Frankincense

Oxidation products of α-pinene, (+)-limonene and δ-3-carene may sensitize skin. Store in dark, sealed, refrigerated container.

A 65-year-old aromatherapist with multiple sensitivities reacted to 5 percent frankincense oil and weakly to 1 percent, an isolated case.

B. serrata may contain α-thujone and β-thujone at low concentrations. Thujone is potentially neurotoxic but levels in frankincense are insignificant.

B. serrata may also contain estragole at low concentrations, a theoretical carcinogen risk, but counteracted by (+)-limonene and other anticarcinogenic constituents.

Likely not hazardous in pregnancy based on data for sabinene, α-pinene, (+)-limonene and octyl acetate.

Frankincense (olibanum) is the oil distilled from the gum resin of Boswellia species in the Burseraceae family. At least 5 species are commercially used with markedly different chemistry:

Boswellia frereana, Somalia/Oman, high α-pinene (41 to 80 percent). Boswellia papyrifera, Eritrea/Ethiopia/Sudan, high octyl acetate (50 to 60 percent). Boswellia sacra (= B. carteri), Saudi Arabia/Oman/Yemen/Somalia, α-pinene or (+)-limonene chemotype. Boswellia serrata, India, high α-thujene. Boswellia neglecta and B. rivae, Ethiopia/Somalia, niche.

For many years the Latin names of frankincense species have been confused. B. carteri and B. sacra are now considered the same species. Most commercial oil comes from Somalia (mainly B. frereana), with the rest from Yemen and India.

Species identification is often unclear on commercial labels. Some oils have been misattributed. Buy from reputable suppliers, request a certificate of analysis.

B. sacra has been proposed by UNEP-WCMC for CITES addition to the threatened plant list. Sustainable sourcing is a major concern for the industry.

Frankincense has been used in religious ritual for at least 3000 years, ancient Egyptian, ancient Jewish (Temple incense), Christian (one of the three Magi gifts). 'Olibanum' comes from Arabic 'al-luban'.