Leather

Since leather here touches hands rather than food, the question is skin contact, and specifically chromium. Tanning chromium is trivalent, Cr(III), which is stable and is not the hazard people have in mind. The hazard is hexavalent chromium, Cr(VI), which is never added deliberately but can form when Cr(III) oxidizes through poor processing, low-quality fats and oils, or heat and light in storage and use. The EU restricts it: REACH Annex XVII entry 47 caps Cr(VI) at 3 mg/kg of dry leather weight in articles that touch skin - though the standard test method, ISO 17075, has a detection limit right at 3 ppm, so "compliant" and "undetectable" are effectively the same result. A 2019 study of Nicaraguan and European leathers measured Cr(VI) release from undetectable up to 6.0 mg/kg, worst in uncoloured grey leathers at 2.8-6.0, and made the more useful point for anyone already chromium-sensitized: total chromium release ran at least ten times the Cr(VI) figure, and Cr(III) alone can trigger a reaction, so meeting the limit does not make chrome-tanned leather safe for that group. Vegetable tanning avoids chromium entirely. The plastic question is separate and larger: most "vegan leather" is polyurethane or PVC on a fabric backing, and much pigmented real leather carries a polymer topcoat, so a leather-looking surface is not automatically a plastic-free one.

Leather has no place in a hot path and none in a dishwasher - hot water shrinks and hardens it, and drying it quickly afterwards makes it crack. Heat and light during use and storage are also among the conditions that encourage Cr(VI) to form in chrome-tanned leather, which is a reason to keep a leather-tied brewer off a hot windowsill rather than a reason to worry about the brewer.

Look at a cut edge. Real leather shows a fibrous, felted cross-section whose color fades through the thickness; PU and PVC show a uniform skin sitting on an obvious knit or woven backing; bonded leather shows a pressed, papery core. Grain is the second tell - a hide's pores and scars are irregular and never repeat, while an embossed or coated surface repeats on a pitch you can spot once you look for it. A drop of water soaks into unfinished or vegetable- tanned leather in seconds and beads on anything heavily finished. On labels, US sellers are bound by the FTC Leather Guides at 16 CFR 24.2: non-leather must be disclosed as imitation leather, simulated leather, vinyl, vinyl coated fabric or plastic; a backing that is not visible on casual inspection must be disclosed; and ground, shredded or bonded leather cannot simply be called leather. "Vegan leather" has no legal content at all. Ask a brand two things - what tannage, and is the surface finished with a pigment or polymer topcoat.

Keep it on the dry side, clean it with a damp cloth rather than soaking it, and condition it occasionally so the fibers do not dry out and crack. Full-grain vegetable-tanned leather darkens and softens with use and lasts decades. A heavily finished "genuine leather" item fails at the coating, which crazes and flakes off, and bonded leather peels within a couple of years and cannot be repaired.

Raw hide would rot, and tanning exists precisely to stop that, so leather biodegrades slowly and chrome-tanned scrap is handled as a problem waste stream in many jurisdictions rather than as compost. Nothing takes leather curbside. Undyed, unfinished vegetable-tanned leather is the only version with a plausible compost story, and even that takes years. A PU-coated or bonded item is a plastic laminate at end of life no matter how much hide is in it.