Why Is Code 7 a Mess for Bioplastics?

You’ve probably seen the small triangular chasing-arrows symbol with a number inside on plastic products. The symbol is the resin identification code — a system developed by the Society of the Plastics Industry in 1988 to help recyclers identify what specific plastic a product is made of. Numbers 1 through 6 correspond to the six most common conventional plastics: PET, HDPE, PVC, LDPE, PP, PS. Number 7 means “other” — anything that doesn’t fit the first six.

That “other” category includes a long list of materials: polycarbonate, ABS, nylon, acrylic, fiberglass-reinforced plastics, and almost every bioplastic ever developed. For the bioplastics industry — PLA, PHA, starch-based plastics, and most other compostable plastics — being lumped into Code 7 has caused persistent operational problems. Recyclers don’t know how to handle it. Composters get plastic items they don’t want. Consumers get conflicting signals about what to do with their compostable cup.

This post walks through why bioplastics get classified as Code 7, what specifically goes wrong with that classification, and what’s being done to fix it.

The history of the resin codes

The resin identification codes were introduced in 1988 to address growing public confusion about plastic recycling. The original intent was technical — to help recyclers identify and separate different plastic types so they could be properly processed.

The six numbered categories cover the dominant commercial plastics at the time:
– Code 1: PET (polyethylene terephthalate) — water and soda bottles
– Code 2: HDPE (high-density polyethylene) — milk jugs, detergent bottles
– Code 3: PVC (polyvinyl chloride) — pipes, some packaging
– Code 4: LDPE (low-density polyethylene) — plastic bags, films
– Code 5: PP (polypropylene) — yogurt cups, food containers
– Code 6: PS (polystyrene) — foam food containers, packing peanuts
– Code 7: Other — everything else

The “everything else” category was always intended as a catch-all, not a sustainability statement. In 1988, when these codes were created, bioplastics barely existed commercially. PLA wasn’t manufactured at industrial scale until 2002. The fact that bioplastics fall into Code 7 is essentially an artifact of the system being designed before they existed.

What’s actually in Code 7

A non-exhaustive list of plastics that share Code 7 classification:

Petroleum-based plastics in Code 7:
– Polycarbonate (PC) — water bottles, eyeglass lenses
– ABS (acrylonitrile butadiene styrene) — LEGO bricks, plumbing
– Acrylic (PMMA) — clear sheets, lighting fixtures
– Nylon (PA) — fishing line, fabric
– POM (polyacetal) — gears, mechanical parts
– Fluoropolymers (PTFE, PVDF) — Teflon, specialty coatings

Bioplastics in Code 7:
– PLA (polylactic acid) — cups, deli containers, foodware
– PHA (polyhydroxyalkanoate) — bags, coatings
– PBS (polybutylene succinate)
– Cellulose esters
– Starch-based plastics
– Various proprietary blends

A consumer looking at a Code 7 symbol has no way to know whether the product is petroleum-derived polycarbonate that should go to a specialty recycler, ABS that should go to electronics recycling, PLA that should go to commercial composting, or PHA that might compost in a home pile. The single number conveys essentially nothing useful.

What goes wrong at recycling facilities

The operational problem at recycling facilities:

Optical sorting systems don’t separate Code 7s from each other. Modern recycling facilities use near-infrared (NIR) optical sorting to identify and separate plastics by type. NIR systems can reliably distinguish PET from HDPE from PP from PS. They generally don’t distinguish among the various Code 7 materials.

The Code 7 stream becomes mixed contamination. A bin labeled “Code 7 mixed plastic” might contain polycarbonate, ABS, PLA, and PHA all together. None of these recycle well as a mixed stream. The PLA can contaminate PET recycling if not properly separated, because PLA looks similar to PET to optical sorters.

Most facilities don’t accept Code 7. Many MRFs (materials recovery facilities) simply send Code 7 plastic to landfill because the value of mixed Code 7 isn’t worth the sorting and processing costs. This is fine for petroleum-based Code 7 plastics that don’t compost; it’s harmful for bioplastics that could have been composted.

