#245 
Hazard Analysis and 
Risk-Based Preventive Controls 
for Food for Animals 
Guidance for Industry 
Submit comments on this guidance at any time.  Submit electronic comments to 
https://www.regulations.gov/.  Submit written comments to the Dockets Management Staff 
(HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 
20852.  All comments should be identified with the docket number FDA-2018-D-03888. 
For further information regarding this document, contact AskCVM@fda.hhs.gov. 
Additional copies of this guidance document may be requested from the Policy and Regulations 
Staff (HFV-6), Center for Veterinary Medicine, Food and Drug Administration, 7500 Standish 
Place, Rockville, MD 20855, and may be viewed on the Internet at https://www.fda.gov/animal-
veterinary, https://www.fda.gov/regulatory-information/search-fda-guidance-documents, or 
https://www.regulations.gov/. 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Veterinary Medicine 
July 2022 Contains Nonbinding Recommendations 
 
Table of Contents 
 
INTRODUCTION ........................................................................................................ 1 
PURPOSE ..................................................................................................................... 3 
CHAPTER 1  THE FOOD SAFETY PLAN ................................................................ 5 
1.1  Purpose of this Chapter .......................................................................................... 5 
1.2  What is a Food Safety Plan? .................................................................................. 5 
1.3  Who Prepares the Food Safety Plan for a Facility? ............................................... 6 
1.4  Who Signs the Food Safety Plan for a Facility? .................................................... 6 
1.5  Is the Food Safety Plan the Same as a HACCP Plan? ........................................... 6 
1.6  What if a Facility Already has a HACCP Plan? .................................................... 7 
1.7  Is there a Required Format for a Food Safety Plan? .............................................. 7 
1.8  What Circumstances Require Review (Reanalysis) of My Food Safety Plan? ..... 7 
1.9  References for Chapter 1 ....................................................................................... 8 
CHAPTER 2  CONDUCTING A HAZARD ANALYSIS ........................................... 9 
2.1  Purpose of this Chapter .......................................................................................... 9 
2.2  Overview of a Hazard Analysis ............................................................................. 9 
2.3  Recommended Activities in Conducting Your Hazard Analysis ........................ 10 
2.3.1  Conduct Preliminary Steps ......................................................................... 10 
2.3.2  Hazard Analysis Worksheet ........................................................................ 11 
2.4  Conducting a Hazard Analysis ............................................................................. 13 
2.4.1  Identify Known or Reasonably Foreseeable Hazards (Hazard  
Identification) ............................................................................................. 13 
2.4.2  Evaluate Known or Reasonably Foreseeable Hazards (Hazard     
Evaluation) ................................................................................................. 14 
Assessing severity of the illness or injury ............................................. 15 
Assessing probability the hazard will occur .......................................... 15 
2.4.3  Assessing the Combination of Severity and Probability............................. 19 
2.4.4  Evaluating Environmental Pathogens When Animal Food is Exposed to the 
Environment ............................................................................................... 19 
2.4.5  Evaluation of Other Factors ........................................................................ 19 
2.5  Use of Your Written Evaluation as Explanation/Justification Whether a Hazard 
Requires a Preventive Control ............................................................................. 21 
2.6  Identifying Preventive Controls ........................................................................... 22 
2.7  Is the Preventive Control Applied at this Step? ................................................... 23 
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2.8  References for Chapter 2 ..................................................................................... 24 
CHAPTER 3  HAZARDS ASSOCIATED WITH THE MANUFACTURING, 
PROCESSING, PACKING, AND HOLDING OF ANIMAL FOOD .................. 26 
3.1  Purpose of this Chapter ........................................................................................ 26 
3.2  Known or Reasonably Foreseeable Hazards ........................................................ 26 
3.3  Biological Hazards ............................................................................................... 28 
3.3.1  Foodborne Pathogens Associated with Animal Food ................................. 30 
Bacterial pathogens ................................................................................ 30 
Non-bacterial pathogens ........................................................................ 32 
3.3.2  Ingredient-Related Biological Hazards ....................................................... 33 
3.3.3  Process-Related Biological Hazards ........................................................... 33 
Bacterial pathogens that survive process controls ................................. 34 
Bacterial pathogens that grow ................................................................ 34 
Bacterial pathogens in ingredients added after applying process   
controls................................................................................................... 36 
Bacterial pathogens introduced after packaging due to lack of container 
integrity .................................................................................................. 36 
3.3.4  Facility-Related Biological Hazards ........................................................... 37 
Sources of facility-related biological hazards ........................................ 37 
Transient and resident facility-related environmental pathogens .......... 39 
Facility-related environmental pathogens associated with wet and dry 
processing environments ........................................................................ 40 
Wet processing environments ................................................................ 40 
Dry processing environments ................................................................ 41 
3.4  Chemical Hazards ................................................................................................ 42 
3.4.1  Ingredient-Related Chemical Hazards ........................................................ 44 
Pesticides................................................................................................ 44 
Heavy metals .......................................................................................... 45 
Natural toxins ......................................................................................... 46 
Animal drugs .......................................................................................... 48 
Unapproved color and food additives .................................................... 50 
Chemical hazards that may be intentionally introduced for purposes of 
economic gain ........................................................................................ 51 
Radiological hazards .............................................................................. 51 
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Environmental chemical contaminants .................................................. 52 
3.4.2  Process-Related Chemical Hazards ............................................................ 52 
Animal drug carryover in animal food ................................................... 52 
Nutrient deficiencies or toxicities as chemical hazards ......................... 53 
3.4.3  Facility-Related Chemical Hazards ............................................................ 54 
3.5  Physical Hazards .................................................................................................. 54 
3.6  References for Chapter 3 ..................................................................................... 56 
CHAPTER 4  PREVENTIVE CONTROLS .............................................................. 65 
4.1  Purpose of this Chapter ........................................................................................ 65 
4.2  Overview of Preventive Controls ......................................................................... 65 
4.3  Preventive Control Considerations ...................................................................... 66 
4.4  Process Controls................................................................................................... 66 
4.4.1  Use of Parameter Values and Operating Limits in Process Controls ......... 67 
4.5  Process Controls for Biological Hazards ............................................................. 68 
4.5.1  Use of Lethality Treatments as Process Controls ....................................... 69 
Heat treatment (thermal processing) ...................................................... 69 
High pressure processing (HPP) ............................................................ 74 
Irradiation ............................................................................................... 75 
4.5.2  Use of Time and Low Temperature as Process Controls ............................ 78 
Refrigeration .......................................................................................... 78 
Freezing ................................................................................................. 80 
4.5.3  Use of Product Formulation as Process Controls ....................................... 80 
Water activity (aw) ................................................................................. 80 
Acidity (pH) ........................................................................................... 83 
Preservatives .......................................................................................... 84 
4.5.4  Use of Dehydration/Drying as Process Controls ........................................ 84 
4.6  Preventive Controls for Chemical Hazards .......................................................... 85 
4.6.1  Preventive Controls for Nutrient Deficiencies and Toxicities .................... 85 
4.6.2  Drying and Storage Conditions as Preventive Controls for Mycotoxins .... 87 
4.6.3  Sequencing and Flushing as Preventive Controls for Drug Carryover ....... 87 
4.7  Preventive Controls for Physical Hazards ........................................................... 88 
4.7.1  Preventive Controls for Metal Hazards ....................................................... 88 
4.7.2  Preventive Controls for Glass Hazards ....................................................... 89 
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4.7.3  Preventive Controls for Hard Plastic Hazards ............................................ 89 
4.7.4  Preventive Controls for Conditions of Animal Food That Can be Hazards 89 
4.8  Sanitation Controls............................................................................................... 90 
4.8.1  Cleaning Strategies and Sanitation Controls ............................................... 91 
4.8.2  Use of Sanitation Controls to Prevent Cross-Contamination ..................... 93 
4.9  Supply-Chain Controls ......................................................................................... 94 
4.10  Recall Plan ......................................................................................................... 94 
4.11  References for Chapter 4 ................................................................................... 95 
CHAPTER 5  OVERVIEW OF PREVENTIVE CONTROL MANAGEMENT 
COMPONENTS ........................................................................................................ 99 
5.1  Purpose of this Chapter ........................................................................................ 99 
5.2  Overview of Preventive Control Management Components ............................... 99 
5.3  Who is Responsible for Conducting Preventive Control Management  
Component Activities? ........................................................................................ 99 
5.4  Recordkeeping Requirements for Preventive Control Management     
Components ....................................................................................................... 100 
5.5  Preventive Control Management Components Examples ................................. 100 
5.6  Monitoring ......................................................................................................... 101 
5.6.1  What Will Be Monitored? ......................................................................... 102 
5.6.2  How Will Monitoring Be Done?............................................................... 102 
5.6.3  How Often Will Monitoring Be Done (Frequency)? ................................ 102 
5.6.4  Who Will Do the Monitoring? .................................................................. 103 
5.6.5  What Records Do I Need to Document Monitoring? ............................... 103 
5.7  Corrective Actions and Corrections ................................................................... 104 
5.7.1  Corrective Actions .................................................................................... 104 
5.7.2  Corrections ................................................................................................ 105 
5.7.3  Corrective Action and Correction Records ............................................... 106 
5.8  Verification Activities ........................................................................................ 108 
5.8.1  Verification ............................................................................................... 108 
5.8.2  Validation .................................................................................................. 109 
5.8.3  Verification of Monitoring ........................................................................ 111 
5.8.4  Verification of Decisions about Corrective Actions ................................. 112 
5.8.5  Verification of Implementation and Effectiveness ................................... 113 
Calibration............................................................................................ 113 
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Product testing ..................................................................................... 114 
Environmental monitoring ................................................................... 115 
Record review ...................................................................................... 117 
5.8.6  Reanalysis ................................................................................................. 119 
5.9  References for Chapter 5 ................................................................................... 122 
APPENDIX A  Glossary of Terms ............................................................................ 123 
APPENDIX B  Table of Abbreviations and Acronyms Used in this Guidance .... 128 
APPENDIX C  Flowchart  Hazard Analysis .......................................................... 131 
APPENDIX D  Example Hazard Analysis Worksheet ............................................ 133 
 
 
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Hazard Analysis and 
Risk-Based Preventive Controls for 
Food for Animals 
 
Guidance for Industry 
 
This guidance represents the current thinking of the Food and Drug Administration (FDA, 
Agency, or we) on this topic.  It does not establish any rights for any person and is not binding 
on FDA or the public.  You can use an alternative approach if it satisfies the requirements of the 
applicable statutes and regulations.  To discuss an alternative approach, contact the FDA staff 
responsible for this guidance as listed on the title page. 
 
INTRODUCTION 
 
In Title 21 of the Code of Federal Regulations (21 CFR) part 507 (part 507), we have established 
our regulation entitled Current Good Manufacturing Practice, Hazard Analysis, and Risk-Based 
Preventive Controls for Food for Animals.  We published the final rule establishing part 507 in 
the Federal Register of September 17, 2015 (80 FR 56170).  Part 507 establishes requirements 
for current good manufacturing practice for animal food (CGMPs), for hazard analysis and risk-
based preventive controls for animal food (PCAF), and related requirements as shown in Table 1.   
 
Table 1.  Subparts Established in 21 CFR Part 507 
SUBPART  TITLE 
A  General Provisions 
B  Current Good Manufacturing Practice 
C  Hazard Analysis and Risk-Based Preventive Controls 
D  Withdrawal of a Qualified Facility Exemption 
E  Supply-Chain Program 
F  Requirements Applying to Records That Must be Established and Maintained 
 
Part 507, subparts A, C, D, E, and F contain the complete animal food preventive controls 
requirements (the PCAF requirements).  This guidance document focuses on subpart C, the 
primary preventive controls requirements, and also discusses relevant recordkeeping 
requirements of subpart F.  See our Guidance for Industry (GFI) #235 entitled Current Good 
Manufacturing Practice Requirements for Food for Animals that addresses the requirements in 
subpart B.1  Although subpart E, the supply-chain program, is a type of preventive control, we 
address this preventive control in our Draft GFI #246 entitled Hazard Analysis and Risk-Based 
Preventive Controls for Food for Animals: Supply-Chain Program.2 
 
The PCAF requirements implement certain provisions of the FDA Food Safety Modernization 
Act (FSMA) established in section 418 of the Federal Food, Drug, and Cosmetic Act (FD&C 
 
1 https://www.fda.gov/media/97464/download  
2 https://www.fda.gov/media/113923/download 
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Act) (21 U.S.C. 350g).  Part 507 includes several complete or partial exemptions from the PCAF 
requirements.  For example, establishments not required to register as a food facility under 
section 415 of the FD&C Act (see 21 CFR 1.226) are exempt from part 507 (see 21 CFR 
507.5(a)).  See 21 CFR 507.5 for the full list of exemptions.   
 
In part 507, you means the owner, operator, or agent in charge of a facility (see 21 CFR 
507.3).  However, for the purposes of this guidance document, where appropriate, you also 
may refer to the preventive controls qualified individual (PCQI) in addition to the owner, 
operator, or agent in charge of a facility. 
 
Establishing risk-based preventive controls designed to protect your animal food and the 
consumer (humans purchasing the animal food and animals consuming the food) from 
biological, chemical (including radiological), and physical hazards, enables you to apply a 
proactive and systematic approach to your food safety program.  Risk-based preventive controls 
will not give you a zero-risk system for manufacturing, processing, packing, and holding animal 
food; rather, risk-based preventive controls are designed to minimize the risk of known or 
reasonably foreseeable animal food hazards that may cause illness or injury to humans or 
animals if they are present in the animal food you produce.   
 
This guidance document covers facilities that manufacture, process, pack, or hold food intended 
for all animal species including food-producing animals (e.g., cattle, swine, poultry, and 
aquaculture species), companion animals (e.g., dogs, cats, horses, and guinea pigs), laboratory 
animals, and animals maintained in zoological parks. Animal food means food for animals 
other than man and includes pet food, animal feed, and raw materials and ingredients (see 21 
CFR 507.3).  Therefore, the animal food discussed in this guidance includes raw materials and 
ingredients used to make animal food, partially manufactured animal food that may be further 
processed, and animal food ready for consumption.   
 
This guidance document is intended to help you comply with the PCAF requirements in subparts 
C and F of part 507: 
  a food safety plan 
  hazard analysis 
  preventive controls 
  monitoring 
  corrective actions and corrections 
  verification (including validation) 
  recall plan 
  associated records 
 
You need to apply preventive controls and the associated preventive control management 
components only if, after conducting a hazard analysis of each type of animal food 
manufactured, processed, packed, or held at your facility, you determine there are known or 
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reasonably foreseeable biological, chemical, or physical hazards that require a preventive 
control.  We do not expect that all known or reasonably foreseeable hazards for an animal food 
require a preventive control in all facilities. 
 
It is important for you to be aware of the known or reasonably foreseeable hazards that may be 
associated with your animal food, processes, and facility.  When you understand the known or 
reasonably foreseeable hazards, it is easier to design and implement an effective food safety plan. 
 
This guidance is not directed to persons who are exempt from the preventive controls 
requirements of part 507.  However, such persons may find some of the principles and 
recommendations in this guidance helpful in manufacturing, processing, packing, and holding 
animal food to help ensure the safety of that animal food. 
 
The contents of this document do not have the force and effect of law and are not meant to bind 
the public in any way, unless specifically incorporated into a contract.  This document is 
intended only to provide clarity to the public regarding existing requirements under the law. 
FDA guidance documents, including this guidance, should be viewed only as recommendations, 
unless specific regulatory or statutory requirements are cited.  The use of the word should in 
Agency guidance means that something is suggested or recommended, but not required. 
 
PURPOSE 
 
The purpose of this guidance is to help you develop a food safety plan that complies with FDAs 
PCAF requirements.  This guidance does not include every possible scenario for your food safety 
plan and the type of animal food you manufacture, process, pack, or hold, but is designed to 
assist you as you develop your food safety plan.   
 
Specifically, this document provides guidance on how to: 
 
  identify the biological, chemical (including radiological), and physical agents that are 
known or reasonably foreseeable hazards in manufacturing, processing, packing, and 
holding of animal food   
  understand the components of a food safety plan and the importance of each component   
  conduct a hazard analysis and develop a food safety plan for the animal food that you 
produce   
  identify preventive controls for biological, chemical, and physical hazards requiring a 
preventive control and understand how to apply those preventive controls   
  implement preventive control management components (i.e., monitoring, corrective 
actions and corrections, and verification (including validation))   
  understand and implement the food safety plan as well as all recordkeeping requirements 
associated with the food safety plan   
 
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We recommend that you consider how this guidance relates to your operations and tailor your 
food safety plan to the specific circumstances for the animal food you produce at your facility.  
You have the flexibility to identify and implement preventive controls and associated preventive 
control management components from among all procedures, practices, and processes that 
provide assurances that the hazard requiring a preventive control is controlled (i.e., significantly 
minimized or prevented).   
 
Terms we use that are defined in the regulation and that we define for purposes of this guidance 
are in quotations the first time they are introduced.  For a list of definitions used in this guidance, 
see Appendix A.  For a list of abbreviations and acronyms used in this guidance, see Appendix 
B.   
 
   
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CHAPTER 1  THE FOOD SAFETY PLAN 
 
1.1  Purpose of this Chapter 
 
The guidance provided in this chapter is intended to help facilities that are subject to the 
preventive controls requiremApents of the Preventive Controls for Animal Food (PCAF) 
regulation understand what a food safety plan is.  A facility subject to the preventive controls 
requirements must prepare, or have prepared, and implement a written food safety plan.  See 21 
CFR 507.31(a).   
 
1.2  What is a Food Safety Plan? 
 
A food safety plan is a written plan prepared by (or whose preparation is overseen by) a 
preventive controls qualified individual (21 CFR 507.31(a) and (b)), and it must include the 
elements listed in 21 CFR 507.31(c). 
 
Below, we describe the written documents required in the food safety plan.  See 21 CFR 
507.31(c).   
 
