Skip to content
SupplyList
Menu

Guaiazulene

Guaiazulene suppliers and sourcing guide

Guaiazulene is a deep blue hydrocarbon, principally 1,4-dimethyl-7-isopropylazulene, made by dehydrogenating sesquiterpenes from guaiac wood oil or by synthesis. It is a low-melting crystalline solid that is soluble in oils. Cosmetic makers buy it in small quantities as a blue color for creams, lotions, shampoos and other externally applied products, often as a dilution in PEG-40 castor oil.

See suppliersWhat to ask for on the COA
Category
Colors
Also known as
1,4-Dimethyl-7-isopropylazulene · CAS 489-84-9 · Azulene
Facts checked
November 2026

Forms and grades of guaiazulene

Suppliers sell different products under the same name. Specify the one you need.

  • Crystalline

    The pure color at not less than 99 percent total color, melting just above room temperature.

  • Water-dispersible dilution

    Guaiazulene diluted in PEG-40 castor oil, the diluent the regulation names for cosmetic color mixtures.

  • Oil-soluble dilution

    Pre-diluted in oils or esters for easier dosing at low use levels.

What to check on the COA

Compare each result with your own specification when the lot arrives.

Total color
Guaiazulene content by GC or HPLC, required to be not less than 99 percent.
Melting point
Melting point, which the regulation sets at 30.5 to 31.5 °C, as an identity and purity check.
Heavy metals
Lead, arsenic and mercury by ICP-MS or AAS, reported against the limits in the color additive regulation and the supplier specification.
Oxidation products
Color and appearance against a standard, since guaiazulene darkens and degrades when oxidized.

Storage, lots and expiry

Storage and shelf life

Store sealed under nitrogen or with minimal headspace, refrigerated and protected from light; guaiazulene oxidizes and changes color with light, heat and air. Shelf life is set by the supplier specification, with total color retested on aged stock.

Lots and expiry dates

Purity and color can drift as the material oxidizes, so record receipt date and storage conditions with each lot and recheck color before use. Buy small lots and rotate first-expired, first-out.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.

Guaiazulene suppliers

Manufacturers and distributors whose own websites say they sell it.

We are checking guaiazulene suppliers now

Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.

Sell guaiazulene? Request a listing

Frequently asked questions

What forms of guaiazulene can brands buy?

Common forms include crystalline, water-dispersible dilution and oil-soluble dilution. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for guaiazulene include?

Expect total color, melting point, heavy metals and oxidation products, each with its method, specification and result for that lot.

How should guaiazulene be stored?

Store sealed under nitrogen or with minimal headspace, refrigerated and protected from light; guaiazulene oxidizes and changes color with light, heat and air. Shelf life is set by the supplier specification, with total color retested on aged stock.

What is the regulatory status of guaiazulene?

21 CFR 73.2180 identifies the color additive guaiazulene as principally 1,4-dimethyl-7-isopropyl-azulene. 21 CFR 73.2180 permits guaiazulene in externally applied cosmetics, exempt from certification. 21 CFR 73.2180 allows PEG-40 castor oil as a diluent in guaiazulene color mixtures for cosmetics and requires total color of not less than 99 percent.

More colors

All 48 colors

Sell ingredients to brands?

Request a free listing for the ingredients you make or distribute. No paid placement.

Request a listing