FDA Food Contact Testing: 21 CFR 170–189 Compliance Guide for Plastic, Silicone, and Metal

For an exporter shipping food contact articles into the United States, "FDA food contact testing" sounds like a single deliverable — a test report that says the article is "FDA-approved." The reality is more structured. The United States Code of Federal Regulations Title 21 (21 CFR), parts 170 through 189, sets out a layered framework that evaluates substances, articles, and the conditions under which they may contact food. The framework is not a single test — it is a series of decisions about which part applies, which substances are covered, what the test conditions should be, and what documentation will accompany the article. This article walks through the parts that matter for plastic, silicone, and metal FCMs, the three FDA approval paths, and the most common reasons shipments get stopped at U.S. customs.

Why 21 CFR 170–189 Is the Most Misread Section of the FDA Code for FCM Exporters

21 CFR 170–189 is the section most often quoted by exporters as "FDA food contact regulations," but it is rarely read in structure. The sections are organised as follows:

• 21 CFR 170 — administrative and general provisions for food additives, including the definition of "food additive" and the framework for indirect additives.
• 21 CFR 171–180 — direct food additives and specific food additive listings.
• 21 CFR 174 — indirect food additives: general.
• 21 CFR 175 — indirect food additives: adhesives and components of coatings.
• 21 CFR 176 — indirect food additives: paper and paperboard components.
• 21 CFR 177 — indirect food additives: polymers (the largest section, with sub-parts by polymer family).
• 21 CFR 178 — indirect food additives: adjuvants, production aids, and sanitizers.
• 21 CFR 179 — irradiation-produced food additives (a smaller and operationally narrow set).
• 21 CFR 180–189 — tolerance exemptions, food additives permitted in food on an interim basis, and a set of specific substances.

For food contact articles made from plastic, silicone, or metal, the operationally important parts are 174, 175, 176, and 177. The FDA's own overview of the framework — including how the parts are sequenced and which indirect additive categories they cover — is published on FDA's Food Ingredients and Packaging Terms page, which serves as the public entry point for the regulation.

Three common misreads are worth flagging up front:

1. "FDA-approved" vs. "FDA-cleared." A 21 CFR listing is not an FDA approval of the supplier — it is a regulation that permits the substance to be used under specific conditions. The supplier or importer is responsible for demonstrating that the article complies.
2. "FDA food-grade." There is no "FDA food-grade" certification mark. The framework requires a substance-by-substance and condition-by-condition demonstration of compliance. A supplier statement that a resin is "FDA food-grade" is a marketing claim, not a regulatory determination.
3. 21 CFR 170–189 vs. NSF/ANSI 51. The CFR framework covers the substance and the conditions of use; NSF/ANSI 51 covers commercial foodservice equipment in its finished form. An article that complies with 21 CFR may still need NSF/ANSI 51 certification to be accepted by a U.S. commercial buyer.

Plastic (21 CFR 174–177): PP, PE, and Other Polyolefins — What Triggers a Food Contact Notification

Plastic food contact articles are the most common category exported from China and other Asia-based suppliers into the U.S. market. The framework structure for plastics is 21 CFR Part 177 (Indirect Food Additives: Polymers), which contains sub-parts by polymer family. The most-used sub-parts are:

For most plastic FCM articles, compliance is established by demonstrating that each component of the formulation is covered by a 21 CFR listing (e.g., 21 CFR 177.1520 for the base resin), and that the extractables tests under the conditions specified in the regulation are within the limits. The FDA testing programme for PP, PE, and OP plastic materials covers the workhorse extractables test under 21 CFR 177.1520, including the food simulants and temperature conditions that apply.

When does a Food Contact Notification (FCN) become required? An FCN is required when the article contains a substance that is not covered by an existing 21 CFR listing — typically a new additive, a new resin grade from a non-listed manufacturer, or a recycled-content plastic that does not fall under a general clearance. The notification is filed with the FDA and, once effective, is added to the Inventory of Effective Food Contact Substance Notifications. The Inventory is the public database where downstream buyers verify that a substance has been reviewed.

Silicone (21 CFR 177.2600): Rubber Articles Intended for Repeated Use — Extractables Testing

Silicone and other rubber food contact articles that are intended for repeated use (gaskets, baking mats, seals, tubing) are governed by 21 CFR 177.2600 (Rubber articles intended for repeated use). The regulation defines two extractables tests depending on the food type:

Silicone articles that pass both the aqueous and fatty extractables tests can be used across the full spectrum of food types. Articles tested only against one food simulant are limited to that food category. The repeat-use aspect of the regulation is operationally important — a silicone baking mat that is reused 100 times has a fundamentally different extractables profile than a single-use film. The 177.2600 framework is designed to evaluate the steady-state release profile after repeated use, not just the first contact.