  Hazard analysis to identify and evaluate known or reasonably foreseeable hazards for 
each type of animal food at your animal food facility to determine whether there are 
hazards requiring a preventive control (see 21 CFR 507.33(a)(1)).  Some facilities may 
not identify any known or reasonably foreseeable hazards associated with animal food at 
their facilities, or after evaluation may determine there are no known or reasonably 
foreseeable hazards requiring a preventive control.  This hazard analysis must be written 
regardless of whether there are any hazards requiring a preventive control.  See 21 CFR 
507.33(a)(2).   
  When the hazard analysis determines there are known or reasonably foreseeable hazards 
requiring a preventive control, the food safety plan also includes the following written 
documents: 
  Preventive controls (see 21 CFR 507.34), as appropriate to the facility and the 
o
animal food, that may include: 
  process controls  
  sanitation controls  
  supply-chain controls  
  recall plan  
  other preventive controls  
  Procedures for monitoring the implementation of the preventive controls, as 
o
appropriate to the nature of the preventive control and its role in the facilitys 
animal food safety system.  See 21 CFR 507.40(a).   
  Corrective action procedures, as appropriate to the nature of the hazard and the 
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nature of the preventive control.  See 21 CFR 507.42(a)(1).   
  Verification procedures, as appropriate to the facility, the animal food, and the 
o
nature of the preventive control and its role in the facilitys animal food safety 
system.  See 21 CFR 507.49(b).   
  Recall plan.  See 21 CFR 507.38(a)(1).   
o
 
This written food safety plan is a record that you must maintain.  See 21 CFR 507.31(d); and, 21 
CFR part 507, subpart F, particularly 21 CFR 507.208.  In addition, you must maintain records 
documenting implementation of the food safety plan.  See 21 CFR 507.55 for a list of records 
that must be maintained to document implementation of the food safety plan.   
 
1.3  Who Prepares the Food Safety Plan for a Facility? 
 
A preventive controls qualified individual (PCQI) must prepare (or oversee the preparation of) 
the food safety plan.  See 21 CFR 507.31(b).   
 
A PCQI is a qualified individual who has successfully completed training in the development 
and application of risk-based preventive controls at least equivalent to that received under a 
standardized curriculum recognized as adequate by FDA, or is otherwise qualified through job 
experience to develop and apply a food safety system (see 21 CFR 507.3).  A standardized 
curriculum recognized as adequate by FDA includes, for example, the animal food training 
course developed by the Food Safety Preventive Controls Alliance (FSPCA) (Ref. 1).  The PCQI 
does not need to be an employee of the facility but should be familiar with the facility and the 
facilitys operations.   
 
1.4  Who Signs the Food Safety Plan for a Facility? 
 
The food safety plan must be signed and dated by the owner, operator, or agent in charge of the 
facility when the food safety plan is first completed and whenever the plan is modified.  See 21 
CFR 507.206.   
 
1.5  Is the Food Safety Plan the Same as a HACCP Plan? 
 
Although a food safety plan and Hazard Analysis and Critical Control Point (HACCP) plan are 
similar, they are not identical.  A HACCP plan is a written document based upon the principles 
of HACCP and which delineates the procedures to be followed.  HACCP is a systematic 
approach to the identification, evaluation, and control of food safety hazards.  HACCP systems, 
which are the result of the implementation of a HACCP plan, have been mandated by U.S. 
Federal regulations issued by the FDA for processing seafood and juice and by the United States 
Department of Agriculture Food Safety and Inspection Service (USDA/FSIS) for processing 
meat and poultry.  No HACCP system has been mandated by FDA for any animal food.  HACCP 
principles have been voluntarily adopted however by some segments of the animal food industry, 
such as some rendering facilities.   
 
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1.6  What if a Facility Already has a HACCP Plan? 
 
If you have an existing HACCP plan, you should determine if your HACCP plan satisfies all the 
requirements for the food safety plan in the PCAF regulation.  You can use existing programs, 
procedures, and records and supplement those with any additional information required.  If you 
are using or planning to use a HACCP plan at your animal food facility, you may find helpful a 
complete discussion of the differences between a food safety plan and a HACCP plan in Chapter 
1 of the draft GFI entitled Hazard Analysis and Risk-Based Preventive Controls for Human 
Food.3   
 
1.7  Is there a Required Format for a Food Safety Plan? 
 
There is no standardized or required way to organize a food safety plan.  The food safety plan 
may be in electronic or hardcopy format.  The food safety plan is a record subject to the 
requirements in 21 CFR part 507, subpart F (see 21 CFR 507.31(d)).   
 
You have flexibility in your approach to documenting your hazard analysis and in your approach 
to documenting preventive controls established for those hazards requiring a preventive control.  
The formats shown in this guidance are for illustrative purposes and may not be complete.  You 
can use whatever format works best for your facility, provided that the food safety plan includes 
all the required information.  The FSPCA training materials also provide example food safety 
plans for animal food that may be helpful (Ref. 1).   
 
One approach for organizing the food safety plan to allow for signing and dating is to collect in a 
single location (e.g., a binder or folder) all the required documents with a cover page for the 
owner, operator, or agent in charge of the facility to sign and date.  See 21 CFR 507.206.  
However, because the food safety plan also could be various documents kept in different 
locations within the facility, another approach is for the owner, operator, or agent in charge of 
the facility to sign and date a list of the required documents (e.g., as in a table of contents).   
 
1.8  What Circumstances Require Review (Reanalysis) of My Food Safety Plan? 
 
The food safety plan is a dynamic document that reflects your current hazard analysis, preventive 
controls, and other required elements (see 21 CFR 507.31).  The food safety plan as a whole 
must be reanalyzed at least once every 3 years (21 CFR 507.50(a)).  However, reanalysis of the 
plan as a whole or the applicable portion of the plan is required whenever a significant change in 
the activities conducted at your facility creates a reasonable potential for a new hazard or a 
significant increase in a previously identified hazard; you become aware of new information 
about potential hazards associated with the animal food; when appropriate after an unanticipated 
animal food safety problem that requires a corrective action; or, you find that a preventive 
control, combination of preventive controls, or the food safety plan as a whole is ineffective.  See 
21 CFR 507.50(b).  You also must conduct a reanalysis of the food safety plan when FDA 
determines it is necessary to respond to new hazards and developments in scientific 
understanding.  See 21 CFR 507.50(f).  In the event that we make such a determination, we will 
 
3 https://www.fda.gov/media/100002/download  
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publicize such information in a format accessible to the public.   
 
1.9  References for Chapter 1 
 
1.  Food Safety Preventive Controls Alliance. 2017. Food Safety Preventive Controls 
Alliance Home Page. Accessed July 20, 2021.  
https://www.ifsh.iit.edu/fspca 
 
   
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CHAPTER 2  CONDUCTING A HAZARD ANALYSIS 
 
2.1  Purpose of this Chapter 
 
The guidance provided in this chapter is intended to help you conduct a hazard analysis in 
accordance with the PCAF requirements.  The hazard analysis must be written regardless of the 
outcome or results of the analysis, and must include two elements:  (1) a hazard identification, 
and (2) a hazard evaluation to determine whether there are any hazards requiring a preventive 
control.  See 21 CFR 507.33.   
 
2.2  Overview of a Hazard Analysis 
 
The term hazard analysis is not defined in part 507.  See Box 2-1 for a definition of hazard 
analysis.   
 
Box 2-1.  Definition of Hazard Analysis 
Hazard Analysis 
 
The process of identifying and evaluating known or reasonably foreseeable hazards to 
determine whether there are any hazards requiring a preventive control. 
 
This chapter guides you through the steps we recommend in conducting your hazard analysis.  
You are not required to use a certain format for conducting your hazard analysis.  However, you 
may find it useful to use the Flow Chart in Appendix C and the Hazard Analysis and Preventive 
Controls Worksheet in Appendix D (also see Box 2-3 in this chapter).  You may use other 
formats (including the use of a written narrative) as long as your hazard analysis contains the 
elements of hazard identification and hazard evaluation and a determination of whether any of 
the hazards require a preventive control.   
 
Use your completed hazard analysis to determine whether any hazards require preventive 
controls.  Your completed hazard analysis will be useful in determining the appropriate 
preventive control(s), if any, to use in your facility.  The hazard identification and evaluation in 
your hazard analysis should help provide justification for your decisions.   
 
You may group animal food products together for your hazard analysis if the animal food safety 
hazards and controls are essentially the same for all animal food products in the group, but you 
should clearly identify any product or process differences.  Your written hazard analysis can be a 
resource for you if inspectors, investigators, auditors, or your customers ask you to explain how 
you determined that a preventive control is not required for a known or reasonably foreseeable 
hazard.   
 
A proper analysis of biological, chemical (including radiological), and physical hazards 
associated with your animal food and your facility calls for good judgment, detailed knowledge 
of the properties of the raw materials and other ingredients, detailed knowledge of your 
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manufacturing, processing, packing, and holding processes, and access to relevant scientific 
expertise.   
 
2.3  Recommended Activities in Conducting Your Hazard Analysis 
 
We recommend that you conduct certain preliminary steps, and set up a Hazard Analysis 
Worksheet, as a useful framework for organizing and documenting your hazard analysis.   
 
2.3.1  Conduct Preliminary Steps 
 
Box 2-2.  Recommended Preliminary Steps 
1.  Designate the preventive controls qualified individual (you may also assemble a food safety 
team). 
2.  Describe the animal food, its distribution, intended use, and the intended animal species, 
life stage, or production class. 
3.  Develop a process flow diagram (include the related process descriptions as needed) and 
conduct an on-site visit to verify the diagram is accurate. 
 
You must have a preventive controls qualified individual (PCQI) prepare, or oversee the 
preparation of, your food safety plan.  See 21 CFR 507.31(b).  The food safety plan includes 
your written hazard analysis.  See 21 CFR 507.31(c)(1).  We recommend that a food safety team 
of individuals with expertise in the day-to-day operations of your facility help you conduct your 
hazard analysis under the oversight of a PCQI.  Team individuals may include personnel from 
different areas, such as production, quality control, sanitation, or maintenance.  Using individuals 
from different functions within the facility can help provide a complete understanding of your 
process and the things that could result in hazards in your animal food.   
 
You can supplement the expertise of the food safety team with competent technical experts from 
other functional areas within the firm (where applicable), such as research and development, 
technical applications groups, and quality management, even though they may not be on-site at 
the facility.  You also may find it helpful to bring in technical experts from outside of the firm 
such as experts from universities, cooperative extension services, trade associations, private 
consulting firms, raw materials and ingredients suppliers, or other sources.   
 
The effectiveness of your food safety team is impacted by the quality and completeness of the 
information you provide to them about your facility and animal food to be assessed.  Therefore, 
for this team to conduct the hazard analysis for the food safety plan, we recommend that you 
define and document the following details about your facility:  (1) animal food type (including 
identification of the animal species, life stage or production class, and intended use) and its 
distribution, and (2) a process flow diagram (that includes the related process descriptions as 
needed).   
 
A description of the animal food and how the animal food will be distributed and used helps the 
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PCQI understand elements of, or handling of, the animal food that may impact animal food 
safety such as proper storage conditions and any required labeling information (e.g., Do not 
feed to cattle or other ruminants).  To help your PCQI, the description could include the: (1) full 
name of the finished animal food, description of the general formulas, or description of the type 
of animal food, (2) species and life stage or production class, (3) the packaging type and 
material, and (4) storage and distribution details.  Finished animal food could be ready for 
consumption or it could be an ingredient or mixture of ingredients that will be further processed, 
mixed, or blended before the food is suitable for feeding to animals.   
 
Understanding how the animal food will be fed to the animal (e.g., fed in fields, troughs, or in a 
pet owners home) and knowing the intended animal being fed (e.g., dairy cow or dog) helps to 
determine which hazards require a preventive control.  For example, a facility manufacturing pet 
food should consider that the animal food will be directly handled by humans and fed in the 
home as opposed to livestock animal food that is added to a trough usually without direct contact 
by humans.  Therefore, handling of pet food by humans in the home is an important factor to 
consider when conducting your hazard analysis (see 21 CFR 507.33(d)(8)).   
 
The purpose of a process flow diagram is to provide a clear, simple description of each of the 
steps involved in the processing of your animal food and its associated ingredients as they flow 
through your facility from receipt to distribution.  The process flow diagram should cover all 
steps in the process that the facility performs, including receiving and storage steps for raw 
materials or other ingredients, preparation, processing, packaging, storage, and distribution of the 
product.  Additionally, the process flow diagram should identify the equipment used.  An 
accurate process flow diagram serves as a useful organization format by identifying each of the 
process steps that you need to assess for the hazard analysis.  You should verify the process flow 
diagram onsite in order to ensure no steps have been overlooked.   
 
The purpose of including related process descriptions is to help explain what happens at each of 
the process steps within your facility.  For example, a process description that includes where 
and when micro ingredients (e.g., vitamins, minerals, drugs, and other materials normally 
required in small amounts and measured in milligrams, micrograms, or parts per million) are 
added to an animal food or whether a micro ingredient is added manually can help you identify 
the known or reasonably foreseeable hazards associated with your facility or your animal food.   
 
2.3.2  Hazard Analysis Worksheet 
 
Once your PCQI (and food safety team if applicable) gathers the information you will use to 
conduct your hazard analysis, we recommend that you set up a method to organize your hazard 
analysis.  The Hazard Analysis Worksheet (HA worksheet) we provide in this guidance can be a 
useful tool to organize your written hazard analysis, although, as stated in section 2.2, you may 
use any method that results in a written hazard analysis.  In this section, we discuss how to set up 
the HA worksheet.  See Box 2-3 for an example of an HA worksheet.  For an alternative form, 
see the FSPCA model food safety plan (Ref. 1).   
 
The HA worksheet is organized by column.  The information needed for the first four columns is 
explained in this chapter and Chapter 3.  Chapter 4 describes more thoroughly the information 
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needed for columns five and six.   
 
Column 1  Ingredient and Processing Step:  List the ingredients used in your process as a way 
of identifying hazards associated with an ingredient (you may group similar ingredients such as 
grains); and the processing steps.  A process flow diagram and detailed process description (see 
Box 2-2) can help you identify the processing steps included in your hazard analysis.   
 
Column 2  Known or Reasonably Foreseeable Hazard:  List the results of your identification of 
the known or reasonably foreseeable hazards from your hazard analysis.  Include biological, 
chemical, or physical hazards that could be introduced or increased from ingredients, your 
process, or the environment.  See section 2.4.1.   
 
Column 3  Does the Known or Reasonably Foreseeable Hazard Require a Preventive Control:  
For each known or reasonably foreseeable hazard identified in column 2, record the conclusions 
of your hazard analysis  i.e., the determinations you make whether each known or reasonably 
foreseeable hazard requires a preventive control (Yes or No).  See section 2.4.2.   
 
Column 4  Explanation/Justification:  You should justify, or explain, your Yes or No 
conclusion for column 3 based on your evaluation of the hazard.  Record the key factors or a 
summary of the evaluation that led to the determination for each hazard of whether a preventive 
control is required.  Explaining your reasons for a No conclusion can be just as important as 
explaining your reasons for a Yes conclusion.  See section 2.5.   
 
Column 5  Preventive Control(s) Applied:  Identify the preventive control(s) you will apply to 
significantly minimize or prevent the hazard requiring a preventive control (indicated by Yes 
in column 3).  You might list, for example, the type of preventive control (e.g., process, 
sanitation, or supply-chain-applied controls), or list the specific preventive control you select 
(e.g., irradiation, time and temperature, or a ).  See section 2.6, and Chapter 4.   
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If the identified hazard does not require a preventive control, (indicated by No in column 3), 
you can leave the corresponding cell blank or put in N/A for not applicable.   
 
Column 6  Is the Preventive Control Applied at this Step:  The HA worksheet allows you to 
break your production process into multiple steps (such as receiving or processing), and you may 
apply your preventive control at a step in the process other than the step where you list the 
hazard.  Specify whether the preventive control will be applied at the specific processing step 
(i.e., Yes or No).  See section 2.7.   
 
 
 
 
 
 
 
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Box 2-3.  Example Hazard Analysis Worksheet (see Appendix D) 
(Column 1)  (Column 2)  (Column 3)  (Column 4)  (Column 5)  (Column 6) 
           
Ingredient  Known or  Does the Known  Explanation/  Preventive  Is the Preventive 
and  Reasonably  or Reasonably  Justification  Control(s)  Control Applied 
Processing  Foreseeable  Foreseeable  Applied  at this Step? 
Step  Hazard  Hazard Require   
a Preventive   
Control?   
  Yes or No 
Yes or No 
           
           
 
2.4  Conducting a Hazard Analysis 
 
2.4.1  Identify Known or Reasonably Foreseeable Hazards (Hazard Identification) 
 
You must identify known or reasonably foreseeable hazards for each type of animal food 
manufactured, processed, packed or held at your facility (see 21 CFR 507.33(a)).  The hazard 
identification must consider known or reasonably foreseeable hazards that include biological, 
chemical (including radiological), and physical hazards that may be present in the animal food 
for any of the following reasons:  (1) the hazard occurs naturally, (2) the hazard may be 
unintentionally introduced, or (3) the hazard may be intentionally introduced for purposes of 
economic gain.  See 21 CFR 507.33(b)(1) and (2).   
 
We recommend that you start with an exercise such as a brainstorming session to identify 
hazards that are known to be, or have the potential to be, associated with your facility or animal 
food (the known or reasonably foreseeable hazards).  A brainstorming session can help you 
generate a list of biological, chemical, and physical hazards.  Things you could consider as you 
work through this procedure include:   
 
  Information about the animal food type (including identification of the animal species, 
life stage or production class, and intended use) and its distribution.   
  Raw materials and other ingredients used in the animal food.  Hazards, such as pathogens 
known to be associated with specific types of animal food, may be introduced during 
product manufacturing.  For example, various ingredients may contain pathogenic 
bacteria that need to be significantly minimized or prevented to produce a safe pet food.   
  In-plant experience regarding what hazards may be associated with the finished animal 
food.  This may include product testing results, consumer complaints, or knowledge of 
facility personnel about the condition, function, and design of the facility relevant to 
contamination.   
  Activities conducted at each step in the manufacturing process.  Some activities may 
unintentionally introduce hazards into the animal food (e.g., chopping with a metal blade 
may introduce metal fragments; conveying with a broken plastic leg cup may introduce 
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plastic fragments; or, an improper bin cleanout may result in nutrient toxicities or 
deficiencies in animal food).   
  Equipment used to make the animal food.  Some types of equipment are more difficult to 
clean than others or are more prone to damage, which may increase the risk of hazards 
(e.g., biological or physical) being introduced into the animal food.   
  Sanitation practices.  You should consider the sanitary conditions within the facility (e.g., 
cleanliness of equipment and processing environment) and employee hygiene.   
  External information.  Sources may include scientific papers, epidemiological studies 
(e.g., data from previous foodborne illness incidents associated with ingredients or 
processes relevant to an animal food), information from applicable government or 
industry food safety documents, and if available, historical data for similar animal food.   
 
After reviewing all relevant information, the PCQI (with the food safety team if applicable) can 
develop a list of known or reasonably foreseeable hazards that may be introduced or increased 
(e.g., due to pathogen growth) at each step in your manufacturing process.  A process flow 
diagram can be a useful tool to identify where in your process a known or foreseeable hazard 
could be introduced.   
 
