In this episode, host Beatrice Bizzaro from HPC Italy is joined by Ivy YuXia Liu (Terrapex Canada) and Jack Sheldon (Antea Group USA) to explore the growing global concern around emerging contaminants such as PFAS, microplastics, and 6PPD. The discussion examines how advances in science are uncovering previously unknown environmental and human health risks, while also highlighting the challenges organisations face in navigating uncertainty, evolving regulations, and risk management strategies.
Episode 2 of Rethinking EHS, Season 3 focuses on the rapid rise of emerging contaminants and their impact on environmental and human health.
Advances in scientific research are revealing hidden risks from widely used chemicals, bringing emerging contaminants like 6PPD into focus as they transform into harmful byproducts, while growing public awareness, especially around PFAS “forever chemicals”, is accelerating regulatory and scientific action, with microplastics quickly gaining similar attention.
At the same time, organisations face challenges navigating fragmented and evolving regulations, particularly in the US, making risk management complex.
Ultimately, the episode underscores the need for organisations to proactively understand and manage their risks now, while individuals can contribute by reducing their everyday environmental impact.
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Guest quotes:
Ivy Ng:
“Advances in science are revealing previously unknown threats to the environment and human health.”
Jack Sheldon:
“There’s a lot to build on. We have a baseline of information, but still many unknowns when dealing with emerging contaminants.”
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Timestamps:
00:00:00 – Introduction & overview of emerging contaminants
00:01:27 – What are emerging contaminants?
00:04:05 – Deep dive into 6PPD and its environmental impact
00:08:34 – PFAS vs microplastics: public awareness and regulation
00:12:10 – Human health risks and uncertainties
00:13:24 – How organisations are responding to PFAS
00:18:17 – Solutions: stormwater management and treatment systems
00:21:34 – Future outlook for PFAS and emerging contaminants
00:23:48 – Safer alternatives and regulatory developments
00:28:37 – Key actions for organisations and individuals
00:31:23 – Closing reflections
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Sponsor
Rethinking EHS is brought to you by the Inogen Alliance. Inogen Alliance is a global network of 70+ companies providing environment, health, safety, and sustainability services, working together to provide one point of contact to guide multinational organizations to meet their global commitments locally. Visit https://www.inogenalliance.com to learn more.
Produced by Madcontent.co.nz
Links
https://www.Inogenalliance.com/resources
https://www.Inogenalliance.com/podcast
Beatrice on LinkedIn https://www.linkedin.com/in/beatrice-bizzaro/
Ivy on LinkedIn https://www.linkedin.com/in/ivy-liu-p-geo-qpra-4a797520/
Jack on LinkedIn https://www.linkedin.com/in/jack-sheldon-680a941a/
Transcript
00:00:00
Beatrice Bizzaro:
Hello everyone, and welcome. Welcome to Season 3 of Rethinking EHS: Global Goals, Local Delivery, an Inogen Alliance podcast.
My name is Beatrice Bizzaro. I am Technology Lead at HPC, Global Water Working Group Lead at Inogen Alliance, and your host for today’s episode on emerging contaminants — microplastics, PFAS, and 6PPD.
Over the last year, we’ve seen growing interest and concern around the behaviour and impact of many man-made substances and chemicals on the environment. And when I say environment, I’m referring not only to the natural environment, but also to the built environment — both of which directly influence us as human beings.
A very warm welcome to our speakers: Ivy YuXia Liu from Terrapex, and Jack Sheldon from Antea Group USA. It’s a pleasure to have you both here today.
00:00:58
Beatrice Bizzaro:
To kick us off, I’d like to start with a high-level question. There is currently a lot of global attention and momentum around man-made substances such as microplastics, as well as chemicals like 6PPD, which we’ll discuss further today.
Why are these being labelled as emerging contaminants, and what issues are they generating?
00:01:27
Ivy YuXia Liu:
Emerging contaminants are gaining global attention because advances in science are revealing previously unknown threats to both the environment and human health.
In my case, I’ll be talking about 6PPD and its transformation products, including 6PPD-quinone. This is a clear example of how a commonly used chemical — originally developed as an additive in tyres — can transform in the environment into a previously unknown and highly toxic compound.
This has highlighted how transformation products we didn’t previously understand can create significant environmental impacts, particularly in urban areas. It has also increased pressure on regulators and scientists to rethink material design and risk assessment.
00:02:10
Jack Sheldon:
In the US, when we talk about emerging contaminants, we’re really talking about uncertainty — there’s still a lot we don’t know.
Take PFAS, for example. It started with high-profile litigation cases that resulted in multi-million dollar settlements. That led to a huge amount of media attention, and now it’s something people see in the news almost every day.
Once the public becomes interested, everything else follows — science, policy, and regulation. That’s where we are with PFAS. Microplastics are catching up quickly, and 6PPD-quinone is also gaining attention, though slightly behind.
00:04:05
Beatrice Bizzaro:
Ivy, as a subject matter expert, can you tell us more about 6PPD — where it’s found and why it’s so relevant today?
