The Pressure Is On.

In Part 13 of our StepLadder Series, we discussed the US Food and Drug Administration's (FDA) regulation of adhesives used in food-contact applications. Part 14 explores the use of a subset of adhesives – pressure-sensitive adhesives – and differences in terms of how they are regulated compared to traditional adhesives.

What Is a Pressure-Sensitive Adhesive (PSA)?

Generally speaking, pressure-sensitive adhesives (or PSAs) are adhesives that are used directly in contact with certain foods, often to facilitate a labeling function. In contrast with many traditional adhesive applications, a functional barrier is not required. In the absence of a barrier, however, the list of substances authorized for use in PSAs is significantly more limited, and the Food Types and Conditions of Use are similarly more restrictive. Common examples of PSAs used in food-contact applications include Universal Product Code (UPC) labels and barcodes for loose fruits, vegetables, dry goods, and meats sold individually or in bulk in the grocery store.

21 C.F.R. Section 175.125

FDA's food additive regulation for pressure-sensitive adhesives appears in 21 C.F.R. Section 175.125 (Pressure-Sensitive Adhesives), and contains a list of substances that may be used as components of the food-contact surface of labels or tapes applied directly to food. The finished labels or tapes containing the PSA, in turn, may be manufactured using any number of authorized substrates, including paper, polymers, and other materials (these substances must similarly be evaluated on a case-by-case basis to ensure that they are suitable for the intended use in food-contact applications). The regulation contemplates in all cases that the PSA will be manufactured from "one or a mixture of two or more substances" authorized in paragraphs (a) or (b), depending on application:

  • 21 C.F.R. § 175.125(a): authorizes the use of listed substances as components of PSAs in contact with (or applied to) poultry, dry goods, and processed, frozen, dried, or partially dehydrated fruits or vegetables.
  • 21 C.F.R. § 175.125(b): authorizes the use of listed substances as components of PSAs in contact with raw fruit and raw vegetables.

Many (but not all) of the substances listed in Section 175.125(a) also may be used in applications described by Section 175.125(b), as it is presumed that the propensity of any component of the PSA to migrate will be the same or lower when in contact with raw fruit and raw vegetables, compared to applications such as poultry (where interface with an aqueous or fatty matrix may allow for greater potential migration).

Section 175.125 incorporates, by cross-reference, substances that are Generally Recognized as Safe (GRAS) for direct addition to food; substances authorized for use by way of a prior sanction or approval; certain authorized color additives; and components of chewing gum base that appear in 21 C.F.R. Section 172.615 of the food additive regulations (subject to certain limitations).

Considerations Specific to PSA Assessments

While the list of substances that are explicitly authorized for use in PSA applications is relatively small, it is not uncommon for manufacturers of PSAs to establish that other, unlisted materials, also may be used on the basis of an FCN, or alternatively, an exemption or exception from the need for a food additive regulation (such as the "No Migration" position discussed in one of our earlier StepLadder articles).

When evaluating unlisted substances for use in PSA applications, it is often important to understand and define the specific parameters of the intended use. For example, the following information is relevant to an evaluation of an unlisted component of a PSA under a "No Migration" approach:

  • The volume or amount of the food that will be labeled with the PSA.
  • The size or surface area of the label containing the PSA.
  • The type(s) of food that the PSA will contact.
  • The temperature Conditions of Use that the PSA will experience when used as intended.

By definition, PSAs are almost always considered single-use applications, because they are applied directly to food that will be consumed one time. However, because the PSA label itself typically covers only a small portion of the overall surface area of the food, the use of worst-case (100%) calculations is often a helpful starting point for demonstrating that the upper-bound potential migration of any of the component(s) of the PSA (or its corresponding exposure in the diet when applying an appropriate Consumption Factor (CF)) is quite small. These small values, in turn – when evaluated in light of appropriate toxicology and safety principles – often result in a determination that the components of the PSA are either not reasonably expected to migrate to food under the intended conditions of use (the "No Migration" position), or the resulting dietary exposure is sufficiently small such that it may be considered GRAS. Of course, obligations under FDA's Good Manufacturing Practice (GMP) and Suitable Purity principles continue to apply.

About the Steptoe StepLadder Series

Steptoe LLP is pleased to publish the Stepladder series of articles for our clients, prospective clients, and interested companies as a way of educating attorneys and non-attorneys alike about legal and regulatory principles related to food packaging in meaningful ways. While there are many sources of information available online, the StepLadder series is intended to be accessible to, and understandable by all, to help support business decisions related to food packaging compliance.

This information is provided for educational purposes only, is not legal advice, and does not establish an attorney-client relationship with Steptoe. Our lawyers made us write that. If you have legal questions, please consult an attorney. Preferably from a team well-versed in food packaging regulation – and definitely from a group of attorneys that have a good sense of humor. Because you are what you eat... unless your food packaging isn't a 'food additive,' in which case you're not food packaging.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.