📕 THE FULL RECEIPTS — 19 pages, $4.99: https://declassifiedhistory.gumroad.com/l/shelf-audit-15-what-the-label-saysEvery finding with the FDA letter, OSHA citation or lab test it came from, named.Five keratin/Brazilian-blowout treatments carry a real FDA letter, OSHA citation, or lab test for formaldehyde behind a "formaldehyde-free" label. Two don't. Here's what the paperwork says.FORMALDEHYDE FOUND (documented by OSHA, the FDA, or an independent lab): • Brazilian Blowout — FDA warning letter, Aug 2011: FDA's own testing found 8.7–10.4% formaldehyde in a bottle printed "No Formaldehyde." Settled a class-action for $4.5M. • GK Hair (formerly Global Keratin) — FDA warning letter; independent testing found 1.4–4.4% formaldehyde; recalled in Canada, France, Ireland. Reformulated since — today's bottle is a separate question. • Marcia Teixeira — distributor fined $12,600 by OSHA; independently tested at 1.2–3.4% depending on the lab and batch. • Keratin Complex Smoothing Therapy (original line) — distributor fined $12,600 by OSHA; formaldehyde confirmed independently. NOT Peter Coppola's later, separately-branded line — different bottle, era. • Cadiveu / Brasil Cacau — named in the same 2011 OSHA salon air testing as Brazilian Blowout; no separate FDA letter of its own, the thinnest receipt.WORTH A SECOND LOOK (no FDA letter or OSHA citation by name): • Kerasilk (Goldwell) and Cezanne run on glyoxylic acid, not methylene glycol — a real, different chemistry, no federal citation by name. The honest rest: peer-reviewed research shows glyoxylic acid can itself release formaldehyde gas under the same heat these treatments use, and case reports (incl. one in the NEJM) link it to kidney injury in a cluster of patients. Still-developing research, not a proven-clean bill of health.WHERE TO FIND THEM (salon-professional listings we found, not a brand checkout page): Kerasilk: https://www.imagebeauty.com/products/goldwell-kerasilk-keratin-treatment-smoothing-lotion Cezanne: https://www.amazon.com/Cezanne-Formaldehyde-Keratin-Smoothing-Treatment/dp/B00X6AIOB8A National Institutes of Health study (JNCI, Oct 2022, ~33,000 women) found women using straighteners 4x+/year had more than double the uterine cancer risk by 70 — 60% of the users studied were Black women. Category-level context, not a per-brand finding.One question that matters before you book: ask your stylist what chemical system is in the bottle. Methylene glycol is the tell the FDA and OSHA were reading in 2011. Glyoxylic acid isn't an automatic pass either — just a different question worth asking.Every claim here is a documented finding — an FDA letter, OSHA citation, lab test, or peer-reviewed study — reported as that source's finding, both sides shown where a brand disputes or has reformulated. Not medical advice.Some links below may be affiliate links; I may earn a small commission at no extra cost to you. It never changes which brands make this list or where they land. (FTC 16 CFR 255.)CHAPTERS: 0:00 The Formaldehyde-Free Promise 0:46 The Loophole: Methylene Glycol vs. Formaldehyde 3:07 #5 Cadiveu / Brasil Cacau 5:03 #4 Keratin Complex Smoothing Therapy 6:49 #3 Marcia Teixeira 8:08 #2 GK Hair 9:50 #1 Brazilian Blowout, And The Stalled FDA Ban 12:04 The NIH Study, In Context 13:34 Worth A Second Look: Kerasilk & Cezanne 15:55 What To Ask Your Stylist Before You Book