For more than 10 years, steps have been taken in North America to move post- consumer paper cups into residential and commercial recycling streams. The pace of change has picked up significantly in the past year, partly in response to highly publicized demonstrations and media stunts by environmental activists whose primary message seems to be, “Paper cups can’t be recycled; most cups end up in landfill.”
Why the sudden concern about whether single-use paper cups are recycled?
Estimates from the paper and recycling sectors suggest that between 600,000 and 800,000 tons of postconsumer single-use paper cups are used each year in the U.S. and Canada combined. This suggests that more than 50 billion cups are used annually, depending on the source of the data and the actual size and composition of the cups. To put the cup issue in perspective, total food service packaging in the U.S., including paper and plastic packaging, generates between 1 percent and 2 percent of municipal solid waste (MSW). From a disposal perspective, cups are not a big problem—but the question of whether paper cups have value beyond a single use is worth investigating.
A historical journey
Disposable paper cups first appeared in the U.S. in the early 1900s with the invention of the paper cup that came to be known as the Dixie cup. These cups began to replace shared drinking cups that were used at water fountains as public health concerns began to grow. Hospitals and schools rapidly adopted paper cups for sanitary reasons. Early research showed that paper cup cost per use was lower than that of washing and sanitizing reusable glasses, and the era of the single-use cup began.
Paper cups used for hot and cold beverages are made of solid bleached sulphate (SBS) paperboard with a poly coating added for waterproofing. The actual composition of paper cups varies considerably, but the majority are at least 90 percent paper fiber. Originally, clay or wax lining was used for waterproofing; however, with the development of polyethylene (PE), plastic linings and coatings were almost universally adopted. Use of PE and related materials for lining provides better performance and overcomes the undesirable smells and tastes associated with clay and wax. Most cups today are coated with PE, which is not biodegradable. While some use polylactic acid (PLA), a biodegradable bioplastic, other concerns with PLA prevent it from becoming a clear winner over PE.
Three types of questions generally are asked when evaluating the sustainability of paper cups:
- Do we really need single-use cups? Could reusable cups help to reduce the use of single-use cups overall?
- What percentage of the fiber in the cup is recycled, and is the virgin fiber from sustainably managed forests?
- Is the cup itself recoverable after use? Can it be recycled or composted?
What are our chances of returning to the prepaper-cup era and significantly reducing the volume of single-use paper cups? Starbucks’ experience provides a good example of the challenge.
Starbucks has provided financial incentives for customers to bring their own reusable cups since 1985, but no more than a few percent have ever done so. In 2008, a new initiative hoped to encourage 25 percent of customers to bring their own cups, but that number has never budged past 2 percent.
When Starbucks introduced a $1 reusable plastic cup and lid in 2012, the initial response was strong. But well over half of American adults surveyed in early 2013 by a major polling firm said they “probably or definitely would not buy one.” Many of us would find it difficult to remember to bring the reusable cup to the purchase occasion.
Recycled fiber in paper cups
If bringing reusable containers to food service establishments isn’t practical, how about increasing the recycled fiber content of single-use paper cups to improve sustainability?
McDonald’s, the largest quick-serve restaurant chain in the U.S., does not use recycled fiber in its paper cups, but the company does use recycled fiber in many of its other consumer-facing packages. The chain’s latest environmental, social and governance (ESG) reporting indicates that in 2015, 53 percent of its consumer-facing fiber-based packaging was made using “certified sustainable or recycled” sources, and the goal for 2020 is 100 percent. McDonald’s provides background on sourcing fiber from sustainable forests but not on the percentage of recycled fiber used in its packaging.
Starbucks, the second largest quick-serve chain, was a leader in working with the U.S. Food and Drug Administration (FDA) to allow 10 percent postconsumer fiber in its paper cups as early as 2006. The company set a goal in 2017 to double postconsumer recycled fiber in its paper cups to 20 percent by 2022. Other Starbucks’ products, such as napkins, also contain recycled fiber.
Estimates from the paper and recycling sectors suggest that between 600,000 and 800,000 tons of postconsumer single-use paper cups are used each year in the U.S. and Canada combined.