Chapter 3 of this guidance can be used to help you identify known or reasonably foreseeable 
hazards for your animal food.  Chapter 3 provides a review of biological, chemical, and physical 
hazards.  The hazards described in Chapter 3 do not represent all possible hazards, nor are all of 
these hazards found in all facilities or types of animal food.  You are responsible for identifying 
known or reasonably foreseeable hazards for each type of animal food manufactured, processed, 
packed, or held at your facility, even if they are not listed in Chapter 3.   
 
2.4.2  Evaluate Known or Reasonably Foreseeable Hazards (Hazard Evaluation) 
 
Each known or reasonably foreseeable animal food hazard must be evaluated to assess the 
following (see 21 CFR 507.33(c)(1)):   
  Severity of the illness or injury to humans or animals if the hazard were to occur.   
  The probability of occurrence of the hazard in the absence of a preventive control.   
 
Your written hazard analysis also must:   
 
  Include an evaluation of environmental pathogens whenever an animal food is exposed to 
the environment prior to packaging and the packaged animal food does not receive a 
treatment or otherwise include a control measure (such as a formulation lethal to the 
pathogen) that would significantly minimize the pathogen (see 21 CFR 507.33(c)(2)).   
  Consider the effect of certain factors on the safety of the finished animal food for the 
intended animal such as design of the facility and storage and distribution (see 21 CFR 
507.33(d)).   
 
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Assessing severity of the illness or injury 
 
To assess the severity of the illness or injury if the hazard were to occur, you should consider 
certain factors, including:   
 
  Susceptibility of the animal to the illness or injury (e.g., dogs are more susceptible to 
aflatoxin than most other species).   
  Susceptibility of humans to the illness or injury (e.g., infants, children, and 
immunocompromised individuals may be more susceptible to certain foodborne illnesses 
from handling pathogen contaminated pet food, or through consuming products derived 
from animals that had consumed contaminated food).   
  The potential magnitude and duration of the illness or injury (e.g., how long an animal 
may be sick, whether the illness requires veterinary care and hospitalization, and 
production loss such as a decline in milk or egg production).   
  The possible impact of secondary problems (e.g., chronic sequelae such as kidney 
damage or neurological disease).   
 
If your facility does not have the expertise to assess the severity of an illness or injury that could 
result from a known or reasonably foreseeable hazard, you (and your PCQI) could consult with 
outside experts.   
 
Assessing probability the hazard will occur 
 
The probability (i.e., likelihood) of occurrence of a particular hazard in the absence of a 
preventive control can be influenced by:   
  frequency of association of the hazard with the animal food or facility  
  effectiveness of facility programs such as current good manufacturing practices (CGMPs) 
or other prerequisite programs  
  method of manufacture in the facility  
  conditions during transportation  
  expected storage conditions during holding at the facility or after distribution  
  intended use of the animal food  
 
Knowing your animal food, ingredients, processes, packaging, transportation, distribution, and 
the use of the animal food is helpful in estimating the likely occurrence of known or reasonably 
foreseeable hazards.  Hazards likely to occur in one operation or facility may not be likely to 
occur in another operation or facility producing the same or similar animal food because 
different equipment and processes may be used, the ingredients and their source may be 
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different, or different transportation services are used.  For example, one facility manufactures 
with only local grains while another facility receives most of its grains from out of state where 
growing and harvesting conditions may differ.  You should consider each facility location 
individually when estimating the likelihood of occurrence of an animal food safety hazard.   
 
You also could consider your facilitys implementation of prerequisite programs when 
evaluating the probability that a hazard will occur in the absence of a preventive control.  Proper 
implementation of an adequate prerequisite program may decrease the probability the hazard will 
occur.  This probability may decrease to such a level that you determine the hazard does not 
require a preventive control.  If you rely on a prerequisite program in your evaluation of the 
probability of occurrence of a hazard, adequate information about the prerequisite program must 
be included in your hazard analysis as part of your evaluation (see 21 CFR 507.33(c)).  Adequate 
information in your hazard analysis could include a copy or sufficient description of standard 
operating procedures (SOPs) for your prerequisite program to document the procedures your 
facility follows to reduce the probability a hazard will occur in the absence of a preventive 
control.  During an inspection, FDA could determine that your prerequisite program or its 
implementation does not adequately reduce the probability of the hazard occurrence and that a 
preventive control (and associated preventive control management components) is necessary for 
the hazard.   
 
Examples of prerequisite programs include CGMPs (21 CFR part 507, subpart B), compliance 
with requirements on the use of animal proteins in ruminant feed (21 CFR 589.2000 and 
589.2001, the bovine spongiform encephalopathy (BSE) regulations), and a facilitys standard 
operating procedures.  For example, the BSE agent is a hazard that may cause severe illness in 
cattle and humans.  A facility that handles protein derived from mammalian tissues or cattle 
material prohibited in animal food may consider compliance with FDAs BSE regulations as a 
prerequisite program.  If the facility is properly implementing the requirements in the regulation, 
the facility may conclude that their prerequisite program adequately reduces the probability that 
the BSE agent will occur in the absence of a preventive control.  This conclusion may lead the 
facility to determine that the hazard does not require a preventive control.  We recommend that 
you provide an explanation for your decision, based on your evaluation, in the 
explanation/justification section (column 4) of your hazard analysis worksheet.   
 
When estimating likelihood of occurrence, you should consider information from available 
sources, which may include the following:   
  data from foodborne illness incidents  
  data from recalls  
  data from the Reportable Food Registry4  
  information in the scientific literature  
  facilitys historical information  
 
 
4 https://www.fda.gov/food/compliance-enforcement-food/reportable-food-registry-industry  
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Data from foodborne illness incidents 
 
You should consider foodborne illness incidents associated with the same or similar animal food 
types.  The Centers for Disease Control and Prevention (CDC) and FDA provide some 
information on outbreaks in humans from exposure to animal food.  See Box 2-4 for sources.  
See references in section 2.8 for links to access this information.   
 
Box 2-4.  Sources of Data about Outbreaks 
Food and Drug Administration (FDA) 
  Outbreaks of Foodborne Illness  reports for FDA regulated foods (Ref. 2) 
 
Centers for Disease Control and Prevention (CDC) 
  Foodborne Outbreak Online Database  searchable by pathogen for U.S. outbreaks 
related to animal food (Ref. 3) 
 
Data from recalls 
 
Recalls provide useful information for understanding the types of hazards found in animal food.  
We classify recalls as specified in 21 CFR 7.3(m).   
 
Recall classification means the numerical designation (i.e., I, II, or III) FDA assigns to a 
particular product recall indicating the relative degree of health hazard presented by the recalled 
product.   
 
  Class I is a situation in which there is a reasonable probability that the use of, or exposure 
to, a violative product will cause serious adverse health consequences or death (21 CFR 
7.3(m)(1))  
  Class II is a situation in which use of, or exposure to, a violative product may cause 
temporary or medically reversible adverse health consequences or where the probability 
of serious health consequences is remote (21 CFR 7.3(m)(2))  
  Class III is a situation in which use of, or exposure to, a violative product is not likely to 
cause adverse health consequences (21 CFR 7.3(m)(3))  
 
Federal and State Web sites post information on food recalls.  See Box 2-5.  Also see references 
in section 2.8 for links to access this information.   
 
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Box 2-5.  Sources of Data about Recalls 
  FDA Recalls, Market Withdrawals, and Safety Alerts (Ref. 4) 
 
  U.S. Department of Agriculture, Food Safety and Inspection Service Recall Archive 
(Ref. 5) 
 
Data from the Reportable Food Registry 
 
The Reportable Food Registry (RFR) is an electronic portal for industry to report when there is 
reasonable probability that the use of or exposure to an article of food will cause serious adverse 
health consequences or death.  The RFR helps FDA better protect public health by tracking 
patterns and targeting inspections.  The responsible party at a registered food facility is required 
to report when there is a reasonable probability that the use of, or exposure to, an article of food 
will cause serious adverse health consequences or death to humans or animals.  (See section 417 
of the FD&C Act).  We release an annual RFR report that provides a synopsis of a one-year 
reporting period (Ref. 6).  When conducting your hazard analysis, the RFR reports can be helpful 
to understand the types of hazards that have previously been associated with animal food and to 
identify new and emerging animal food hazards.   
 
Information in the scientific literature 
 
Peer-reviewed scientific journals and other sources of technical literature (e.g., Codex 
Alimentarius Commission (Codex), the Food and Agriculture Organization, and the World 
Health Organization) provide considerable information on foodborne hazards, their occurrence, 
potential for growth in food, and their control (Refs. 7, 8 and 9).  Codex maintains internationally 
recognized codes of practice that are based on scientific literature and are available in several 
languages.  USDA provides a microbial modeling program that is available online and can be 
used to evaluate potential growth of pathogens under a variety of conditions (Ref. 10).  Keep in 
mind that modeling programs may not reflect exactly what will occur in a particular animal food, 
but they can provide an estimate of relative risk of different scenarios.   
 
We provide guidance documents about animal food safety, which represent FDAs current 
thinking on a topic.  Trade associations also provide animal food safety recommendations for 
specific types of animal foods and industry needs.  Another useful resource is the Google Scholar 
search engine. 
 
Facilitys historical information 
 
You may already have considerable information on your products from various laboratory tests 
on finished animal food, ingredients, in-process materials, or environmental monitoring.  In 
addition, you may have experienced a contamination problem in the past that suggests a hazard is 
known or reasonably foreseeable, or received consumer complaints about certain hazards, such 
as physical hazards.  You should consider your facilitys historical data when conducting your 
hazard evaluation.   
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2.4.3  Assessing the Combination of Severity and Probability 
 
You can separately assess:  (1) the severity of illness and injury if the hazard were to occur, and 
(2) the probability of the hazards occurrence in the absence of a preventive control.  However, 
you also can consider the combination of severity and probability when evaluating the known or 
reasonably foreseeable hazard to determine if the hazard requires a preventive control.   
 
For example, an illness or injury may have a moderate severity (e.g., may require medical or 
veterinary intervention in most cases), but the probability that the hazard will occur in the 
absence of a preventive control is low (e.g., rarely occurs in your type of animal food).  If you 
look at the severity of the illness/injury and the probability that the hazard that causes the 
illness/injury will occur in the absence of a preventive control independently, the determination 
of whether the hazard requires a preventive control may be difficult in situations when the 
severity is moderate but probability is low (or the reverse).  Looking at the severity and 
probability in combination may be helpful in making the determination of whether the hazard 
requires a preventive control.   
 
Evaluating the combination of severity and probability can be done in different ways.  See the 
FSPCA animal food curriculum for an example of a system to evaluate severity and probability 
in combination (Ref. 1).  If you evaluate the combination of severity and probability for the 
hazard using a specific system, we will consider that system part of your hazard analysis, which 
must be written (see 21 CFR 507.33(a)(2)).   
 
2.4.4  Evaluating Environmental Pathogens When Animal Food is Exposed to the 
Environment 
 
If the animal food you make is exposed to the environment in your facility before packaging, the 
animal food could be contaminated with environmental pathogens such as Listeria 
monocytogenes (L. monocytogenes) or Salmonella.  You must then include an evaluation of 
environmental pathogens in your hazard evaluation if the animal food you make is exposed to 
the environment before packaging and does not receive a treatment or include a control measure 
that would significantly minimize the pathogen.  See 21 CFR 507.33(c)(2).   
 
2.4.5  Evaluation of Other Factors 
 
When evaluating hazards, you must consider the effect of the following on the safety of the 
finished animal food for the intended animal (21 CFR 507.33(d)):   
 
  The formulation of the animal food:  The addition of certain ingredients such as acids and 
preservatives may be critical to the safety of the finished animal food, because they may 
inhibit growth of, or even kill, microorganisms of public (human and animal) health  
significance.  This could impact the evaluation at steps during production and storage 
with respect to pathogen growth.  A multicomponent animal food may have individual 
ingredients that do not support growth of undesirable microorganisms (e.g., because of 
pH or a ), but when the ingredients are put together, the resulting intrinsic factors (e.g., 
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pH and a ) may favor the growth of undesirable microorganisms.   
w
  The condition, function, and design of the facility and equipment:  The condition, 
function, or design of a facility or its equipment could potentially result in hazards in 
finished animal food.  For example, some equipment in a pet food facility (e.g., some 
extruders, dryers, and conveying equipment) may be difficult to clean (e.g., because of 
close fitting components or hollow parts) and thus provide more opportunities for 
pathogens to become established in a niche environment than equipment designed to 
address the problem of pathogen harborage in niche environments.  Equipment designed 
with metal-to-metal contact (e.g., metal scrapers or hammer blades) may generate metal 
fragments (a physical hazard).  A facility that manufactures, processes, packs, or holds 
animal food such as raw pet food may have cold, moist conditions that are conducive to 
the development of a niche where the pathogen L. monocytogenes can become 
established and contaminate animal food-contact surfaces and finished animal food.   
  Raw materials and other ingredients:  A finished animal food can become contaminated 
through the use of contaminated animal food ingredients.  For example, corn can be 
contaminated with aflatoxin, a chemical hazard.  Machinery-harvested ingredients may 
be contaminated with physical hazards because the machinery may pick up foreign 
material from the field or not adequately separate foreign material from the harvested 
crop.   
  Transportation practices:  The safety of a finished animal food may be affected by 
transportation practices for incoming raw materials and ingredients or for the outgoing 
finished animal food.  For example, you could consider whether an ingredient may 
require time and temperature control to ensure safety, or a bulk ingredient may need 
protective covering to prevent physical hazards.  You also should be aware of applicable 
requirements of the Sanitary Transportation of Human and Animal Food regulation in 21 
CFR part 1, subpart O, which helps ensure that motor vehicle and rail vehicle 
transportation practices do not create food safety risks.   
  Manufacturing/processing procedures:  Hazards may arise from 
manufacturing/processing procedures such as mixing of micronutrients that could result 
in nutrient deficiencies or toxicities (e.g., excessive vitamin D in dog food, excessive 
copper in food for sheep, or inadequate thiamine in thermally processed cat food) in the 
finished animal food.  Some animal food facilities may use automated systems for 
ingredient addition.  When not operating correctly, these systems can add ingredients to 
the wrong batch, fail to add ingredients, or add the incorrect amount of an ingredient to a 
batch resulting in a nutrient deficiency or toxicity hazard or drug hazard.  In the 
production of nonmedicated animal food in a medicated feed facility, the 
manufacturing/processing procedures may result in unsafe contamination from drug 
carryover to the nonmedicated animal food due to inadequate cleanout procedures or 
improper sequencing of different animal food (e.g., the use of monensin, which is safe for 
use for cattle but toxic to horses, could result in unsafe contamination from drug 
carryover).   
  Packaging activities and labeling activities:  The packaging of an animal food can vary 
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(e.g., reusable totes, single use poly bags, cans, or pouches).  Improper packaging could 
introduce a hazard into the animal food.  You should ensure the finished animal food will 
be labeled appropriately.  Some animal food may need labeling information to ensure 
safe use of the finished animal food.  For example, the manufacturer of a copper 
supplement might include the use levels for animal food for different species or a labeling 
statement specifying the maximum safe level of copper in an animal food intended for 
sheep.   
  Storage and distribution:  Some finished animal food is stored and distributed under 
certain conditions to maintain safety (e.g., refrigerated pet food).  There may be an 
increased probability that a hazard will occur in the absence of a preventive control for 
such animal food.   
  Intended or reasonably foreseeable use:  Animal food is often manufactured to meet the 
specific nutrient requirements of the intended species.  For example, a diet manufactured 
for beef cattle may contain higher levels of copper compared to a diet intended for sheep 
due to the differences in nutrient requirements.  The intended or reasonably foreseeable 
use is that the diet will be fed to beef cattle and not to sheep because a high copper diet 
would be toxic to sheep.  Some animal food, e.g., pet food, is expected to be fed in the 
home, where humans might be exposed to biological hazards from handling the pet food.   
  Sanitation, including employee hygiene:  Sanitation measures and practices can impact 
the likelihood of a hazard being introduced into animal food.  For example, the frequency 
with which a production line is shut down for a complete cleaning can impact the 
potential for animal food residues to transfer pathogens from equipment to the animal 
food (e.g., pathogens present on raw meat that could carry over into the next production 
cycle on a line).  Practices directed at worker health and hygiene such as handwashing 
can reduce the potential for transfer of pathogens such as Salmonella.   
  Any other relevant factors, such as the temporal (e.g., weather-related) nature of some 
hazards (e.g., levels of some natural toxins):  Hazards such as aflatoxin are subject to a 
weather-dependent effect in that aflatoxin levels in some raw agricultural commodities 
are more of a problem in some years than in others.   
 
2.5  Use of Your Written Evaluation as Explanation/Justification Whether a Hazard 
Requires a Preventive Control 
 
You must include in your food safety plan your written hazard evaluation, which is part of your 
written hazard analysis (see 21 CFR 507.31(c)(1)).  Your evaluation should provide justification 
for determining that a known or reasonably foreseeable hazard does or does not require a 
preventive control.   
 
If you use the HA worksheet shown in Box 2-3 and Appendix D, your determination about 
whether a hazard requires a preventive control is shown by a Yes or No answer in column 3.  
You base this determination on your written evaluation of the severity of the illness or injury if 
the hazard occurs and the probability the hazard will occur in the absence of a preventive control, 
as well as any other relevant evaluation factors you consider (see 21 CFR 507.33(c) and (d)).   
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In column 4 of the HA worksheet, you would explain or justify your column 3 Yes or No 
answer.  Depending on the length of your written hazard evaluation, the justification may be the 
entirety of your evaluation, could be a shortened summary of your evaluation, or could be a 
reference to a separate document in your food safety plan.   
 
For example, your facility identifies metal fragments as a known or reasonably foreseeable 
hazard.  You have implemented a system of prerequisite programs with SOPs for the use of 
screens and magnets that include daily observation and cleaning as needed of the screens and 
magnets.  You evaluate this hazard by assessing the severity of the injury a metal fragment could 
cause.  Based on your written evaluation, you determine that the metal hazard would result in 
minimal or no illness or injury to the animals consuming your animal food.  You also determine 
there would be no illness or injury to humans consuming products derived from food-producing 
animals that ate your animal food contaminated with metal fragments or through handling the 
animal food.  You then assess the probability the metal hazard will occur in the absence of a 
preventive control.  Based on your written evaluation, you determine that the probability of 
occurrence of the metal hazard in the absence of a preventive control is low, in part because of 
the implementation of your system of prerequisite programs.   
 
