Ten things widely believed about cosmetics, and what the documents actually say.
This site does one thing: it puts a source you can open next to every factual claim. It is not a review site and it never will be — nothing here describes anyone's experience of using a product, because we have not used them. What follows is the whole editorial position, readable in about thirty seconds.
- Widely believed
- “A 7.4 is the same copper whichever brand you buy — the numbers are a standard code.”
- What the document says
- Nobody owns the chart. The level/tone convention is industry practice, not a standard — no ISO, no annex, no legal definition — so the tone digits genuinely differ between manufacturers.
- There Is No Standard Behind the Hair-Colour Number Chart
- Widely believed
- “Purple shampoo strips the yellow out of bleached blonde hair.”
- What the document says
- Lightening does not remove warmth, it exposes it. A violet shampoo deposits a direct dye that sits on the fibre and washes out. Only further lifting or an oxidative toner changes the pigment itself.
- Purple Shampoo Does Not Remove Brass. It Covers It.
- Widely believed
- “If hair dye brings me out in a rash, a PPD-free box is the safe one.”
- What the document says
- Probably not. The EU files toluene-2,5-diamine — the usual PPD substitute — under the same phenylenediamine warning block, at the same 2% free-base cap after mixing. The regulation's own labelling choice contradicts the marketing.
- “PPD-Free” Is Not the Same as Hypoallergenic
- Widely believed
- “Hair dye causes cancer. The WHO classified it.”
- What the document says
- Four different studies asked four different questions and headlines fuse them. IARC classes working as a hairdresser as Group 2A and personal use of hair colourants as Group 3, not classifiable.
- Hair Dye and Cancer: Four Findings Usually Quoted as One
- Widely believed
- “A reconstruction treatment or an argan-oil mask repairs damaged hair.”
- What the document says
- Cuticle loss and cortical protein loss do not grow back. An oil can lubricate, reduce swelling on wetting and lay a surface film — real effects, all of them cosmetic and temporary. “Repair” is a marketing word, not a regulated one.
- Argan Oil Does Not Repair Hair — and “Repair” Is Not a Regulated Word
- Widely believed
- “If it is third on the list, you can work out roughly how much is in there.”
- What the document says
- The order rule ranks ingredients by weight down to 1%, and below that line they may be listed in any order. You can locate the 1% line. You cannot derive a percentage from it, and every article that says you can is wrong.
- You Cannot Work Out Percentages From an Ingredient List
- Widely believed
- “A high score in an ingredient checker means the product is dangerous.”
- What the document says
- That is hazard — whether a substance could cause harm under any conditions. Risk depends on dose, formulation, rinse-off versus leave-on, exposure site and frequency. A score that ignores all five is an index into the literature, not a verdict.
- Hazard Is Not Risk: How to Read Any Ingredient Score
- Widely believed
- “Grau 2 means ANVISA registered the product and approved it.”
- What the document says
- Grau 1 and Grau 2 are a risk classification decided by what a product claims. Registro versus notificação is a separate axis. Only nine product groups need registration; most Grau 2 products are merely notified.
- In Brazil, “Grau 2” Does Not Mean “Registered”
- Widely believed
- “‘Clean’ and ‘non-toxic’ on a pack mean something a regulator checks.”
- What the document says
- In the US, no — FDA does not define “organic” for cosmetics and has no definition of “clean” or “non-toxic”; MoCRA created none. In the EU there is an enforceable rule, and “free from” claims routinely fail it.
- “Clean” Is a Retail Category, Not a Safety Standard
- Widely believed
- “If a cream is on the shelf saying it does that, somebody approved the claim.”
- What the document says
- Intended use decides the category, and the marketing is the evidence. The same molecule in the same jar is a cosmetic or a drug depending on the sentence on the pack. Nobody pre-approves a cosmetic; MoCRA registration is not approval.
- Where a Cosmetic Stops and a Drug Begins
How we know
No product testing
Nothing on this site describes anyone's experience of using a product. That is a deliberate limit, not an omission: a publisher who has not used a thing may not write as though they have, and in the United States the rule against it is 16 CFR Part 465, in force since October 2024. A personal review also expires the moment a formula changes, and a reader cannot check it. A concentration limit, a committee conclusion and a published study can all be checked by anyone, indefinitely. Why an information site rather than a review site.
Claim-level citations
Sources are numbered and attached to the sentence that makes the claim, not dumped in a bibliography. Where a document has a public address, we link the document itself and not somebody's summary of it, and the link text is the resolvable identifier — 10.1021/cr1000145, CELEX 02009R1223-20260501, 21 CFR 701.3. What counts as a source here.
Corrections in public
Errors of fact are fixed in public and logged permanently, with the date, what we said, what was wrong with it and what it says now. Corrections requested by a brand get the same treatment as any other, and we record that a brand asked. The corrections log.
Recent corrections
The log opens with the entry recording that this site replaced an unrelated Portuguese-language blog on this domain, and which legacy addresses were forwarded where. Read the log.