Leather Types
Is Leather Biodegradable? What Happens to Tanned Leather in Landfill
Tanned leather can break down, but speed depends on tanning, finish and conditions. See what a 2024 composting test found and where sources disagree.
Tanned leather can break down, but slowly and unevenly, and the answer depends on the tanning method, the finish and the conditions. Tanning stops a hide rotting, so leather does not behave like raw skin. No source we read gives one reliable figure for leather in landfill. For where leather sits in the wider picture, see our guide to leather types, textures and finishes.
What the sources say
These numbers do not line up, and they should not be forced to. The lab test used an intensive aerobic composting simulation following ISO standards on bovine leather. The encyclopedia figure comes with no conditions at all. A landfill is a different environment from a compost heap, and we found no measurement of leather in a real landfill.
| Source | What it reports | Fact |
|---|---|---|
| Encyclopedia | Leather takes 25 to 40 years to decompose; no tanning type or conditions given | – |
| 2024 lab composting test | Wet-blue (chrome-tanned intermediate) leather degraded totally in 31-35 days | – |
| Same test | Vegetable-tanned leather showed first signs at 60 days, not fully disintegrated at 90 days | – |
| Same test | Leatherette, Pinatex and Desserto showed no degradation after 90 days | – |
Tanning type changes the result, but not as you might expect
It is tempting to say vegetable-tanned leather rots and chrome-tanned leather does not. The 2024 test found the opposite order for the samples it used: wet blue degraded fully in about a month, while vegetable-tanned leather was still intact after 90 days. A 2025 study also composted wet blue under thermophilic (self-heating) conditions, but its authors say they did not aim to test it against standard compostability criteria.
Wet blue is an unfinished stage. Finished leather carries dyes, resins and coatings, and a 2024 composting study found these matter: bio-based polyurethane finishes and acrylic wax were biodegradable, while isocyanate and nitrocellulose lacquer finishes showed only moderate biodegradation. So a chrome-tanned, heavily coated jacket may not behave like the lab's wet-blue sample.
Chrome tanning is the most common method. Wikipedia notes chromium is a heavy metal and that even after treatment a residual load can cause difficulties when landfills are used. Read more on our page about vegetable-tanned leather.
Leather compared with faux leather
Faux leathers behave differently. Wikipedia notes PVC does not decompose in landfill like leather and can release dioxins, and that polyurethanes can degrade by hydrolysis. The 2024 test found no degradation in leatherette after 90 days. See is vegan leather real leather? for those materials.
A leather-promotion account says real leather "returns to nature," but its post gives no data, tanning types or time frames. Treat that as advocacy, not evidence.
Where to go from here
The Leather Collection states that chrome tanning is the dominant method worldwide and can pollute water and soil when waste is not managed, and describes vegetable tanning as a traditional alternative; it makes no claim about biodegradability. Their article on leather and its environmental footprint goes into tanning and waste. For what leather is made of, see what is leather made of, and for end-of-life options, can leather be recycled.
FAQ
How fast does leather decompose?
Sources disagree and use different conditions: 25-40 years in one encyclopedia entry, and 31-35 days for wet blue in a lab composting test.
Can leather be composted?
In one 2024 test, wet-blue leather composted fully in 31-35 days while vegetable-tanned leather did not within 90 days. Finishes change the result.
HitKB Editorial Team
HitKB articles are researched from published sources, cited in the text, and reviewed before publication.