The specs were drafted to increase understanding of the challenges processors face when working with complex municipal streams, ISRI stated in a press release.
ISRI’s board will consider approving the draft specs at its Feb. 10 winter meeting. The board has the power to adopt, amend or reject the recommendations, or it could table them pending further review.
The MRF glass specifications cover three-color mixed container glass generated by materials recovery facilities (MRFs). In today’s industry, a variety of collection approaches and different types of sortation and cleaning equipment means wide variations in the quality of glass coming from MRFs.
The draft document sets the maximum tolerance for non-glass residue at 35 percent. The maximum tolerance for fines, which can’t be optically sorted, is 30 percent. Lower rates of contamination and fewer fines would mean higher glass values.
The specifications also account for the fact some common materials can cause significant problems in the glass mix. One example is ceramics, including dinner plates, mugs and cups. In the glass specs, the maximum tolerance for those materials is 2 percent.
Inbound MRF specifications
ISRI also drafted specifications for mixed recyclable materials entering MRFs.
The document delineates which types and condition of paper, OCC, cartons, plastic, metals and glass are typically accepted at MRFs and which are not. It also talks about a host of additional materials that may be accepted under specific circumstances, such as the presence of mandates or policies to recycle the material, advanced facility capabilities, customs, local markets or other factors.
It also lists materials that are unacceptable under any circumstances. That list includes electronics, hazardous materials, medical waste, organics and more.