What is linalool?

What linalool is

We work from documents and have not tested any products. This page collects what a handful of public sources say about one fragrance chemical, and it marks where they stop.

PubChem, the US National Library of Medicine’s chemistry database (record retrieved 2026-11-14), describes linalool as “a monoterpenoid that is octa-1,6-diene substituted by methyl groups at positions 3 and 7 and a hydroxy group at position 3.” It adds that linalool “has been isolated from plants like Ocimum canum” and “has a role as a volatile oil component, an antimicrobial agent, a fragrance and a plant metabolite.” It also calls it a monoterpenoid and a tertiary alcohol.

DermNet (retrieved 2026-11-14) puts it in skin terms: a fragrance chemical extracted from “herbs, flowers, and woods”. Its companion, limonene, is described there as coming from citrus peel.

Names it appears under

PubChem lists CAS registry numbers 78-70-6 and 22564-99-4 for the record. Its first ten names and synonyms are: Linalool; 78-70-6 (the CAS number); 3,7-Dimethylocta-1,6-dien-3-ol; Linalol; LINALYL ALCOHOL; beta-Linalool; 3,7-Dimethyl-1,6-octadien-3-ol; allo-Ocimenol; 1,6-Octadien-3-ol, 3,7-dimethyl-; and dl-Linalool.

These are database synonyms. The sources we read do not say which name, if any, a manufacturer must or does print on a product, so we cannot tell you what the INCI (ingredient label) name is. Our guide to fragrance allergen names on ingredient labels covers what we could and could not establish about label wording.

Where it occurs

We state this only as far as the sources do. PubChem says linalool has been isolated from plants such as Ocimum canum, and that (+/-)-linalool has been reported in Camellia sinensis, Aristolochia triangularis and other organisms. PubChem also says its entry for 3,7-Dimethyl-1,6-octadien-3-ol is a metabolite found in or produced by Saccharomyces cerevisiae. DermNet says herbs, flowers and woods.

An Acta Dermato-Venereologica study says the main components of lavender oil are linalool and linalyl acetate, and that both autoxidise in contact with air into sensitising hydroperoxides. Our pages on whether lavender oil is a fragrance and essential oils go into the labelling side. A PMC review reports that when product ingredient declarations were studied, limonene and linalool were the most frequently identified substances, with differences between product types. A 2019 PubMed abstract (PMID 31313746, Dermatitis) says linalool is widely used in cosmetics and household products.

Why it matters on a fragrance-free site

Linalool is a fragrance ingredient, so it is exactly the kind of substance a fragrance-free label is meant to keep out. The more specific issue in the literature is oxidation.

DermNet says limonene and linalool “are themselves occasional contact sensitisers”, and that “on exposure to oxygen in the air, both substances oxidise into hydroperoxides which are much more potent sensitisers.”

A 2019 PubMed abstract (PMID 31313746, Dermatitis) says contact allergy to linalool was long considered rare because positive patch tests to it were infrequent, but that exposure to air produces oxidation products, “of which the hydroperoxides have a far stronger sensitizing potency than the pure compound.” It also cautions that some positive reactions may be false-positive irritant responses.

A PMC review summarising a 2012 EU Scientific Committee on Consumer Safety opinion says that for the most commonly used fragrance terpenes, limonene and linalool, “hydroperoxides resulting from autoxidation constitute the major allergens”. It adds that in animal experiments the oxidation products of terpenes including linalool were markedly more allergenic than the unoxidised substances, and that antioxidants are used to delay oxidation.

A review of patch testing calls linalool a prehapten: the form added to products, whereas the oxidised forms are the haptens that cause contact allergy. It concludes that it is “impossible to establish positive clinical relevance exclusively by assessing the ingredient labels,” and that chemical analysis would be needed to establish the amount of each oxidation product. A third review says contact allergies to linalool and limonene hydroperoxides are common, but that diagnosing relevant allergy is complicated.

What individual studies report

These are single studies, reported as they state themselves, not as general conclusions.

• One Spanish prospective study (PMID 27896835, Contact Dermatitis 2017) patch-tested 3639 consecutive patients at 22 dermatology departments. It reports positive reactions to linalool hydroperoxides in 1.3%, 2.9% and 4.9% of patients at the three concentrations tested, and concludes that they can be considered common causes of contact allergy.
• A 2026 abstract (PMID 41713461, Contact Dermatitis) reports a prevalence range of 3.9% to 11.7% of positive patch tests, often with doubtful or irritant reactions, and describes a 21-day repeated open application test in 12 sensitised people and 20 controls. It reports positive reactions in some sensitised participants and none in controls, and states that reactions were dose-dependent in sensitised individuals.
• A 2024 abstract (PMID 38386591, Dermatitis) reports a 28-day repeated open application test with creams made to reflect real-world doses in consumer products. Of 47 participants, one had a positive reaction at the highest concentration, and the authors conclude that such creams could rarely elicit an allergic reaction on intact skin after four weeks.
• The lavender oil study above reports positive reactions to oxidised lavender oil in 2.8% of patients tested.

Taken together, the reports point in different directions on how often real products cause reactions, and we do not try to resolve that. They agree on the chemistry the sources describe: oxidation matters, and the label may not tell you the oxidation state.

What the FDA says about labels

The FDA’s Fragrances in Cosmetics page (retrieved 2026-11-11) says that “under U.S. regulations, fragrance and flavor ingredients can be listed simply as ‘Fragrance’ or ‘Flavor.’” It also says even some products labeled “unscented” may contain fragrance ingredients. So a US cosmetic label may not name linalool even if it is present. See fragrance-free vs unscented, how to read an ingredient list and our explainer on the FDA and fragrance trade secrets.

How this site treats it

This part is our own rule, not a regulation or a medical judgement. When we check a product, we read the maker’s published ingredient list. Our watch list of named fragrance substances includes linalool, so a product whose maker list names it is flagged against the fragrance-free test. The watch list is ours and does not come from any regulator. The test itself looks for fragrance, parfum, aroma, perfume, essential oils and fragrance chemicals; see what parfum means and the EU’s 26 fragrance allergens.

A plain line

Fragrance ingredients are not inherently harmful. The issue is what labels mean for people who react to them. For questions about your own skin, ask a clinician or an allergy or dermatology society.

What we don’t fully know

We found no source for the name linalool carries on labels, so we do not state it, and PubChem’s synonym list does not settle it. We found no source on natural versus synthetic production, and no regulator text on linalool itself. We read abstracts rather than full papers, so details such as study design beyond what an abstract says are not covered. The rest is listed under “unknowns” on this page.