Acidified and Low-Acid Canned Food Processing

The purpose of this page is provide additional information to prospective processors or distributors of acidified and/or low-acid canned foods. These foods are subject to an additional set of regulatory requirements beyond the good manufacturing practices (21 CFR 110) that must be adhered to by all food manufacturers. Due to several incidents involving Clostridium botulinum intoxications as a result of poorly-processed foods in these categories, FDA implemented a set of rules that require firms to register as processors and to file their processes (21 CFR 108) with FDA. 21 CFR 108 also requires such manufacturers to ensure that employees who oversee these processes have adequate training, generally in the form of an FDA- or university-sponsored better process school. Additionally, the agency has outlined special sets of GMPs for acidified (21 CFR 113) and low-acid canned (21 CFR 114) foods.

Naturally acid foods are defined as those foods that have a naturally-occurring pH of less than or equal to 4.6. Most pathogenic microorganisms will not grow or reproduce in an environment with this level of acidity. Low-acid foods are those with a pH in excess of 4.6. Acidified foods are low-acid foods to which acids are added in order to lower pH to 4.6 or less. Examples of acidified foods include pickled vegetables and eggs. Low-acid canned foods are defined as foods that undergo a thermal process prior to being placed in a hermetically-sealed (airtight) container. Examples of low-acid canned foods include canned beans or peas.

You may be required to consult a process authority to determine whether the process for making your product(s) and your firm may need to be registered with the federal Food and Drug Administration. Process authorities are highly-qualified individuals who through industry or regulatory experience, advanced academic training, or a combination thereof, are sufficiently knowledgeable about microbial hazards and safe food processing that they can evaluate foods and the processes used to manufacture them in order to determine whether they are compliant with regulatory requirements. FDU sanitarians as a rule lack this training and experience, so you will need to obtain this information from a third-party, private or academic entity. Written verification of the appropriate category and any additional requirements for your product from the process authority will be required before you can complete the product registration process.

Additionally, if the process authority determines that you are producing an acidified or thermally-processed low-acid canned food that falls under the 113 or 114 regulations, you will be required to submit documentation that the firm has registered as an acidified or low-acid food products firm with FDA and that your process or processes have been filed with FDA. You can obtain more information about process-filing and registration from your process authority or from FDA.

Evaluation of Products - Guidelines and Expectations

The department has certain expectations when it comes to reporting by process authorities on behalf of prospective food manufacturers in the state of Louisiana. These include the following items:

Product Classification

This refers to a specific classification of the food product in question as an acid food, acidified food, or low-acid food.

Acid Foods are those foods having a natural pH of 4.6 or below.

Low-acid Foods are those foods having a finished equilibrium pH of greater than 4.6 and a water-activity (Aw) of greater than 0.85.

Acidified Foods are low-acid foods to which acids or acid foods are added to reduce the finished equilibrium pH to less than 4.6 and having a water-activity of 0.85 or above.

Any classification that does not adhere to one of the three categories above must be accompanied by a detailed explanation.

Please note that simply providing a statement with an equilibrium pH and water-activity for a finished food will not satisfy the reporting requirements documented herein.

Legal Authority

In conjunction with the above, the PA should provide information as to whether the product should be regulated under 21 CFR 108.25, 21 CFR 108.35, 21 CFR 110/117 or some combination thereof. If the product falls under FDA's acidified or low-acid canned food regulations, the PA should verify and acknowledge that the firm has been provided with the information needed to register as an acidfied or low-acid canned foods processor and file one or more processes with that agency.

A link to the registration and process filing forms for the Food and Drug Administration is provided here.

Product Characteristics

The PA should provide the following information regarding the product(s) in question:

  • Product identity and packing medium
  • Finished equilibrium pH and water activity (Aw)

Documentation of Equipment and Materials

This is a list of the specific equipment used along with an inventory of ingredients used in manufacturing. The ingredient list should specify whether the item is fresh or prepackaged. 

Documentation of Process

This is a list of the steps taken to process the product(s). This should include all aspects of preparation, including any terminal heat treatments, as applicable. The documentation needs to be very specific and should include cook/retort times and temperatures as well as particular equipment used in each step of the process. Determination of equilibrium pH for pH-controlled foods should be outlined explicitly, including time intervals, frequency of testing, and equipment used for testing. The report should include any process recommendations that the process authority may deem appropriate (e.g., addition of a chemical preservative such as sodium benzoate, use of a "hot-fill" at a specific time and temperature, et cetera). The submitting firm must note whether any changes are being made to the process as a result of such recommendations.

Personnel Training

If the food is required to be regulated under 21 CFR 108.25 or 108.35, the report should include information on the approved training attended or scheduled by the responsible party for the product(s). Approved training courses include Better Process Control Schools (BPCS) as well as FDA-sponsored training courses in acidified and low-acid canned foods processing (FD 202 or 304); alternative training courses will have to be evaluated for acceptance based on provider background, length, and content.

A list of known approved training courses currently on offer is located here.






    • Plans Review Packet - a packet can be downloaded here under "Plans Packet for LACF or Acidified Food Manufacturers"