We’re not talking about the misuse of plastic. We’re talking about recycled plastic—turned into new, durable, lightweight products that, in many cases, carry a lower carbon footprint than the alternatives.
And yet, plastic remains the media’s and the public’s favorite villain, the MONTSER.
Why?
Because the dominant narrative focuses on worst-case images:
Turtles tangled in rings.
Seagulls with bellies full of caps.
Microplastics in oceans, lungs, and blood.
Yes, those problems exists—and they’re serious.
But… do they describe the material or poor waste management? Or maybe people throwing things where they shouldn’t due to a lack of knowledge and/or education?
While plastics recycling struggles to be heard, paperboard, aluminum, and stainless steel have earned almost unquestioned reputations as “sustainable materials”, building and incredible positive narrative.
How they present themselves (and why it works):
Paperboard/Cardboard: brown, simple, “natural.”
Aluminum: shiny, “infinitely recyclable.”
Stainless steel: durable, “premium,” “forever.”
Glass: transparent, pure.
The issue: public image doesn’t always match real impact. The plastics sector has been more technical than real message creator—and late to conversations with policy makers.
But what is what people rarely hear about the alternatives?
Paperboard /Cardboard:
High water and energy demand in manufacturing.
Laminates (paper + PE/aluminum) that complicate recycling a lot.
Limited performance with humidity/grease (needs coatings) if not useless.
Fibers degrade after several cycles (needs virgin top-up), ok plastic molecular chain also, let’s accept it.
Aluminum
Very high CO₂ in primary production (bauxite, energy).
Real-world recycling depends on cleanliness/design (capsules, trays).
Even recycled, the process is still energy-intensive.
Stainless Steel
Not suitable for single-use packaging due to weight and cost.
Production involves alloys (nickel, chromium) and high temperatures.
Glass
Heavy → higher transport emissions and breakage risk, which drives extra secondary packaging and, when product is lost, a footprint that often dwarfs the packaging itself.
Energy-intensive melting (≈1,400–1,600 °C) and process CO₂ from carbonates; recycled content is constrained by cullet quality/color, contamination, and long-distance logistics.
Returnable systems aren’t free: reverse logistics and washing (energy/water/chemicals) only pay off with short loops and high return rates; glass is also ill-suited for on-the-go/safety-critical uses.
Plastic
- Lightweight → lower CO₂ per functional unit than glass/aluminum (less mass to make, move, and store).
- High performance at low thickness (seal, barrier, toughness) → less product loss, often the biggest part of the footprint.
- Design-for-recycling works: mono-material PE-PE or PP-PP, clear PET, fewer inks/labels, no carbon black, tethered caps → higher recovery.
- Quality is improving fast: better sorting (NIR/markers), decontamination/deodorization, compatibilizers (e.g., PE/EVOH) → more stable PCR.
- Often wins in logistics: higher pallet density, fewer trucks, better cube utilization than heavy/fragile alternatives.
But let’s compare total CO2 from “virgin” material creation to couple of times being recycled and some transportation distribution.
We should do a functional unit comparison: packaging of 1Liter of water in 1-L packs.
Why this way: comparing “per kilo of material” can mislead. The honest comparison is the packaging job for the same product.
Common assumptions (for all materials):
Functional unit: 1 L of ambient temperature (non-refrigerated) water.
Typical 1-L pack weights: Plastic (PET/rPET) 30 g,– Paperboard 33 g, Glass 400 g (single use), Aluminum 3,03 cans × 14 g = 42.42 kg for 1, L.
Road transport 100 km (heavy goods vehicle): 0.0065 kg CO₂/kg per leg (same factor for everyone; the weight changes).
1st and 2nd recycled runs: identical (same factor).
For paperboard we show two cases:
A) Monomaterial paperboard (no metal foil).
B) Realistic aseptic carton (brik)—paper + PE + aluminum foil—with hydrapulping and extra transport for polyAl (≈25% of weight, 300 km per cycle).
Emissions (kg CO₂) for 1,000 L – manufacturing + 100-km transport
(3 uses: virgin + 2 recycled; columns in the requested order)
Article content
UK Government – Greenhouse gas reporting: conversion factors (2024) & University of Bath, ICE Database and own analysis
For 1-L water, weight rules. Monomaterial paperboard (33 g) weighs almost the same as plastic (30 g), and its per-kg factor is slightly lower → hence its slightly lower total CO₂ in this specific function.
If paperboard is a real brik (multilayer) with aluminum foil, its manufacturing and recycling need more energy (hydrapulping, drying, separation), plus there’s a logistics penalty to move polyAl(dedicated transfer). Result: total rises to ~100.13 kg, ending up above plastic (96.59 kg).
Glass is penalized by weight (a lot of mass per liter). Aluminum is penalized by manufacturing CO₂(very high per kg), despite being recyclable.
Limitations:
This table does not include real recycling rates by country, rejects/merma, or your exact routes. If your truck maxes out by volume (not weight), or if polyAl travels farther/to another plant, the outcome changes. Key message: compare by real use with your actual logistics chain.
Some Conclusions
- There are no inherently “good” or “bad” materials. There are uses and contexts.
- Judge materials by function, not identity. No material is inherently “good” or “bad”; performance depends on the job to be done and the system around it.
- Compare by functional unit and full system boundaries. Always model CO₂ per packaging job (e.g., 1,000 L delivered), including pack weight, secondary packaging, storage, return logistics, and real loss rates.
- 1-L ambient water: monomaterial paperboard can be competitive on weight; realistic multilayer briks (hydrapulping + polyAl logistics) often lose that edge; recycled plastic tends to win when barrier/hygiene/format variety are required.
- Glass excels only in short, closed, high-return loops; outside of that theweight and potential breakage dominate the footprint and costs.
- Aluminum is valuable for specific properties (light/oxygen barrier, formability), but minimize primary content and maximize recycled content with designs that are easy to recover.
- Design for recycling first: favor monomaterials, light-weighting, simpler labels/inks/closures, and avoid problematic laminates unless strictly necessary.
- Protect the product above all. Prevent oxidation, leakage, or breakage; product waste usually carries a higher footprint than the pack itself.
- Match choices to local infrastructure. “Theoretically recyclable” is meaningless without proper collection and sorting.
- Price what you ask for. Recycled content, quality assurance, and robust traceability add cost—and should be reflected it in the price.
What should we optimize first: total CO₂, real-world recyclability, or product protection (avoiding waste)?
