If so, you can hardly be blamed. Changes in market conditions and recycling technology have required changes to the definitions of several grades of waste paper, and the creation of new grades.
The Institute of Scrap Recycling Industries, Inc. (ISRI) maintains a current specifications list with 52 grades of waste paper, plus an additional 35 specialty grades for highly specific commodities. Despite this, various geographic regions adhere to different grade specifications which may or may not share terminology, and sometimes use the same terms to refer to different commodities.
Mixed Paper
A good example is Mixed Paper.* As recently as the 2006 specification there were two grades: Soft Mixed Paper and Mixed Paper. More recent specifications call for three: Residential Mixed Paper, Soft Mixed Paper, and Hard Mixed Paper (HMP).
*There are several grades of “mixed” paper, including a few specialized ones having to do with things like industrial trimmings that are beyond the focus of this article.
Curbside, multi-commodity recycling produces a dirtier stream of waste paper, and the Residential Mixed Paper grade applies to that, with appropriate higher allowance for prohibited materials and outthrows. Soft Mixed Paper remains unchanged, and the old Mixed Paper has been renamed Hard Mixed Paper, a reflection of the industry trend toward higher specificity in grade definitions.
Supermix
Unfortunately, this is not the end of confusion when it comes to Mixed Paper. There is a South African grade called Super Mix (SMW) which consists of a 50/50 mix of two other grades, Heavy Letter One (HL1) and Heavy Letter Two (HL2). Neither grade corresponds to the ISRI specification for Soft Mix or Hard Mix, yet Supermix has been used to refer to a mix of those grades as well. In Australia a Supermixed Wastepaper grade is in use. Additionally, some urban recycling centers in the USA use Supermix as a catch-all term.
The issue is not that people using the term are technically wrong – they know what they mean and presumably so do their markets. The problem is the added confusion and imprecision generated. In an era of ever-increasing scrutiny of recyclable materials, it is of benefit to all to have clear, up-to-date, unambiguous grade specifications.
ISRI Mixed Paper Grades
- (1) Residential Mixed Paper
Consists of a mixture of various qualities of paper not limited as to type of fiber content, normally generated from residential, multi-material collection programs.
Prohibitive Materials may not exceed 2%
Outthrows plus prohibitives may not exceed 5% - (2) Soft Mixed Paper
Consists of a clean, sorted mixture of various qualities of paper not limited as to type of fiber content.
Prohibitive Materials may not exceed 1%
Outthrows plus prohibitives may not exceed 5% - (3) Hard Mixed Paper (HMP)
Consists of a clean, sorted mixture of various qualities of paper containing less than 10% groundwood content.
Prohibitive Materials may not exceed 1/2 of 1%
Outthrows plus prohibitives may not exceed 3%
