What “food grade” points to, and what it leaves undefined

The rule uses the words and never defines them

21 CFR 182.1 is the general provision for the substances listed in part 182, and paragraph (b) writes the phrase into the meaning of good manufacturing practice: the substance “is of appropriate food grade and is prepared and handled as a food ingredient.” Section 184.1(b) repeats it for affirmed ingredients, requiring that a direct human food ingredient “be of appropriate food grade.” Neither section says what the phrase means, and the definitions in 21 CFR 170.3, which apply across the food subchapter, carry no entry for it.

The same paragraph of § 182.1 shows where the content actually comes from. On request, it says, the Commissioner will offer an opinion “based on specifications and intended use, as to whether or not a particular grade or lot of the substance is of suitable purity for use in food.” Two inputs, a specification and an intended use, and neither of them is a word on a label. That is the practical reading for a purchase: “food grade” on a quote or a drum is a claim that some specification was met with some use in mind. It becomes something a buyer can check only when both are written down.

Where the phrase gets content, it gets an edition

21 CFR 170.30(h)(1) is the provision that attaches a document. A listed or affirmed ingredient is regarded as GRAS only if, among other requirements, “it complies with any applicable food grade specifications of the Food Chemicals Codex, 2d Ed. (1972), or, if specifically indicated in the GRAS affirmation regulation, the Food Chemicals Codex, 3d Ed. (1981).” Several ingredient entries do so indicate, and cite a page: acetic acid at § 184.1005 (page 8), magnesium chloride at § 184.1426 (page 177), potassium bicarbonate at § 184.1613 (page 239) and propylene glycol at § 184.1666 (page 255) each “meets the specifications of the Food Chemicals Codex, 3d Ed. (1981).” The part 182 entries for phosphoric acid (§ 182.1073) and glycerin (§ 182.1320) name the product and good manufacturing practice, and no specification at all. The sodium hydroxide entry and its 1981 edition are discussed in this library’s paper and pulp collection, in the guide on what “membrane grade” states, and are not repeated here.

The federal text read for this guide therefore cites the Codex at three editions: 1972 and 1981 in parts 170 and 184, and a 7th edition of 2010 for one test method and one set of specifications in the boiler water section, § 173.310, which names the United States Pharmacopeial Convention as the place to obtain it. The Codex is a purchased standard. Its publisher’s page returned 403 to an unauthenticated request on September 14, 2026; no edition was read for this guide and no limit from any edition is reproduced here. A specification that says “FCC” without an edition has not chosen between those documents, and a certificate that reports conformance to “FCC” has not said which one it was tested against.

A listing describes a substance, route and all

§ 184.1(a) states what an affirmation’s text is for: the regulations “shall sufficiently describe each ingredient to identify the characteristics of the ingredient that has been affirmed as GRAS and to differentiate it from other possible versions of the ingredient that have not been affirmed as GRAS.” The entries do that with identity and with route. § 184.1426 describes magnesium chloride as the hexahydrate, occurring naturally as the mineral bischofite and prepared by dissolving magnesium oxide, hydroxide or carbonate in aqueous hydrochloric acid and crystallising the hexahydrate out. § 184.1666 records two routes for propylene glycol, one through the chlorohydrin formed from propylene and one by heating glycerol with sodium hydroxide. § 184.1005 records that acetic acid is produced by fermentation of carbohydrates or by organic synthesis, and names three synthetic routes.

Where an entry records a route, the route is part of the description the affirmation rests on, and whether a given supply sits inside that description is a question to put to the producer in writing rather than to infer from a label. Note also that part 182 and part 184 can describe neighbouring things differently. § 182.1(a) names vinegar, by way of illustration, among common food ingredients, while § 184.1005 affirms acetic acid, CAS 64-19-7, against a Codex specification. A dilute acetic acid solution and a vinegar are therefore not interchangeable descriptions on a purchase document, and the concentration of either is a number with a basis—a problem worked through in this library’s oil and gas collection under “Twenty degrees Baumé is a hydrometer reading.”

One federal sentence, two registry records

The magnesium chloride entry shows why identifiers have to be checked against each other and not merely copied. § 184.1426(a) gives the formula of the hexahydrate and, in the same sentence, the registry number CAS Reg. No. 7786-30-3. PubChem assigns 7786-30-3 to anhydrous magnesium chloride, CID 5360315, and records the hexahydrate, CID 24644, under its own number, 7791-18-6.