If you use the HA worksheet in Box 2-3 and Appendix D, your column 4 justification could be a 
short statement referencing your SOPs for the use of screens and magnets.  Because you rely in 
part on your system of prerequisite programs in your evaluation of a hazard, adequate 
information about your system (e.g., a copy or an adequate description of the SOP) must be 
included in your hazard analysis.   
 
If your HA worksheet is the only place that you document your written evaluation, you must 
include your HA worksheet in your food safety plan and your worksheet must include your 
assessment of the severity of illness or injury and the probability of occurrence of the hazard in 
the absence of a preventive control (see 21 CFR 507.33(c)(1)).  Therefore, you may want to 
include additional columns to the HA worksheet to record your severity and probability 
assessments.  See the FSPCA curriculum for animal food for an alternate example of a hazard 
analysis worksheet (Ref. 1).   
 
2.6  Identifying Preventive Controls 
Preventive Controls 
 
Those risk-based, reasonably appropriate procedures, practices, and processes that a person 
knowledgeable about the safe manufacturing, processing, packing, or holding of animal food 
would employ to significantly minimize or prevent the hazards identified under the hazard 
analysis that are consistent with the current scientific understanding of safe food 
manufacturing, processing, packing, or holding at the time of the analysis.  (21 CFR 507.3) 
 
For each hazard that you identified in column 2 as known or reasonably foreseeable and then 
indicated in column 3 as requiring a preventive control, you must identify and implement at least 
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one preventive control to significantly minimize or prevent the hazard (see 21 CFR 
507.34(a)(1)).  See Chapter 4  Preventive Controls for a detailed description of preventive 
controls.   
 
If a preventive control can be applied at a point or step in the animal food production process and 
is essential at that point to prevent or eliminate the hazard requiring a preventive control, or 
reduce it to an acceptable level, you should classify the point or step as a critical control point 
(CCP).  There are several preventive control approaches, which may or may not include CCPs, 
that you can consider depending on the known or reasonably foreseeable hazard and where in the 
process flow you determine the control measure should be applied.  These include:   
  process controls (21 CFR 507.34(c)(1))  
  sanitation controls (21 CFR 507.34(c)(2))  
  supply-chain controls (21 CFR 507.34(c)(3))  
  other preventive controls (21 CFR 507.34(c)(5))  
 
Process controls are applied at specific processing steps where parameters such as time and 
temperature must be controlled to significantly minimize or prevent a hazard.  Sanitation controls 
may be important to prevent contamination with microbial pathogens.  Supply-chain controls 
involve use of the supply-chain program for a hazard that the receiving facility has identified in 
raw materials or ingredients and that will be controlled by the supplier (see 21 CFR part 507, 
subpart E).  Other preventive controls, that do not meet the definition of process controls, 
sanitation controls, or supply-chain controls, include any other procedures, practices, and 
processes necessary to significantly minimize or prevent a hazard.  Examples of other controls 
include hygiene training and other current good manufacturing practices.   
 
For every hazard you determine requires a preventive control, you must identify and implement 
at least one preventive control.  See 21 CFR 507.34(a)(1).  Importantly, remember that more than 
one hazard may be addressed by a preventive control.  For example, several vegetative 
pathogens, such as Salmonella, L. monocytogenes, and pathogenic E. coli, are killed by sufficient 
heating.  If you use the HA worksheet in Box 2-3, record the preventive controls that you choose 
in column 5 of the HA worksheet for each Yes answer in column 3.  If the hazard does not 
require a preventive control, you would not complete columns 5 and 6.   
 
2.7  Is the Preventive Control Applied at this Step? 
 
When evaluating the known or reasonably foreseeable hazards, you should identify the step or 
steps in your production of animal food where the hazard may occur (such as receiving, 
processing, packaging, or storage).  Once you determine that a hazard requires a preventive 
control, you then identify a preventive control that will significantly minimize or prevent the 
hazard and determine where in your production process to apply the preventive control.  
Determining that a hazard occurs at a particular processing step does not mean that the hazard 
must be controlled at that processing step.   
 
For example, you may identify Salmonella as a hazard in raw meat ingredients at the receiving 
23 
  Contains Nonbinding Recommendations 
 
step of your production process.  You determine that the hazard does not need to be controlled at 
receiving because the raw meat is going to undergo a preventive control during processing that 
will significantly minimize the Salmonella hazard.  If you use the HA worksheet in Box 2-3, 
record in column 6 that the hazard would not be controlled at the receiving step and would 
instead be controlled during the processing step (i.e., Yes or No).   
 
2.8  References for Chapter 2 
 
1.  Food Safety Preventive Controls Alliance. 2016. Preventive Controls for Animal Food 
Participant Manual. First Edition v.1.0.  
 
2.  Food and Drug Administration. 2017. Outbreaks of Foodborne Illness. Accessed 
August 09, 2021.  https://www.fda.gov/food/recalls-outbreaks-emergencies/outbreaks-
foodborne-illness  
 
3.  Centers for Disease Control and Prevention. 2021. List of Selected Multistate 
Foodborne Outbreak Investigations. Accessed August 09, 2021. 
https://www.cdc.gov/foodsafety/outbreaks/multistate-outbreaks/outbreaks-list.html  
 
4.  Food and Drug Administration. 2017. Recalls, Market Withdrawals, & Safety Alerts 
(FDA email sign-up webpage). Accessed April 22, 2022. 
https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts 
 
5.  United States Department of Agriculture Food Safety and Inspection Service. 2017. 
Recall Case Archive. Accessed August 09, 2021. 
https://www.fsis.usda.gov/wps/portal/fsis/topics/recalls-and-public-health-alerts/recall-
case-archive 
 
6.  Food and Drug Administration. 2016. Reportable Food Registry Annual Report. 
Accessed April 22, 2022.  https://www.fda.gov/food/reportable-food-registry-
industry/reportable-food-registry-annual-report 
 
7.  Codex Alimentarius Commission. 2012. Prevention and Reduction of Food and Feed 
Contamination. Accessed August 09, 2021.  http://www.fao.org/feed-
safety/resources/resources-details/en/c/1051489/ 
 
8.  Food and Agriculture Organization of the United Nations. 2017. Food Safety & Quality 
at FAO homepage. Accessed August 09, 2021.  http://www.fao.org/food/food-safety-
quality/home-page/en/ 
 
9.  World Health Organization. 2017. Food safety. Accessed August 09, 2021. 
http://www.who.int/foodsafety/en/ 
 
10. United States Department of Agriculture. 2016. USDA Pathogen Modeling Program. 
Accessed August 09, 2021.  https://www.ars.usda.gov/northeast-area/wyndmoor-
pa/eastern-regional-research-center/residue-chemistry-and-predictive-microbiology-
24 
  Contains Nonbinding Recommendations 
 
research/docs/pathogen-modeling-program/pathogen-modeling-program-models/pmp/ 
 
   
25 
  Contains Nonbinding Recommendations 
 
 
CHAPTER 3  HAZARDS ASSOCIATED WITH THE MANUFACTURING, 
PROCESSING, PACKING, AND HOLDING OF ANIMAL FOOD 
 
3.1  Purpose of this Chapter 
 
The guidance provided in this chapter is intended to help you consider the biological, chemical, 
and physical hazards that may be known or reasonably foreseeable hazards in animal food 
facilities and that may be applicable to your facility and animal food.  It is important for you to 
understand the hazards that may be associated with your products, using the raw materials and 
other ingredients, processes, and equipment specific for those products, as well as the 
environment of your specific facility. This chapter does not provide an exhaustive compilation of 
hazards or details about each hazard.  Where possible, we cite scientific literature, regulations, or 
guidance that may provide useful detailed discussion or analysis of hazards.  The hazards 
described in Chapter 3 are not found in all facilities or types of animal food.   
 
Although this chapter sometimes describes the types of preventive controls that may be 
appropriate for you to implement to control specific hazards, see Chapter 4  Preventive Controls 
of this guidance for more detailed discussion of preventive controls.   
 
3.2  Known or Reasonably Foreseeable Hazards 
 
Animal food can become contaminated with biological, chemical (including radiological), or 
physical hazards.  Table 3-1 contains some examples of biological, chemical, and physical 
hazards in animal food that may be relevant, depending on the type of animal food (e.g., pet food 
or livestock food) being manufactured, processed, packed, or held at your facility.   
 
Table 3-1.  Examples of Known or Reasonably Foreseeable Hazards 
Hazard 
Hazard Sub-Category  Examples 
Category 
Biological  Bacteria  Salmonella spp. 
Listeria monocytogenes (L. monocytogenes) 
Pathogenic Escherichia coli (E. coli) 
Biological  Parasites  Toxoplasma gondii 
Cryptosporidium 
Biological  Prions  Prion causing Bovine Spongiform Encephalopathy 
(BSE) 
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  Contains Nonbinding Recommendations 
 
Hazard 
Hazard Sub-Category  Examples 
Category 
Chemical  Pesticide residues  Organochlorines 
Organophosphates 
Carbamates 
Chemical  Heavy metals  Lead 
Cadmium 
Mercury 
Chemical  Natural Toxins  Aflatoxin 
Fumonisin 
Ochratoxin 
Plant toxins (glucosinolates) 
Tissue toxins 
Chemical  Drug residues  Animal drugs (e.g., penicillin, pentobarbital) 
Drug carryover  Carryover of ionophores (e.g., monensin) into horse 
feed 
Chemical  Unapproved color and  D&C Red No. 6 
food additives 
Propylene glycol (specifically in cat food) 
Ethylene glycol 
Melamine 
Chemical  Intentionally  Triazines (melamine, cyanuric acid) 
introduced for the 
purpose of economic 
gain 
Chemical  Radionuclides  Radium 226 and 228 
Chemical  Environmental  Dioxins 
Polychlorinated Biphenyls (PCBs) 
Polyaromatic Hydrocarbons (PAH) 
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  Contains Nonbinding Recommendations 
 
Hazard 
Hazard Sub-Category  Examples 
Category 
Chemical  Nutrient deficiencies or  Minerals (e.g., inadequate calcium or salt (sodium 
toxicities  chloride); excess calcium, selenium, or salt) 
Vitamins (e.g., inadequate thiamine (cat food); 
excess vitamin D) 
Chemical  Industrial chemicals  Cleaning chemicals 
Non-food-grade lubricants 
Physical  Physical  Metal 
Glass 
Hard plastic 
 
In your hazard analysis, you must identify and evaluate the known or reasonably foreseeable 
biological, chemical, and physical hazards related to your animal food (which includes raw 
materials and other ingredients (ingredient-related hazards)), processes (process-related hazards), 
and your animal food-production environment (facility-related hazards).  See 21 CFR 507.33.  
Throughout this chapter, we discuss biological, chemical, and physical hazards from the 
perspective of ingredient-related hazards, process-related hazards, and facility-related hazards.   
 
3.3  Biological Hazards 
 
The biological hazards that are the focus of this guidance are bacterial pathogens (e.g., 
Salmonella spp., L. monocytogenes, and pathogenic E. coli), and certain parasites (e.g., 
Toxoplasma gondii) that may be associated with animal food or animal food processing 
operations and that can cause illness or disease in humans or animals.  The other biological 
hazards mentioned in Table 3-1 include other parasites (e.g., Cryptosporidium spp.) and prions 
(e.g., prions causing BSE in cattle).  Biological hazards could also include viral pathogens.  
When conducting your hazard analysis to identify known or reasonably foreseeable hazards, you 
should consider whether a pathogenic virus is a concern for your facility by reviewing any 
current scientific evidence and other information about introduction of pathogenic viruses into 
animal food (e.g., from animal food ingredients, animal food-packaging materials, or 
transportation vehicles) and transmission of these viruses through animal food.   
 
Animal food can become contaminated with bacterial pathogens.  These pathogens can be:   
  ingredient-related hazards  i.e., introduced from raw materials and other ingredients  
  process-related hazards  e.g., if the pathogens:   
  survive the manufacturing process 
o
  increase in number due to lack of time/temperature control or due to the animal 
o
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  Contains Nonbinding Recommendations 
 
foods formulation  
  are introduced into a finished animal food due to loss of container integrity  
o
  facility-related hazards  e.g., if the pathogens are introduced from:   
  insanitary animal food processing equipment  
o
  cross-contamination between raw and cooked products  
o
  contaminated air  
o
  sewage or contaminated water  
o
Table 3-2 is a Quick Reference Guide to help you identify bacteria and parasites and potential 
sources or entry points in your facility.  The hazards listed in Table 3-2 will not apply to all 
animal food at all facilities.   
 
Table 3-2.  Quick Reference Guide for Some Sources of Bacteria and Parasites in Animal 
Food 
Primary Source  Bacteria and Parasites (and Some Example Sources) 
  Salmonella spp. (raw meat and poultry, raw eggs or egg 
product, animal protein product (such as meat and bone 
Ingredient-related 
meal and fish meal), plant protein products (such as canola 
meal, soybean meal), fruits and vegetables, and flavor 
agents) 
L. monocytogenes (raw agricultural commodities) 
Pathogenic E. coli (raw meat, fruits and vegetables, plant 
protein product) 
Clostridium botulinum  
Toxoplasma gondii (raw meat) 
Cryptosporidium spp. (contaminated water used as an 
ingredient) 
  Salmonella spp. 
Process-related  L. monocytogenes 
Pathogenic E. coli 
Clostridium botulinum 
  Salmonella spp. (pests, dust, floors, cold wet areas, 
equipment, drains, condensate, coolers, and soil) 
Facility-related 
L. monocytogenes (floors, cold wet areas, equipment, 
drains, condensate, coolers, and soil) 
29 
  Contains Nonbinding Recommendations 
 
 
3.3.1  Foodborne Pathogens Associated with Animal Food 
 
Bacterial pathogens 
 
Bacterial pathogens can be classified based on whether they form spores (sporeformers) or 
whether they exist as vegetative cells and do not form spores (non-sporeformers).  Spores are not 
hazardous as long as they remain in the spore state.  Spores are very resistant to heat, chemicals, 
and other treatments that would normally kill vegetative cells of both sporeformers and non-
sporeformers.   
 
When spores survive a processing step designed to kill vegetative bacteria, they may become a 
hazard in the animal food if they are exposed to conditions that allow germination and growth as 
vegetative cells.  This can be particularly serious when a processing step has removed most of 
their competition.  Thus, other controls such as reduced pH or a  or temperature control 
w
(refrigeration or freezing) may be needed to control sporeformers that remain following the 
processing step designed to kill vegetative bacteria.  As a result, when spores are a concern, the 
process steps used to kill them are often much more stringent than those necessary to kill 
vegetative cells.   
 
Salmonella spp. is the bacterium responsible for salmonellosis in humans and animals.  For 
animals, different animal species typically develop disease in response to different Salmonella 
serotypes.  For livestock and poultry food, the following are some examples of the food and the 
Salmonella serotypes that have been associated with disease in the particular animal species 
consuming the animal food:   
  food for poultry with Salmonella Pullorum, Salmonella Gallinarum, or Salmonella 
Enteritidis 
  food for swine with Salmonella Choleraesuis  
  food for sheep with Salmonella Abortusovis  
  food for horse with Salmonella Abortusequi  
  food for cattle with Salmonella Newport or Salmonella Dublin  
 
We consider animal food for livestock and poultry to be adulterated when it may be injurious to 
health because it is contaminated with a Salmonella serotype that is likely to cause disease in the 
animal species intended to consume that animal food and the animal food will not subsequently 
undergo a commercial heat step or other commercial process that will kill the Salmonella (see 
our Compliance Policy Guide (CPG) Sec. 690.800 entitled Salmonella in Food for Animals.)5  
The Salmonella serotypes listed above are not commonly found in animal food at manufacturing 
facilities.  Therefore, you may determine that Salmonella is not a known or reasonably 
foreseeable hazard for your animal food, or is not a hazard requiring a preventive control, if you 
manufacture only livestock or poultry food.   
 
5 Food and Drug Administration. 2013. CPG Sec. 690.800 Salmonella in Food for Animals. 
https://www.fda.gov/media/86240/download 
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  Contains Nonbinding Recommendations 
 
 
We consider all pet food contaminated with any Salmonella serotype to be adulterated when the 
pet food will not subsequently undergo a commercial heat step or other commercial process that 
will kill the Salmonella.6  Infected dogs and cats can either be asymptomatic or exhibit clinical 
signs of gastroenteritis.  In severe cases, clinical signs can also include fever, dehydration, rapid 
heart rate, rapid breathing, shock, and death.  Infected dogs and cats can shed the bacteria in their 
feces for up to 6 weeks, whether they are exhibiting clinical signs or are asymptomatic (Ref. 1).   
 
Pet food contaminated with Salmonella also poses a significant risk to humans who handle that 
pet food.  In addition, Salmonella-contaminated pet food can lead to contamination of surfaces or 
objects in the home that can result in infections in humans touching these surfaces or objects.  
Salmonella contamination of surfaces or objects in the home can occur, for example, from: (1) 
contact with the contaminated pet food, (2) contact with the pet (or its feces) that has consumed 
the contaminated pet food, or (3) a human who has handled contaminated pet food or the 
infected pet and then subsequently handled the surface or object.  Examples of Salmonella 
contaminated surfaces or objects include pet bowls, pet bedding, pet toys, floors, and kitchen 
surfaces (Ref. 2).   
 
The association between human outbreaks of salmonellosis and Salmonella-contaminated pet 
food is well documented.  For example, the CDC reported that from January 1, 2006, to October 
31, 2008, 79 human cases of salmonellosis were linked to Salmonella Schwarzengrund in dry 
dog food manufactured by a facility in the U.S. (Ref. 3).  In 2012, 49 individuals were infected 
with Salmonella Infantis, which was linked to dry dog food manufactured by a different facility 
in the U.S. (Ref. 4).  In 2019, the CDC reported a multistate outbreak of multidrug-resistant 
Salmonella infections in humans linked to contact with pig ear dog treats.  A total of 154 people 
were infected with the outbreak strains of Salmonella (Ref. 5).  There also are published reports 
of transmission of Salmonella to humans via contact with Salmonella-infected pets (Refs. 6, 7 
and 8).   
 
Listeria monocytogenes (L. monocytogenes) is the bacterium responsible for listeriosis in 
humans and animals.  Clinical signs of listeriosis in dogs and cats can range from the non-
specific such as vomiting, diarrhea, and fever to the more specific signs such as neurological 
(imbalance or circling), or abortion in a pregnant animal.  If the animal becomes septicemic (an 
infection throughout its body), the clinical signs can range from high fever and lethargy to shock 
or death.   
 
There have been recalls of L. monocytogenes contaminated pet food (e.g., raw dog and cat food) 
due to the potential to cause listeriosis in humans or pets (Refs. 9, 10, and 11).  Transmission of 
L. monocytogenes from contaminated pet food to humans or pets could be similar to transmission 
of Salmonella.   
 
