Every commercial batch of low-acid canned food and every jar of acidified pickles, salsa, or sauce sold in the United States traces back to a document most consumers never see: a scheduled process, established by a qualified process authority under 21 CFR Parts 113 and 114. That document — not the recipe, not the equipment manual, not the HACCP plan — is what the FDA holds a processor to at inspection, and what stands between a product line and a Clostridium botulinum recall. Understanding what a process authority does, what a scheduled process contains, and how the two connect to FDA filing obligations is not optional literacy for thermal and acidified food processors. Teams building or scaling a thermal or acidified line can Book a Demo to see how iFactory keeps scheduled process critical factors, monitoring records, and deviation logs auditor-ready in one system.
PROCESS AUTHORITY · THERMAL VALIDATION · ACIDIFIED FOODS · FDA 21 CFR 108 / 113 / 114
Process Authority Explained: Thermal & Acidified Food Validation, Scheduled Processes, and FDA Filing Without the Guesswork
A plain-language walkthrough of what process authorities actually do, how scheduled processes get established, which FDA form your product needs, and what happens when a batch deviates — written for food safety and operations teams who need to get this right the first time.
pH 4.6
Maximum finished equilibrium pH for acidified foods under 21 CFR Part 114
10 days
Window to register a food canning establishment on Form FDA 2541 after starting operations
60 days
Window after registration to file a scheduled process before packing a new product
21 CFR
Parts 108, 113, 114 — the three regulations that govern this entire space
Who Is a Process Authority — and Why the FDA Requires One
A process authority is defined under 21 CFR 113.83 and 21 CFR 114.83 as a person or organization with expert knowledge of thermal processing requirements for low-acid foods packaged in hermetically sealed containers, or expert knowledge in the acidification and processing of acidified foods, acquired through appropriate training and experience. In practice, that means someone with the microbiological, engineering, and regulatory background to determine — for a specific product, a specific container, and a specific piece of equipment — the exact combination of conditions that produces a commercially sterile or safely acidified product. The FDA does not license process authorities. It relies on their qualifications, their documentation, and their willingness to sign their name to a scheduled process letter that the processor then files and follows.
The requirement for a process authority exists because low-acid canned foods and acidified foods share a hazard that ordinary GMP controls cannot manage: Clostridium botulinum, a spore-forming anaerobic bacterium common in soil that produces one of the most lethal toxins known when it grows in improperly processed sealed food containers. Two catastrophic historical outbreaks in the 1970s led to the current regulatory architecture — mandatory registration, scheduled process filing, and Better Process Control School training for supervisors — because voluntary compliance with sterilization science had proven insufficient across a large, diverse industry.
Low-Acid Canned vs Acidified: Two Regulatory Paths, One Common Hazard
The regulations split food into two families based on pH and how safety is achieved. Understanding which path your product falls under is the first decision a process authority helps a processor make, because it determines which CFR part applies, which FDA form gets filed, and what critical factors must be controlled during production.
21 CFR PART 113
Low-Acid Canned Foods (LACF)
Thermally processed low-acid foods packaged in hermetically sealed containers
Definition
Finished equilibrium pH above 4.6 and water activity above 0.85 — canned vegetables, meats, poultry, seafood, soups, dairy products, and similar shelf-stable sealed products.
Safety mechanism
Thermal destruction of Clostridium botulinum spores to achieve commercial sterility — a sterilizing value (F₀) sufficient to reduce spore populations by a defined logarithmic factor.
Process filing form
Form FDA 2541d for retorted methods, 2541f for water activity control, or 2541g for aseptic low-acid systems.
Governed by
21 CFR 108.35 for registration and filing, and 21 CFR Part 113 for GMPs and process controls.
21 CFR PART 114
Acidified Foods
Low-acid foods to which acid or acid foods are added to reduce pH to 4.6 or below
Definition
Finished equilibrium pH of 4.6 or lower and water activity above 0.85 — pickles, salsas, dressings, sauces, marinated vegetables, and similar acid-preserved foods.
