Building the Foundations: How the IDI is Setting Leather’s Sustainability Story on Solid Ground

Inge Flowers, Program Manager of the new Institute for Data Integrity (IDI), explains why reliable life cycle assessment data has become critical for the future of leather, and what it will take to produce it.

Ask anyone who has tried to make the environmental case for leather and they will tell you the same thing. Even if the data you need is there in the first place, there are queues of people waiting to dispute it. That problem is one of the reasons the IDI was created.

“When you want to do a lifecycle assessment on something that contains leather, the information that’s out there is old or behind paywalls, or it’s difficult to get hold of or just plain unreliable,” says Inge. The consequences of this are not just academic. Fashion brands conducting LCAs on products made with so-called ‘vegan leather’ or equivalents versus genuine leather frequently find that the plastic alternative appears more sustainable, simply because the data underpinning the analysis is flawed. For this and other reasons, direct LCA comparisons are rarely helpful.

The IDI’s mission is to change that. It will collect and publish life cycle inventory data with an emphasis on transparency, methodological clarity and the protection of commercial confidentiality. This way, “you know how it’s been made, you know what the assumptions are and you know what you are and aren’t getting,” Inge explains.

A Sector-Wide Problem

The IDI is not alone in recognising the problem. Inge notes that the livestock sector is now collecting more robust data in response to assumptions about farming’s environmental impact that she says don’t reflect what science is actually showing. She is also aware of similar efforts underway in the wool industry.

For Inge, there is a longer-term opportunity in this new openness. “Leather, cotton, silk and wool are all being shown, at the moment, as materials where the foot printing results say, ‘well actually these materials are bad, you’re better off using the plastic alternatives.’ And that’s because the methods don’t always capture the full information. So we’re all in the same boat.” She sees potential for the IDI to expand beyond leather into other natural materials rather than have each sector build something separately.

The Allocation Debate

One of the most contested questions in leather LCA methodology is how much of the environmental burden from farming should be attributed to the hide, as opposed to the meat and dairy it is a by-product of. Inge describes it as an “eternal and never-ending debate.”

Under current LCA rules, a by-product takes on some share of the upstream impact. Only a waste stream can be argued to carry none. The practical effect is that if leather is classified as a by-product, as it currently is, it absorbs a portion of the farming footprint which can make the material look unsustainable by comparison to alternatives that avoid upstream allocation entirely. Many synthetic material LCAs have managed to avoid or minimize the allocation of the extraction of the oil they are made from.

Inge is tracking a body of work, primarily from Europe, that is pushing back on this. There is an argument that if the share of the farming impact assigned to leather is large enough to make it appear unsustainable, then logically it ought to be reclassified as waste, which would mean it carries zero impact. The circularity of this argument is not lost on her, but she understands the practical motivation is keeping hides out of landfill. “They’re arguing that it has such little value that it shouldn’t take on a farming impact”.

Signs of a Turning Tide

Inge has been working on leather’s sustainability positioning for the best part of a decade, and she has watched the story shift over that time. Eight years ago, she recalls, the only voices making a positive case for leather in the public domain were from within the industry itself. The default answer, from Google searches, from media coverage, from public perception, was that leather was bad.

Around four years ago, she says, that began to change. Independent journalists started writing more nuanced stories and highlighting the facts that leather was compostable, circular, renewable and durable in ways that synthetic alternatives were not. More concretely, she has been in conversations where major international brands that had adopted categorical no-leather policies subsequently went back to leather after being presented with tannery data. “The tanners brought data forward and said, ‘let us talk to you about it.’ And now those companies are using leather again.”

She remains cautious about the pace of change. “There is a sense that the tide is turning a bit. I just don’t know if it is fast enough or will be enough of a tide to maintain the size of the leather industry that we’re used to.”

What the IDI Will Eventually Hold

The long-term vision for the IDI’s data platform is cradle-to-grave: farming, through tanning and manufacture, into use and finally disposal. The goal is a level of detail that goes beyond generic averages. Ideally, a brand conducting an LCA on a leather product would be able to select data by farming region, animal type and tanning method, rather than rely on a single global or generic figure.

Inge identifies the use phase as the most challenging. Current apparel LCA methodologies assume a generic number of uses regardless of whether the item in question is a pair of fast-fashion trainers or a pair of investment leather shoes. It is obvious that assumption systematically disadvantages durable materials. “We want to do the science, do the research, get some very intelligent, very driven people to find out what those numbers are so that we can then add that to the conversation.”

Building the Foundations in 2026

Inge is candid about where the IDI currently sits. “We’re almost literally two minutes old,” she says. Much of 2026 will be spent on what she calls foundation work: data governance, IT infrastructure and the online platform through which the data will eventually be made available. The immediate practical priority is tannery data, and she is clear that collecting it is proving more involved than it might sound.

“Most tanneries are used to their environmental audits, but the level and type of information we’re asking them for is different. So they’re having to rearrange their data management systems to be able to provide us with information.” Tanneries, she says, have been notably cooperative, which she attributes to a shared recognition that the industry needs this information.

The IDI also has ambitions to open conversations with sustainability assessment platforms to understand what form of data they would need to be able to integrate IDI datasets into their tools. Inge says: “I would love for it to feed into other assessments. Another piece of work for 2026 is to start conversations with a whole range of exciting organizations that are out there. Some of them are platforms that brands rely on for their material assessments and there are a couple of smaller ones as well. The reality is we’re at the beginning of the journey and we need to start having the conversations.”

She uses a construction analogy to describe where the IDI is now: “The first months on a building site look as though nothing is happening, because all the activity is underground. There is the provision of the utilities and the building of the foundations. The integrity of the structure that will eventually stand above ground depends entirely on how well that invisible work is done.”

For an industry that has long struggled to make its sustainability case heard, getting those foundations right may be the most important work the IDI does.