Subway, the third largest chain, does not report recycled fiber content in cups specifically but indicates that napkins, tissue and towel products are made with 100 percent recycled material with 40 percent to 75 percent postconsumer content.
However, it is not always clear in sustainability reporting whether “recycled material” means postconsumer recycled fiber only or includes converting scrap from the manufacturer of paper products.
Historically, postconsumer recycled fiber has not been used for direct food-contact packaging for sanitary reasons. As pulping and papermaking technology has improved and processing temperatures increase, recycled fiber has become more feasible for use in packaging that will have direct food contact.
Even with this evolution, cup manufacturers interested in acquiring postconsumer recycled fiber face several challenges. Recycled fiber does not have the same strength as virgin pulp and must be deinked and bleached, which can make it more expensive. No U.S. SBS mills have recycled fiber pulping capacity on-site, so recycled fiber “market pulp” must be purchased. Yet, only a handful of U.S. mills produce postconsumer market pulp, so the supply of postconsumer recycled fiber is limited and often more costly.
Compost or recycle?
If increasing the postconsumer recycled content of cups in any substantial way is impractical, can cups at least be composted or recycled? The answer to this question has typically been, “No,” because of the poly lining in cups, which is not biodegradable and holds some challenges for material recovery facilities (MRFs) and end-user mills.
Starbucks’ and Closed Loop Fund’s recently launched NextGen Cup Challenge addresses the issue of the nonbiodegradable poly lining by supporting the development of new types of cups. A number of new cup producers have emerged in recent years, particularly in Europe, offering thinner lining, more easily separated lining and more biodegradable lining, but so far none has become a clear winner.
Recycling cups involves at least three stages: collection, sorting/baling at the MRF and pulping the recovered cups. A benefit of recycling over composting is that the high-quality, long, white fiber used to make cups is captured and reused, usually in a paper product that requires lower quality fiber than the cups require.
One of the most challenging aspects of cup recycling might be getting enough cups together in one place to make processing them worthwhile. Given that 80 percent of paper cups are taken out of the stores in which they are purchased, where cups end up at the end of their lives is largely unknown. Consumers have a confusing array of correct decisions to make to get a cup on track to the MRF, which varies depending on where they are when they are finished with the cups. Consumers need to be at a public location that has a recycling program that accepts cups, has signage that ensures the cups get into the right bin and they need to put their cups in the right bins. The right bin may change from one public location to another, and the right bin may be different again at home depending on the residential recycling program.
To maximize cup collection, more commercial establishments would need to offer cup recycling, consumers would need to participate and more municipalities, residential haulers and MRFs would need to get together to ensure recycling programs specifically include paper cups. U.S. cities including San Francisco; Seattle; Washington; and Chattanooga, Tennessee; and several Canadian cities have designed recycling programs that are currently collecting cups and delivering them to MRFs.
When paper cups are included in recycling programs, many more cups might reach the MRF. Yet, if they are sorted and baled with mixed paper, they may still be considered a contaminant. With growing use of optical scanners and robotics, paper cups could be sorted out and included with other bleached paperboards, creating a high-quality fiber bale.
It has been said that cups cannot be recycled because of the poly lining. Yet tissue mills have been using poly-coated SBS scrap from cup converters for decades. Recycled tissue mills are in a good position to recycle the poly-coated fiber used to make cups because many of them have depolying and/or deinking systems in place.
The collection bottleneck
It is a big step forward for major food service organizations to increase the percentage of postconsumer recycled fiber used in cups. However, increasing the supply of postconsumer recycled fiber (with the potential for lowering cost) may require higher participation in commercial and residential recycling programs combined with greater production capacity for market pulp.
Single-use paper cups are recyclable with current mill technology, and innovation is increasing at MRFs and paperboard mills. With the loss of China as a major buyer for U.S. recovered paper, U.S. MRFs and mills are finding new ways to use recovered paper. Because of the fiber quality, demand for recovered paper cups is likely to expand. The main bottleneck is collection: Ensuring paper cups are included in recycling programs and handled properly at MRFs and that businesses and consumers participate in the collection process are critical to recovering the high-quality fiber in paper cups.