21 CFR 172.510: The Botanicals, and Their Conditions

21 CFR 172.510 is the section of the US food additive regulations that permits natural flavoring substances and natural adjuvants. Unlike its neighbor 172.515, it does not list chemicals. It lists 130 botanicals by common and scientific name, and it attaches a condition to 31 of them.

Those conditions decide what a material can go into, so they repay a close reading. Sixteen entries may be used in alcoholic beverages and nowhere else. Wormwood, white cedar, tansy, yarrow and oak moss have to leave the finished food or beverage thujone free. Cherry pits and cherry-laurel leaves cap prussic acid at 25 parts per million. Cinchona bark is beverages only, under 83 parts per million of total cinchona alkaloids. Sassafras and camphor tree have to be safrole free.

What the section permits, and in what form

The opening condition matches 172.515. The material is used in the minimum quantity required to produce its intended physical or technical effect, and otherwise in accordance with all the principles of good manufacturing practice. There is no numeric ceiling, so a formulator has to be able to defend a level as the amount the flavor needs.

Paragraph (b) then names the forms these botanicals may take: plant parts, fluid and solid extracts, concentrates, absolutes, oils, gums, balsams, resins, oleoresins, waxes and distillates. It also states how they may be combined, which is alone or with flavoring substances and adjuvants that are generally recognized as safe, previously sanctioned, or regulated elsewhere in Part 172.

Reading the table without misreading it

Two conventions trip people up, and both are in the source rather than in any summary of it.

"Do." is a ditto mark. It repeats the limitation from the row above, and it is not an abbreviation for anything. Five entries carry their condition this way, which means a reader who skips the row above learns nothing. Arnica flowers, for example, shows only "Do.", and the row above it confines Angola weed to alcoholic beverages.

One Limitations cell holds a botanical name. Quebracho bark shows "Schinopsis lorentzii (Griseb.) Engl." in the limitations column, which is a synonym for the species named in column two rather than a condition of use. Quebracho bark carries no restriction.

The conditions, grouped

Condition	Entries
In alcoholic beverages only	16
Finished food or beverage thujone free	5
Prussic acid not above 25 ppm	4
In beverages only, under 83 ppm cinchona alkaloids	2
Safrole free	2
Other, including hypericin-free St John's wort and Tagetes as oil only	2

The thujone group deserves its own note. Being thujone free is not defined by a number in the regulation. Footnote 1 points instead to an analytical method, section 9.129 of the AOAC Official Methods of Analysis, 13th edition, incorporated by reference. The requirement is what that method reports, not a threshold printed in the CFR.

The entry that catches people out

The wormwood row does not name a species. Its scientific name column reads "Artemisia spp", which is the whole genus, and the thujone condition attaches to all of it.

That reaches further than absinthe. Tarragon is Artemisia dracunculus. Davana is Artemisia pallens. Estragon oil is the same plant as tarragon. Every one of them sits under the same entry as wormwood, and every one of them inherits the requirement that the finished food be thujone free. A formulator who reads the row as "wormwood" and moves on has missed three common materials.

This is also where a FEMA number stops being enough. FEMA 3043 is tarragon and FEMA 3116 is wormwood oil, and the FEMA GRAS conclusion for either says nothing about thujone, because thujone is an FDA condition rather than a FEMA one. The two have to be read together.

172.510 and 172.515 answer different questions

They sit next to each other and cover opposite kinds of material. Section 172.515 lists more than 700 synthetic flavoring substances by chemical name. Section 172.510 lists 130 botanical sources by species. A synthetic vanillin question is answered by one, a wormwood question by the other, and a formula containing both needs both.

Neither is the only route. A botanical can also reach food as generally recognized as safe under 21 CFR 182.10 for spices and other natural seasonings, or 21 CFR 182.20 for essential oils and oleoresins. Those sections carry no per-entry conditions, so which section a material sits under changes the answer.

Checking a botanical

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Search the corpus by name, CAS number, or Flavor and Extract Manufacturers Association (FEMA) number. Every result shows FEMA GRAS status, flavor category, and whether the ingredient is natural. No account needed.

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Ambrose publishes a reference page for every current FEMA GRAS substance, and the pages for materials under a 172.510 condition now state that condition alongside the permission. See wormwood oil, tarragon, cinchona bark red, cherry pits extract and sassafras leaves. The companion piece on 21 CFR 172.515 covers the synthetic list, and what FEMA GRAS means covers where the FEMA conclusion comes from and what it does not settle.

21 CFR 172.510: Natural Flavoring Botanicals