Pathogenic Strains of Escherichia coli (E. coli) are bacteria associated with foodborne illness 
in humans and animals.  Dogs and cats with foodborne illness caused by pathogenic E. coli can 
be asymptomatic or have symptoms ranging from mild gastroenteritis to hemorrhagic diarrhea.  
 
6 Ibid 
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  Contains Nonbinding Recommendations 
 
A study conducted to evaluate the prevalence of microbial organisms in various types of pet food 
found strains of non-O157:H7 Shiga toxin-producing E. coli in some raw pet food and jerky type 
treats (Ref. 12).  Transmission of pathogenic E. coli from contaminated pet food to humans could 
be similar to transmission of Salmonella.   
 
Clostridium botulinum is a spore-forming bacterium that grows best in low oxygen conditions 
and can produce toxins (e.g., neurotoxins or enterotoxins).  The bacteria form spores that can 
survive in a dormant state until exposed to conditions that support their germination and growth 
(e.g., low oxygen conditions).  Clostridium botulinum is one example.  There are seven types of 
C. botulinum designated by letters A through G.  Type C is most important in most animal 
species, but types D, B, and occasionally A and E can be a cause of disease (Ref. 13).  Most 
domestic animals are susceptible to intoxication by C. botulinum toxin, however some species 
are more susceptible (e.g., mink, horses, and cattle) than others (e.g., dogs and cats) (Ref. 14).  C. 
botulinum is often found in the intestinal tracts of poultry, cattle, and swine (Ref. 15).  Poultry 
carcasses (and some slaughter by-products) that are manufactured into animal food (such as food 
for mink) can be a source of botulinum toxin if the animal food is not properly treated (e.g., not 
heat treated, acidified, refrigerated, or frozen) and a low oxygen condition occurs during 
production (Ref. 15).  Another source of C. botulinum has been uneviscerated, salt-cured, whole 
fish products greater than 5 inches in length.  Uneviscerated, salt-cured, whole fish products have 
caused several outbreaks of botulism and death in humans (see our CPG Sec 540.650 entitled 
Uneviscerated Fish Products that are Salt-cured, Dried, or Smoked (Revised)7).  In 2018 and 
2020, uneviscerated, dried fish greater than 5 inches in length intended for use in pet food were 
recalled due to the potential to cause illness in pets (Refs. 16 and 17).   
 
C. botulinum toxin could also occur in inadequately processed low-acid canned food (LACF).   
However, with respect to microbiological hazards, activities subject to 21 CFR part 113 (which 
covers LACF) are not subject to the requirements in 21 CFR part 507, subparts C and E, 
provided the facility is in compliance with 21 CFR part 113. See 21 CFR 507.5(b).   
 
Non-bacterial pathogens 
 
Toxoplasma gondii (T. gondii) is a parasite that causes toxoplasmosis in humans and many 
animals (Ref. 18).  A common route of transmission in humans is through ingestion of 
contaminated and undercooked meat.  Inadvertent ingestion can also occur through handling 
contaminated utensils or eating food contaminated by those utensils.  Humans also can become 
infected through indirect ingestion after handling cat feces containing oocysts (a fertilized egg) 
or from handling anything contaminated with cat feces containing oocysts (e.g., dirt while 
gardening, eating unwashed fruits and vegetables, or drinking contaminated water).  Pregnant 
women who become infected can pass the infection to their fetus.  Immunocompromised people 
and pregnant women are at the highest risk for toxoplasmosis.  Young or immunocompromised 
animals can also develop clinical infections, causing a variety of diseases depending on the 
tissues infected (e.g., pneumonia, encephalitis, liver necrosis). 
 
7 https://www.fda.gov/regulatory-information/search-fda-guidance-documents/cpg-sec-540650-uneviscerated-fish-
products-are-salt-cured-dried-or-smoked-revised 
32 
  Contains Nonbinding Recommendations 
 
 
A meta-analysis published in 2015, looked at the prevalence of T. gondii in food-producing 
animals used for meat in the U.S. (Ref. 19).  The study found T. gondii infection is more 
widespread in lamb, goats, non-confinement-raised chickens, and non-confinement-raised pigs.  
The consumption of raw meat significantly increases the seroprevalence (i.e., the overall 
occurrence of a disease in a given population at one time, as measured by blood tests) of T. 
gondii in cats (Ref. 20).  This includes cats that are outdoors and hunting prey, but also includes 
cats fed raw meat-based diets.  A pet food manufacturer, especially one making raw pet food for 
cats, might consider this parasite as a known or reasonably foreseeable biological hazard in meat 
from the species of animals in which T. gondii is more likely to be found.   
 
Transmissible Spongiform Encephalopathy Agents  Transmissible spongiform 
encephalopathies, or prion diseases, are diseases caused by abnormal, misfolded forms of the 
prion protein.  The prion protein occurs normally in vertebrate animals and is found at highest 
levels in central nervous system tissues.   
 
Prion diseases of animals in the United States are bovine spongiform encephalopathy (BSE) in 
cattle, scrapie in sheep and goats, and chronic wasting disease (CWD) in deer and elk.  Of the 
prion diseases, only BSE is transmitted primarily through animal food.  BSE transmission can 
occur when tissues from infected cattle are rendered and the meat and bone meal (MBM) is 
recycled as an additive in cattle food, and then eaten by non-infected cattle.  This type of tissue 
recycling was banned in the United States in 1997 by FDAs BSE regulation (21 CFR 589.2000), 
which prohibits the use of mammalian protein, with certain exceptions, in food for ruminants.  
Though scrapie and CWD are not considered foodborne diseases, the BSE regulation protects 
against the potential for transmission by this route because it prohibits the use of mammalian 
protein in food for all ruminant animals, including food for sheep, goats, deer, antelopes, buffalo, 
and elk.   
 
Measures that exclude mammalian-derived tissue, such as bovine derived MBM, from ruminant 
feed (including measures that prevent bovine derived MBM entering ruminant feed via cross-
contamination during manufacturing and distribution), which are required under 21 CFR 
589.2000 and 21 CFR 589.2001, are considered by FDA to be effective against the transmission 
of the BSE agent.  See Chapter 2  Conducting a Hazard Analysis of this guidance for additional 
information.   
 
3.3.2  Ingredient-Related Biological Hazards 
 
See Table 3-2 in this chapter of this guidance for information that can help you identify 
ingredient-related biological hazards that may be associated with specific animal food.  See 
Chapter 4  Preventive Controls for recommendations on control of biological hazards.   
 
3.3.3  Process-Related Biological Hazards 
 
This section helps you identify process-related biological hazards for the animal food that you 
produce.  Some process-related biological hazards can occur if something goes wrong with a 
process control.  For example, pathogens that you intend to control by heat treatment could 
33 
  Contains Nonbinding Recommendations 
 
survive if your animal food is not subjected to an adequate time-temperature combination during 
application of the heat treatment.  Also, pathogens that you intend to control by refrigeration 
could multiply and/or produce toxin if there is a lack of proper refrigeration during animal food 
holding.   
 
Other process-related biological hazards are not related to something going wrong with a process 
control.  For example, if you use a process control that significantly minimizes (including 
eliminates) pathogens in a pet food and then add flavoring after the control, pathogens in the 
flavoring could be introduced into the pet food after the process control step.  Also, pathogens 
could be introduced into animal food after packaging if there is a lack of container integrity.   
 
In the following sections on process-related biological hazards, we describe examples of these 
kinds of process-related biological hazards.  See Chapter 4, section 4.5, for recommendations on 
control of some specific process-related biological hazards.   
 
Bacterial pathogens that survive process controls 
 
If a process control that you designed to kill bacterial pathogens does not work as intended, the 
bacterial pathogens, spores, or both that you intended to control can be present in your animal 
food.  See Chapter 4  Preventive Controls for an overview of recognized and established 
processing conditions to control pathogens and for factors to consider when designing your 
process to prevent problems.  For example:   
 
  Some animal food does not heat consistently throughout.  If the minimum process for 
lethality is not achieved at the coldest spot of the animal food, pathogens may survive the 
heat treatment.   
  Certain characteristics of animal food make it either easier or harder to destroy bacterial 
pathogens, if present.  For example, it is more difficult to kill pathogens in animal food 
with high oil content; oils tend to shield pathogens from the effects of heat.  The presence 
of moisture, both in and surrounding the animal food, makes destruction easier.  If these 
characteristics have not been considered in designing the process, pathogens may survive 
the treatment.   
  Different bacterial pathogens have different heat resistances and spores of bacterial 
pathogens are more heat tolerant than vegetative cells.  If the process is not designed to 
control the most resistant pathogen of concern in the animal food, pathogens may survive 
the treatment.   
 
Bacterial pathogens that grow 
 
Due to time and temperature abuse 
 
Bacterial pathogens introduced from contaminated ingredients into an animal food that does not 
undergo a lethality process, or pathogens that survive a lethality process as a result of a problem 
with a process control, can multiply (grow) and, depending on the pathogen, produce toxin as a 
result of time and temperature abuse of the animal food.  Time and temperature abuse occurs 
34 
  Contains Nonbinding Recommendations 
 
when animal food is allowed to remain at temperatures favorable to bacterial pathogen growth 
for sufficient time resulting in unsafe levels of the pathogens or their toxins in the animal food.  
Animal food that is subjected to time and temperature abuse can support growth of pathogens 
such as Salmonella.  For example, holding raw materials and ingredients that require 
refrigeration at room-temperature for several hours prior to processing can lead to pathogen 
growth.  Time and temperature abuse can cause pathogenic bacteria to grow to such levels that 
the process control normally used may not be adequate to significantly minimize (which includes 
eliminating) the hazard.   
 
In evaluating the potential of bacterial pathogens to grow in your animal food, you should 
consider the following factors:   
  the types of pathogenic bacteria that are known or reasonably foreseeable  
  whether those pathogens can grow in the animal food  
  the expected initial level of the pathogenic bacteria in the animal food  
 
See Chapter 4  Preventive Controls for an overview of processing conditions to minimize 
pathogen growth by controlling temperatures to prevent pathogen growth and controlling time of 
exposure to temperatures at which growth can occur.   
 
Due to poor formulation control 
 
Animal food types most susceptible to biological hazards due to problems with formulation (e.g., 
pH, a , and preservatives) are those that do not undergo a process control that will significantly 
w
minimize, or prevent, biological hazards during manufacturing and that may require refrigeration 
or freezing for safety during their manufacture and shelf life (e.g., some raw or minimally 
cooked pet food).  For these animal food types, product formulation can play an important role in 
significantly minimizing or preventing hazards.  Well-controlled formulation parameters such as 
pH, a , and use of preservatives can work in concert to establish an ecosystem designed to 
w
inhibit the growth of the pathogens that may be present.   
 
To determine the potential for a process-related hazard due to poor formulation control, we 
recommend that you know the formulations or ingredient lists of your incoming ingredients, as 
well as the equilibrated pH, titratable acidity, a , percent moisture and percent sodium, as 
w
appropriate, of the finished animal food.  Much of the animal food susceptible to biological 
hazards due to problems with formulation is made up of multiple ingredients, each with its own 
specific set of formulation parameters.  Any individual ingredient not meeting the formulation 
parameters established to ensure that the preventive control is achieved may result in an animal 
food that does not inhibit the growth or toxin formation of a pathogen that may be present in the 
animal food.  In determining the potential for a process-related biological hazard due to poor 
formulation control, we also recommend that you consider the interactions that may occur among 
the various raw materials and other ingredients when combined.  See Chapter 4, section 4.5.3, for 
an overview of formulation-based controls.   
 
Due to reduced oxygen packaging 
 
35 
  Contains Nonbinding Recommendations 
 
From a food safety standpoint, packaging serves two functions:  (1) it prevents contamination of 
the animal food; and (2) it makes possible, or extends the effectiveness of, food preservation 
methods.  For example, packaging can maintain the atmosphere in a controlled or modified 
atmosphere package or a vacuum package, or it can prevent rehydration of a dried animal food. 
Modified atmosphere packaging and vacuum packaging methods are grouped into a category that 
we call reduced oxygen packaging (ROP).  ROP is used to prevent the growth of spoilage 
organisms, thereby extending the shelf life of the product.  There are some other product quality 
benefits as well, such as reductions in rancidity, shrinkage, and color loss.   
 
However, ROP does not control the growth of all bacterial pathogens and can create a process-
related biological hazard.  The extended shelf life provides more time for toxin production or 
pathogen growth if pathogens are present and temperatures are suitable for growth.  Lower 
oxygen levels favor pathogens that can grow in the absence of oxygen over the aerobic spoilage 
organisms that require oxygen for growth.  For this reason, you may get toxin production before 
you get spoilage.   
 
The primary concern with ROP is C. botulinum, although there also may be concerns with other 
pathogens such as L. monocytogenes, particularly in refrigerated animal food (e.g., pet food).  If 
you have identified C. botulinum as a known or reasonably foreseeable hazard in your animal 
food, you should not use ROP unless barriers for C. botulinum are present.  These barriers could 
include a , pH, salt, thermal processing in the final container, and freezing with frozen storage 
w
and distribution.  Each of these barriers by itself can be effective in the control of C. botulinum 
growth.  Refrigeration below 38F (3.33C) can prevent growth of all strains of C. botulinum, 
but because temperatures above this are commonly employed for refrigeration, temperature 
should not be relied on as the only control.  Combinations of barriers that individually would not 
control growth of C. botulinum can work together to prevent growth.   
 
For a further discussion on the potential for ROP to create a process-related biological hazard as 
it relates to human food, see Annex 6 of the 2017 FDA Food Code.8   
 
Bacterial pathogens in ingredients added after applying process controls 
 
The manufacture of certain animal food involves, by design, the addition of ingredients after 
application of process controls.  For example, flavorings and fats may be added after extrusion 
(i.e., the process control) but prior to packaging in the production of some pet food.  A facility 
that produces animal food containing ingredients added after a process control should consider 
the potential for the added components to be a source of a process-related biological hazard as 
part of its hazard analysis.   
 
Bacterial pathogens introduced after packaging due to lack of container integrity 
 
Animal food manufactured and processed (e.g., heat treated) in a container or clean filled after 
treatment can become contaminated if its container loses seal integrity, thereby exposing the 
processed animal food to biological hazards.  Poorly formed or defective container closures can 
 
8 https://www.fda.gov/food/fda-food-code/food-code-2017 
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increase the risk of microbial pathogens entering the container through container handling that 
occurs after the product has been filled and the container has been sealed.   
 
3.3.4  Facility-Related Biological Hazards 
 
Facility-related biological hazards in animal food could occur from exposure or contact with 
contaminated equipment during procedures such as conveying, mixing, cooling, or packaging.  
In addition, animal food that is subjected to a preventive control (e.g., heat treatment, high 
pressure processing) to significantly minimize pathogens identified as hazards requiring a 
preventive control, may be recontaminated through exposure to a facility environment that 
contains these pathogens (Ref. 21).  As discussed in the following sections on facility-related 
biological hazards, there are challenges to preventing recontamination.   
 
The PCAF requirements specify that your hazard evaluation must include an evaluation of 
environmental pathogens whenever an animal food is exposed to the environment prior to 
packaging and the packaged animal food does not receive a treatment or otherwise include a 
control measure (such as a formulation lethal to the pathogen) that would significantly minimize 
the pathogen (see 21 CFR 507.33(c)(2)).  See 21 CFR 507.3 for the definition of environmental 
pathogen.  In the following sections, we provide information on potential sources of facility-
related environmental pathogens in different types of animal food facilities.   
 
Effectively designed and implemented CGMPs are key to keeping biological hazards out of your 
animal food.  However, the application of CGMPs cannot guarantee that a processed animal food 
will not become contaminated from the environment.  This is one reason why the PCAF 
requirements specify that sanitation controls include procedures, practices, and processes to 
ensure that the facility is maintained in a sanitary condition adequate to significantly minimize or 
prevent hazards such as environmental pathogens (see 21 CFR 507.34(c)(2)).  To verify 
implementation and effectiveness of a sanitation control, the PCAF requirements specify that (as 
appropriate to the facility, the animal food, and the nature of the preventive control and its role in 
the facilitys animal food safety system) you must conduct activities that include environmental 
monitoring for an environmental pathogen or for an appropriate indicator organism, by collecting 
and testing environmental samples, if contamination of an animal food with an environmental 
pathogen is a hazard requiring a preventive control.  See 21 CFR 507.49(a)(3).   
 
Sources of facility-related biological hazards 
 
The likelihood of product contamination with a facility-related environmental pathogen increases 
as the prevalence of the environmental pathogens in the processing environment increases.  The 
prevalence of the environmental pathogens in the processing environment can be influenced by 
the raw materials used in the process, the type of process, and the hygienic practices applied to 
keep the processing area clean and, as necessary, sanitized.  Table 3-3 is a guide to help you 
identify some of the sources of facility-related biological hazards that can contaminate the 
animal food processing environment; Table 3-3 does not provide an exhaustive list of such 
sources.   
 
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  Contains Nonbinding Recommendations 
 
Table 3-3.  Some Sources and Modes of Contamination of Facility-Related Biological 
Hazards 
Source  Modes of Contamination 
Raw agricultural commodities and  Transfer of biological hazards from the ingredient 
other ingredients (e.g., raw meat  to equipment and utensils 
and poultry, raw milk, raw offal, 
Transfer of biological hazards from the ingredient 
oil seeds, fruits and vegetables, 
to personnel handling the ingredient 
meat and bone meal) 
Inadequate cleaning of containers used to store 
ingredients containing hazards 
Food handlers and maintenance  Transfer of biological hazards from one point to 
personnel  another on their person (e.g., shoes and other 
clothing) 
Improper hand washing 
Transfer of biological hazards to animal food 
through improper handling or maintenance 
practices (e.g., insufficient cleaning and sanitizing 
animal food-contact surfaces after equipment 
maintenance) 
Air and water   Lack of appropriate air filtration for cooling, 
drying, air conveying 
Improper air flow from raw materials and other 
ingredients areas to finished animal food areas 
Aerosols from improper cleaning practices 
Insects and pests (e.g., flies,  Transfer of biological hazards from outside the 
cockroaches, rodents)  facility or from one point to another in the facility 
as pests travel 
Contact with finished animal food 
Transport equipment (e.g.,  Transfer of biological hazards throughout the 
forklifts, racks, carts, conveyor  facility via wheels on equipment 
belts) 
Cross-contamination from using the same 
equipment for ingredients and finished animal 
food 
 
 
 
 
38 
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Transient and resident facility-related environmental pathogens 
 
Once bacterial pathogens have been introduced into the processing environment, experience has 
shown that pathogens may be present as transient contamination or as resident contamination 
within a facility.   
 
