Under 21 CFR 113.3, a retort is any closed vessel or other equipment used for the thermal processing of foods. Retort processing heats a low-acid food in a hermetically sealed container to the scheduled process for that product. Retort pouch is the commercial name for a flexible pouch in that equipment. Ask which rule covers the container.

What retort processing is

21 CFR Part 113 is titled "Thermally Processed Low-Acid Foods Packaged in Hermetically Sealed Containers."

Section 113.3 defines a retort as "any closed vessel or other equipment used for the thermal processing of foods." A hermetically sealed container is "a container that is designed and intended to be secure against the entry of microorganisms and thereby to maintain the commercial sterility of its contents after processing."

Low-acid foods, in that section, are "any foods, other than alcoholic beverages, with a finished equilibrium pH greater than 4.6 and a water activity (aw) greater than 0.85." Tomatoes and tomato products having a finished equilibrium pH less than 4.7 are not classed as low-acid foods. A beverage is in this part only when it meets that definition. The plant has to say which definition this SKU meets.

A minimum thermal process is "the application of heat to food, either before or after sealing in a hermetically sealed container, for a period of time and at a temperature scientifically determined to be adequate to ensure destruction of microorganisms of public health significance." The scheduled process is "the process selected by the processor as adequate under the conditions of manufacture for a given product to achieve commercial sterility." It "shall be at least equivalent to the process established by a competent processing authority to achieve commercial sterility."

Commercial sterility of thermally processed food, in § 113.3, is the condition achieved by heat that renders the food free of microorganisms capable of reproducing in the food under normal nonrefrigerated conditions of storage and distribution, and free of viable microorganisms (including spores) of public health significance. The same definition also covers commercial sterility achieved by the control of water activity and the application of heat. Part 113 does not state a number of months of shelf life. The scheduled process is for that food and that container.

Section 113.5 states that the criteria in §§ 113.10, 113.40, 113.60, 113.81, 113.83, 113.87, 113.89, and 113.100 apply in determining whether the facilities, methods, practices, and controls used in the manufacture, processing, or packing of low-acid foods in hermetically sealed containers are adequate to protect the public health. Section 113.83 states that scheduled processes for low-acid foods shall be established by qualified persons having expert knowledge of thermal processing requirements for low-acid foods in hermetically sealed containers and having adequate facilities for making such determinations. Critical factors that may affect the scheduled process shall be specified in it.

Section 113.40(j) states that all systems, whether or not specifically mentioned in Part 113, for the thermal processing of low-acid foods in hermetically sealed containers shall conform to the applicable requirements of the part, and that the methods and controls shall be as established in the scheduled process.

Retort pouch, can, and aseptic

The phrase retort pouch does not appear in § 113.3. Pouch retort and retort packages are commercial names for the same idea: a hermetically sealed container that is thermally processed. Part 113's term is the hermetically sealed container, and the filing is for each container size.

Can. Section 113.3 describes gross headspace using "the top of the double seam of a can or the top edge of a glass jar." Section 113.60(a) requires a qualified person to visually examine either the top seam of a can randomly selected from each seaming head, or the closure of any other type of container being used, and to record the observations. Teardown examinations for double-seam cans are in § 113.60(a)(1). Section 108.35(c)(2) requires the scheduled-process information for each low-acid food in each container size.

Retort pouch. FDA's guidance on Form FDA 2541 and the process-filing forms states: "Although some hermetically sealed containers (e.g., pouches and glass bottles) used to package thermally processed low-acid foods generally would not be viewed as 'cans,' the term 'low-acid canned foods' has been used for decades as a shorthand description for 'thermally processed low-acid foods packaged in hermetically sealed containers,' and we continue to use that term (and its abbreviation, LACF) for the purposes of this document."

Where the equipment is a still retort for pressure processing in water, § 113.40(b)(7) states: "Dividers, racks, trays, or other means of positioning of flexible containers shall be designed and employed to ensure even circulation of heating medium around all containers in the retort." That sentence is for that water still-retort equipment. It does not name every system a pouch can run on. The scheduled process names the system. Section 113.60(a)(3) states that for closures other than double seams and glass containers, appropriate detailed inspections and tests shall be conducted by qualified personnel at intervals of sufficient frequency to ensure proper closing machine performance and consistently reliable hermetic seal production, and that records of such tests shall be maintained.

Meat and poultry pouches. 9 CFR 431.1 defines a canned product as "a meat or poultry food product with a water activity above 0.85 which receives a thermal process either before or after being packed in a hermetically sealed container." In that part, a flexible container is "a container, the shape or contour of which, when filled and sealed, is significantly affected by the enclosed product," and a retort is "a pressure vessel designed for thermal processing of product packed in hermetically sealed containers." That retort definition is the USDA definition. It is not the sentence in § 113.3. Section 431.2(a) requires the establishment to evaluate empty containers, closures, and flexible pouch roll stock so they are free of structural defects and damage that may affect product or container integrity. The same section names preformed flexible pouches.

