Weight Is Destiny

In November 2025, Mary Creagh, the Environment Minister, stood before Parliament to defend the UK's new packaging fees. Her case rested on a single claim: "Waste management costs are largely driven by weight."¹

Stay with me for what comes next.

Three clicks away, on her own department's website, sits a document called the LAPCAP methodology. LAPCAP is the model the government uses to calculate what it actually pays local authorities to manage packaging waste. And there, in plain text, it says something rather different: "Volume is commonly the limiting factor in dry recycling collections."²

The minister says weight drives costs. Her department's cost model says volume is "commonly the limiting factor." Both can be partly true--but they point to different cost drivers, and the model explicitly adjusts kerbside dry-recycling collection costs using volume. And in the gap between them, a material Britain recycles at over 80% is being taxed out of existence.

(illustrative): ~3.5-7.7p

This is what a craft brewer pays, per bottle, to put a 500ml glass container into the UK market under Extended Producer Responsibility.³

The calculation is not complicated. The EPR base fee for glass is GBP 192 per tonne.⁴ Example 500ml glass bottles often fall around 0.18-0.40 kg (product-spec dependent).⁵ Multiply the weight by the rate: at GBP 192 per tonne, that is roughly 3.5-7.7p per bottle.

For one bottle.

Laura James runs Gower Brewery in Wales. Since April 2025, when EPR fees went live, her supplier has added GBP 5,000 to each delivery. Across a year, for approximately 500,000 bottles, that means GBP 45,000 in additional costs.⁶ Not for new equipment. Not for better ingredients. For the privilege of using a material that has been recycled in Britain since the Romans.

(illustrative): ~0.4-0.8p

This is what a soft drinks company pays for a 500ml plastic bottle under the same system.

The calculation follows the same logic. Plastic bottles carry a higher base fee -- GBP 423 per tonne, more than double the glass rate.⁴ But example 500ml PET bottles vary widely (lightweighted designs can be under 10g). Using 0.01-0.02 kg as an illustrative range, at GBP 423 per tonne that is roughly 0.4-0.8p per bottle.⁵

Less than a penny. For the same volume of liquid.

The ratio is not close. Glass pays roughly ten times more per container than plastic. Not because glass is harder to recycle -- it is easier. Not because glass ends up in landfill more often -- it does not. Glass simply weighs more. And under a weight-based fee, weight is destiny.

GBP 192 vs GBP 423

On paper, the government charges plastic more heavily. The per-tonne rate for plastic -- GBP 423 -- is more than double that of glass at GBP 192.⁴

This looks like the system is working. Plastic is harder to recycle. Plastic has lower material value. Plastic causes more environmental harm. Surely plastic should pay more.

But the per-tonne comparison is a conjuring trick. It hides the variable that actually determines what producers pay: weight per unit.

THE RECEIPT: EPR COST PER 500ML CONTAINER (ILLUSTRATIVE)

The plastic rate is double. The plastic cost is roughly one-tenth. Because plastic bottles are substantially lighter than glass bottles, container for container -- though this ratio varies with bottle design.⁵

This is arithmetic, not interpretation. And the arithmetic produces an outcome the government claims to oppose: the material with the higher recycling rate pays more.

0.3 T/m³

This is the bulk density of glass, according to WRAP, the organisation whose data underpins the government's cost model.⁷ Glass packaging occupies space efficiently. It packs down. It does not fill collection vehicles with air.

Plastic bottles have a bulk density of 0.023 T/m³.⁷ They are thirteen times less dense than glass. They are, in the language of waste logistics, "bulky." They fill trucks before those trucks reach their weight limits. They take up space.

And this matters because of a sentence buried in the LAPCAP methodology -- the sentence the minister did not mention.

The government's own model states that collection costs are "apportioned across materials based on the proportion of each material by volume."² Not weight. Volume. Because the LAPCAP model reflects what actually constrains collection: "Volume is commonly the limiting factor in dry recycling collections."²

Read that again. The government calculates what to pay councils based on volume. Then it calculates what to charge producers based on weight. The input metric and the output metric do not match.

The Transformation

Here is where the conjuring happens.

Inside LAPCAP, the government converts tonnage data into volume using those bulk density figures from WRAP. It does this precisely because weight alone does not reflect cost. A tonne of plastic takes up vastly more space than a tonne of glass. If you want to know what collection actually costs, you need to account for volume.

But when the fees are set, the government uses only weight. The conversion that happens inside the cost model -- the conversion that exists because weight is inadequate -- vanishes. What reaches producers is a pure weight-based charge.

If this were a household budget, it would be like calculating your grocery costs per ingredient, then billing yourself per kilogram. Your feathers would bankrupt you. Your gold bars would be free.