The PET contamination problem is specifically problematic for PLA. PLA has the same optical signature as PET in some NIR systems. PLA cups mixed into a PET bottle recycling stream can contaminate the entire batch — PLA melts at lower temperatures than PET, causing process problems and reducing the quality of recycled PET.

What goes wrong at composting facilities

The mirror image of the recycling problem happens at composting facilities:

Composting facilities don’t always trust Code 7 items as compostable. A Code 7 PLA cup looks identical to a Code 7 polycarbonate water bottle. Composting operators can’t easily distinguish them visually.

Mixed contamination at composting. A delivery to a commercial composter containing both PLA foodware (compostable) and ABS bins (not compostable) creates sorting problems. Some composters reject Code 7 items entirely to avoid the contamination risk.

The certification issue. Some Code 7 plastics are BPI-certified compostable; some aren’t. The Code 7 number itself doesn’t distinguish. Operators have to verify each product separately.

The labeling improvements happening

Several initiatives have tried to address the Code 7 mess specifically for bioplastics:

BPI seal. The BPI logo and “Compostable” text on products provides a different, more reliable signal than the Code 7 number. When the BPI seal is present, the product is certified compostable regardless of what Code number is also displayed.

TUV OK Compost INDUSTRIAL and HOME marks. European certification organization TUV’s certification marks provide similar signal independent of the Code 7 system.

Compostable Industry Council (CIC) labeling. The CIC has developed standardized labeling for compostable products that includes the BPI seal, intended disposal pathway, and other relevant information.

Modified resin codes. Some industry proposals have suggested expanding the resin code system with sub-categories under Code 7 to distinguish PLA, PHA, and other bioplastics. This hasn’t been adopted broadly yet.

Alternative coding systems. Some companies use proprietary labeling: “Compostable PLA,” “Plant-Based,” “Made from Sugarcane” — text labels that bypass the Code 7 ambiguity but aren’t standardized across the industry.

The state-by-state regulatory response

Several states have moved to address the labeling problem through legislation:

California’s AB 1689 (2020) and amendments require specific labeling for compostable products that goes beyond the Code 7 system. Products labeled “compostable” must have either BPI certification or equivalent verification, and the labeling must be clear about whether the product is home compostable or industrial compostable only.

Washington and Oregon have similar requirements.

The FTC’s Green Guides (federal-level guidance, not state-specific) recommend that compostability claims be clear about the conditions under which the product actually composts.

The regulatory direction is toward clearer, more specific labeling that doesn’t rely on the Code 7 system to communicate compostability.

For B2B operators

If you’re sourcing compostable foodware or packaging, the practical implications:

Don’t rely on Code 7 to communicate compostability. The Code 7 symbol tells consumers and waste handlers essentially nothing. You need additional clear labeling.

Use BPI seal prominently. This is the clearest signal that the product is actually compostable. Include the BPI seal on packaging and customer-facing materials.

Specify disposal pathway clearly. “Industrially compostable — dispose in commercial composting” is more useful than just “compostable.” For customers without commercial composting access, this signals the proper alternative pathway.

Train staff on the distinction. Staff at restaurants and foodservice operations should be able to explain to customers why a Code 7 PLA cup is compostable and what to do with it. Without that explanation, customers default to either recycling (wrong) or trash (also wrong) based on familiarity.

Consider transition labeling for tableside service. Some operations use small signage at busing stations or compost bins to clarify “PLA cups go here.” The labeling helps customers make correct decisions despite the confusing Code 7 system.

What’s coming

The Code 7 problem will likely be addressed gradually through several converging changes:

Standardized compostable labeling — likely to emerge as the practical solution. Industry groups and state regulators are converging on labeling that explicitly identifies compostable products separately from the Code 7 system.