Safety mechanism
Acidification to a pH that prevents germination of C. botulinum spores, combined with a mild thermal process to destroy vegetative cells of spoilage and pathogenic organisms capable of growing at lower pH values.
Process filing form
Form FDA 2541e — the dedicated acidified method process filing form covering acidification specifics, natural and finished pH values, and process modes.
Governed by
21 CFR 108.25 for registration and filing, and 21 CFR Part 114 for GMPs and process controls.
A third category sits alongside these two — acid foods, whose natural pH is already 4.6 or lower without added acid. Acid foods are not regulated under Part 114 unless something in their formulation shifts them into acidified territory, which is a determination the process authority makes on a product-specific basis. Products that seem acid on their face — tomato products at the borderline pH, fruit preparations with low-acid inclusions — often turn out to require Part 114 treatment once the equilibrium pH after processing is measured accurately.
Critical Factors: What the Scheduled Process Actually Controls
The scheduled process is not a single number. It is a set of critical factors — measurable, controllable parameters — that together define what a safe production run looks like. The specific factors depend on the product, but the underlying set that process authorities work with is small and consistent. Every one of them must be listed on the FDA filing form, monitored during production, and recorded in operating logs available to FDA inspectors on request.
pH
Equilibrium pH
The pH throughout the finished product after equilibration between solid and liquid phases. For acidified foods, must be 4.6 or lower; measurement method and timing are specified in the scheduled process.
°F
Process Temperature
Minimum retort or thermal process temperature, minimum initial product temperature going into thermal processing, and hold temperature for hot-fill-and-hold operations.
min
Process Time
Minimum time at process temperature required to achieve the sterilizing value or vegetative-cell destruction the scheduled process is designed to deliver.
aw
Water Activity
The measure of free moisture available to microorganisms — controls whether the product is subject to Part 113/114 or the Water Activity/Formulation Control filing (Form 2541f).
c
Container & Closure
Container type, dimensions, headspace, seal integrity specifications, and closure treatment — all of which affect heat penetration and product safety.
F₀
Sterilizing Value / Formulation Factors
The equivalent time at reference temperature (F₀) for LACF, or acid strength, preservative levels, salt concentration, and product consistency for acidified foods.
The scheduled process document from the process authority lists each critical factor along with the minimum or maximum value that must be maintained. Deviations from any listed value require action — sometimes reprocessing, sometimes segregation and hold, sometimes destruction — because the scheduled process is only valid within the boundaries it was designed to. Running slightly hotter or slightly longer than the schedule is generally acceptable; running below temperature, below acid strength, or above pH is not, and cannot be waved through by operator judgment.
SCHEDULED PROCESS · CRITICAL FACTOR MONITORING · DEVIATION LOGS
Track Every Critical Factor the Way the CFR Actually Requires
iFactory captures retort temperature, hold time, pH readings, calibration records, and deviation events in a live system — so critical factor logs, container closure checks, and corrective actions are ready when the FDA inspector asks.
Which FDA Form Does Your Product Need?
The FDA maintains a family of process filing forms in the 2541 series, and choosing the wrong one is a common first-time filer error. Every commercial processor of acidified or low-acid canned foods first registers the establishment on Form FDA 2541 within ten days of starting operations, and then files a scheduled process on the applicable form within sixty days of registration and before packing any new product.
Filings are submitted electronically through the FDA Unified Registration and Listing System (FURLS). The completed scheduled process filing form captures every critical factor from the process authority letter, along with product identifiers, container specifications, and process source references. Filing does not constitute FDA approval — the agency reviews filings during factory inspections and public health investigations, but the responsibility for process adequacy rests with the processor and the process authority who established it.
Establishing a Scheduled Process: What Actually Happens
Processors do not write scheduled processes for themselves. They engage a qualified process authority, provide product samples and formulation details, and receive back a written scheduled process letter that becomes the basis for FDA filing and daily production control. The work behind that letter is where the science lives.
1
Submit Product
Processor sends samples, full formulation, target container, and equipment specifications to the process authority.
