Box Recovery is Up, but Curbside Contamination Could Hold Back Recycling

April 20, 2018

We’re getting more boxes on our porches than ever before, and with the added consumer convenience comes more recycling responsibilities. Used boxes (OCC) collected via curbside recycling didn’t always have such a large global impact, but with more large retailers and distribution centers closing and ecommerce sales on the rise, we’re increasing our reliance on curbside OCC which has a much higher risk of contamination. As more curbside bins overflow with boxes, we wanted to find out what happens to boxes after they hit the bin, and what are the implications that come with curbside recycling?

The lay of the land

Before jumping into the deep end of box recovery and recycling, let’s lay the groundwork for understanding this vast and varied world of corrugated. First off, the paper industry is massive, and all kinds of paper are recovered and recycled to create new paper. The EPA divvies up these types of recovered paper (RCP) into five classifications: old corrugated containers (OCC), mixed paper, old newspapers (ONP), high grade deinked paper, and pulp substitutes. In this post, we’re focusing on the paper grade with the highest rates of recovery — OCC. 

In the paper industry, the corrugated board that’s used to make shipping boxes is called containerboard. Containerboard is made of three layers — two sheets of linerboard with a wavy, corrugated layer in between. After used corrugated boxes are collected, they’re considered OCC — old corrugated containers. The name isn’t glamorous, but OCC is an important commodity around the world, and in the U.S., it accounts for the highest percentage of recovered packaging.

One more thing that’s important to know is the distinction between recovery and recycling. Recovery is the act of collecting waste with the intention processing it for reuse or resale. After a material is processed and made into something new, only then is it considered recycled. But recycling is just one option for recovery.

World containerboard production
Source: RISI

OCC’s environmental impact

Over the past ten years, recovery rates of U.S. OCC have increased 25%, reaching 92% of the total containerboard created. In fact, most corrugated boxes made in the U.S. are made from recovered OCC. According to a 2014 lifecycle assessment (LCA), average domestic containerboard is made from about 52% recovered fiber. 

This increasing recovery rate not only eases our reliance on virgin material, but it means that boxes are staying in the OCC lifecycle longer. The longer a box can stay in the lifecycle, the longer it’s sequestering carbon dioxide, keeping it from being released into the atmosphere. The corrugated lifecycle assessment cited a 35% per-unit reduction in greenhouse gas emissions between 2006 and 2014.

US paper recovery rate
Source: EPA

Tracking OCC through its lifecycle

After OCC is recovered, it takes one of three main routes: recycling, exports or landfills.


To be recycled, OCC is pulped, cleaned, deinked, then mixed with water to be disintegrated into a paper slurry. Any adhesives, tape, or labels are sifted out and discarded along with paper fibers that have reached the end of their lifecycle and are too short for reuse. 

The percentage of the recycling stream that comes from paper has more than doubled to make up 51% of total recycled material as of 2012 with more than half of recovered OCC being used to make new containerboard for boxes. 

OCC has globally risen to meet demand, lessening the strain on virgin material from tree farms, with post-consumer OCC (OCC that is collected from consumers rather than factories) making up 75.1% of containerboard production in the U.S.


Approximately one third of U.S. OCC is exported, with the majority going to China until recently. This year, China’s tighter restrictions on OCC contamination went into effect. The significant dip from a 1.3% to a 0.5% allowance put a huge strain on exports from the U.S. Ultimately, this loss was offset by a significant boost in OCC exports to southeast Asian countries. China’s stricter regulations has also started murmurs of more domestic use of corrugated.

Still, contaminated OCC is a rising concern for recovery facilities as more is collected curbside (post-consumer) than ever before. With more curbside OCC recovery, comes a higher risk of contamination. Paired with the high contamination factor of single stream recovery, it’s a problem that’s top-of-mind for U.S. recovery companies. In the past few weeks, Waste Management has exported less OCC to China than they have in years. 


Paper fibers can be reused about seven times before they’re too short and reach the end of their lifecycle. In the sifting process, these shorter paper fibers along with debris and adhesives are discarded as waste (recovery facilities call this residue) and taken to a landfill along with any soiled OCC. OCC that’s soiled with dirt, water, or grease (looking at you, pizza boxes) can taint an entire bail and increase the percentage of contamination if it’s not caught.

MRF contamination rates

Contamination is a growing problem for OCC

In recovery, contaminants are classified as any material that’s dirtying up a stream. Anything from oil to shattered glass is considered a contaminant when it’s in the wrong stream. The impact of contaminants on potential recyclables varies depending on how recovered materials are processed, and recovery processes vary greatly from city to city depending on the machines available.