For exporters shipping silicone bakeware or food-contact silicone gaskets into the U.S., the testing programme is more involved than for a single-use plastic film. The article must be conditioned, extracted under reflux for at least the first 7 hours, and the extractives quantified. The laboratory must be experienced with the reflux apparatus and the analytical finish (typically gravimetric for total extractives).

Metal (21 CFR 175.300 + NSF/ANSI 51): Coatings, Stainless Steel, and Aluminum

Metal food contact articles sit in a different part of the 21 CFR framework. There is no positive list of stainless steel grades or aluminum alloys; instead, the FDA evaluates the finished article in contact with food. Two parts of 21 CFR are operationally important:

• 21 CFR 175.300 (Resinous and polymeric coatings). This covers the coating on a metal substrate — for example, the enamel coating on a cast iron pan, the non-stick coating on an aluminum frypan, or the food-grade lacquer on a metal can. The coating must be cleared separately from the substrate.
• 21 CFR 177 (sub-parts for food-contact polymers). Plastic coatings, plastic linings, and plastic gaskets on metal articles fall under Part 177.

For the bare metal substrate, the FDA's position is generally that austenitic 300-series stainless steel (304, 316, and equivalents) and aluminum in common cookware and foodservice formats are recognised as safe when used in contact with food under conditions appropriate to the food type. Decorative coatings, anti-fingerprint coatings, anodizing layers, and other surface treatments are evaluated case by case — the substrate alone does not make the article compliant.

For commercial foodservice equipment — the equipment that goes into a commercial kitchen, not a domestic one — the operational standard is NSF/ANSI 51. The standard establishes minimum public health and sanitation requirements for materials and finishes used in the manufacture of commercial foodservice equipment (broilers, beverage dispensers, cutting boards, stock pots, and their components — tubing, sealants, gaskets, valves). NSF publishes the standard; NSF's Food Equipment Standards portfolio is the public reference for which standards apply to which equipment category. Many U.S. retailers and foodservice operators will not accept an article without NSF/ANSI 51 certification for the relevant category.

The metal FCM pathway is therefore a layered structure: 21 CFR covers the substance and the coating; NSF/ANSI 51 covers the commercial equipment in its finished form. An exporter shipping a metal frypan with a non-stick coating into the U.S. commercial market needs both the 21 CFR clearance for the coating and the NSF/ANSI 51 certification for the finished article.

The 3 Test Conditions That Decide Whether Your Product Is Compliant

For plastic FCM articles tested under 21 CFR 177.1520, three test conditions drive the outcome of the Migration Test. Each one must be selected to match the intended end-use of the article.

1. Time of contact. Single-use articles (films, disposable cups) are tested for the actual contact time. Repeated-use articles (containers, re-usable kitchenware) are tested for the worst-case contact time plus the cumulative release profile. Prolonged-contact articles (storage containers) follow a different test schedule.
2. Temperature of contact. Room temperature, hot fill (typically 70–100 °C), boiling (100 °C), and cooking temperatures (above 100 °C) trigger different test protocols. An article intended only for refrigerated storage has a less demanding temperature profile than one intended for microwave reheating.
3. Food type. Aqueous, acidic, alcoholic, and fatty foods trigger different food simulants. For polyolefins under 21 CFR 177.1520, the FDA's reference food simulants are distilled water (aqueous), 10% ethanol (acidic), 50% ethanol (higher-alcohol), and a vegetable oil or 95% ethanol substitute (fatty). Selecting the wrong simulant is one of the most common reasons a test fails to demonstrate compliance for the actual end-use.

The migration test is meaningful only when all three conditions match the end-use. A test report based on aqueous food simulant at room temperature does not establish compliance for a fatty food at cooking temperatures — and customs or a retailer that reviews the documentation will reject the report on those grounds.

Conditional vs. No-Objection Letter vs. FCN: 3 FDA Approval Paths Explained

For a substance that may be used in food contact but is not the subject of a specific 21 CFR listing, the exporter has three FDA approval paths to choose from. The choice depends on the substance, the dietary exposure, and the prior history of the substance.

