About / How the rules get into the tools
How the rules get into the tools
Rules last checked 25 September 2026.
Every rule the label tools apply, whether an allergen name, a threshold, a hazard statement or an ingredient name, is copied from the published text of the law, stored with the article or entry it comes from, and tested against that text every time the site is built.
1. The published texts
The tools work from the texts the rules are published in, kept on file in the versions the tables were checked against:
- European Union: the consolidated Cosmetics Regulation (EC) No 1223/2009 and Regulation (EU) 2023/1545, which extended its fragrance-allergen list; the EU glossary of common ingredient names (Implementing Decision (EU) 2025/1175); and the consolidated CLP Regulation (EC) No 1272/2008 for candles and home fragrance, all from EUR-Lex. The food rules come from Regulation (EU) No 1169/2011: its articles from legislation.gov.uk, checked against the EU's later amendments on EUR-Lex.
- United Kingdom: the same regulations as they apply in Great Britain, the Food Information Regulations 2014 and the amendments known as Natasha's Law in England, Wales, Scotland and Northern Ireland, from legislation.gov.uk. Northern Ireland follows the EU texts for cosmetics and CLP.
- United States: 21 CFR Parts 101, 701 and 740 and 16 CFR Parts 500, 1500 and 1700 from the eCFR; the Federal Food, Drug, and Cosmetic Act sections added by MoCRA and FALCPA, and the Federal Hazardous Substances Act, from the US Code; NIST Handbook 133 for the unit conversions; and FDA's substance registry for ingredient names.
- Hazard pictograms: the official GHS artwork published by the United Nations Economic Commission for Europe.
Every guide and reference page names the exact documents and articles it relies on: in a Sources list, or, on the INCI name pages, the glossary entry itself.
2. Copied as data, with the source attached
The rules live in tables that are separate from the code that uses them: the declarable allergens with their CAS and EC numbers, the leave-on and rinse-off thresholds, the ingredient names with their glossary numbers, the hazard statements and pictograms, the food allergens. Every value carries the document and the article, annex entry or section it was copied from. A change in the law is then a change to one table row, not a hunt through code. And if a value has not yet been checked against its source, the tool shows a note with the result instead of presenting it as settled.
3. Tested against the text on every build
Automated tests compare the tables with the text of the documents they were copied from: each allergen name and its CAS and EC numbers against the Official Journal text, each hazard statement against the CLP annexes, each US ingredient name against FDA's registry record. The CAS and EC numbers must also pass their own check digits. The site is not published while any of those tests fails, so a typo in a table, or a rule changed in one place and not another, cannot reach a label.
4. Checked again every month
Once a month every source is checked for anything new: amending acts, newer consolidated versions, corrections to the Official Journal, pending amendments recorded on legislation.gov.uk, and changes to the US texts. When a rule changes, the table changes first; the reference pages are generated from the tables, and the guides that describe the rule are updated with them. The "rules last checked" date on each page moves only when that check has actually been done.
5. What stays with you
Some facts belong to your product, not to the law, so the tools ask you for them: the allergen breakdown of each fragrance, from your supplier's declaration; the hazard classification of a candle or diffuser fragrance, from your supplier's safety data sheet; and which allergens a food recipe contains. The tools apply the rules to those facts. They do not classify a mixture or assess a product's safety, and the precautionary statements are your choice: the CLP tools list Annex IV's statements in the label's language to pick from, and never pick one for you. One fill-in is offered while you wait for a supplier's figures: the estimate tag on the soap and skincare tools uses typical allergen contents for a few essential oils from a published reference, and every label that uses it says so.