Q.01

What does FDA compliant mean for food packaging?

"FDA compliant" packaging has no definition of its own in the law. In practice it means that every substance in the packaging that could migrate into the food is used under one of the legal bases FDA recognises, and only within that basis's conditions of use. Under the FD&C Act, a packaging substance that may "directly or indirectly" become a component of food is a "food additive" unless it is generally recognised as safe (GRAS) or prior-sanctioned [1]. A food additive used without a regulation or an effective notification is deemed unsafe [2].

Approach: I read the FD&C Act (21 U.S.C. 321 and 348, 2023 U.S. Code edition) and the current eCFR text of 21 CFR Parts 170-189. I also checked FDA's inventories of food contact substances listed in 21 CFR and of effective food contact notifications (FCNs).

When does packaging come under FDA rules?

  • A material used to make containers and packages falls under the food additive definition if it may reasonably be expected to become a component of the packed food, or to affect its characteristics [3].
  • Physical effects such as protecting the contents, keeping the shape and preventing moisture loss do not count. If nothing migrates from the package into the food, the component "is not a food additive" (21 CFR 170.3(e)(1)) [3].

The five accepted legal bases (21 CFR 174.5(d)) Substances that "may be safely used as components of articles that contact food", under good manufacturing practice and any prescribed limits, are [4]:

  1. GRAS in or on food.
  2. GRAS for its intended use in food packaging.
  3. Prior sanction or approval. This means explicit FDA or USDA approval of a specific use before September 6, 1958. It exempts that use from the food additive provisions, but not from the adulteration or misbranding provisions (21 CFR 181.5) [5].
  4. A listing regulation in 21 CFR Parts 174-178 or § 179.45. These are the "indirect additive" regulations for adhesives, coatings, paper and polymers. For example, FDA's inventory lists PET (CAS 25038-59-9) under several sections, including 177.1630 [6].
  5. An effective food contact notification (FCN) under FD&C Act section 409(h) (21 U.S.C. 348(h)). Key points:
    • The manufacturer or supplier notifies FDA at least 120 days before marketing, setting out its own determination that the use is safe.
    • The notification becomes effective after 120 days unless FDA objects [2].
    • An FCN covers only the substance made by the manufacturer or supplier it names. A different manufacturer selling the same substance for the same use must file its own FCN (21 CFR 170.100(a)) [7].
    • FCNs carry use limits. For example, FCN 2136 excludes contact with infant formula and human milk [8].

Threshold of regulation exemption (21 CFR 170.39 and 174.6) FDA can exempt a substance from regulation as a food additive by letter, so no petition is needed [9]. All of these conditions must be met [10]:

  • The substance is not a carcinogen, and any carcinogenic impurity has a TD50 of no less than 6.25 mg/kg bw/day.
  • The dietary concentration is at or below 0.5 ppb (at or below 1.5 µg/person/day), or, for a regulated direct additive, at or below 1% of the ADI.
  • It has no technical effect in the food.
  • It has no significant environmental impact.

These exemptions are not published in the CFR. FDA keeps them on a list instead [10].

What a compliance claim also has to cover

  • Conditions of use. A listing or FCN covers specific uses only: food types, temperatures, limits. Use outside those conditions is not covered.
  • Good manufacturing practice (21 CFR 174.5(a)) [4]:
    • The amount that migrates "shall not exceed" what is reasonably required for the intended effect in the article, or any prescribed limit.
    • It must not be intended to have a technical effect in the food itself.
    • Components "shall be of a purity suitable for its intended use."
  • Other FD&C Act provisions still apply (21 CFR 174.5(b)). For example, a regulated packaging material that gives a food an off-odour or off-taste can still render it adulterated under section 402(a)(3) [4].
  • Food contact authorisation does not cover use in food (21 CFR 174.5(c)). It does not imply the substance may be used as a direct food additive [4].
  • When a full petition is needed instead of an FCN (21 CFR 170.100(c)). FDA requires a food additive petition, unless it agrees to accept an FCN, if [7]:
    • cumulative dietary exposure reaches 1 ppm or more (3 mg/person/day), or 200 ppb or more (0.6 mg/person/day) for a biocide; or
    • there is an unreviewed carcinogenicity bioassay that is not clearly negative.

In practice, a supplier's "FDA compliant" statement should name, for each component, the 21 CFR section, FCN number, GRAS or prior-sanction basis, or threshold of regulation exemption it relies on. It should also state the food types and conditions of use that basis covers. If you share a formulation or a supplier's compliance letter, I can check each component against the 21 CFR listings and the FCN inventory.

Q.02

How do I check a supplier's food contact claim?

