Aqueous Coating Explained: Here's What You Need to Know

Have you been waiting for the day when you can order a takeaway coffee and dispose of the cup in your backyard compost? Well, the time has come. Home compostable cups are on the market!

Aqueous coating, also known as water-based dispersion coating, is a new technology that allows manufacturers to create home compostable coffee cups (as long as they’re certified to home compostable standards by a third party).

But not all cups with an aqueous coating are created equal. It’s a good idea to learn about their composition, production process, and compostability at home so you know what to look for (and how to avoid greenwashing).

Our BioPak crew understands that this can be a complicated topic, so let’s look at what aqueous cups are and how they contribute to our goal of establishing a circular economy.

Aqueous cups are paper cups lined with a water-based dispersion coating. ‘Aqueous’ refers to the technique used to create a barrier on the cup that prevents liquid from seeping through and makes the cup more durable. Cups with an aqueous coating are often considered to be a more eco-friendly solution because they contain less material compared to other coffee cups on the market.

But here’s the thing: just because cups have an aqueous coating doesn’t necessarily mean they’re fully compostable or eco-friendly. They have to meet certain certification standards (more on that in a minute).

Aqueous coating is made by immersing synthetic polymers into water. This is then printed onto the paper, which we use for our cups, like ink. Once the water evaporates, it leaves the paper watertight, allowing the cup to hold your coffee without leaking or getting soggy.

Since the aqueous coating is applied directly to the paper, it reduces the amount of polymers required. In fact, aqueous cups only use a third of synthetic polymers compared to bioplastic and plastic-lined cups. What’s more, aqueous cups don’t need an extra waterproof layer because the coating is absorbed into the paper fibres of the cup.

Regular lining vs Aqueous water dispersion coating

Before putting an aqueous cup in your home compost, you need to make sure that it’s certified home compostable. At BioPak, our aqueous cups are certified home compostable to AS5810 standards. But this is not always the case for aqueous cups from other manufacturers.

Some manufacturers may claim they “adhere to composting standards”, but how can you be sure they’re telling the truth? 

Thankfully, it’s quite simple. You can check if they have a home compostable certification from a third party and their license can be verified at the Australasian Bioplastics Association (ABA) database.

Think of it like this, a person can claim to adhere to driving rules and regulations, but you’ll only know if they are qualified to drive if they actually have a driver's licence. Without a licence, you can’t be certain they’ll drive as safely as other licensed drivers.

Similarly, home compostable cup manufacturers need to be transparent about their certification so you can be confident in your coffee cup’s compostability. At BioPak, we provide our customers with our unique and verifiable home compostable-certified licence number and print each of our home compostable cups with the home compostable logo.

Due to the technology involved in creating aqueous cups, they only contain a small number of polymers. Much less than other cups on the market. BioPak’s aqueous cups are certified home compostable to AS5810 standards because they fit within the acceptable 1% threshold for contamination.

Our aqueous cups are certified home compostable after going through a strict test regime to make sure they’ll start to break down within 180 days and completely disintegrate after 12 months. 

When you pair BioPak’s aqueous cups with sugarcane lids, you have a completely home compostable solution for your coffee runs. Discover our home compostable range here.

Image of the BioPak Aqueous BioCup home compostable logo – illustrating the certification type (Home Compostable AS5810) and BioPak’s Licence Number (20177 / 20175).

Aqueous cups are also certified industrially compostable to AS4736 Australian standards, as well as home compostable. 

At BioPak, we recognise there are limitations to the existing industrial composting infrastructure. That’s why we began Compost Connect – a composting initiative connecting foodservice businesses to compost services. Our way of promoting a circular economy.

Compost Connect helps you reduce your landfill costs by connecting you with your local composters. By entering your postcode here, you can find your local composter, register your business, pick a schedule and become part of a sustainable movement.

Greenwashing is all too common in the packaging industry. Companies have been known to make misleading claims about aqueous cups or water-based lining paper cups. Here are some of those claims.

“Aqueous-lined cups are recyclable”

Some manufacturers will claim their aqueous cups are recyclable when, in actual fact, there are no recyclable cups on the market. You can check the recyclability of your food or beverage packaging at the Australasian Recycling Label website. 

“Aqueous-lined cups are biodegradable”
Another claim you might find with water-based cups is that they’re biodegradable. But the thing is, everything biodegrades eventually (even plastic). Some things take a few weeks, while others take centuries. Make sure your manufacturer is transparent about how long it takes their product to biodegrade.

“Aqueous-lined cups are plastic-free”
Water-based lining cups still contain small amounts of polymers, so they’re not plastic-free. Currently, there are no plastic-free cups on the market. The technology for entirely plastic-free and ocean-degradable cups is still in development (watch this space). 

“Aqueous-lined cups adhere to compostable standards”
Any company can claim to “adhere to compostable standards”, but you will have no way of knowing if their products are genuinely compostable unless they’re certified. When a third party checks to ensure products comply with certain industry standards, you can be certain the products you use are compostable. 

Without a legitimate certification, false compostable claims are dangerous for the customer and the environment. Verify the home compostability certification at the ABA database.

BioPak’s Aqueous coated cups

Right now, home compostable paper cups use water-based dispersion coating because other plastic-free solutions are still being developed for the market. BioPak is currently assisting in the research and development of a plastic-free and ocean-degradable alternative by two of the industry’s leading manufacturers. We are working on launching the product soon.

In the meantime, we continue to deliver the latest technology in food and beverage packaging to the market. We carefully select materials and invest in certifications so you can understand the impact of our products on the environment at every stage of their lifecycle. 

With continuous efforts by the government and industry leaders, we look forward to the development of new solutions that reduce the negative effects of disposable food packaging on the environment. Until then, you’ll find us sipping from our certified home compostable cups (AS5810) — the best circular solution we have right now.

The impact of packaging waste on the environment can be minimized by prudently selecting materials, and understanding the impact at every stage in the product lifecycle. Knowledgeable efforts by industry, governments and consumers will promote continuous improvement. An understanding of the environmental impact of packaging will ensure that new solutions don’t have an adverse impact on human health and the environment.

To date, some products made with aqueous-coated paper have been certified Industrially and even Home compostable, as compostability standards allow for a small amount of non-compostable materials (<1%). However, certifying bodies are in the process of reviewing these standards to ensure new technologies and materials are thoroughly assessed and don’t leave microplastics behind. This may lead to compostability certificates being withdrawn in the future.

A positive update on our Aqueous cups – they are now certified home compostable to Australian (AS5810) standards. This means that when paired with one of our sugarcane lids, customers can enjoy a takeaway coffee knowing that they can compost the cup and lid right in their own backyard! This is a huge win for BioPak and precisely why we invested in this new technology. Our cups received this certification in March 2023.