For most plastic FCM articles exported from China and other Asia-based suppliers, the first path (21 CFR listing) is the workhorse. The exporter confirms that the resin grade, additive package, and any recycled content are covered by an existing listing — typically 21 CFR 177.1520 for polyolefins — and the testing programme verifies that the extractables are within the limits specified. The second and third paths are engaged when a new substance, a new supplier, or a recycled-content plastic is involved.

For recycled-content plastics, the FDA operates a separate recycled plastics guidance framework that combines process criteria (input material, recycling process, surrogate contaminant challenge) with migration testing. The framework is more demanding than the virgin-plastic pathway, and exporters shipping PCR-content food contact articles into the U.S. should plan for a longer review.

Common FDA Rejection Reasons: 5 Mistakes That Stop Shipments at U.S. Customs

From the review queue at RTS, five mistakes account for the majority of FDA-related shipment rejections we see at U.S. customs or with U.S. retailers. They are listed in order of frequency:

1. Missing or invalid prior notice. All food contact articles imported into the U.S. require prior notice. The prior notice must include the manufacturer, the shipper, the country of origin, and the intended use. A missing or inaccurate prior notice stops the shipment at the port.
2. Absence of documentation linking the article to an effective FCN or 21 CFR clearance. Customs may ask the importer to demonstrate that the substance is covered by an effective FCN or a 21 CFR listing. If the documentation is missing, the shipment is held until the importer supplies it.
3. Labelling that fails to identify the manufacturer or country of origin. U.S. Customs and FDA labelling requirements apply even to food contact articles that are not sold at retail. The label must identify the manufacturer and the country of origin. Multi-language labels without English are a frequent defect.
4. Detection of a substance at a level exceeding the listed extraction limit or SML. The laboratory testing was not aligned with the end-use conditions (the wrong food simulant, the wrong temperature, the wrong time), or the article contains a substance that is not on the listing at all. A non-conforming test result blocks both customs entry and major retailer acceptance.
5. The article being a duplicate of a previously refused article without corrected documentation. If a previous shipment of the same article was refused and the importer is attempting to bring in a duplicate without corrected documentation, the new shipment is treated as the same article and refused on the same grounds.

The first two are the most frequent in our experience. The corrective action for both is documentation discipline — every shipment should travel with (a) a prior notice reference, (b) a current Declaration of Conformity or Compliance, (c) the underlying test report, and (d) the FCN reference or 21 CFR listing citation.

RTS FDA Food Contact Test Plan: From Specification Review to Certificate of Compliance

For an exporter walking through the FDA pathway for the first time, our team uses a four-stage test plan that compresses the typical 8–12 week programme. The sequence is:

1. Stage 1 — Specification and formulation review. The article specification, the resin grade, the additive package, and the intended end-use (food type, temperature, contact time) are reviewed against the relevant 21 CFR part. Any gap between the formulation and the listing is flagged before testing begins.
2. Stage 2 — Extractables / migration testing. The article is extracted under the food simulants and conditions specified in 21 CFR 177.1520 (for olefin polymers) or 21 CFR 177.2600 (for silicone and rubber articles). Extractives are quantified gravimetrically and the result is compared to the regulatory limit.
3. Stage 3 — Substance coverage check. Each intentionally added substance is verified against the relevant 21 CFR listing or the FCN inventory. For new substances, the FCN pathway is initiated; for recycled content, the FDA recycled plastics guidance is applied.
4. Stage 4 — Certificate of Compliance and supporting documentation. A Certificate of Compliance is issued for the article, citing the 21 CFR listing(s) and the test results. The supporting documentation — formulation declarations, test report, prior notice template — is consolidated into a file that the importer can present at customs or to a retailer.

For articles with NSF/ANSI 51 relevance (commercial foodservice equipment), Stage 4 extends to the NSF certification pathway, which is a separate process. The 21 CFR test plan closes the substance compliance loop; the NSF certification closes the equipment acceptance loop.

For an intake conversation on the FDA food contact testing programme, exporters can contact the RTS testing team with the article specification, the intended end-use, and the destination U.S. state (some state-level PFAS restrictions apply). The FDA plastic materials testing program covers the workhorse extractables test under 21 CFR 177.1520; the broader food contact materials testing program covers silicone, metal, ceramic, and paper-based FCMs.

Lara Hong

Lara Hong is a Business Development Manager at Zhejiang RTS Test Co., Ltd., a pioneer in third-party inspection, testing, and certification consulting services for global trade and e-commerce. Specialized in helping manufacturers and exporters navigate compliance requirements, product testing standards, and market access regulations. Dedicated to delivering trust for quality life — bridging the gap between producers and global buyers through accurate, fair, and standardized testing services.