2
Test & Analyze
pH mapping, buffer capacity, heat penetration studies, temperature distribution studies, and where required, inoculated pack studies.
3
Determine Process
Process authority calculates the minimum thermal process or acidification parameters needed to ensure safety with margin.
4
Issue Letter
Written scheduled process letter listing critical factors, acceptable ranges, monitoring requirements, and process source date.
5
File & Operate
Processor files Form 2541e or 2541d/f/g with FDA, then operates under the scheduled process with monitoring and records.
The scheduled process letter is a durable document. It stays valid as long as the product formulation, container, and equipment remain unchanged. Any material change — a new supplier for a critical ingredient that could shift pH or buffer capacity, a container size change, a different retort model, a modified fill temperature — triggers a re-evaluation by the process authority and, if the change alters critical factors, a new scheduled process and a new FDA filing.
When a Batch Deviates: The Three-Path Response
Deviations from scheduled processes happen — a retort that missed temperature for part of the cycle, a batch whose finished pH tested above 4.6, a fill temperature that dropped below the minimum on a hot-fill line. 21 CFR 108, 113, and 114 all treat deviation not as failure but as a defined situation with three permitted responses. Every acidified food deviation, and every LACF deviation, must fall into one of the three paths below and be documented in the deviation log.
Path A
Fully Reprocess
Apply a process, established by a competent processing authority as adequate to ensure safety, to the affected product. The reprocess may be the original scheduled process, another established process, or a specifically designed corrective process depending on the deviation.
Path B
Set Aside for Evaluation
Segregate the affected product and hold it under conditions that prevent further hazard while a process authority evaluates whether the product is safe as manufactured. Written evaluation and disposition instructions from the process authority are required.
Path C
Destroy the Affected Product
If the product cannot be safely reprocessed or evaluated to a safe disposition, it must be destroyed and documented as such. This is the correct answer for many severe deviations and is not a failure of the system — the system is working exactly as intended.
The three paths share a common documentation requirement: a deviation log entry describing what happened, when, which batch was affected, which path was chosen, who authorized it, and what corrective actions followed. FDA inspectors reviewing a facility after a public health event will trace back through deviation logs to establish whether deviations were handled correctly, and gaps or inconsistencies in that record are among the most frequent regulatory findings on acidified and LACF inspections.
Recordkeeping That Auditors and Investigators Actually Check
Registration and filing get processors into the system. Recordkeeping keeps them in good standing. The record set required under Parts 113 and 114 is more granular than most first-time processors realize, and the FDA reviews these records during routine inspections and during recall investigations to determine whether scheduled processes were followed batch by batch. Records that cannot be produced on request are treated the same as records that never existed.
01
Process Authority Letter and Scheduled Process
The letter from the process authority establishing the scheduled process, along with the process source data — heat penetration studies, temperature distribution studies, pH studies. Must be retained by the process authority permanently and by the processor for the operating life of the product.
02
Critical Control Point Monitoring Logs
Logs recording each critical factor at the frequency specified in the scheduled process — retort temperatures, hold times, pH readings, batch numbers, initial temperatures, cook times. Reviewed and signed by the qualified supervisor.
03
Instrument Calibration Records
Calibration logs for pH meters, thermometers, retort recording devices, and any other measuring equipment used to verify critical factors. Calibration frequency is defined by the scheduled process and equipment specifications.
04
Container Closure Inspection Logs
Records of container closure examinations at defined intervals — visual inspections, teardown examinations for cans, seal integrity checks for glass and flexible packaging. Frequency is specified in Parts 113 and 114.
05
Deviation Log and Corrective Action Records
A log of every deviation from the scheduled process, the path chosen (reprocess, evaluate, destroy), the process authority consultation if required, and the corrective action taken to prevent recurrence.
06
Distribution Records and Recall Plan
Records of distribution to the first point of sale for every lot code produced, along with a written recall plan defining how affected product would be located and recovered in a public health emergency.