The minister's defence, when pressed, acknowledges volume exists: "We have taken into account other factors that influence collection costs, including the estimated volume of each material in bins and collection vehicles."¹ But "taken into account" is not "charged by." The fee structure remains weight-based. And weight-based means glass pays.

Of course. Given the structure, how could it not?

GBP 45,000

Return to Laura James and Gower Brewery. GBP 45,000 per year, just for bottles.⁶

A small brewery operating on margins measured in pennies does not have GBP 45,000 in slack. It comes from somewhere: wages not raised, equipment not upgraded, an expansion not pursued, or prices increased until customers disappear.

Scale this across Britain's independent brewing sector. Scale it across every small producer who chose glass for environmental reasons and now finds that choice punished.

British Glass says glass is less than 5% of packaging placed on the UK market by volume, yet could bear around 30% of total pEPR costs.⁸ Five percent of the problem. Thirty percent of the bill.

Encirc, one of the UK's major glass bottlers, announced restructuring in December 2025 -- eight months after EPR fees went live. Their statement was explicit: "The packaging tax known as 'Extended Producer Responsibility', the influx of unsustainable low-cost imports and high energy costs are key factors contributing to this."⁹ Encirc fills approximately 40% of the UK's wine, beer, and spirits containers. They employ nearly 2,000 people.

If the policy continues unchanged, Britain may solve its glass recycling problem by eliminating the glass.

80.4%

This is the recycling rate for glass in Britain, according to DEFRA's latest data.¹⁰

Plastic achieves 53.7%.¹⁰

Glass recycling rates are approximately 50% higher than plastic in relative terms. Glass can be recycled indefinitely without degradation. It does not leach microplastics. It does not require complex sorting technology. The infrastructure exists. The economics work -- or worked, until the government decided to charge by weight.

The minister's other defence is value: "Glass is a heavy material with a low resale value. A unit of glass packaging costs more for a local authority to manage as waste than an item made up of more lightweight and high-value material."¹

This deserves examination. Glass has lower resale value per tonne than aluminium, certainly. But the relevant comparison is cost-to-recycle minus revenue-from-sale. Glass recycling is mature, cheap, and runs at 80%. Plastic recycling is complex, expensive, and runs at 54%. The net cost comparison is not what the minister implies.

And there is another factor the value argument ignores: damage. Plastic that escapes the system persists for centuries. Glass that escapes the system breaks down. The externalised cost -- the cost that appears in no ledger -- falls heavily on plastic. Weight-based fees ignore this entirely.

The Ledger

The opposition has a point, and it is worth stating clearly. Weight is not irrelevant to waste management costs. Transport costs correlate with weight. Vehicle wear correlates with weight. Some disposal fees -- where materials reach landfill -- are charged by weight.

But this is the strongest version of the case, and it still fails.

First: the government's own model, used to calculate what councils are actually paid, says volume is commonly the limiting factor for collection. Collection is the largest cost component. The minister's department contradicts the minister.

Second: glass achieves 80% recycling. Very little reaches landfill. The weight-based disposal costs that might justify higher fees barely apply to glass.

Third: even if weight mattered for some cost components, that does not justify ignoring volume entirely. A hybrid metric -- weighting both factors -- would be coherent. A pure weight-based metric, given the government's own volume-based cost model, is not.

The system was not designed to be incoherent. It was designed to be simple. "Weight is verifiable," officials will tell you. "Weight is auditable." And this is true. But verifiable and accurate are not synonyms. The metric was chosen because it was easy, not because it was right.

43%

That is the proportion of brands and retailers now considering switching away from glass packaging, according to a 2025 industry survey by British Glass.¹² Of those considering the switch, 77% said they would move to plastic.¹²

You see the pattern.

A weight-based fee makes glass the most expensive material per container. The most expensive material per container is the one producers stop using. And the material they move to -- plastic, with its lightweighted designs paying fractions of a penny per bottle -- is the one the fee structure rewards. Not because plastic is better for the environment. Because plastic is lighter. Nick Kirk, Technical Director of British Glass, observed that "packaging is bought in units not weight" -- yet the fee structure charges by weight regardless.¹³

This is where administrative incoherence becomes something more precise. If the weight-based metric were simply a mistake, the solution would be straightforward: adopt the hybrid metric the government's own cost model already uses. The glass industry has asked for exactly this. Sarah Champion MP put the arithmetic before Parliament in May 2025: "brands and retailers do not buy packaging by weight, but by unit... Recyclable glass can be 20 times heavier than less recyclable packaging, resulting in vastly disproportionate EPR fees."¹⁴ She noted that DEFRA had received substantial evidence of material-switching but that "this policy choice does not seem based on evidence."¹⁴

