Mass balance explained: How it works and why it faces criticism

Premium Beauty News with Corentin Dautreppe, AFP (Photo: nastya_ph / iStock ©)

11 July 2026

Mass balance explained: How it works and why it faces criticism

"Recycled plastic packaging," "fair trade chocolate"—claims such as these can strongly influence purchasing decisions and are therefore tightly regulated. However, the accounting method known as mass balance can make them difficult to interpret, adding complexity—and sometimes a lack of transparency—for both consumers and stakeholders across the processing supply chain. How does the methodology approved by the European Union for calculating the recycled plastic content of plastic bottles work?

At first glance, a fair trade chocolate bar and recycled plastic packaging appear to have little in common. Yet the companies behind these products are among the strongest advocates—or critics—of the mass balance approach. Behind the term lies a practical, albeit complex, accounting method used to track the use of recycled or certified raw materials (organic or Fairtrade goods, for instance) throughout the supply chain.

"Regularly mixed" products

According to Fairtrade International, it is difficult to keep fair trade-certified cocoa, tea or sugar physically separated from conventionally sourced ingredients throughout the entire value chains. Maintaining segregation can even disadvantage producers by increasing processing and logistics costs, the organization says.

As a result, Fairtrade and non-fair trade ingredients are "regularly mixed", owing to "complex manufacturing processes" and the "high market concentration" among processors.

To address this, Fairtrade allows the use of the mass balance approach. Under this system, manufacturers may mix certified and non-certified goods throughout the manufacturing process, provided that the volumes sold under the Fairtrade label align with the volumes supplied. For example, a chocolate bar sold in France by discount retailer Lidl under the Fairtrade Max Havelaar label states on its packaging: "For technical production reasons, the cocoa in this product may be mixed with non-certified cocoa; however, the total volume of cocoa is guaranteed to the producers under Fairtrade terms."

By contrast, French chocolate maker Kaoka promotes its products as "guaranteed free from mass balance", stating that "our fair-trade ingredients are 100% physically traceable and are not mixed with cocoa and sugar that are not fair-trade certified." According to Kaoka, the widespread adoption of mass balance leads to a "loss of information when buying chocolate," undermines the credibility of fair trade and creates "unfair competition" within the cocoa industry.

The mass balance approach extends well beyond fair-trade certification. In late June, the European Union endorsed the method for calculating the recycled plastic content of plastic bottles.

Here again, manufacturers point to practical constraints. At the outlet of a steam cracker — the petrochemical installation that breaks down hydrocarbons into basic chemical building blocks — an ethylene molecule produced from recycled plastic is chemically indistinguishable from one derived from virgin fossil feedstock, explains Plastics Europe, the association representing the European plastics industry. As a result, companies such as Eastman, ExxonMobil, Ineos, LyondellBasell and TotalEnergies cannot physically trace recycled molecules through the production process. Instead, they can certify only the proportion of recycled feedstock entering the system — for example, that 5% of the material fed into a steam cracker originated from recycled plastic, explains Jean-Yves Daclin, Director General of Plastics Europe France.

A marketing tool

When recycled content is accounted for using the mass balance approach, manufacturers can allocate the recycled share of the feedstock to a specific portion of the finished output. In practice, this means they could attribute, for example, all of a plant’s recycled input to 5% of the products manufactured and market those products as containing 100% recycled content — even though it is impossible to determine the actual amount of recycled material in any individual item. The aim is to offer products with a stronger sustainability claim to customers seeking recycled materials.

Zero Waste Europe, an NGO focused on waste prevention and the circular economy, warns that it "risks undermining" the very definition of recycled content.

Lauriane Veillard, a representative of the organization, argues that marketing a product as fully recycled without being able to verify its actual recycled content could amount to greenwashing.

"We do not consider it misleading," responds Jean-Yves Daclin, Director General of Plastics Europe. However, he stresses that this is acceptable only if there is "absolute transparency" towards customers, making it clear that the claim reflects an accounting allocation of recycled feedstock rather than the physically measurable recycled content of the individual product.