Expanded resin codes — possible but slow. Industry proposals for sub-codes under Code 7 for bioplastics specifically have been discussed but adoption is gradual.

Better optical sorting technology — improving. Newer NIR systems can distinguish more material types, including separating PLA from PET more reliably.

Industry-specific labeling — likely for foodservice and packaging specifically. As more foodware moves to compostable, industry-specific labeling for that category is likely to standardize.

For operations making procurement decisions today, the practical reality is that the Code 7 system is unhelpful and the BPI seal plus clear customer-facing communication is the right approach.

A broader context

The Code 7 confusion is a useful case study in how labeling systems become misaligned with the products they’re supposed to classify. The original Code system worked reasonably well for the plastics in commercial use in 1988. As new materials emerged — bioplastics, mixed-resin laminates, novel coatings — the system became less informative.

This is a normal pattern with any labeling system: it works well at the time of design and gradually becomes inadequate as the underlying products change. The compostable foodware industry has been working around the Code 7 problem with supplementary labeling (BPI seal, certification marks, plain-language text) for years now. The eventual fix will likely be a new labeling system specifically for compostable products that bypasses the Code 7 problem entirely.

For broader compostable foodware sourcing context, see compostable food containers, compostable cups and straws, and other product category coverage. The current generation of compostable foodware is generally clearly labeled with BPI certification regardless of the Code 7 confusion. The labeling problem is real but it’s not a barrier to actually sourcing and using compostable products.

The take-home

Code 7 is a catch-all category that fails to communicate useful information about bioplastics. Don’t rely on it. Use BPI certification, clear disposal pathway labeling, and customer-facing communication to bridge the labeling gap. Push regulators and industry organizations to develop better labeling systems. The Code 7 mess is a transitional problem — the industry is gradually moving toward labeling that actually helps consumers and waste handlers make correct decisions.

The compostable foodware industry has overcome bigger challenges than confusing labels. The labeling will get better. In the meantime, supplement the inadequate Code 7 system with the clearer signals that actually exist: certifications, plain-language descriptions, and customer education.

A specific note on the chasing-arrows imagery

One additional source of confusion: the triangular chasing-arrows symbol itself implies recyclability to most consumers. The symbol was originally adopted from the EPA’s recycling logo, which created a public association between “chasing arrows = recyclable.” When this symbol appears with a Code 7 on a compostable PLA cup, consumers reasonably assume the cup should go in their recycling bin — exactly the wrong disposal decision.

Some industry advocates have argued for removing the chasing-arrows symbol from compostable products entirely, replacing it with a different visual identity (a soil/compost-themed symbol, perhaps). This proposal hasn’t gained traction yet but the logic is sound — using the recycling symbol on a non-recyclable product is misleading even when paired with text disclaimers.

For consumer-facing materials, the most effective practical workaround is bold, plain-language text that bypasses the symbol confusion entirely: “Commercial composting only” or “Not for recycling — compost only” directly on the product. The text overrides the symbol’s misleading implication.

What this means for new entrants

If your operation is just beginning to source compostable foodware and you’re encountering the Code 7 confusion for the first time, the practical workflow is:

1. Source from suppliers whose products are BPI-certified and prominently labeled.
2. Request supplier-provided customer-facing materials (signage, brochures, training videos) that clarify the disposal pathway.
3. Train staff on the distinction between recyclable and compostable.
4. Install clear bin labeling that uses plain language, not just symbols.
5. Audit periodically that the system is working — bin contamination rates of less than 5% indicate good signal clarity.

This workflow addresses the labeling problem operationally rather than waiting for the labeling system to be fixed. The work isn’t elegant but it’s effective.

For B2B sourcing, see our compostable supplies catalog or compostable bags catalog.

Background on the underlying standards: ASTM D6400 defines the U.S. industrial-compost performance bar, EN 13432 harmonises the EU equivalent, and the FTC Green Guides govern how “compostable” can be marketed on packaging in the United States.