McDonald's recently started collaborating with Starbucks and Closed Loop Partners to create a more recyclable and/or compostable cup that can be mass produced. It sounds like a pretty sustainable venture. Once the new cup is created you can recycle or compost the cup anywhere, right? The answer isn't quite that simple.

Let's start by examining the current materials and recyclability of the drink cups that Starbucks and McDonalds utilize. For cold drinks, like iced coffee, iced tea, or smoothies, the cups are made of polypropylene (PP) or number 5 plastic. Lids are made from Polyethylene terephthalate (PET) or number 1 plastic. McDonald's also uses waxed paper cups for fountain drinks and the lids for those are made from rigid polystyrene (PS) or number 6 plastic. Straws are all made from polypropylene (PP). For hot drinks, the cups are waxed paper and the lids are rigid polystyrene (PS). Starbucks cups usually have a cardboard sleeve. Polypropylene (PP) is accepted by some recycling programs, but plastic straws aren't recyclable because they are too small and lightweight to capture. Rigid polystyrene (PS) is accepted in few recycling programs due to the lack of buyers for recycled polystyrene. Polyethylene terephthalate (PET) is the most readily recycled plastic, but the flat shape of lids makes it hard to capture in the recycling process. The paper sleeve is recyclable anywhere. The waxed paper cup is not recyclable because the paper is bound to a thin layer of plastic which keeps the paper from breaking down in the pulping process.

The challenge is how to make the waxed paper cup recyclable or compostable. The plastic coating on the inside of the cup keeps the cup waterproof. An uncoated cup is not an option because it would leak after a while. The plastic coating on the cup would have to come off more easily and quickly for the cup to be easily recyclable. A compostable cup would have to have a biodegradable plastic lining, which wouldn't make it very cheap. Many compostable plastic and paper products are generally only compostable in commercial composting facilities. Even then they still take a very long time to break down compared to food and yard waste. The other issue is that most waste haulers throughout the United States only accept yard waste for composting, and many places don't have composting services at all.

Even if the cups become more recyclable, sorting them out is another issue. Paper cups can only be separated from other materials manually because its shape and size don't allow it to be separated like flat paper and cardboard. They don't attract to magnets or electric current, don't shatter like glass and can't be optically sorted like plastic. Since only McDonalds and Starbucks cups would be recyclable, workers on the sorting line would have to separate them from the non-recyclable cups made by other brands. The other issue is the coffee or cream residue left in the cup, which can contaminate paper fibers. Unlike plastic, metal or glass containers, paper can't be washed or melted to remove dirt or residue. Even if the paper from the cup can be recycled, the plastic coating in the cup is still virtually impossible to recover from the pulping process.

In addition to the difficulties of designing, recycling or composting the cups, the overall reduction in environmental impact is questionable. Even the most recyclable items like office paper, cans, and plastic bottles don't always get recycled due to a lack of recycling bins, collection programs, or proper signage. In the United States, less than 40% of plastic drink bottles and less than 60% of aluminum cans get recycled. Paper production is a very energy-intensive process that requires the use of highly toxic chemicals like chlorine gas to bleach the paper and releases chlorinated dioxins. Plastic takes less energy to produce but is not biodegradable. Using recycled content does save energy, but recycled paper fibers can't be used to make new cups. Paper cups have a seam down one side where the side is rolled together and attached with the base of the cup. This seam makes it unsafe to use recycled content because recycled paper contains a small amount of ink from printing or writing. The paper cups would be, therefore, downcycled or turned into products of lower value. With China's current ban on mixed paper, there isn't much demand for that commodity.

Instead of putting money into creating a "better" single-use cup, McDonalds and Starbucks should develop an attractive and effective way for people to use their own reusable cups or mugs when purchasing beverages. It takes a tiny fraction of the amount of energy and water to clean a reusable cup than it takes to manufacture and recycle a disposable paper or plastic one. Even though Starbucks sells reusable cups, the current process of dispensing beverages is designed for disposable cups only. In order to make reusable cups feasible, there needs to be a sanitary and hassle-free way to measure the quantities of drinks by size, track customer orders, and offer a good incentive for the average person to bring their own cup.