California Air Resources Board, and according to the US EPA

  • Inhalation of concentrated ethylene dichloride vapor can induce effects on the human nervous system, liver, and kidneys, as well as respiratory distress, cardiac arrhythmia, nausea, and vomiting. Chronic (long-term) inhalation exposure to ethylene dichloride produced effects on the liver and kidneys in animals.

Additives

According to the European Commission report: “The use of PVC (poly vinyl chloride) in the context of a non-toxic environment (p.35, 2022), a commonly used pigment is titanium dioxide, “which exhibits a white colour and is also used in other products as a colorant such as wall paint and sunscreen (Skocaj et al. 2011). There it serves a dual purpose: it gives the PVC a bright white colour and also protects it from harmful UV radiation. It is classified as biologically inert (Skocaj et al. 2011), Recently titanium dioxide has however been classified as a carcinogen category 2 via inhalation.”

Cadmium has traditionally been used as a stabiliser and lead as a pigment, although metals have been found to have a higher migration rate from plasticised PVC than uPVC, according to the European Commission (p. 38, 2022)

In the below table, I’ve compared uPVC and PVC using my Building Biology criteria for evaluating building materials. Despite uPVC being free of plasticisers, its overall health and environmental impacts led me to rate it similarly to PVC.

Each of these rating criteria is given a score between 0 and 3:
3: highly recommended
2: recommended
1: avoid if a better material is available
0: hazardous and should be avoided

This decision stems from considering the entire lifecycle and environmental footprint of uPVC. While it avoids specific health issues related to plasticisers, other significant concerns, such as its production process and end-of-life implications, persist.

This evaluation highlights the complexity in selecting materials that align with both sustainability and health, emphasizing the need for thorough and holistic assessments in our material choices.

I understand it can feel unsettling to discover a material perceived as ‘healthy’, isn’t quite what it’s marketed to be, particularly given its widespread use due to benefits like thermal efficiency and cost. Yet, as professionals dedicated to shaping the spaces where life happens, we have a responsibility to look beyond surface narratives to the deeper truths.

This journey towards greater transparency and deeper understanding is not one we have to embark on alone. If you're a home builder or designer who feels a growing need to navigate these complexities with more clarity and confidence, the Healthy Building Materials Mastermind is designed for you.

In our Mastermind cohort, we don't just scratch the surface. We dive deep into the health and environmental impacts of various building materials (you’ll see how I’ve rated more than 70 materials, plus in depth insights), from foundations to roofs and everything in between. But more than that, we foster a community of like-minded professionals – a collective of forward-thinkers who are not afraid to challenge the status quo and lead the way in sustainable, health-conscious building practices.

By joining the next Healthy Building Materials Mastermind cohort, you’re not just gaining access to comprehensive knowledge and resources; you’re becoming part of a movement. A movement that champions informed choices, prioritizes health and sustainability, and shapes the future of our industry.

Learn more about how you can join this elite community of change-makers here.

Together, let’s pave the way for a more informed, responsible, and health-focused building industry."

Zara D’Cotta is a Building Biology New Build Consultant, Keynote Speaker and Founder of The Healthy Home.

We envision an Australia where every home is a testament to health-centric design and construction. Our goal is to be the guiding light for time-strapped building industry professionals, ensuring every home designed and built under their watch prioritises the health and well-being of its occupants.