Do I Need an SID for My Product? FDA Filing Rules Made Simple: Understanding FDA SID Requirements for Acidified and Low-Acid Canned Foods

One of the most important requirements for exporting or selling shelf-stable foods in hermetically sealed containers in the United States is obtaining a Submission Identifier (SID). This number is directly tied to the safety of your process and, without it, your products risk being detained at port or rejected during inspection.

This article explains in detail what SID is, which products require it, how it connects to Food Canning Establishment (FCE) registration, and what role the FDA filing forms (Forms 2541) play in the process. By the end, you should have a clear understanding of whether your product requires SID, and what steps you need to take to remain compliant.

What Is SID?

SID, short for Submission Identifier, is a unique code assigned by the FDA to each process filed under the LACF and Acidified Foods regulations. The requirement is rooted in 21 C.F.R. Part 108, Subpart B (2015), which outlines procedures for food canning establishments, and is further elaborated in 21 C.F.R. Part 113 (Low-Acid Canned Foods) and 21 C.F.R. Part 114 (Acidified Foods).

To put it simply:

• Each manufacturer of LACF or Acidified Foods must first register their facility with the FDA under the Food Canning Establishment (FCE) system.
• Once the facility is registered, the manufacturer must file the thermal process (or other control method) for each product packaged in hermetically sealed containers.
• Each filing is assigned a SID number, which becomes the permanent identifier for that process.

When a product is imported into the United States, the SID must be provided as an Affirmation of Compliance Code (AofC) at the border. Without it, shipments may be refused, delayed, or subjected to costly detention.

Why Does FDA Require SID?

Hermetically sealed containers create an oxygen-free environment that, if improperly processed, can allow the growth of Clostridium botulinum, the bacterium responsible for botulism.

Because botulism is potentially fatal even in very small doses, the FDA requires rigorous controls for all shelf-stable foods that are:

• Low-acid (pH greater than 4.6, water activity greater than 0.85), or
• Acidified (low-acid foods that are adjusted to pH 4.6 or below with acid or acidified ingredients), or
• Made shelf-stable through water activity control (aw ≤ 0.85), or
• Manufactured using aseptic systems.

In short, the SID ensures that every process used to manufacture these foods has been scientifically validated and filed with the FDA.

Products That Do and Do Not Require SID

Products that require SID include:

1. Low-Acid Canned Foods (LACF):

Foods with a finished equilibrium pH greater than 4.6 and a water activity (aw) greater than 0.85, packaged in hermetically sealed containers, and intended to be stored at ambient temperature.

Examples:

• vegetables (green beans, corn, peas) in cans or pouches,
• Curries, gravy, sauces packaged in pouches or cans.
• Canned meats, poultry, or seafood (tuna, sardines, chicken).
• Milk products like flavoured milk, panner, cold coffee etc.

2. Acidified Foods:

Low-acid foods to which acid(s) or acid food(s) are added to reduce the pH to 4.6 or below, with a water activity above 0.85, in a sealed container.

Examples:

• Pickled vegetables (mango pickle, lemon pickle, gherkins).
• Salsa, chutneys, and relishes.
• Acidified sauces (barbecue sauce, pasta sauce with added vinegar, ketchup).

3. Aseptic Products:

Foods sterilized before packaging, then placed into pre-sterilized containers under sterile conditions.

Examples:

• Ultra-high temperature (UHT) processed milk in Tetra Pak cartons.
• Shelf-stable fruit purees and juices

4. Water Activity Controlled Products:

Foods that achieve shelf stability by reducing available water to ≤ 0.85, thereby preventing microbial growth.

Examples:

• Dehydrated soups and powdered food mixes.
• Certain confectionery items.
• Milk based deserts

Products that do not require SID include:

• Frozen foods: meals, desserts, seafood products sold under frozen conditions.
• Refrigerated foods: items that must always remain under refrigeration, such as fresh salsa or refrigerated pickles.
• Foods outside hermetically sealed packaging: for example, bakery items wrapped in permeable films.