Transient contamination 
 
Bacterial pathogens, including environmental pathogens, are typically introduced into the 
processing facility through incoming raw materials and other ingredients, personnel, or pests.  It 
is important to ensure that these microorganisms remain transient and do not become established 
in the environment where they can grow and multiply.  Transient contaminants can, however, 
result in a diversity of pathogens in the processing environment that can show up in the 
processing lines and finished animal food.  This phenomenon could occur in animal food 
operations using a wide variety of raw materials and other ingredients (e.g., raw meat, meat and 
bone meal, canola meal) because these materials can contain very diverse microflora.  In general, 
routine cleaning and sanitizing in accordance with CGMPs is adequate to protect against 
contamination by transient bacteria in the processing facility.   
 
Resident contamination 
 
Bacterial pathogens causing resident contamination can also be introduced into the processing 
facility, where the pathogens then become established in a harborage site, multiply, and persist 
for extended periods of time, even years.  A harborage site, or niche, is a site in the environment 
or on equipment (e.g., junctions, cracks, holes, and dead-end areas) that enables the 
accumulation of residues (e.g., animal food debris, dust, and water) and permits the growth of 
microorganisms such as Salmonella and L. monocytogenes.  These sites may be difficult to 
inspect or access and therefore can help protect environmental pathogens during routine cleaning 
and sanitizing.  While routine cleaning and sanitation practices are adequate to protect against 
the presence of transient contaminants, such practices do not control the presence of resident 
contaminants once they have become established.  Sanitation controls, including proper 
personnel practices, and good equipment and facility design are important in preventing transient 
bacterial pathogens from becoming resident strains.   
 
Once an environmental pathogen has become established as a resident contaminant, there is a 
persistent contamination risk for animal food processed in that facility.  Intensified sanitation 
procedures will be needed to significantly minimize the contamination.  Salmonella and L. 
monocytogenes are the pathogens most likely to set up residence in animal food processing 
facilities.  Also, the potential exists for other pathogens (e.g., pathogenic E. coli) to become 
established as resident contaminants.   
 
Key determinants for the pathogens to become established in an animal food processing 
environment are:  (1) the temperature at which the animal food processing environment is 
maintained; (2) the available moisture in the animal food processing environment; and (3) the 
availability of nutrients for growth.  For processed animal food, this typically translates into two 
primary categories of animal food processing environments:   
39 
  Contains Nonbinding Recommendations 
 
  frozen/refrigerated and wet  
  warm/ambient and dry  
 
In both cases, proper cleaning is needed to minimize nutrient availability for growth of 
environmental pathogens.  The pathogen most often associated with cold and wet processing 
environments is L. monocytogenes, and the pathogen most often associated with warm and dry 
processing environments is Salmonella (Refs. 22 and 23).   
 
Facility-related environmental pathogens associated with wet and dry processing 
environments 
 
Animal food processing operations can generally be classified into one of two simple categories 
 wet processing environments or dry processing environments (Table 3-4).  This very simple 
distinction has significant implications for the best strategies for controlling animal food 
contamination from environmental pathogens.   
 
Table 3-4.  Some Examples of Animal Food Processed in Wet and Dry Processing 
Environments 
Processing Environment 
Examples of Animal Food 
Conditions 
Wet  Frozen raw pet food 
Refrigerated pet food 
Dry  Milk powders 
Extruded animal food 
Rawhide pet chews/treats 
Jerky treats 
Dehydrated animal food 
Meat and bone meal 
Freeze-dried raw pet food 
 
Wet processing environments 
 
The most effective strategy to prevent the contamination of finished animal food with L. 
monocytogenes is to maintain an environment as dry as possible.  Wet environments have some 
obvious characteristics that can lead to contamination by L. monocytogenes, such as:   
 
  wet floors due to constant wet cleaning will facilitate the transfer of L. monocytogenes 
from an environmental source to animal food-contact surfaces  
 
40 
  Contains Nonbinding Recommendations 
 
  wet floors can create harborage sites if they are not well maintained and have broken or 
cracked grout or tiles.  These structures may provide protected harborage to 
environmental pathogens even when the floors are cleaned and sanitized  
 
  condensation on overhead structures as a result of air temperature and humidity control 
issues and from use of water in heating and cooling operations creates a means of transfer 
of L. monocytogenes from non-animal food-contact surfaces to exposed animal food and 
animal food-contact surfaces  
 
  frost formation due to condensation at freezer entry and exit points provides an 
opportunity for moisture accumulation and a constant source of water in which L. 
monocytogenes can multiply  
 
Wet floors can serve as potential vectors for L. monocytogenes via the movement of people and 
equipment and material handling items such as totes and pallets.  For example, wet floors can 
serve as a potential vector for pathogen transfer when personnel walk through standing water on 
poorly designed floors and drains and during cleaning.  L. monocytogenes is not usually airborne; 
however, in wet environments, aerosols from high pressure water hoses used during cleaning 
operations help spread L. monocytogenes throughout the environment and from one surface (e.g., 
floors) to another surface (e.g., animal food-contact surfaces such as conveyors, tables, and 
animal food containers).  In many facilities, certain processing operations are inherently wet such 
as raw material preparation and mixing and formulation of liquid components.  In these cases, 
we recommend that you use personnel, equipment traffic, and cleaning practices that minimize 
water accumulation and aerosol formation to prevent in-process and finished animal food 
recontamination.   
 
We recommend that wet processing areas be dried out as much as possible.  This could be a 
challenge for some segments of the animal food industry that depend on the unlimited use of 
water for equipment and facility cleaning practices.   
 
Dry processing environments 
 
Environmental moisture control is critically important in preventing Salmonella contamination in 
low-moisture products (Ref. 23).  Water in the dry processing environment is one of the most 
significant risk factors (perhaps the single most important factor) for Salmonella contamination 
because water allows for pathogen growth, significantly increasing the risk for animal food 
contamination.  Water, present even in very small amounts for short, sporadic time periods, may 
allow Salmonella to grow in the environment.  Moisture may be obvious from sources such as 
water droplets or puddles from wet cleaning, but not so obvious from sources such as high 
relative humidity or moisture accumulating inside equipment.   
 
Salmonella can, to varying degrees, be introduced into low-moisture food manufacturing 
facilities and become established in those environments.  Once water enters a harborage site, 
microbial growth can occur and the potential risk of contamination of the environment and of the 
product is increased.  (Ref. 24).   
 
41 
  Contains Nonbinding Recommendations 
 
The presence of water in the dry processing environment can result from improper use of water 
during cleaning and can enhance the probability of contamination from pathogens such as 
Salmonella (Ref. 24).  Other sources resulting in the presence of water in a dry area include 
condensate formation, leaking water or steam valves, infiltration of water following heavy rains 
(e.g., leaky roofs), and the use of water during fire emergencies.  We recommend that you 
remove water immediately from the primary Salmonella-controlled hygiene areas (areas where 
animal food that will not undergo a lethality process is exposed to the environment) following 
such events to keep the plant environment as dry as possible.   
 
You should maintain dry conditions at all times in primary Salmonella-controlled hygiene areas, 
except for the occasions when you have determined that controlled wet cleaning is necessary.  
Potential problems arise when there is visible water present in the dry areas or when there are 
areas in which standing water has dried.  Salmonella may be found both in wet spots and in spots 
where standing water has dried (Ref. 25).  The latter situation may present an additional risk of 
spread via the generation of airborne contaminated dust (Ref. 21).   
 
3.4  Chemical Hazards 
 
The chemical hazards that are the subject of this guidance include chemical hazards that are 
natural components of ingredients (e.g., glucosinolates) or natural toxins (e.g., mycotoxins), 
contaminants of raw materials and other ingredients (e.g., pesticides and drug residues), and 
chemical hazards as a result of manufacturing errors (e.g., nutrient deficiencies or toxicities). 
Animal food can become contaminated with chemical hazards that can be:   
  ingredient-related hazards  that is, introduced from raw materials and other ingredients 
such as natural toxins or contaminants on or in ingredients  
  process-related hazards  e.g., from manufacturing errors, or cross-contamination  
  facility-related hazards  e.g., from chemicals used on animal food processing equipment 
or utensils, or chemicals stored in the facility  
 
Some chemical hazards may cause immediate effects (e.g., gastrointestinal symptoms, shock, or 
death), such as those caused by industrial chemicals (e.g., caustic cleaning compounds).  Other 
chemical hazards may cause more chronic effects after long-term exposure to the chemical (e.g., 
weight loss, depression, liver failure, neurological disease, or cancer) such as those caused by 
lead or some mycotoxins.   
 
An example of a range of acute to chronic toxic effects can be seen in sheep fed animal food 
with excess levels of copper (Refs. 26 and 27).  Acute toxic effects in sheep include sudden onset 
of abdominal pain, diarrhea, loss of appetite, shock, or death.  Chronic toxic effects of copper in 
sheep include similar symptoms to acute exposure, but present over a longer period of time.  
Chronic toxic effects in sheep also include difficulty breathing, jaundice, and death.   
 
FDA has set action levels and tolerances for some chemical contaminants in animal food in our 
GFI entitled Action Levels for Poisonous or Deleterious Substances in Human Food and 
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  Contains Nonbinding Recommendations 
 
Animal Feed.9  These levels represent limits at or above which FDA may take legal action to 
remove products from the market.  Where no established action level or tolerance exists, FDA 
may take legal action against the product at the minimal quantifiable (or in some cases 
detectable) level of the contaminant.  Action levels and tolerances are established based on the 
unavoidability of the poisonous or deleterious substances and do not represent permissible levels 
of contamination where it is avoidable.  FDA has established temporary tolerances for 
polychlorinated biphenyls (PCBs) in animal food and food packaging material (see 21 CFR 
509.30).   
 
Under the FD&C Act, certain substances, such as food additives, color additives, and new animal 
drugs, require premarket approval before they may be legally used.  Approval for food additives, 
color additives, and new animal drugs can have limitations so that the substance can only be used 
legally on or in animal food for specific purposes, specific species, or for a specific life stage or 
production class.   
 
Chemical substances in an animal food are not always considered hazards and their occurrence 
may be unavoidable.  The particular chemical and its level in the animal food (depending on the 
species, life stage, or production class the animal food is intended for) are factors to consider in 
determining whether the chemical is a hazard.  The preventive controls that you identify and 
implement for controlling specific chemical hazards should be based on the characteristics of the 
chemical and how the chemical is introduced into your animal food.   
 
For additional information on the control of chemical hazards, see Chapter 4, section 4.6.   
 
In the remainder of this section on chemical hazards, we briefly describe characteristics of some 
chemical hazards that can be present in animal food and processing environments, including 
ways they can be introduced into animal food.  Effectively designed and implemented CGMPs 
can be key to keeping many process-related chemical hazards and facility-related chemical 
hazards out of your animal food.   
 
Table 3-5 is a guide to help you identify some sources of chemical hazards when conducting 
your hazard analysis. This is not an exhaustive list.   
 
 
 
 
 
 
 
 
 
 
 
 
9 https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-action-levels-
poisonous-or-deleterious-substances-human-food-and-animal-feed.  
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  Contains Nonbinding Recommendations 
 
Table 3-5.  Quick Reference Guide for Some Sources of Chemical Hazards 
Source  Examples 
Ingredient-related  Pesticide residues and mycotoxins on raw agricultural 
chemical hazards  commodities and grains 
Heavy metals in or on raw agricultural commodities or in mineral 
ingredients or premixes 
Natural toxins (e.g., glucosinolates in the Brassicaceae family) 
Animal drug residues 
Unapproved food or color additives 
Radiological hazards 
Dioxins 
Process-related chemical  Nutrient deficiencies or toxicities due to manufacturing error 
hazards 
Radiological hazards from use of contaminated water supply 
Animal drug carryover from medicated to non-medicated animal 
food 
Food or color additives not approved for certain species due to 
incomplete cleanout of equipment 
Facility-related chemical  Contamination with industrial chemicals such as cleaners or 
hazards  sanitizers 
Chemicals not used in processing animal food but stored in the 
facility such as fertilizers 
Heavy metals due to leaching from containers or utensils 
 
3.4.1  Ingredient-Related Chemical Hazards 
 
Pesticides 
 
Pesticide chemical residues may be of concern in food crops and in foods of animal origin.  The 
term pesticide chemical is used for any substance (with certain exceptions) that is a pesticide 
within the meaning of the Federal Insecticide, Fungicide, and Rodenticide Act (see FD&C Act,  
201(q)).  Pesticides (e.g., insecticides, fungicides, rodenticides, insect repellants, herbicides, and 
some antimicrobials) are designed to prevent, destroy, repel, or reduce pests (Ref. 28).   
 
All pesticide chemicals sold or distributed in the United States must be registered by the 
Environmental Protection Agency (EPA).  See 40 CFR part 180.  The EPA also establishes 
tolerances (maximum amounts) for pesticide chemical residues in or on food.  Pesticide chemical 
residues in or on food render the food adulterated under section 402(a)(2)(B) of the FD&C Act 
44 
  Contains Nonbinding Recommendations 
 
unless EPA has set a tolerance for that residue in or on that food and the residue quantity is 
within that tolerance limit or there is an exemption from the tolerance requirement for that 
residue (see FD&C Act,  408(a)(2)(B)).  FDA and the USDA enforce tolerances in food under 
their jurisdiction, using a memorandum of understanding to coordinate activities among FDA, 
USDA, and EPA (Ref. 29).  A detailed description of how FDA enforces tolerances for pesticide 
chemical residues in animal food is available in FDAs CPG Sec. 575.100 entitled Pesticide 
Residues in Food and Feed - Enforcement Criteria.10  For more information regarding pesticide 
chemical residues and the FDA Pesticide Residue Monitoring Program, see the annual reports 
available on FDAs website.11   
 
Reasons for adulteration of animal food products with a pesticide chemical residue are the 
improper treatment of a raw agricultural commodity with a registered pesticide or the raw 
agricultural commodity being exposed to non-registered pesticides.   
 
Heavy metals 
 
Heavy metals are naturally occurring elements such as lead, arsenic, cadmium, and mercury.  
Increased levels of heavy metals in the environment are often a result of industrial and 
agricultural practices (e.g., use of pesticides containing heavy metals, use of manure as a 
fertilizer, or release of industrial waste) (Ref. 30).  Mercury is known to accumulate in certain 
fish species.  One study of food found mercury concentrations in tested cat and dog food that 
ranged from 1 to 604 nanograms per gram (ng/g).  The pet food samples with the highest 
concentrations of mercury all contained fish as the primary ingredient (Ref. 31).  Though not 
environmental, another potential source of contamination of animal food during manufacturing is 
the leaching of heavy metals from containers or utensils that come in contact with the animal 
food.   
 
Mineral supplements and premixes for animal food have been found to be a common source of 
high levels of heavy metals (Refs. 32 and 33).  Raw minerals are typically mined or recycled.  
Mineral ore deposits are often a mixture of several different inorganic forms of the mineral and 
may include several other minerals as well as contaminants.  For example, in some regions, lead 
is a natural contaminant of calcium carbonate (limestone) (Ref. 34).   
 
Consumption of animal food contaminated with heavy metals can cause adverse health 
consequences to the animal.  For example, lead exposure in birds can cause anorexia, loss of 
condition, wing and leg weakness, and anemia.  In dogs, lead exposure presents predominantly 
as gastrointestinal abnormalities; however, anxiety, hysterical barking, jaw champing, salivation, 
blindness, ataxia, muscle spasms, and convulsions may develop (Ref. 35).  Whether an animal 
develops an injury or illness as a result of exposure to minerals (including heavy metals) depends 
upon the species, level of the mineral in the animal food, and frequency of exposure (Ref. 26).   
 
Information on heavy metals in animal food is available (Refs. 26, 36, and 37).  If you have 
identified one or more heavy metals as a known or reasonably foreseeable hazard for your 
 
10 https://www.fda.gov/media/75151/download 
11 https://www.fda.gov/food/pesticides/pesticide-residue-monitoring-program-reports-and-data 
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animal food, we recommend you review multiple references for your hazard analysis.  These 
resources may recommend different maximum levels of a heavy metal in animal food for the 
same species depending on the parameters of the safety review conducted.  You should use the 
lowest maximum level of the heavy metal recommended by the resources when establishing your 
preventive control.  You should ensure the reference that you use takes into consideration both 
animal food and human food derived from animals, if appropriate.   
 
Natural toxins 
 
Mycotoxins 
 
Natural toxins (i.e., naturally occurring toxins), such as mycotoxins, are recognized as hazards in 
raw or processed agricultural commodities.  The term mycotoxins is used for a group of 
natural toxins which include, among others, aflatoxins, fumonisins, deoxynivalenol (vomitoxin), 
zearalenone, ochratoxin, and ergot alkaloids, that are recognized as hazards in raw or processed 
agricultural commodities.  Mycotoxins are toxic secondary metabolites produced by certain fungi 
(i.e., molds) that can infect raw agricultural commodities (e.g., grains, fruits, and nuts) and 
proliferate in the field and during storage.  
 
The occurrence of mycotoxins in raw agricultural commodities is not entirely avoidable.  
Occurrence of these toxins on commodities susceptible to mold infestation is influenced by 
environmental factors such as temperature, humidity, and extent of rainfall during the pre-
harvesting, harvesting, and post-harvesting periods.  The molds that produce mycotoxins 
typically grow and become established in the raw agricultural commodity during stressful 
growing conditions (e.g., when there is insect damage to the crop or a drought) and holding 
conditions (e.g., wet storage from condensation).   
 
Mycotoxins may produce various toxicological effects.  Some mycotoxins are teratogenic, 
immunotoxic, mutagenic, or carcinogenic and are associated with various diseases in susceptible 
animal species and humans.  The FDA has set species specific recommended maximum levels 
for aflatoxins, fumonisins, and deoxynivalenol in some animal food (Table 3-6).  FDA has not 
established levels for other mycotoxins such as ochratoxin and zearalenone.  When these 
mycotoxins are found in animal food the FDA reviews each finding on a case-by-case basis.   
 
Hazardous levels of mycotoxins have been found in individual ingredients as well as finished 
animal food.  When mycotoxins are found in individual ingredients, FDA guidance (included in 
Table 3-6 below) may be used to identify if the ingredient may safely be used in food for 
different species.  For example, corn containing 20 parts per billion (ppb) or more aflatoxin 
should not be used in animal food for dairy animals since it could result in unsafe residues of 
aflatoxin in milk (greater than 0.5 ppb).  Aflatoxin levels at or below 300 ppb in corn can be used 
in animal food for finishing beef cattle because the level does not pose a health concern for the 
beef cattle or to humans consuming food derived from the beef cattle.   
 
