Most disputes between a buyer and an aroma ingredient supplier trace back to the same root cause: the enquiry named a product but did not identify a molecule. Trade names drift, common names overlap, and the same botanical term can describe materials with quite different compositions. CAS and FEMA numbers exist to remove that ambiguity, and using them properly costs nothing.

What a CAS number does

A CAS Registry Number is a unique identifier assigned to a specific chemical substance. It says nothing about quality, purity or grade, but it settles precisely which substance is under discussion. This matters more than it sounds. Peppermint oil, for instance, resolves to two different CAS numbers depending on the botanical source — 8006-90-4 for Mentha piperita and 68917-18-0 for Mentha arvensis — and those are genuinely different oils at different price points.

What a FEMA number does

A FEMA number is assigned by the Flavor and Extract Manufacturers Association in the United States and indicates that the substance has been evaluated for use as a flavour ingredient. Where a CAS number answers which molecule, a FEMA number speaks to cleared for flavour use. A material can have a CAS number and no FEMA number, which is a signal worth noticing if the intended application is food or beverage.

Where names alone go wrong

Eucalyptus oil means very little without a cineol percentage — crude and 70 percent IP/BP are different commercial products.
Menthol without an optical specification does not distinguish L-menthol from other isomers.
Anethole can be synthetic or derived from basil, with the same CAS but a different origin story that may matter for a natural claim.
Cooling agent covers several quite distinct molecules with different onset and duration.

Writing an enquiry that gets a useful answer

State the product name, the CAS number, the grade or specification if one applies, the intended application, and the annual volume. Ask for a technical data sheet, a certificate of analysis and a safety data sheet before commercial terms rather than after. A supplier who cannot produce those quickly for a material they claim to manufacture is usually trading rather than producing.

Why this matters more in a regulated supply chain

If your finished product is sold into food, oral care or pharmaceutical channels, your input documentation becomes part of your own audit trail. Specifying loosely and reconciling later is how a batch ends up quarantined. Every product in the Gem Aromatics portfolio is published with its CAS number, and FEMA reference where one applies, precisely so an enquiry can start from an unambiguous identifier.