You know that material or format you wish were recyclable, but Material Recovery Facilities (MRFs) don’t accept it? You’re not alone. Almost every brand has one, and right now, the gap between ‘recyclable in theory’ and ‘recyclable in practice’ has never been more urgent to close. That’s why, at SPC Advance 2025, we went behind the scenes where recyclability meets reality: MRFs.
MRF acceptance — whether a MRF will take a material to sort and sell to reprocessers — isn’t just about recyclability, and vice versa. For a material to make it onto a MRF’s list of materials it accepts for sortation, the facility must be able to safely process, reliably sort, keep clean, and consistently find end markets.
At SPC Advance 2025, leaders from Casella, WM, ReMA, and the Chittenden Solid Waste District broke down why MRFs can or can’t take certain materials. Dive into the key takeaways so you can design with MRF realities in mind.
1. The Contamination Constraint: MRFs Have Extremely Tight Quality Specs for End Markets
In MRFs across the country, there’s a contamination gap: MRFs aim for an approximately 1.5% contamination rate across their outgoing bales, but the contamination rate for incoming materials is often around 15%. Closing this gap is a critical factor in a MRF’s decision to accept a material or format.
When it comes to contamination, a lot can go wrong. Food residue, dirt, adhesives, inks, or coatings can leak onto otherwise-recyclable material. And when they do, they lower the material’s quality, cause mis-sorts, or make it harder for MRFs to produce end market-ready bales.
Here’s how How2Recycle members can help close this gap and ensure their packaging gets sorted on its path to further circularity:
- Designing to reduce contamination can make an immediate difference. Try optimizing for rinseability, closures that stay attached during processing, and avoiding “look-alike” formats that resemble non-accepted materials.
- Invest in education. At SPC Advance, we heard that communities with dedicated education teams can achieve contamination rates as low as 3-4% for inbound materials. With proper labels and consumer education, clarity can cut contamination way down.
2. End Markets Are the Deciding Factor on Whether Packaging Is Accepted
In the complex world of MRF operations, one aspect of acceptance is black and white: “Is there an end market?” No matter how recyclable the polymer or how advanced the sorting technology, if a bale has no stable end market it’s not feasible for MRFs to put the materials on their acceptance list.
However, there is some gray space across materials:
- Glass: In the U.S., MRF acceptance of glass varies across regions because glass is heavy and expensive to ship, meaning glass recycling is often only viable when reprocessors are nearby. Areas with local end markets can sort and sell recycled glass more easily, while more remote regions face higher hurdles.
- Fiber: A similar regional phenomenon exists for fiber end markets in the U.S. Across the Midwest, fibers have strong end market feasibility. On the West Coast, however, they’re not quite as strong, which can drive up the costs of bales.
- Flexible films: All panelists agreed that they would need to see consistent, long-term end markets before curbside acceptance of flexible films could expand meaningfully.
Here’s how How2Recycle members can support acceptance:
- Build and support markets for post-consumer recycled (PCR) content to drive up demand and stabilize acceptance. In other words, help give MRFs a place to send sorted materials.
- Collaboration toward standardized designs can increase the likelihood that a format reaches the scale needed to justify MRF investment.
3. Sortation Technology Is Advancing Quickly, But It’s Not a Magic Fix Yet
Many MRFs now rely heavily on optical sorters — some facilities even use nine or more optical units — to separate fiber from containers and identify different material types. Plus, AI auditing and robotics are emerging technologies, but often they only fill very specific roles like last-chance sorting or end-of-line cleanup.
At SPC Advance, we got a reality check on the delta between MRF technology at present and the potential. We learned that:
- Optical sorting, using advanced sensors or cameras, isn’t plug-and-play. And changing calibration to capture one material can reduce capture rates for others.
- Robots will not replace people any time soon on MRF lines. Oftentimes, reducing contamination still requires manual quality control and human intervention.
- MRF retrofitting happens slowly, even when new technology is promising, due to capital costs and operational complexity.
What can How2Recycle members do to improve sortation technology? Designing packaging that works within the limits of today’s infrastructure is essential. Technology that’s years away won’t solve today’s recyclability challenges.
The Potential Ahead: AI, Producer-Led Sorting Systems, and Infrastructure Investments
Despite current constraints, the panelists didn’t shy away from the potential progress ahead, like: EPR investments in MRF infrastructure, AI audits enabling faster contamination corrections, and rapid innovation in optical sorting and robotics improving.
How can How2Recycle members and packaging stakeholders seize this potential? As you develop packaging strategies and make design decisions, you can:
- Participate in EPR and market-building programs
- Support data transparency and system-wide design alignment
- Design for sortation first
- Minimize ambiguous or “look-alike” formats
- Drive up PCR demand
By understanding the constraints MRFs face and designing with those realities in mind, packaging professionals can turn good intentions into accepted materials as we advance a circular packaging economy.