Aseptic. Section 113.3 defines aseptic processing and packaging as "the filling of a commercially sterilized cooled product into presterilized containers, followed by aseptic hermetical sealing, with a presterilized closure, in an atmosphere free of microorganisms." The minimum-thermal-process definition covers heat before sealing and heat after sealing. The aseptic definition is the path on which the product and the container are brought to a commercially sterile condition and then filled and sealed. Retort equipment, as § 113.3 defines it, is the closed vessel or other equipment used for the thermal processing. Section 108.35(c)(2) names Form FDA 2541d for the low-acid retorted method, Form FDA 2541f for the water activity/formulation control method, and Form FDA 2541g for low-acid aseptic systems.

Regulatory basics

Section 108.35(c)(1) states that a commercial processor, when first engaging in the manufacture, processing, or packing of thermally processed low-acid foods in hermetically sealed containers in any State, as defined in section 201(a)(1) of the Federal Food, Drug, and Cosmetic Act, shall, not later than 10 days after first so engaging, register with FDA on Form FDA 2541. The information includes the processor's name, principal place of business, the location of each establishment, the processing method in terms of the type of processing equipment employed, and a list of the low-acid foods so processed in each establishment.

Section 108.35(c)(2) states that a commercial processor shall, not later than 60 days after registration and prior to the packing of a new product, provide FDA information as to the scheduled processes for each such low-acid food in each container size. The information includes, among other items, the processing method, the type of retort or other thermal processing equipment, minimum initial temperatures, times and temperatures of processing, sterilizing value (Fo) or other equivalent scientific evidence of process adequacy, critical factors affecting heat penetration, and the source and date of the establishment of the process. The section states: "the filing of such information does not constitute approval of the information by the Food and Drug Administration."

FDA's LACF registration page points processors to Form FDA 2541 for establishment registration and to Forms FDA 2541d, 2541f, or 2541g for an LACF process filing. The registration guidance states that after you register an establishment, FDA assigns a Food Canning Establishment (FCE) number identifying the physical processing plant at the address on Form FDA 2541. Submit a separate Form FDA 2541 for each physical processing plant.

Acidified foods use a different filing. Section 108.25(c)(2) states that a commercial processor of acidified foods shall, not later than 60 days after registration and before packing any new product, provide FDA information on the scheduled processes, and that this information shall be submitted on Form FDA 2541e. Filing does not constitute approval. This note does not decide whether a SKU is a low-acid food or an acidified food.

Section 113.10 states that operators of retorts, other processing systems, aseptic processing and packaging systems, product formulating systems, and container closure inspectors shall be under the operating supervision of a person who has attended a school approved by the Commissioner for instruction appropriate to the preservation technology involved and who has been identified by that school as having satisfactorily completed the prescribed course. That person shall supervise only in those areas for which the school identifies the training.

Section 113.87(b) requires a system for product traffic control in the retort room to prevent unretorted product from bypassing the retort process. A retort basket, truck, car, or crate that contains retorted product shall be plainly and conspicuously marked with a heat-sensitive indicator, or by other effective means, and a visual check shall be performed to determine whether the appropriate change occurred.

Section 113.89 states that whenever any process is less than the scheduled process, or critical factors are out of control, the commercial processor shall either fully reprocess that portion of the production, keeping full records, or set that portion aside for further evaluation as to any potential public health significance. That evaluation shall be made by a competent processing authority. Section 113.100(b) states that not later than 1 working day after the actual process, and before shipment or release for distribution, a representative of plant management who is qualified by suitable training or experience shall review all processing and production records for completeness and to ensure that the product received the scheduled process.

Section 113.60(c) states that each hermetically sealed container of low-acid processed food shall be marked with an identifying code that shall be permanently visible to the naked eye. The code shall identify the establishment where packed, the product, the year packed, the day packed, and the period during which packed.

For a canned meat or poultry product, 9 CFR 431.3(a) states that prior to processing for distribution in commerce, an establishment must have a process schedule for each canned meat or poultry product to be packed. Section 431.3(b)(1) states that process schedules must be developed or determined by a processing authority. Section 431.1 says shelf stability and commercial sterility are synonymous in that part. It does not state a number of months on the shelf.

Part 113, section 113.5, is the current good manufacturing practice section for this thermal process. Food and dietary-supplement cGMP, including 21 CFR Part 117 and Part 111, is a different question, covered in what cGMP is. Ask which parts apply to the SKU. This note is not a product-specific determination.