00:04:10
Ivy YuXia Liu:
6PPD is an anti-degradation chemical widely used in tyres since the 1970s to prevent cracking and damage caused by ozone exposure.
However, when tyre particles are released into the environment, 6PPD reacts with ozone and transforms into a toxic byproduct known as 6PPD-quinone.
This compound was only identified in 2020 after years of research. It has been linked to what’s known as urban runoff mortality syndrome, where coho salmon die in large numbers in urban streams before spawning.
Coho salmon are a keystone species, meaning their decline signals broader environmental issues. They are also culturally and economically important.
This connection between everyday activities — like driving — and environmental consequences highlights the urgent need for better infrastructure, stormwater management, and safer chemical alternatives.
00:07:14
Jack Sheldon:
In the US, 6PPD-quinone is largely being treated as a stormwater issue. What’s interesting is that we’re seeing action led more at the municipal level rather than federal or state levels.
Local governments are increasingly driving efforts to address these contaminants.
00:08:08
Beatrice Bizzaro:
PFAS are currently dominating the global conversation, but microplastics are gaining attention quickly. Jack, how are these being addressed in the US?
00:08:34
Jack Sheldon:
A big factor is terminology — PFAS are often called “forever chemicals,” which creates public concern and drives awareness.
This has led to significant regulatory and scientific focus, overshadowing other contaminants. However, microplastics are easier for people to understand, which is helping them gain attention.
Right now, the focus on microplastics is largely around drinking water. Some states are pushing for better sampling and monitoring, and we’re seeing collaboration between states to push for federal action.
00:12:10
Beatrice Bizzaro:
Ivy, what do we know about the health impacts of 6PPD-quinone?
00:12:10
Ivy YuXia Liu:
Research is still emerging, but early studies — mainly from animal models — suggest potential links to skin allergies, respiratory issues, and reproductive effects.
These compounds have also been detected in human biological fluids, including breast milk and cord blood.
There are some associations with diseases such as colorectal cancer and Parkinson’s disease, though the exact risks to humans are still uncertain.
That uncertainty itself is a major concern.
00:13:57
Beatrice Bizzaro:
Jack, when it comes to PFAS, where are organisations most successful right now?
00:13:57
Jack Sheldon:
There are really two approaches.
Some organisations are overwhelmed by uncertainty and choose to do nothing. Others are more proactive and are working to understand their environmental, operational, and brand risks.
Those proactive organisations are ahead of the curve.
There’s an enormous amount of information — new technologies, new regulations — and it’s difficult to keep up. That’s why tools like regulatory dashboards and risk screening tools are becoming essential.
At Antea Group USA, we’ve developed tools to help clients understand risk across supply chains, operations, and compliance landscapes globally.
00:18:17
Beatrice Bizzaro:
Ivy, what does stormwater control look like in practice when managing 6PPD-quinone?
00:18:48
Ivy YuXia Liu:
There are three main approaches:
Other options include floating wetlands and phytoremediation using plants.
00:21:02
Beatrice Bizzaro:
Looking ahead 5–10 years, what does the future of PFAS management look like?
00:21:34
Jack Sheldon:
Right now, we’re focused more on managing PFAS rather than destroying them — for example, containing them in the subsurface.
However, I’m optimistic. Many emerging technologies are focused on breaking down PFAS, and we’re seeing promising developments.
Ultimately, I think the solution will involve combining multiple technologies rather than relying on a single approach.
00:23:18
Beatrice Bizzaro:
Ivy, what would you like to see in terms of future management of 6PPD?
00:23:48
Ivy YuXia Liu:
There’s a lot of research underway into safer alternatives. Some companies are exploring chemicals with lower hazard profiles, while others are developing materials like graphene-based alternatives.
From a regulatory perspective, Washington State is leading the way with a proposed pathway to ban 6PPD in tyres by 2035.
Globally, we’re seeing collaboration across manufacturers to develop safer solutions.
00:28:07
Beatrice Bizzaro:
As a final thought, what is one action you would recommend to organisations and the general public?
00:28:37
Jack Sheldon:
For organisations: understand your risk now — don’t wait.
For individuals: be aware of your impact. Reduce plastic use, stay informed, and think about what you’re sending to landfills and wastewater systems.
00:30:12
Ivy YuXia Liu:
I agree. Organisations should stay informed and actively monitor developments in safer alternatives, especially for chemicals like 6PPD.
00:30:48
Beatrice Bizzaro:
A very special thank you to Ivy YuXia Liu and Jack Sheldon for sharing their insights.
This episode is part of our celebration of 25 years of Inogen Alliance — highlighting global collaboration, local expertise, and a shared commitment to building a more resilient future.
Make sure to tune in next week for our bonus episode.
If you enjoyed today’s episode, please follow Rethinking EHS on Spotify, Apple Podcasts, YouTube, and LinkedIn — and share it with your network.
Until next time, thank you for listening.