 
 
 
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Table 3-6.  Mycotoxins Associated with Ingredients Used in Animal Food 
Ingredients in which the 
Mycotoxins  Related Guidance 
Mycotoxin may be Found 
Aflatoxins  Corn, Cottonseed, Peanuts  CPG Sec. 683.100 entitled Action 
Levels for Aflatoxins in Animal 
Feeds12 
Fumonisins  Corn  GFI #112 entitled Fumonisin Levels in 
Human Foods and Animal Feeds13 
Deoxynivalenol  Wheat, Barley  Guidance for Industry and FDA entitled 
(Vomitoxin)  Advisory Levels for Deoxynivalenol 
(DON) in Finished Wheat Products for 
Human Consumption and Grains and 
Grain By-Products used for Animal 
Feed14 
Ochratoxin  Oats, Wheat, Flax (Linseed),  Reviewed on a case-by-case basis 
Soybean Meal 
Zearalenone  Grains (e.g., wheat, barley,  Reviewed on a case-by-case basis 
oats) 
 
Mycotoxins are not significantly degraded by food processing and can contaminate finished 
processed animal food (Ref. 38).  In 1998, 2005, 2011, 2013, 2020, and 2021 aflatoxin 
contamination of dog and cat food resulted in illness, dog mortalities, and extensive recalls of 
affected dog and cat food (Refs. 39, 40, 41, 42, 43, and 44).   
 
Plant toxins 
 
Plants are known to produce a number of toxicants and anti-nutritional factors, such as protease 
inhibitors, hemolytic agents, and neurotoxins, which often serve the plant as natural defense 
compounds against pests or pathogens.  An anti-nutritional factor, or anti-nutrient, is a naturally-
occurring substance found in plant-derived foods that interferes with absorption or proper 
functioning of nutrients in the body (Ref. 45).  For example, most cereal grains contain protease 
inhibitors, which can diminish the nutritive value of proteins.  For the purpose of this guidance, 
anti-nutritional factors are included in plant toxins as they are known or reasonably foreseeable 
 
12 https://www.fda.gov/media/121202/download 
13 https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-fumonisin-levels-
human-foods-and-animal-feeds 
14 https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-and-fda-advisory-
levels-deoxynivalenol-don-finished-wheat-products-human 
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hazards associated with some ingredients.   
 
There are a variety of plant toxins with different health effects.  Many legumes contain relatively 
high levels of lectins and cyanogenic glycosides.  Lectins, if not destroyed by cooking or 
removed by soaking, can cause severe nausea, vomiting, and diarrhea.  The levels of cyanogenic 
glycosides in cassava and some legumes can lead to death or chronic neurological disease if 
these foods are eaten uncooked (Ref. 46).  Plants from the family Brassicaceae contain 
glucosinolates which may be deleterious to animal health such as impairing thyroid function in 
many species (Ref. 47).   
 
Some plant-based ingredients, including those plant ingredients that may contain natural toxins, 
are approved as food additives (see discussion below Unapproved Color and Food Additives).  A 
food additive regulation may specify a method of manufacture, restrict the intended animal 
species, restrict the percentage of the food additive in a finished animal food, set a maximum 
level of the natural toxins, or a combination of these measures.  For example, the approval for 
heat toasted crambe meal specifies, among other things, that glucosinolate calculated as 
epiprogoitrin cannot be more than 4 percent of the meal by weight.  The approval also restricts 
use to feed for feedlot cattle as a source of protein in an amount not to exceed 4.2 percent of the 
total ration (see 21 CFR 573.310).   
 
Tissue toxins 
 
The presence of thyroid gland tissue in cattle and lamb products has been associated with 
exogenous thyrotoxicosis (hyperthyroidism) in humans due to bioactive thyroid gland hormones 
(Ref. 48).  For this reason, USDA prohibits the use of thyroid glands and laryngeal muscle tissue 
for human food (Ref. 49).   
 
Cases of exogenous thyrotoxicosis in dogs have been associated with pet treats that contained 
detectable thyroid hormones (Ref. 50).  In early 2017, FDA received reports of ill dogs that, 
upon further investigation, resulted in the recall of two different brands of dog food because of 
elevated levels of thyroid hormone (Refs. 51 and 52).  Laryngeal tissue (gullets) obtained from 
beef and lamb slaughter establishments used in the manufacture of pet treats could be a potential 
source of thyroid tissue that could result in thyrotoxicosis in pets.  Removal of the thyroid gland 
does not ensure that all thyroid tissue is eliminated from the gullet.  Because of this potential 
hazard, New Zealand restricts the use of tissue from the thyroid gland or surrounding structures 
(larynx) in pet food (Ref. 53).  In 2017, FDA provided letters to industry and to veterinarians 
with information on thyroid hormones in pet food (Refs. 54 and 55).  When identifying known or 
reasonably foreseeable hazards, pet food and pet treat manufacturers should determine whether 
laryngeal tissue (gullet) is included in their source material and thus could result in 
thyrotoxicosis in pets consuming food or treats derived from this material.   
 
Animal drugs 
 
Animal drugs can be chemical hazards introduced into your animal food such as through an 
ingredient containing residues (ingredient-related chemical hazard) or through drug carryover or 
cross contamination during manufacturing (process-related chemical hazard).  An example of an 
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ingredient-related hazard is drug contamination in an animal food as a result of using a raw 
material that contains drug residues.  A drug contamination that is a result of a process-related 
hazard typically is the result of cross-contamination of animal food from either incorrect 
sequencing of medicated feeds or incorrect cleanout of equipment between batches of medicated 
and non-medicated animal food.  See section 3.4.2 for process-related drug contamination.   
 
Animal drug residues in ingredients 
 
In the United States, animal drugs require approval by FDA before they can be marketed for 
administration to animals.  For animal drugs used in food-producing animals, FDA establishes a 
tolerance for the drug residue in human food as part of the approval process.  Animal drug 
residues detected in food derived from food-producing animals (i.e., animal tissues such as meat, 
milk, and eggs) are considered a hazard for human food if an established animal drug tolerance is 
exceeded.   
 
Many slaughter products not used in human food (e.g., not fit for human consumption for various 
reasons) are used in animal food.  Animal food derived from meat, organs (e.g., liver, kidney, 
heart, brain, and thymus), fat, or skin may contain drug residues (Ref. 56).  Although the 
metabolism and elimination of drugs may vary widely within and between species, as a general 
rule, the highest drug concentrations will be found in the liver or kidney (e.g., penicillin in 
kidneys or sulfa drugs in liver).  Depending on the chemical property of the drug, residues of 
certain drugs may become concentrated during animal food manufacturing and processing.  For 
example, drugs that are highly lipid soluble will often be found at the highest concentration in 
animal food rich in fats/oils.  In 2013, two companies recalled various pet treats after antibiotic 
residues were found upon testing of the treats by a New York State laboratory (Ref. 57).  In 
2014, FDA issued an import alert for poultry jerky-type treats due to the presence of antibiotic 
and/or antiviral residues as a result of positive test results for these residues in jerky treats from 
certain countries (Ref. 58).   
 
Another example of a drug residue in animal tissues is pentobarbital, which is a component of 
euthanasia solutions that are used to humanely kill animals.  Pentobarbital is not approved for 
euthanasia use in food-producing animals.  Animal food that contains a detectable level of 
pentobarbital, using an FDA validated method, is considered adulterated under  402(a)(2)(C)(ii) 
of the FD&C Act.  Pentobarbital residues in animal tissues are most likely the result of 
euthanasia of horses or other animals not intended for human consumption.  Pentobarbital is 
stable in tissue, aqueous environments, and resists degradation at rendering temperatures (Refs. 
59 and 60).  There are reports of pentobarbital toxicosis in domestic species, zoological animals, 
and wildlife (Refs. 61, 62, and 63).  In 2015, cases of toxicosis linked to pentobarbital in 
horsemeat resulted in the death of two animals and illness of a third in a wildlife preservation 
center in the United States (Ref. 64).  In 2017, pentobarbital in dog food resulted in illness in 
four dogs and the death of a fifth dog (Ref. 65).   
 
Pentobarbital residues should be identified as a known or reasonably foreseeable hazard for 
facilities that salvage skeletal muscle, organs, or other tissues from animals that died other than 
by slaughter if the cause of death is unknown, or the animal was known to be euthanized with 
chemicals.  The salvaged skeletal muscle, organs or other tissues are generally used for food for 
49 
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carnivorous animals such as those at zoos, wildlife rehabilitation centers, private wildlife 
preservation centers, alligator farms, mink farms, or in pet food products.  We recommend 
operations that salvage skeletal muscles, organs, or other tissues for processing determine 
whether animals have been euthanized using pentobarbital and, if so, exclude those animals from 
use as animal food.   
 
Unapproved color and food additives 
 
Any substance/ingredient intentionally added to an animal food must be used in accordance with 
a food additive regulation (see 21 CFR part 573), unless it is generally recognized as safe 
(GRAS) among qualified experts for its intended use as described in 21 CFR 570.30.  Substances 
that are GRAS for their intended uses in animal food are listed in 21 CFR parts 582 and 584.15  
A substance that is a color additive must be used in accordance with a color additive listing (see 
21 CFR parts 73 and 74).  If a color additive listed in 21 CFR part 74, subpart A, is used, ensure 
that the batch has been certified in accordance with 21 CFR part 80.  If the batch is not certified, 
the color additive is considered unapproved for use in food.  Under the PCAF regulation, an 
unapproved food or color additive is a chemical hazard (see 21 CFR 507.33(b)(1)(ii)).   
 
The Association of American Feed Control Officials (AAFCO) Official Publication contains 
feed (animal food) ingredients and their definitions (Ref. 36).  The Official Publication includes 
FDA approved animal food additives, as well as substances that are GRAS for an intended use in 
animal food.  Other ingredients in the Official Publication are not approved animal food 
additives and may not meet the criteria to be GRAS for a use.  Nevertheless, we do not intend to 
take enforcement action against these other ingredients in the AAFCO Official Publication for 
their marketing in interstate commerce, provided there are no food safety concerns about the use 
or composition of the ingredient that would render the food adulterated under section 402 of the 
FD&C Act.   
 
Some food and color additives are specifically prohibited from use in animal food because the 
additives pose a potential risk to public health or have not been shown by adequate scientific data 
to be safe for use in such food or feed (see 21 CFR part 589, and 21 CFR 81.10).  Examples of 
such food and color additives are gentian violet (see 21 CFR 589.1000), propylene glycol in or 
on cat food (see 21 CFR 589.1001), and FD&C Red No. 4 (see 21 CFR 81.10(d)).  We consider 
a prohibited food additive or color additive to be an unapproved food additive or color additive 
for the purposes of the PCAF regulation and thus a chemical hazard.  
 
The use of a substance (whether a GRAS substance or a food additive) in human food does not 
mean it is GRAS or approved as a food additive for use in animal food.  In fact, the substance 
may be harmful if used in animal food. One example is xylitol, which is found in human foods 
such as chewing gum, sugar-free nut butters, and some baked goods.  However, xylitol is toxic to 
dogs and if ingested can cause severe hypoglycemia, liver disease, or death (Ref. 66).   
 
15 These regulations do not identify all substances that are GRAS because it is impractical for FDA to compile a 
comprehensive list. Under FDAs Animal Food GRAS Notification Program, individuals and firms may voluntarily 
notify FDA if they have concluded that an animal food substance is GRAS for a particular use.  For more 
information, see the animal food Generally Recognized as Safe (GRAS) Notification Program webpage at 
https://www.fda.gov/animal-veterinary/animal-food-feeds/generally-recognized-safe-gras-notification-program.   
50 
  Contains Nonbinding Recommendations 
 
 
Chemical hazards that may be intentionally introduced for purposes of economic gain 
 
The PCAF requirements specify that you must consider, as part of your hazard identification, 
known or reasonably foreseeable hazards that may be intentionally introduced for purposes of 
economic gain (21 CFR 507.33(b)(2)(iii)).  We recommend that you focus on past patterns of 
adulteration, that could suggest a potential for intentional adulteration, recognizing that the past 
occurrences may not be associated with your supplier or your exact type of animal food.  To 
determine if a hazard that may be intentionally introduced for purposes of economic gain is a 
hazard requiring a preventive control, we recommend that your hazard analysis consider the 
country of origin of an ingredient that may contain the hazard and any specific supplier 
associated with an ingredient containing that hazard.   
 
One historical example of intentional adulteration for the purpose of economic gain in animal 
food was the addition of melamine and other triazines into plant protein ingredients (e.g., wheat 
gluten and rice protein concentrate) exported to the United States in 2007 by firms in China (Ref. 
67).  The adulterated plant protein ingredients were used in the manufacture of pet food.  This 
adulteration resulted in a massive pet food recall and illness and death of many dogs and cats.  
The melamine adulterated pet food also ended up in food for poultry, swine, and food-producing 
fish.  This raised concerns about the safety of human food products derived from those food-
producing animals and resulted in the quarantine of thousands of animals until a risk assessment 
was completed (Ref. 68).  Melamine was also intentionally used by one country in milk products 
(for human food), though none of the milk products were exported to the United States (Ref. 69).   
 
The repeated use of melamine over the years, in animal and human food, demonstrates that 
patterns of economically motivated adulteration can emerge and should be considered as part of 
a hazard analysis.  If you identify melamine as an economically motivated chemical hazard in 
your animal food, you need to determine whether melamine is a hazard requiring a preventive 
control (see 21 CFR 507.33).  In particular, you should consider this economic adulterant when 
using plant protein ingredients from a country where melamine adulteration has occurred.   
 
Sources for information about economically motivated adulteration include an on-line food fraud 
database and food fraud mitigation guidance made available by the U.S. Pharmacopeia 
Convention (Ref. 70), and a report from the Congressional Research Service (Ref. 71).   
 
Radiological hazards 
 
Contamination of animal food by radionuclides (a radiological hazard) is a rare event. The most 
common way these radionuclides are incorporated into animal food is through the use of water 
that contains the radionuclides.  This water may be an ingredient in the animal food or used 
during the manufacturing process such as for washing ingredients or equipment.  There are areas 
in the United States where high concentrations of some radionuclides, such as radium-226, 
radium-228, and uranium, can be detected in well water (Refs. 72 and 73).  In those regions, 
radiological hazards could be considered a known or reasonably foreseeable hazard for animal 
food operations using well water.   
 
51 
  Contains Nonbinding Recommendations 
 
Radiological hazards also may result from accidental contamination, e.g., contamination arising 
from accidental release from a nuclear facility or from damage to a nuclear facility from a natural 
disaster.  You should be vigilant regarding accidental releases of radiological hazards and their 
potential to contaminate your animal food, either directly due to contamination of natural 
resources near your facility, or as a result of raw materials and other ingredients that you obtain 
from a region that has experienced an accidental release of radiation.   
 
Environmental chemical contaminants 
 
Environmental contaminants like dioxins, polychlorinated biphenyls (PCBs), and polyaromatic 
hydrocarbons (PAHs) are chemical hazards that have the potential to be introduced into your 
animal food either through an ingredient (e.g., clay anti-caking agents), or during manufacturing 
(e.g., contaminated water source) (Ref. 74).  Some of the dioxin and PCB congeners may be 
carcinogens at low levels of exposure over extended periods of time.  Currently there are no 
tolerances established by the FDA for dioxins in animal food.  However, temporary tolerances 
for residues of PCBs in animal food can be found in 21 CFR 509.30.   
 
Environmental contaminants such as dioxins can get into water from emissions from waste 
incineration and other combustion that get deposited into bodies of water; and discharges into 
water from chemical factories (Ref. 75).  Over the past decade, EPA and industry have been 
working together to dramatically reduce the presence of dioxins in the environment.  Dioxins, 
however, are extremely persistent compounds and break down very slowly; thus, current 
exposures to dioxins in the United States are due to decades-old releases.   
 
3.4.2  Process-Related Chemical Hazards 
 
Some process-related chemical hazards, such as drug carryover, are unintentionally introduced 
into animal food through cross-contamination due to incomplete cleanout of equipment.  Other 
process-related chemical hazards are caused by animal food manufacturing errors resulting in 
nutrient deficiencies or toxicities.  As discussed previously, some ingredient-related chemical 
hazards can also be process-related chemical hazards.   
 
Animal drug carryover in animal food 
 
Many feed mills manufacture animal food that contains one or more approved animal drugs.  
Such animal food is commonly known as medicated feed.  These medicated feeds are subject to 
21 CFR part 225  Current Good Manufacturing Practice for Medicated Feeds.  Part 225 
requires, among other things, that facilities making medicated feed take steps to ensure adequate 
cleanout of their equipment in order to maintain proper drug levels and to avoid unsafe 
contamination of animal food with drugs.  Flushing of equipment and sequential production of 
medicated feed are two commonly practiced procedures for preventing unsafe contamination 
from drug carryover.  See Chapter 4, section 4.6.3 and 21 CFR 225.65.   
 
Failure to perform proper equipment cleanout procedures or failure to adequately follow the 
procedures could result in contaminated animal food that may cause illness or death in animals.  
For example, incomplete cleanout from a previous batch of animal food manufactured with 
52 
  Contains Nonbinding Recommendations 
 
monensin (which is particularly toxic to horses) has been the cause of contamination in animal 
food.  In 2014 and 2015, monensin contamination of animal food resulted in the deaths of horses 
and layer hens (Refs. 76 and 77).   
 
When conducting your hazard analysis, you should identify whether an animal drug used in your 
facility is a known or reasonably foreseeable hazard to another species, production class (e.g., 
layers versus broilers), or life stage (e.g., calf versus adult dairy cow) for which you manufacture 
animal food.  If you identify a carryover drug hazard, you must evaluate it to determine if the 
carryover drug hazard requires a preventive control (see 21 CFR 507.33).  If you determine a 
carryover drug hazard requires a preventive control, your preventive control might include 
physical cleanout of the equipment or sequencing of animal food production and flushing of 
equipment.  You should also consider whether further preventive controls are needed to prevent 
the accidental addition of animal drugs to the wrong animal food that could result in unsafe 
animal food.   
 
Nutrient deficiencies or toxicities as chemical hazards 
 
Nutrient deficiency or toxicity hazards are a concern in animal food because animals often 
consume one animal food type as their sole source of nutrition.  A nutrient deficiency or toxicity 
hazard can result in serious injury, illness, or even death to animals.  A nutrient deficiency 
hazard can occur when a nutrient in the animal food is below the level needed by the intended 
animal and could result in illness or death (e.g., low thiamine in cat food that can result in 
neurological and other symptoms in cats).  A nutrient toxicity hazard can occur when an 
excessive level of a nutrient is in animal food and could result in illness or death of the intended 
animal (e.g., excess sodium in poultry food that can result in trouble breathing, leg paralysis, and 
death).  Because different animal species have different nutritional needs, certain quantities of a 
nutrient that are needed by one species of animal could pose a health risk to another species of 
animal.   
 
