The EU Cosmetics Regulation defines the two terms the claim depends on. A cosmetic product is defined as "any substance or mixture intended to be placed in contact with the external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or with the teeth and the mucous membranes of the oral cavity," and a substance is defined as "a chemical element and its compounds in the natural state or obtained by any manufacturing process, including any additive necessary to preserve its stability and any impurity deriving from the process used," with a mixture being "a mixture or solution composed of two or more substances." On those definitions a cosmetic product is, by construction, either a chemical substance or a combination of chemical substances. The definition covers substances obtained naturally as well as those obtained by manufacture, so a plant oil or water is a chemical substance in the same sense a synthetic preservative is.

On the term itself, no regulator found defines "chemical-free." The FDA states that the law does not require cosmetic labeling to have FDA approval before products go on the market, that FDA does not have a list of approved or accepted claims for cosmetics, and that under the law information on cosmetic labeling, including claims, must be truthful and not misleading. In the EU, claims are controlled by process rather than by a defined vocabulary. Cosmetic claims are covered by Article 20 of Regulation (EC) No 1223/2009 and Regulation (EU) No 655/2013, the common criteria for justification of claims, being legal compliance, truthfulness, evidential support, honesty, fairness and informed decision-making.

The European Commission has published a Technical Document on Cosmetic Claims as guidance to enforcement authorities for case-by-case application of the common criteria, with Annexes III and IV applying as of 1 July 2019, Annex III addressing how the six common criteria apply to "free-from" claims and Annex IV addressing "hypoallergenic" claims.

The CTPA states that many "free from" claims perpetuate myths about safe and legally allowed ingredients.

In the US the equivalent control over "free-of" wording sits with the FTC. Under the Green Guides, specific deceptive messages include misrepresentations that a product is free-of a substance or non-toxic, and a "free-of" claim may still be deceptive where the substance has never been associated with the product category, with the Guides noting that even a technically true statement can be deceptive if it omits material information.

A professional chemistry body has made the same point the claim makes, publicly and as a challenge. The Royal Society of Chemistry stated that everything we eat, drink, drive, play with and live in is made of chemicals, both natural and synthetic, and offered a bounty to the first person who could provide any material it considered 100% chemical free.

Reporting on the challenge notes that no one has claimed the prize.