Verification
How we check this
Anyone can say their sources are good. This is the machine that checks ours, and the number it last returned.
Every ingredient page here rests on primary sources, and the rule we work to is that a source is read before it is cited. That was true because whoever wrote the page took care. Care is not a guarantee, and it does not survive a regulation being amended six months later.
So there is a script. It fetches every source this site cites, extracts every quoted passage from every page, and checks each one appears in a source cited on that same page, word for word. It resolves every link to the US Code of Federal Regulations against the regulator's own structure index, because sections move. It runs on every change, and it re-reads the whole web of sources once a week, because sources change when nobody is editing.
What is failing right now
Nothing. Every quotation on this site matched a source cited on its own page on the last run, and every reachable source resolved. That will not always be true, and when it is not this section will say so rather than quietly improving.
What we cannot check, and why
This is the part most worth reading, because it is the limit of the method rather than a score.
- 24 Quotations we cannot check, because their source is a PDF or refuses machines
- 17 Sources we cannot read from our own infrastructure
Some publishers serve people and refuse machines, and some serve documents our tooling cannot parse. We record those rather than counting them as passes:
eur-lex.europa.eu, 7 citationspubmed.ncbi.nlm.nih.gov, 3 citationswww.ewg.org, 2 citationswww.foodallergy.org, 2 citationswww.resmigazete.gov.tr, 2 citationsacademic.oup.com, 1 citation
A citation on this list was read by a person before it was used. What it has not had is a machine confirming, this week, that it still says what we said it says. That is a weaker guarantee than the rest of the site carries, and it should be read as one.
What the check cannot tell you
That a quotation is accurate is not the same as a page being right. A verbatim quote can be selected badly, framed misleadingly, or given weight it does not deserve. No script catches that, and this one does not claim to.
It also cannot check what a page says in its own voice. Our rule for that is narrow and mechanical: quotation marks mean quoted, verbatim, from a source cited on the page. Where a page uses our own phrasing, or renders what a label would say, it is set in italics instead. So when you see quotation marks here, a machine has checked them.
When the regulations last moved
Much of this site rests on the US Code of Federal Regulations, which is amended continuously. We record the amendment date of every title we cite, so that a change underneath us is something we detect rather than something a reader finds.
Title 21last amended 27 August 2026
Why publish this
Because the alternative is asking you to take our word for it, and this whole site exists because taking someone's word for it is how ingredient information goes wrong. Apps in this category publish scores. A score cannot be audited: you cannot tell whether a 4 out of 10 was reasoned or assigned. Sources can be audited, which is why we publish those instead, and this page is what makes that claim checkable rather than merely stated.
The rules the writing itself follows are in the editorial policy. If you find something this check missed, and there will be things, hello@pura.to is the fastest way to make it our problem.