Oil of guaiac is a fragrance used in soap

Soap

In chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...

. It comes from the palo santo

Bulnesia sarmientoi

Bulnesia sarmientoi is a tree that inhabits a part of the Gran Chaco area in South America, around the Argentina-Bolivia-Paraguay border. Its wood is often traded as Argentine lignum vitae or Paraguay lignum vitae, since it has properties and uses similar to the "true" lignum vitae trees of genus...

 tree (Bulnesia sarmientoi).

Oil of guaiac is produced through steam distillation

Steam distillation

Steam distillation is a special type of distillation for temperature sensitive materials like natural aromatic compounds....

 of a mixture of wood and sawdust from palo santo. It is sometimes incorrectly called guaiac wood concrete

Concrete

Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

. It is a yellow to greenish yellow semi-solid mass which melts around 40-50 ºC. Once melted, it can be cooled back to room temperature yet remain liquid for a long time. Oil of guaiac has a soft roselike odour, similar to the odour of Hybrid Tea

Hybrid Tea

Hybrid Tea is a cultivar group of roses, created by cross-breeding two different types of roses, initially by hybridising Hybrid Perpetuals with Tea roses...

 roses or violets. Because of this similarity, it has sometimes been used as an adulterant

Adulterant

An adulterant is a chemical substance which should not be contained within other substances for legal or other reasons. Adulterants may be intentionally added to more expensive substances to increase visible quantities and reduce manufacturing costs or for some other deceptive or malicious purpose...

 for rose oil.

Oil of guaiac is primarily composed of 42-72% guaiol, bulnesol, δ-bulnesene, β-bulnesene, α-guaiene

Guaiene

Guaienes are a series of closely related natural chemical compounds that have been isolated from a variety of plant sources. The guaienes are sesquiterpenes with the molecular formula C15H24. α-Guaiene is the most common and was first isolated from guaiac wood oil from Bulnesia sarmientoi...

, guaioxide and β-patchoulene. It is considered non-irritating, non-sensitizing, and non phototoxic

Phototoxic

Phototoxicity is a chemically induced skin irritation requiring light . The skin response resembles an exaggerated sunburn. The involved chemical may enter into the skin by topical administration or it may reach the skin via systemic circulation following ingestion or parenteral administration...

 to human skin.

Oil of guaiac was also a pre-Renaissance

Renaissance

The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

 remedy to syphilis

Syphilis

Syphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...

.