Questions to ask a co-packer

NXTCPG's published work is co-manufacturer selection, ingredient sourcing, and quality and scale readiness, in Source & produce. It does not state a retort line. The questions below are what to ask the plant that would run the product. The commercial terms — who manufactures, who packs, who owns the formula, and what a pilot must show — are in how to choose a co-packer. A minimum order is a separate question, covered in MOQ meaning.

  • Does this SKU meet the low-acid food definition in § 113.3, or is it an acidified food filed on Form FDA 2541e? If it is a meat or poultry product, does 9 CFR Part 431 apply?
  • Which container is it: a double-seam can, glass, or a flexible container? Which form was filed: FDA 2541d, 2541f, or 2541g?
  • Who established the scheduled process under § 113.83, or the process schedule under 9 CFR 431.3, and which container sizes and critical factors does it name?
  • Is the establishment registered on Form FDA 2541, and is the scheduled process filed? Section 108.35(c)(2) says that filing is not FDA approval.
  • When the retort is a water still retort, how are flexible containers positioned so the heating medium circulates, as § 113.40(b)(7) requires? What closure inspections are recorded under § 113.60(a)(3)?
  • Who has the Commissioner-approved training in § 113.10, and which operations does that person supervise?
  • What mark shows that a basket has been retorted, under § 113.87(b)? What is the code on the container, under § 113.60(c)?
  • If the process is less than the scheduled process, who evaluates the lot under § 113.89, and who reviews the record before shipment under § 113.100(b)?
  • For a flexible pouch under USDA inspection, how does the establishment evaluate empty containers, closures, and flexible pouch roll stock under 9 CFR 431.2?

Get the answers for this SKU from this plant. Do not copy a time, a temperature, or a container size from another product.

Where this sits with NXTCPG

Choosing the plant sits in Source & produce. If the open question is which co-packer can run a low-acid food in a hermetically sealed container, or a canned meat or poultry product, and which rule applies, start a project. For equipment, minimums, who buys the ingredients, and who owns the formula, use how to choose a co-packer.

FAQ

What is a retort?

Under 21 CFR 113.3, retort means any closed vessel or other equipment used for the thermal processing of foods. That definition is for FDA's rules on thermally processed low-acid foods in hermetically sealed containers. For a canned meat or poultry product, 9 CFR 431.1 uses a different definition: a retort is a pressure vessel designed for thermal processing of product packed in hermetically sealed containers. Ask which rule covers the product.

What is a retort pouch?

21 CFR 113.3 does not define "retort pouch." FDA's LACF registration guidance states that some hermetically sealed containers, for example pouches and glass bottles, used to package thermally processed low-acid foods generally would not be viewed as cans, and that "low-acid canned foods" is FDA's shorthand for that category. In a still retort that pressure-processes in water, 21 CFR 113.40(b)(7) requires dividers, racks, trays, or other means of positioning flexible containers so the heating medium circulates around all containers. For a meat or poultry product, 9 CFR 431.1 defines a flexible container as one whose shape or contour, when filled and sealed, is significantly affected by the enclosed product, and 9 CFR 431.2 addresses flexible pouch roll stock.

How does retort processing differ from aseptic packaging?

21 CFR 113.3 defines aseptic processing and packaging as the filling of a commercially sterilized cooled product into presterilized containers, followed by aseptic hermetical sealing, with a presterilized closure, in an atmosphere free of microorganisms. The same section defines a minimum thermal process as heat applied either before or after sealing. A retorted low-acid food is filed on Form FDA 2541d. A low-acid aseptic system is filed on Form FDA 2541g. 21 CFR 108.35(c)(2) states that filing that information does not constitute approval by FDA.

Does an FCE number or a process filing mean FDA approved the retort?

No. 21 CFR 108.35(c)(2) states that the filing of scheduled-process information does not constitute approval of the information by the Food and Drug Administration. FDA's registration guidance states that after an establishment registers on Form FDA 2541, FDA assigns a Food Canning Establishment number identifying the physical processing plant at the address on that form. The number identifies the plant. The regulation's approval sentence is about the process filing.

What should a brand ask a co-packer about a retorted product?

Ask whether the SKU is a low-acid food under 21 CFR 113.3, an acidified food filed on Form FDA 2541e, or a canned meat or poultry product under 9 CFR 431. Ask who established the scheduled process, which container size it covers, and which form was filed. Ask how flexible containers are positioned when 21 CFR 113.40(b) applies, who supervises under 21 CFR 113.10, and what happens when a process is less than the scheduled process under 21 CFR 113.89. This answer is not a product-specific determination.