The defining factor is whether the product is shelf-stable in a hermetically sealed container. If it is, then the FDA requires both FCE registration and SID filing.

The Role of FDA Form 2541 Series

The FDA uses a series of forms under the 2541 series to manage FCE registrations and process filings. Each form corresponds to a different aspect of compliance. Below is a detailed explanation of each, including which products apply and whether thermal validation is required.

Form FDA 2541a – Food Canning Establishment (FCE) Registration

This form registers the manufacturing facility as a Food Canning Establishment. It must be completed before any process filings can be submitted. Every facility producing LACF or Acidified Foods for sale in the United States must have this. (21 C.F.R. § 108.25(c)(1))

Form FDA 2541d – Food Process Filing for Low-Acid Canned Foods (LACF)

This is used to file processes for low-acid foods (pH > 4.6, aw > 0.85) packaged in hermetically sealed containers. The process must be established and validated by a qualified Process Authority. Validation typically includes heat penetration studies, temperature distribution studies, and Fo value calculations (21 C.F.R. § 113.).

• Examples: canned vegetables, soups, seafood, meat products, ready-to-eat curries.

Form FDA 2541e – Food Process Filing for Acidified Foods

This is used to file processes for foods where acidification (with vinegar, citric acid, etc.) reduces the pH to 4.6 or below. Both acidification parameters and thermal process validation are required. FDA expects documented pH measurements and thermal process studies to ensure product safety. If your product contains inherently acidic base ingredients, and the processing does not involve any heat treatment, then a thermal validation study might not be required. In all other cases a detailed thermal validation study is mandatory (21 C.F.R. § 114.).

• Examples: salsa, chutneys, pickled vegetables, fruit preserves with added acid.

Form FDA 2541f – Food Process Filing for Water Activity Controlled Foods

This is for foods made shelf-stable through water activity control (aw ≤ 0.85). Typically validations study is not mandatory, but FDA requires validated water activity data to demonstrate stability. If thermal heat treatment is involved in the sterlization/pasteruization then thermal validation is required (21 C.F.R. § 113.3(n)).

• Examples: dehydrated soups, dried fruit mixes, powdered seasonings.

Form FDA 2541c – Food Process Filing for Aseptic Systems

This is for aseptically processed and packaged foods where the food is sterilized separately, and packaging is sterilized before filling. Both the sterilization process and aseptic packaging system must be validated extensively. This often requires microbial challenge studies and equipment validation data. A detailed validation is mandatory in this case (21 C.F.R. § 113.40(i)).

• Examples: UHT milk, fruit juices, liquid nutritional supplements.

Thermal Process Validation: Who Needs It?

Thermal validation is a critical component of LACF and Acidified Food compliance. It ensures that the process applied to the product achieves commercial sterility, meaning the destruction of all viable microorganisms capable of growing in the food under normal storage conditions.

Thermal validation typically involves:

• Temperature distribution studies to confirm uniform heating inside the retort.
• Heat penetration studies in the product itself to determine heating and cooling rates.
• Fo/Po calculations to measure the lethality of the process.

All validation work must be overseen by a recognized Process Authority, as mandated under FDA regulations.

Practical Consequences of SID in Import and Compliance

Once a process is filed and an SID is assigned, that SID becomes part of the product’s identity in the U.S. regulatory framework. At import, the SID is submitted electronically as an Affirmation of Compliance (AofC) code.

Without a valid SID:

• Shipments may be detained at port.
• Products may be placed on Import Alert, preventing future shipments.
• Manufacturers may face recalls, warning letters, or even enforcement action.

From a business perspective, the absence of an SID is not just a regulatory oversight; it can disrupt supply chains, damage brand reputation, and incur significant financial losses.

Conclusion: Does Your Product Require SID?

If your product is shelf-stable, sealed in a container, and classified as Low-Acid, Acidified, aseptically processed, or water activity controlled, then yes — you need an SID. If your product is frozen or refrigerated and must stay that way, you do not.

Working with a qualified Process Authority ensures that your filings meet FDA expectations and that your product can be imported into the U.S. without unnecessary delays.