Benzoin Siam absolute

Warm vanilla, white chocolate, sweet resin. Smooth powdery and balsamic facets. Without the cinnamic note of Sumatra benzoin.

Benzoin has no dedicated standard in the 51st Amendment of the IFRA Standards. Benzyl benzoate, a constituent of Siam benzoin, is restricted by IFRA (2020) per product category.

Vanillin and benzyl benzoate are on the EU fragrance allergen list; vanillin was added by Regulation 2023/1545. They must be labelled above 0.001 percent in leave-on or 0.01 percent in rinse-off products.

Store dark, sealed and cool. The absolute is very thick and is often sold pre-diluted; the dilution must be known when calculating limits.

Styrax tonkinensis grows in Laos, northern Vietnam and neighbouring areas. The species name refers to Tonkin. The trade name Siam dates from when the resin was shipped through Bangkok. In Vietnam the tree is called bồ đề and the resin cánh kiến trắng or an tức hương.

The resin is obtained by wounding the trunk. The tree responds by secreting resin, which hardens into milky white to yellow-brown lumps. Laos is a major current source of Siam benzoin.

Siam benzoin differs from Sumatra benzoin (Styrax benzoin) in its acids. The Siam type is rich in benzoic acid esters, especially coniferyl benzoate, and has almost no cinnamic acid. The Sumatra type is rich in cinnamic acid and its esters. Siam is therefore sweeter and smoother, while Sumatra shows a cinnamon-like, slightly smoky note.

The resinoid is made by dissolving the resin in ethanol, filtering off insoluble matter and removing the alcohol. The absolute is the alcohol-soluble part after further treatment. The product is very thick and is often sold diluted in benzyl benzoate, dipropylene glycol or ethanol.

In perfumery, Siam benzoin is a base material for amber accords, often with labdanum and vanilla. It warms white florals and gourmand structures. The library already has a general benzoin page; this page records the absolute from Styrax tonkinensis.