The government's response, recorded in the House of Commons Library research briefing, is four words long: "The Government is not considering the adoption of a units-based metric."¹⁵

Stay with me. The EPR fee methodology was developed through consultations between 2019 and 2023. Among the bodies that sat on DEFRA's Advisory Committee on Packaging and the Packaging and Collections Working Group were the Industry Council for Packaging and the Environment (INCPEN) and the Food and Drink Federation (FDF) -- the trade bodies representing the sectors whose members produce and use lightweight packaging.¹⁶ The same organisations that subsequently bid jointly for Producer Responsibility Organisation status under the scheme they helped shape.¹⁶ These are the sectors for whom a weight-based fee is structurally advantageous: the lighter the packaging, the lower the per-unit cost. A units-based metric would eliminate that advantage.

I am not arguing that anyone in that room set out to disadvantage glass. I am observing that the metric chosen advantages the industries whose representatives were in the room, disadvantages the industry whose representatives were not, and that when asked to reconsider, the government declined. The incentive structure is consistent with the outcome. That is a stronger claim than incoherence.

The minister defended the weight-based approach in Parliament, stating that "waste management costs are largely driven by weight."¹ She held a roundtable on the issue in July 2025 and indicated that debates in the House would "genuinely feed into my decision making."¹ Whether this openness translates to revision remains to be seen. For now, the contradiction between the cost model and the fee structure persists.

Meanwhile, single-use PET, aluminium and steel drinks containers (150ml to 3 litres) are excluded from EPR producer-fee tonnages because they fall under the Deposit Return Scheme planned for October 2027.¹¹ Glass was excluded from DRS. The government cited "cost, complexity and consumer burden" -- but the loudest voices advocating for glass's exclusion were not environmental. The Association of Convenience Stores lobbied explicitly against glass inclusion; its chief executive, James Lowman, said retailers would be "relieved that they won't have to handle the return of glass drinks containers."¹⁷ Of 56 deposit return schemes operating worldwide, 49 include glass.¹⁸ Britain's does not. So glass pays EPR fees while its competitors -- the materials whose containers retailers preferred not to handle alongside glass -- pay nothing. For two and a half years.

I will not tell you what to do with this. That is not my job.

But now you have seen the ledger. The real one. The transformation from volume to weight happens in a methodology document no one reads, and it makes glass -- recycled at 80%, well above plastic's 54% -- the material Britain charges most. The metric advantages the industries whose representatives advised on it. The exclusion advantages the industries that lobbied for it.

The metric is the policy. And the policy is producing exactly the outcome its arithmetic predicts.

The Levers

Three variables determine the per-unit burden on glass. Each is a point where the arithmetic could change.

The metric itself. A hybrid fee combining weight and volume -- reflecting the government's own LAPCAP cost allocation -- would narrow the glass-plastic gap substantially. The LAPCAP methodology already performs this conversion internally. The fee structure could adopt the same logic without new data infrastructure.

The modulation factor. EPR fees include a modulation mechanism intended to reward recyclability.⁴ Glass, at 80.4% recycling, should benefit significantly from this. Whether modulation offsets the weight penalty is the critical calculation -- and it is not currently visible in public fee schedules.

The DRS exclusion window. Until October 2027, single-use PET, aluminium, and steel drinks containers pay no EPR fees because they are assigned to the Deposit Return Scheme.¹¹ Glass, excluded from DRS, bears the full EPR burden without its competitors sharing the system's costs. The length and terms of this exclusion window directly affect the competitive pressure on glass producers.

What Would Change This Analysis

If DEFRA published a full cost-allocation model showing that weight-based fees accurately reflect the net per-unit cost to local authorities -- including collection, sorting, processing, and material revenue -- the metric mismatch identified in this report would narrow or close. The current LAPCAP methodology apportions collection costs by volume,² which is the basis for the gap this report maps. A revised methodology demonstrating that weight-based allocation produces equivalent per-unit cost recovery would change the structural analysis.

If the EPR modulation factors, once fully applied, reduce the effective per-bottle fee for glass to within an order of magnitude of plastic, the competitive distortion would diminish significantly. The modulation mechanism exists in the legislation but its net effect on per-container costs has not been published in sufficient detail to assess.

If the October 2027 DRS launch proceeds on schedule and glass producers receive a corresponding adjustment to EPR fees reflecting the return of competitor materials to the shared cost base, the two-and-a-half-year exclusion window documented here would become a transitional anomaly rather than a structural feature.

If evidence emerges that the advisory bodies' composition did not materially influence the fee methodology -- for instance, if DEFRA's internal impact assessments considered and rejected unit-based or hybrid metrics on independent technical grounds prior to advisory input -- the structural-interest reading of the weight-based choice would weaken considerably.