So the formula and the registry number in one federal sentence resolve to two different substance records. A specification that copies the CAS number from the rule and a certificate that quotes the hexahydrate’s number will not match, and the mismatch will not be either party’s typing error. Write the name, the hydrate, the formula and the CAS number together on the purchase document, and check that all four describe the same substance before anyone compares a result against them.

Limonene: one line of the list, three substances

§ 182.60 lists synthetic flavoring substances and adjuvants, and one of its entries reads “Limonene (d-, l-, and dl-).” One line covers two enantiomers and their racemic mixture, and they do not share a registry number. The PubChem record for (+)-limonene, which is d-limonene, carries CAS 5989-27-5; the occupational-health summary aggregated on that record notes that the racemic mixture of d- and l-limonene “is called limonene or dipentene (138-86-3).” The general limonene record, which does not specify stereochemistry, lists both 138-86-3 and 5989-27-5 among its numbers. A name that sounds specific can resolve to a record that is not.

What separates the forms is measurable, so it can be specified. The Hazardous Substances Data Bank entry on the (+)-limonene record gives a specific optical rotation of +123.8° at 19.5 °C, measured with the sodium D line; a racemic mixture has no net rotation. The same source states that “the purity of commercial d-limonene is about 90-98%,” with no basis or method given, which is a band wide enough that the specification needs an assay with its method rather than a name. The record also notes that the substance “readily oxidizes when in contact with air,” which puts the container, the headspace and the fill date on the receiving record. This section describes identity and specification attributes only. The § 182.60 entry is a condition on a flavoring use by a food manufacturer; it is not a statement about any drum.

Conditions of use belong to the food manufacturer

§ 170.30(i) and § 184.1(b)(1) say the same thing from two directions. An ingredient affirmed with no limitation other than good manufacturing practice is GRAS where its conditions of use are not significantly different from those the affirmation was based on. Where they are significantly different, “such use of the substance may not be GRAS,” and a manufacturer “may not rely on the regulation as authorizing the use.” Where an affirmation carries specific limitations—category of food, functional use, level of use—§ 170.30(j) allows use only within them, and several of the entries above express those limits as maximum levels as served, food category by food category. Every one of those conditions is written for the person putting the ingredient into a food.

Two further provisions cut the link between a listing and a drum. § 184.1(a) states that “the purity specifications in this part do not apply when the ingredient is used in indirect applications,” where the ingredient must instead be of a purity suitable for its intended use under § 170.30(h)(1). And § 170.30(l) records that “New information may at any time require reconsideration of the GRAS status of a food ingredient.” A listing is a regulatory position about a use, at a date. A buyer can record which section a use relies on and who decided that the use falls inside it; no supplier can deliver that decision with the material.

Say the grade you have, and ask for the document

Alliance publishes the grade a product carries in its structured product data, and that record—not the marketing copy, and not the handle—is what a purchase document should quote. Where a grade is not stated for a product, the correct action is to ask rather than to infer one. What designations such as USP, NF and ACS do and do not certify is treated in this library’s laboratory and pharmaceutical research collection under “What a grade designation certifies, and what it does not,” and this guide does not repeat it. A nominal grade or concentration does not establish interchangeability between products or between suppliers, and being merchandised under a food and beverage collection is merchandising: an industry listing is not an application approval.

Alliance sends a Certificate of Analysis when a customer asks, at no charge. Name in the purchase order which document is meant and what it must report—analytes, methods, units and reporting limits—because a sample certificate describes what a product has generally looked like while a lot certificate reports results for the material being shipped. A sample COA is not a lot certificate. Nothing here states that a particular Alliance product is suitable, approved or recommended for use in food or for any other application, or that any use of it falls within a listing. This is source-based editorial guidance, no original testing was performed for it, and independent specialist review is pending.

• Which section of 21 CFR does the intended use rely on, and who determined that the use falls within its conditions?
• Which specification and which edition does the purchase invoke, and is it the edition the listing incorporates?
• Do the name, hydrate or enantiomer, formula and CAS number on the specification all describe the same substance?
• Is each quoted value typical, a guaranteed specification limit, or a measured result for the lot?

Requirement → evidence → decision boundary

An editorial checklist for your review—not a table of product specifications.

Revision record

1.0 · September 14, 2026 — Source-based editorial edition. No original testing or product qualification is claimed.

For food and beverage manufacturers, their preventive controls qualified individuals and purchasing teams specifying ingredients, processing aids and utility chemistry. This collection does not determine the regulatory status of any use, perform a hazard analysis, approve or verify a supplier, set a use level, dose or feed rate, write a cleaning procedure, or establish that any material is fit for use in food or on food-contact equipment.