Better Process Control School: The Supervisor Training Requirement
Beyond registering the facility and filing scheduled processes, 21 CFR Parts 108, 113, and 114 require that operations be under the supervision of a qualified individual who has attended and completed a Better Process Control School course, or an equivalent course accepted by the FDA. This is a training requirement rather than a licensing one, and it applies to supervisors overseeing thermal processing, acidification, container closure, and product formulation for acidified and LACF products.
Better Process Control School courses are offered by university food science programs across the country — Penn State, University of Georgia, University of California Davis, and others — typically as one-week intensive programs covering microbiology of thermal processing, retort operation, container closure examination, acidified food principles, and regulatory requirements. Certificates from these courses are the documentation processors use to satisfy the qualified-supervisor requirement at FDA inspection. A processor operating acidified and LACF lines without a certified supervisor on staff is out of compliance regardless of how well the scheduled process is being followed, which is why supervisor certification tends to be the first item verified at a facility inspection alongside the registration and filing status.
Frequently Asked Questions: Process Authorities and Scheduled Processes
Do I need a process authority if my product is only sold at farmers markets or online?
If your product falls under the definition of an acidified food or a low-acid canned food packaged in a hermetically sealed container and is introduced into interstate commerce, the answer is yes — 21 CFR 108, 113, and 114 apply regardless of sales channel, and interstate commerce is interpreted broadly. Some states also apply parallel requirements to intrastate commerce, and cottage food laws generally do not exempt acidified or LACF products because of the C. botulinum hazard involved. Small-scale producers still need a scheduled process, an FDA filing, and a certified supervisor. Teams uncertain whether their product is regulated can
Book a Demo to discuss the classification.
How long does it take to get a scheduled process established?
The realistic range is four to twelve weeks depending on product complexity, laboratory workload at the process authority, and whether specialized studies like inoculated packs or heat penetration mapping are required. Simple acidified products with well-understood pH behavior and standard container formats can move through the process authority in three to four weeks; low-acid canned products requiring full heat penetration studies and thermal death time analysis typically take eight weeks or more. Building this time into product launch planning is essential — the scheduled process must exist before FDA filing, and filing must precede first commercial production.
What happens if I change my recipe or container after filing?
Any change that could affect critical factors — new ingredient supplier for a critical acidulant, container size change, retort model change, altered fill temperature, modified formulation — must be evaluated by the process authority to determine whether the existing scheduled process still applies. If the change alters critical factors or process conditions, a new scheduled process letter is required and a new FDA filing must be submitted before packing the modified product. Documenting change control and process authority consultation is one of the record items FDA inspectors look for during routine inspections. Contact
iFactory Support to discuss how to track scheduled process versions against production runs.
Where do I find a qualified process authority?
The Association of Food and Drug Officials maintains a directory of process authorities across the United States, and state food safety programs often maintain local lists. University food science departments — Penn State, University of Georgia, University of California Davis, Cornell, North Carolina State, and others — operate process authority laboratories that serve regional processors. Selecting a process authority who is experienced with your specific product category, container format, and equipment type is more important than proximity, because the scheduled process quality depends on the authority's familiarity with the science behind that product family.
Does FSMA Preventive Controls for Human Food replace the process authority requirement?
No. FSMA's Preventive Controls for Human Food rule under 21 CFR Part 117 applies alongside 21 CFR Parts 113 and 114 rather than replacing them. Facilities that manufacture acidified foods remain subject to 21 CFR 108.25 and Part 114 with modified requirements under 21 CFR 117.201; facilities manufacturing LACF remain subject to Part 113 with a partial exemption from certain PCHF requirements under 21 CFR 117.5(d). The process authority, scheduled process, FDA filing, and Better Process Control School obligations continue to apply to these products regardless of FSMA compliance status.
PROCESS AUTHORITY · SCHEDULED PROCESS · CRITICAL FACTOR MONITORING · DEVIATION MANAGEMENT
Turn Scheduled Process Documents Into a Live, Auditor-Ready Production System
iFactory ties process authority letters to real-time critical factor monitoring, container closure logs, calibration records, deviation actions, and distribution traceability — so what the CFR requires and what your line actually does are always the same picture.
