PVA is Still Plastic (An FAQ)
We recently highlighted the fact that laundry pods and laundry sheets that list polyvinyl alcohol (PVA or PVOH) as an ingredient contain plastic. It’s a water-soluble plastic, but plastic nonetheless.
And then you all asked us a ton of great questions! Here are a few of the questions we’ve received from our wholesale partners, customers, and even some of our personal friends to help clarify things a bit more for everyone.
Our Founder, and resident Environmental Engineer (with a focus on wastewater management), Kate, tackles some of your questions. If you have more, drop us a line here to talk!
Q: My sheets say they are plastic-free.
A: Biodegradable plastic is still plastic, just like a recyclable plastic jug is still plastic. If there is PVA (also called PVOH) in the sheets, it is made of plastic.
Q: I asked for more information about PVA and was told “Many studies have shown that PVOH will biodegrade in wastewater treatment facilities, in compost, and in soil provided these environments contain acclimated microorganisms.”
Doesn’t that mean the PVA will break down?
A: Let’s take a look at this portion of your question: "Many studies have shown that PVOH will biodegrade in wastewater treatment facilities, in compost, and in soil provided these environments contain acclimated microorganisms." [emphasis mine].
The latest study from Arizona State University looks specifically at wastewater treatment facilities and finds that the existing facilities do NOT have the acclimated microorganisms or environment required for a complete breakdown. Previous studies have shown the PVA can break down, as this response from the Cleaning Institute explains.
What is of interest to our customers and to us is whether the PVA does, in real-world conditions, break down. We are learning more now about what environments create breakdown conditions in practice, not in theory. I think we will continue to see more studies in this area, and start to better understand the distinction between the ability to break down quickly and whether we truly expect that degradation to occur quickly in real life.
Q: I was told that the bacteria in the wastewater treatment facility has bacteria to break down the PVA...your article seems to indicate otherwise. Can you elaborate on that piece?
A: Absolutely! It is correct that a typical wastewater treatment plant (WWTP) does indeed contain bacteria that are capable of breaking down the PVA. However, just the presence of this bacteria is not enough to fully break down the PVA. There needs to be enough of the bacteria present, for the right amount of time, temperature, with other conditions like how concentrated the sludge/dirty water is.
It's a little bit like throwing a party, and assuming everyone will be served drinks because there is a bartender present. It's important to have the right number of bartenders to match the number of people and give them enough time to move around the party. If you bring 100 people to a restaurant with a single bartender and expect them all to enjoy a drink within 10 minutes, you're going to have a mess and a lot of people that don't get what they expected.
What we're seeing from this (and other earlier) studies is that PVA needs specific microorganisms and conditions to break down, and only THEN should it be considered readily biodegradable.
In the current WWTP, we do not have these conditions. WWTPs in the USA work based on a 'priority list' of pollutants that are set by the USEPA, and this is a very specific list that includes items with high toxicity (for example benzene, lead, mercury). The treatment plants are designed to remove these priority pollutants, but they are not designed for removing items that aren't on the priority list.
As a result, several substances, including various pharmaceuticals, are not fully removed from the process. The only way to change this is to update the EPA's list of priority pollutants or stop adding the pollutants themselves to the wastewater.
We've seen semi-successful campaigns telling people not to flush their expired drugs down the drain because our wastewater infrastructure is not designed to remove them. Same thing goes for kitty litter, like what we've seen happen in the state of California.
I wonder if we will see a similar effort to avoid flushing PVA in the future.