16 C.F.R. § 260.10 : Commercial Practices — FEDERAL TRADE COMMISSION — GUIDES AND TRADE PRACTICE RULES — GUIDES FOR THE USE OF ENVIRONMENTAL MARKETING CLAIMS — Non-toxic claims

(a) It is deceptive to misrepresent, directly or by implication, that a product, package, or service is non-toxic. Non-toxic claims should be clearly and prominently qualified to the extent necessary to avoid deception.
(b) A non-toxic claim likely conveys that a product, package, or service is non-toxic both for humans and for the environment generally. Therefore, marketers making non-toxic claims should have competent and reliable scientific evidence that the product, package, or service is non-toxic for humans and for the environment or should clearly and prominently qualify their claims to avoid deception.

Example: A marketer advertises a cleaning product as "essentially non-toxic" and "practically non-toxic." The advertisement likely conveys that the product does not pose any risk to humans or the environment, including household pets. If the cleaning product poses no risk to humans but is toxic to the environment, the claims would be deceptive.

16 C.F.R. § 260.10