To check a supplier's food contact claim, break it down to each component. For every substance, confirm the specific legal basis the supplier relies on. Then check that basis against FDA's own inventories or 21 CFR, and confirm your food, temperature and use fall within its stated conditions. A letter that just says "complies with FDA regulations" can't be checked until the supplier names the 21 CFR section, FCN number, GRAS or prior-sanction basis, or threshold of regulation exemption for each component.

Approach: I used the current eCFR text of 21 CFR Parts 170-189, FDA's Inventory of Food Contact Substances Listed in 21 CFR (05/04/2026 edition) and FDA's Inventory of Effective Food Contact Substance Notifications (08/31/2026 edition). FDA's threshold of regulation exemption list is not in the datasets I can search.

Step 1: Get a claim you can check Ask for each component's chemical name and CAS number, the basis it relies on, and the conditions the supplier says it covers: food types, temperature, single or repeated use, and use level. Without CAS numbers and section citations, the inventories can't be matched reliably.

Step 2: Check the basis the supplier cites

Claimed basisWhat to check
21 CFR listingLook up the substance in FDA's 21 CFR inventory and confirm the cited section is listed against it. PET (CAS 25038-59-9), for example, is listed under 175.105, 175.300, 175.320, 177.1390, 177.1630, 177.1850, 177.2260, 177.2420, 177.2800, 178.1005 and 179.45 [6]. A section that covers a different article type (adhesive, coating, paper, polymer) doesn't support your use. Then read the section itself, because the limits are in its text (Step 3).
FCNLook up the FCN number in FDA's inventory and check three things. (1) The manufacturer or supplier named on it must be the company actually making your material: an FCN "is effective for the food contact substance manufactured or prepared by the manufacturer or supplier identified in the FCN" (21 CFR 170.100(a)) [7]. (2) The intended use must match yours. (3) Read its limitations. FCN 2136, for example, lists DuPont Teijin Films as notifier and manufacturer. It covers coatings on authorised PET films under Conditions of Use A to H and J, and "is not for use in contact with infant formula and human milk" [8].
FCN still in forceFDA may determine that an FCN is no longer effective, for example on new safety information or because the notifier has stopped supplying the substance. The FCN then stops being effective on the date FDA's notice is published in the Federal Register (21 CFR 170.105(a)-(b)) [11]. An old compliance letter citing an FCN therefore needs checking against the current inventory.
Threshold of regulation exemptionThese exemptions are not published in the CFR. FDA keeps a list giving the requesting company, chemical name, specific use and any limitations; the list "will not include any trade names" (21 CFR 170.39(e)) [10]. Ask for the exemption letter and compare its stated use with yours.
GRAS or prior sanctionAsk what the supplier's GRAS basis is (GRAS in food, or GRAS for use in packaging) or for the prior-sanction document. A prior sanction covers only the specific use approved before September 6, 1958 (21 CFR 181.5) [5].

Step 3: Check the conditions of use, not just the listing Being listed in a section isn't enough. Many entries carry their own limits. In 21 CFR 176.170 (paper and paperboard in contact with aqueous and fatty foods), for example [12]:

  • 1-alkenyl olefins may be used in coatings only with food Types I, II, IV-B and VII-B under conditions of use E, F and G, or with Type VIII food under conditions A to H.
  • 1,2-benzisothiazolin-3-one is limited to use as a preservative in paper coatings, at no more than 0.01 mg/in² of finished paper.

Match the supplier's stated food types and conditions-of-use letters against your actual product and process.

Step 4: Ask for test data where the regulation needs it Some sections set extractive limits. Under 176.170(a), paper is exempt from the paragraph (c) extractive limits only if its food-contact surface consists entirely of the substances listed in paragraph (a). If extraction results exceed the limits, manufacturing records "shall be available" showing that only those substances are present [12]. Ask for the extraction or migration results, or those records.

Step 5: Check the general requirements of 21 CFR 174.5

  • Migration "shall not exceed" what is reasonably required for the intended effect, and components "shall be of a purity suitable for its intended use".
  • A packaging material that gives the food an off-odour or off-taste can still render the food adulterated.
  • A food contact authorisation does not make a substance acceptable as a direct food additive.

[4]

Warning signs in a supplier letter

  • No section number or FCN number for a component.
  • An FCN in another company's name.
  • Uses broader than the listing allows, such as hot-fill or infant formula when the basis excludes them.
  • A claim that the resin is "FDA approved" when the additives in it are not covered.

If you send me the supplier's letter or a list of components with CAS numbers, I can check each one against FDA's 21 CFR and FCN inventories.

Q.03