How to Sort Clover’s Renewable Milk Carton

Milk carton with label that reads "Good things come in renewable materials. Clover is the first dairy in the US to switch to a plant based carton"By now, you have probably seen or bought Clover Sonoma’s “Fully Renewable Carton.” Having introduced the carton in 2020, Clover claims to be the first dairy company in the US to switch to a “renewable,” plant-based milk carton. But what does plant-based mean when it comes down to disposing of the empty carton?  

Is it recyclable?

Unfortunately, because this is a mixed material carton it cannot be recycled in Berkeley. Clover’s carton is made up of paperboard paired with what the company describes as a “green bioplastic” liner. While the FSC (Forest Stewardship Council) certification that the carton boasts is promising, this certification simply means that the paperboard portion of the carton has been produced using sustainable forest management practices.

Paperboard by itself is accepted in Berkeley’s residential curbside recycling program, but the added plastic liner disqualifies the carton from being recycled. Clover isn’t alone in this predicament. All plastic linings, regardless of if they’re made of fossil fuels or plants, make milk cartons non-recyclable in Berkeley. This is because separating the paperboard from the liner is simply not feasible nor cost effective. At the materials recovery facility (MRF) in Berkeley, paper products are baled separately from plastics because they will be recycled into different end products. For example, cardboard is often recycled into cereal boxes. But separating the thin plastic lining from the paperboard of a milk carton costs too much in terms of time and energy spent to be worth the hassle. A 2020 study by The Recycling Partnership found that cartons and aseptic containers are the second most common material to be no longer accepted by residential recycling programs across the US.  

Paperboard milk cartons once had a wax coating which allowed them to be composted, but producers switched to a polyethylene plastic coating several years ago. All milk cartons, including Clover’s, are not recyclable in Berkeley’s residential curbside recycling program. 

Grocery store dairy shelf featuring Clover Sonoma milk cartonsIs it compostable?

Although Clover’s carton has a sugarcane-based liner, the liner is still a form of plastic. It takes too long to break down to be accepted in the City of Berkeley’s municipal composting program, which only accepts BPI certified compostable materials. While many plant-based plastics eventually decompose, this restriction exists because the Recology facility that Berkeley’s green waste is sent to processes materials in as little as 60 days. This means the Clover carton belongs in your gray landfill cart. 

By using a plant-based liner, the Clover “renewable” carton reduces our reliance on fossil-fuel based plastics. However, because it’s made of organic materials, as the carton breaks down in a landfill it will release methane, a greenhouse gas 25 times more effective at trapping heat than carbon dioxide. 

Other options

To avoid a milk carton that has to be landfilled, consider buying your milk in a glass bottle. As early as the 1930s, milk delivery in the US used glass bottles that were washed and reused again. This system was largely replaced by chain grocery stores after World War II, but glass milk bottles are still available today in many Bay Area grocery stores. You’ll pay a deposit when you initially buy it, but you receive the same amount when you return the empty bottle with your next purchase. In addition to being recyclable at the end of its life, a study out of the Center for Sustainable Systems at the University of Michigan found that with just five uses, glass milk bottles are less energy and carbon intensive than plastic milk jugs and paperboard milk cartons.

To learn more about the Ecology Center’s residential curbside recycling program visit our webpage. For information about what’s accepted through Berkeley’s commercial waste service, visit the City of Berkleley’s website. To learn more about how to sort your waste, visit Resourceful, our digital waste sorting guide.

Return to Blog

10 thoughts on “How to Sort Clover’s Renewable Milk Carton

  1. Thanks for your post about Clover milk cartons. I have been putting them (and non-clover paper cartons) into our compost bin, filled with food waste. I thought this was the right thing to do, and now I’m disappointed! I live in Oakland, so maybe my city compost collection goes to a facility which can successfully process these?
    At any rate I will stop putting these into compost until I learn more. Thanks again.

  2. I never used Clover milk because I didn’t like the design on their cartons (!). Ridiculous, I know. But now I can continue not buying that milk for a much better Ecologically sound reason, and be more sceptical toward milk cartons of other brands as well. It sure feels better to return to the milk glass bottles of yesteryear! Thank you!

  3. I am so disappointed! I was told years ago by someone who worked at the Ecology Center that these cartons were compostable, and didn’t realize this had changed. I don’t think that much public information is out there about this switch. There is alot of confusion online and in the public.

    Buying in glass is not realistic for many people due to cost and weight.

    Why would producers switch to a NON compostable milk carton in this day and age. Is there some way we can exert pressure to get them to switch back??


  4. I’ve composted lots of paperboard milk cartons that had petroleum-based polymer linings. It wasn’t my standard practice, and I used it only when I didn’t get round to composting until the container was too leaky to squash and put in the trash, which wasn’t all that often. All the paper in those old containers became soil in one cycle; only the polymer lining was left behind, showing signs of degradation like discoloring to near-black. The liners were easy to separate from the humus. I didn’t realize Clover went to a plant-based polymer until recently, and am now composting dozens of the containers in two large compost piles in our back yard. If the containers fully become soil, then I think backyard composting is one answer, at least for our family. I understand the reluctance of commercial compost operations to get into this, but think plant-based polymers have to be part of the solution to the problem of “plastics.”

  5. Ditto to Darla and Annemarie,
    I haven’t kept up with the new information that milk carton construction had changed from wax coating to polyethylene (plastic) coating, and so based on earlier versions of composting guidelines, have been using those “paper” carton containers (milk, 1/2-1/2, juice, etc) to hold and dump food waste into our green bin. Now informed, I’ll reform my practice.
    Following up on Dan Knapp’s comments and experience, I hope that composting science can soon find the innovation required to enable commercial operators to handle the composting of these kinds of “layered” organic wastes.

Leave a Reply

Your email address will not be published. Required fields are marked *