The vast disparity in recovery capabilities and consumer recycling information has a huge impact on the value of recyclables recovered. Recycle by City is an organization that’s on a mission to streamline how we talk about recycling U.S. cities. In regard to the varied capabilities from city to city, Founder Tracy Bugh said, “Factors like local supply and demand for recycled content, transportation logistics, the capabilities of the local processing facility, and of course, program funding can all play a role in making it feasible and responsible to accept an item in one city, but not the next.”

If a city does recover and sort out recyclables, it’s done with one of three processes, each one with its own pros and cons for cost and recovery rates:

MWP (mixed waste processing, aka “dirty MPF”): This is a single stream waste system where consumers toss all recyclables and trash into one bin, and it’s all sorted at the MWP facility. This has the lowest rate of recovery because more of the recyclables are soiled when mixed with trash, making them unusable.

Source separated recycling (or sorted stream recycling): This is multi-stream recycling in which consumers separate their recyclables by type and they’re processed separately. Since materials aren’t being mixed, source separated recycling results in less contamination and more valuable recovered materials. On the other hand, less materials are typically recovered for processing because collection is more work for the consumer. 

MRF (Material Recovery Facility): This is single stream recycling in which consumers toss all of their recyclables into one bin and machines do the initial sorting. MRFs (pronounced “murfs”) were created by Waste Management in 2001, and they’ve become the most common and modern recovery process in the U.S. MRFs use a mix of manual and machine sorting. Newer facilities have optical sorting machines, magnets, lasers, and other advanced filtering techniques. The machines are improving over time, processing more than 20% more materials per day than ten years ago. 

According to a study by American Forest & Paper Association, 80% of Americans now have access to MRF collection, up from 65% in 2010. Single stream recycling is easier for consumers, resulting in higher recovery volumes. But these higher recovery rates, come at the cost of losing more recyclables to contamination. 

Cost and residue rates (waste going to landfills) are a couple cons to MRFs, but the biggest downside is contamination. Ideally, the expected contamination of single stream recycling would be offset by the volume of recovered waste coming in, but cities like Ontario, Canada are finding that this isn’t the case. In 2016, Waste Management reported an average of 15-16% contamination rate in collected recycling. These contaminants have negative financial and ecological impacts, making recycling programs even more expensive for cities.

With more curbside recovery comes more contamination

MRFs, though fast and technologically advanced, are processing a larger variety of materials so separating and divvying up enough for a bale requires more volume, time, and money, raising the processing cost of recyclable bales and residue bales which are going to landfills.

On top of the influx of various materials, curbside waste processed at MRFs are often a mix of recyclables and non-recyclables which results in a 15-25% contamination for all recovered waste, including OCC. When a non-recyclable like a single-use grocery bag jams up a MRF, it causes total machine shutdowns and a loss of time and money. 

In an interview with Fortune, Sharon Kneiss, the CEO of the National Waste and Recycling Association, said that all of these factors of shifting recovery intake have contributed to a “perfect storm.”

In a 2014 internal memo, ReCommunity Recycling published their concerns about increasing contamination. “Poor quality jeopardizes the usability of recycled materials throughout the supply chain, which is critical to the success of our mission; diverting recyclable materials from landfills.”

How can consumers improve OCC recycling rates?

Keeping the OCC recovery rate on track is the responsibility of MRFs and consumers. MRFs are taking strides to manage the speed and intake of their machines so they’re working at optimal levels, without too much contamination sneaking through. Some are even hiring more manual labor to offset machine error.

With ecommerce replacing much of brick-and-mortar retail, more OCC is coming from consumers like us, getting boxes on our doorsteps and tossing them in the bin for recycling. That means that there is greater responsibility on curbside OCC to not only meet global demand, but to continue sequestering carbon dioxide throughout the corrugated lifecycle. It’s a growing responsibility on consumers to ensure that the OCC we’re tossing out is clean and usable and education will be key. 

We asked Tracy from Recycle By City what advice she has for ensuring that your old boxes are actually usable as OCC and the answers are actually pretty easy — flatten your boxes and keep them dry. “Unflattened boxes take up a lot of space, and when recycling bins fill up, the overflow often ends up in the trash can.”

Tracy also suggests reusing boxes to make the most of this phase of the lifecycle: “Before recycling, remember that boxes are prime for reuse too. If you don’t need them, maybe you know a friend, neighbor, or local business who does. Boxes are expensive to buy and water intensive to make, so if they can get another use or two, that’s the best environmental option.”

As packaging becomes more of a growing investment for ecommerce brands, so should customer education and reminding consumers to not only recycle their boxes, but ensure that they’re in prime condition for a full lifecycle.

For more on the Big Picture of sustainability in packaging, watch this episode of Shipping Things.

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