Tisserand & Young · Essential Oil Safety
A primary reference for essential-oil safety and dermal limits (publisher book page).
https://shop.elsevier.com/books/essential-oil-safety/tisserand/978-0-443-06241-4
IFRA Standards
Fragrance ingredient safe-use standards (IFRA public library).
RIFM
Public home of the Research Institute for Fragrance Materials (scientific evaluation context alongside IFRA).
EU Cosmetics framework
EU cosmetics regulatory overview (topical personal-care context).
https://single-market-economy.ec.europa.eu/sectors/cosmetics_en
More → About → Sources & Citations; also from the first-launch disclaimer, Scene Q&A results, oil safety card, and lab evaluation footnote.