A nutrient deficiency or toxicity hazard also can result from diets containing inappropriate 
proportions of essential nutrients.  For example, the ratio of calcium and phosphorus should be 
considered when formulating an animal food since calcium and phosphorus work together for the 
animals muscle and metabolic functions and are the major mineral constituents of bone.   
 
There have been numerous animal food recalls as well as animal illnesses and deaths from 
nutrient deficiencies or toxicities.  FDA has received multiple reports through its reportable food 
registry (RFR) that were a result of animal food with nutrient deficiencies or toxicities (Ref. 78).  
Examples of RFR reports and recalls include:   
  low levels of thiamine in cat food  
  low levels of vitamin D in food for swine  
  elevated levels of copper in food for sheep  
  elevated levels of vitamin D in dog, guinea pig, and fish food  
  elevated levels of calcium and phosphorus in food for broiler chickens and turkeys  
53 
  Contains Nonbinding Recommendations 
 
  elevated levels of urea in food for cattle  
 
Nutrient deficiency or toxicity hazards can be the result of incorrect levels of nutrients in 
incoming raw materials or ingredients, incorrect recipe/formulation, errors in manufacturing, or a 
combination of these.  If the raw materials or other ingredients do not contain nutrients at the 
expected levels, this may result in either a nutrient deficiency or toxicity hazard when the 
ingredient is incorporated into the animal food based on a preset formulation.  For information 
on control strategies for nutrient deficiency or toxicity hazards, see Chapter 4, section 4.6.1.   
 
Animal food distributed as a sole source of nutrition should be formulated to meet the minimum 
nutrient requirements established by the National Research Council (NRC) when available for 
the intended species (including life-stage and production class) (Ref. 79).  Information in the 
peer-reviewed scientific literature, including NRC publications, also may be used to identify the 
maximum inclusion rate of certain nutrients.  The NRC Mineral Tolerances of Animals also may 
be used to identify appropriate levels of minerals in animal food (Refs. 26 and 37).  Another 
helpful resource for formulating a nutritionally adequate pet food is the AAFCO dog and cat 
food nutrient profiles (Ref. 36).   
 
3.4.3  Facility-Related Chemical Hazards 
 
Industrial chemicals or other contaminants from the animal food processing environment can 
contaminate animal food during production  e.g., if chemicals used to clean a production line 
are not adequately removed from the production line, if heavy metals are leaching from 
containers or utensils, or if a non-food-grade lubricant comes in contact with animal food.  In this 
guidance, we do not discuss preventive controls for facility-related chemical hazards such as 
cleaning chemicals and the leaching of heavy metals from containers or utensils, because such 
hazards are usually addressed through CGMPs (see our GFI #235 entitled Current Good 
Manufacturing Practice Requirements for Food for Animals).16   
 
3.5  Physical Hazards 
 
Physical hazards are broadly classified as sharp hazards, choking hazards, and conditions of 
animal food hazards such as size and hardness.  Injuries from physical hazards may include oral 
cavity damage (e.g., tooth damage or laceration of the mouth or throat), laceration or perforation 
of the gastrointestinal tract, and choking.  In this section, we describe common physical hazards 
 i.e., metal, glass, hard plastic, and conditions of animal food.   
 
Metal (Ferrous and Non-Ferrous):  Metal-to-metal contact during processing can introduce 
metal fragments into products.  For example, metal fragments can break off during mechanical 
cutting and blending operations, and some metal equipment has parts that can break or fall off, 
such as wire-mesh belts.  Metal screens may become worn over time or be torn, introducing 
metal fragments (Ref. 80).   
 
Glass:  Glass fragments in animal food can cause injury to the animal eating the food.  Most 
animal food facilities do not use glass containers for their animal food, but fragments may be 
 
16 https://www.fda.gov/media/97464/download 
54 
  Contains Nonbinding Recommendations 
 
introduced through the environment (e.g., overhead light fixtures made of glass that can fracture) 
or through ingredients that are contaminated with glass.   
 
Hard Plastic:  Hard plastic can be introduced into animal food when tools and equipment such 
as scoops, paddles, buckets, or other containers develop fatigue, crack, and break as they wear.  
Hard plastic also can be introduced into animal food when plastic sieves and screens deteriorate.   
 
Conditions of Animal Food:  The term conditions of animal food as used in this guidance 
refers to the physical, mechanical, and other characteristics (e.g., particle size, hardness, surface 
roughness, digestibility, and ability to soften when moistened) of animal food that can cause 
injuries or illness in animals.  Hazards related to the conditions of the animal food can occur 
when the particle size is too large to eat resulting in starvation (e.g., crumbles too large for small 
birds).  Alternatively, an animal food ground too fine can aerosolize and cause respiratory 
problems and corneal injuries, which occurred with swine food (Ref. 81).  In addition, animal 
food ground too fine, or animal food that contains a large portion of fines (i.e., very small 
particles from the milling or pelleting process), can result in rapid fermentation by gut micro 
flora resulting in bloat in ruminants (e.g., cattle) (Refs. 82 and 83).  Lack of digestibility can 
result in an obstructed digestive tract.  An animal food could have a combination of 
characteristics resulting in injury or death (e.g., some dental treats for dogs) (Ref. 84).   
 
In general, there is overlap between facility-related physical hazards and process-related physical 
hazards.  For example, nuts and bolts used during maintenance procedures could be a facility-
related hazard, but production equipment that has nuts and bolts that could fall out during 
production could be a process-related hazard.  Conditions of animal food hazards are typically 
process-related hazards.  Table 3-7 is a Quick Reference Guide to help you recognize some 
sources of these physical hazards.   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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  Contains Nonbinding Recommendations 
 
Table 3-7.  Quick Reference Guide for Some Sources of Physical Hazards 
Plastic, 
Conditions of 
Source  Metal  Ceramic, and  Other 
Animal Food 
Glass 
Ingredient- Farm field debris  Farm field  Out of  Farm field 
related  debris  specification raw  debris (e.g., 
Chopped, ground, 
materials (e.g.,  stones, 
and pulverized  Packaging 
too finely ground)  wooden 
items where metal  materials 
sticks) 
was not properly 
controlled by 
supplier 
Facility-related  Grinders, hammer- Equipment  Particle size of   
and process- mills, shredders  (inspection  animal food 
related  belts, small  inappropriate for 
Sieves, screens, 
(processing/  wares)  animal 
wire-mesh belts 
species/life-stage 
production  Facility 
Mixing paddles 
environment and  (windows, air  Lack of 
equipment)  Metal cans  flow curtains)  digestibility 
(shavings, lids) 
Facility glass 
Pumps 
Scoops 
Utensils (knives) 
Mixing paddles 
Buckets 
 
3.6  References for Chapter 3 
 
1.  KuKanich, K. S. 2011. Update on Salmonella spp. Contamination of Pet Food, Treats, 
and Nutritional Products and Safe Feeding Recommendations. Journal of the American 
Veterinary Medical Association 238 (11): 1430-1434. DOI: 10.2460/javma.238.11.1430.  
 
2.  Lambertini, E., Buchanan, R.L., Narrod, C., and A.K. Pradhan. 2016. Transmission of 
Bacterial Zoonotic Pathogens between Pets and Humans: The Role of Pet Food. Critical 
Reviews in Food Science and Nutrition 56 (3): 364-418. 
 
3.  Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report, 
November 7, 2008. Accessed July 15, 2021. 
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5744a2.htm 
 
4.  Centers for Disease Control and Prevention. 2012. Multistate Outbreak of Human 
Salmonella Infantis Infections Linked to Dry Dog Food (Final Update). Accessed June 
2, 2022.  https://www.cdc.gov/salmonella/dogfood-05-12/index.html 
56 
  Contains Nonbinding Recommendations 
 
 
5.  Centers for Disease Control and Prevention. 2019. Outbreak of Multidrug-Resistant 
Salmonella Infections Linked to Contact with Pig Ear Pet Treats (Final Update).  
Accessed June 2, 2022.  https://www.cdc.gov/salmonella/pet-treats-07-19/index.html  
 
6.  Hoelzer, K., et al. 2011. Animal Contact as a Source of Human Non-Typhoidal 
Salmonellosis. Veterinary Research 42 (1): 34-34. DOI: 10.1186/1297-9716-42-34. 
 
7.  Sato, Y., et al. 2000. Salmonella virchow Infection in an Infant Transmitted by 
Household Dogs. Journal of Veterinary Medical Science 62 (7): 767-769. DOI: 
10.1292/jvms.62.767.  
 
8.  Morse, E. V., et al. 1976. Canine salmonellosis: A review and report of dog to child 
transmission of Salmonella enteritidis. American Journal of Public Health 66 (1): 82-83.  
 
9.  Food and Drug Administration. 2015. Carnivore Meat Company, LLC Voluntarily 
Issues a Recall Two Batches of Raw Pet Treats. Accessed July 15, 2021. 
https://wayback.archive-
it.org/7993/20170112072755/http://www.fda.gov/Safety/Recalls/ArchiveRecalls/2015/uc
m454400.htm 
 
10. Food and Drug Administration. 2016. Big Dog Natural Recalls Chicken and Fish 
Supreme Dog Food Due to Possible Salmonella and Listeria monocytogenes Health 
Risk. Accessed July 15, 2021.  https://wayback.archive-
it.org/7993/20180126102740/https://www.fda.gov/Safety/Recalls/ucm479873.htm 
 
11. Food and Drug Administration. 2017. Blue Ridge Beef Recalls Product Because of 
Possible Health Risk. Accessed July 15, 2021. 
https://www.fda.gov/safety/recalls/ucm537165.htm 
 
12. Nemser, S. M., et al. 2014. Investigation of Listeria, Salmonella, and toxigenic 
Escherichia coli in Various Pet Foods. Foodborne Pathogen Disease 11 (9): 706-709. 
DOI: 10.1089/fpd.2014.1748.  
 
13. Stampfli, H. R. 2021. Botulism. In Merck Veterinary Manual. Accessed June 2, 2022.  
http://www.merckvetmanual.com/generalized-conditions/clostridial-diseases/botulism  
 
14. The Center for Food Security and Public Health. 2018. Botulism. Accessed July 15, 
2021.  http://www.cfsph.iastate.edu/Factsheets/pdfs/botulism.pdf 
 
15. Myllykoski, J., et al. 2011. Fur Animal Botulism Hazard Due to Feed. Research in 
Veterinary Science 90 (3): 412-418. DOI: 10.1016/j.rvsc.2010.06.024.  
 
16. Food and Drug Administration. 2018. OC Raw Dog, LLC Recalls Freeze Dried Sardines 
Because Product Exceeds FDA Size Restrictions. Accessed July 16, 2021.  
57 
  Contains Nonbinding Recommendations 
 
https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/oc-raw-dog-llc-
recalls-freeze-dried-sardines-because-product-exceeds-fda-size-restrictions 
 
17. Food and Drug Administration. 2020. IcelandicPlus LLC Voluntarily Recalls Whole 
Capelin Fish Pet Treats Because Product Exceeds FDA Size Restrictions.  Accessed 
July 16, 2021.  https://www.fda.gov/safety/recalls-market-withdrawals-safety-
alerts/icelandicplus-llc-voluntarily-recalls-whole-capelin-fish-pet-treats-because-product-
exceeds-fda-size 
 
18. The Center for Food Security and Public Health. 2017. Toxoplasmosis. Accessed July 
15, 2021.  http://www.cfsph.iastate.edu/Factsheets/pdfs/toxoplasmosis.pdf 
 
19. Guo, M., et al. 2015. Prevalence and Risk Factors for Toxoplasma gondii Infection in 
Meat Animals and Meat Products Destined for Human Consumption. Journal of Food 
Protection 78 (2): 457-476. DOI: 10.4315/0362-028x.jfp-14-328. 
 
20. Freeman, L. M, et al. 2013. Current Knowledge about the Risks and Benefits of Raw 
MeatBased Diets for Dogs and Cats. Journal of the American Veterinary Medical 
Association 243 (11): 1549-1558. DOI: 10.2460/javma.243.11.1549. 
 
21. Jones, F. T. 2011. A Review of Practical Salmonella Control Measures in Animal Feed. 
The Journal of Applied Poultry Research 20 (1): 102-113. DOI: 10.3382/japr.2010-
00281. 
 
22. Scott, V. N., et al. 2009. Control of Salmonella in Low-Moisture foods I: Minimizing 
Entry of Salmonella into a Processing Facility. Food Protection Trends 29 (6): 342-353. 
 
23. International Commission on Microbiological Specifications for Foods. 2005. Cereals 
and cereal products Section IV; Flour, starches, and meals; Nuts, oilseeds, and dried 
legumes Section VI; Legume products. In Microorganisms in Foods 6: Microbial 
Ecology of Food Commodities, 409-413 and 460-46. New York, NY: Kluwer 
Academic/Plenum Publishers. 
 
24. Codex Alimentarius International Food Standards. 2015, amended 2018.  Code of 
Hygienic Practice for Low-Moisture Foods. Accessed July 16, 2021. 
http://www.fao.org/fao-who-codexalimentarius/sh-
proxy/en/?lnk=1&url=https%253A%252F%252Fworkspace.fao.org%252Fsites%252Fco
dex%252FStandards%252FCXC%2B75-2015%252FCXC_075e.pdf 
 
25. Zink, D. 2007. The Return of Salmonella: IAFP Special Interest Session on Salmonella 
Growth, Persistence and Survival in Low-Moisture Foods and their Environment - 
Strategies for Control. International Association of Food Protection Annual Meeting. 
Buena Vista, FL. 
 
58 
  Contains Nonbinding Recommendations 
 
26. National Research Council of the National Academies. 2005. Mineral Tolerance of 
Animals. In The Mineral Tolerance of Animals, Washington, DC: National Academies 
Press. 
 
27. Blakley, B. R. 2021. Copper Poisoning in Animals. In Merck Veterinary Manual. 
Accessed July 19, 2021.  https://www.merckvetmanual.com/toxicology/copper-
poisoning/copper-poisoning-in-animals?redirectid=1449 
 
28. United States Environmental Protection Agency. 2017. Setting Tolerances for Pesticide 
Residues in Foods. Accessed July 16, 2021. 
https://www.epa.gov/pesticide-tolerances/setting-tolerances-pesticide-residues-foods 
 
29. Food and Drug Administration. 2009. Memorandum of Understanding with USDA (FSIS 
and AMS) and EPA regarding regulatory activities concerning residues of drugs, 
pesticides, and environmental contaminants in foods. (MOU 225-85-8400). Accessed 
July 19, 2021. 
https://www.fda.gov/AboutFDA/PartnershipsCollaborations/MemorandaofUnderstanding
MOUs/DomesticMOUs/ucm116368.htm 
 
30. Tchounwou, P. B., et al. 2012. Heavy Metals Toxicity and the Environment. 
Experientia Supplementum 101 133-164. DOI: 10.1007/978-3-7643-8340-4_6. 
 
31. Luippold, A., and M. S. Gustin. 2016. Mercury Concentrations in Wet and Dry Cat and 
Dog Food. Animal Feed Science and Technology 222 (Supplement C): 190-193. DOI: 
10.1016/j.anifeedsci.2016.10.021. 
 
32. Li, Y., et al. 2005. A Survey of Selected Heavy Metal Concentrations in Wisconsin 
Dairy Feeds. Journal of Dairy Science 88 (8): 2911-2922. 
 
33. Lopez-Alonso, M. 2012. Trace Minerals and Livestock: Not Too Much Not Too Little. 
International Scholarly Research Notices Veterinary Science 2012 (Article ID 704825): 
1-18. DOI: 10.5402/2012/704825. 
 
34. Food and Agriculture Organization Animal Production and Health. 2010. Health 
Hazards associated with Animal Feed. In Good Practices for the Feed Industry 
Accessed July 19, 2021.  http://www.fao.org/docrep/012/i1379e/i1379e01.pdf 
 
35. Blakley, B.R. 2021. Lead Poisoning in Animals. In Merck Veterinary Manual. 
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59 
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ements/2005/ucm108547.htm 
 
41. Food and Drug Administration. 2011. Cargill Animal Nutrition Recalls River Run and 
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282753.htm 
 
42. Food and Drug Administration. 2013. Hy-Vee Issues Voluntary Recall of Certain Dog 
Food Products-Routine Testing Identifies Higher-Than-Normal Contaminant Levels in 
Select Products. Accessed July 21, 2021. 
https://web.archive.org/web/20161026111320/http://www.fda.gov/Safety/Recalls/ucm34
0891.htm?source=govdelivery 
 
43. Food and Drug Administration. 2020. Sunshine Mills, Inc. Issues Voluntary Recall of 
Certain Dog Food Products Due to Potentially Elevated Levels of Aflatoxin. Accessed 
July 19, 2021. https://www.fda.gov/safety/recalls-market-withdrawals-safety-
alerts/sunshine-mills-inc-issues-voluntary-recall-certain-dog-food-products-due-
potentially-elevated-levels 
 
44. Food and Drug Administration. 2021. Midwestern Pet Foods Voluntarily Expands 
Recall of Pet Food for Aflatoxin Health Risk. Accessed July 19, 2021. 
https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/midwestern-pet-
foods-voluntarily-expands-recall-pet-food-aflatoxin-health-risk 
 
45. Antinutrient. Merriam-Webster Online. Merriam-Webster. Accessed July 19, 2021. 
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46. Food and Drug Administration. 1992. Statement of Policy  Foods Derived from New 
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information/search-fda-guidance-documents/statement-policy-foods-derived-new-plant-
varieties 
 
47. Tripathi, M. K., and A. S. Mishra. 2007. Glucosinolates in Animal Nutrition: A 
Review. Animal Feed Science and Technology 132 (1): 1-27. DOI: 
10.1016/j.anifeedsci.2006.03.003. 
 
48. Hedberg, C. W., et al. 1987. An Outbreak of Thyrotoxicosis Caused by the 
Consumption of Bovine Thyroid Gland in Ground Beef. The New England Journal of 
Medicine 316 (16): 993-998. 
 
49. United States Department of Agriculture and Food Safety and Inspection Service. 1998. 
Disposition of Livestock Thyroid Glands and Laryngeal Muscle Tissue.  Federal 
Register, November 15, 1988, 53 FR 45888. 
 
50. Broome, M. R., et al. 2014. Exogenous Thyrotoxicosis in Dogs Attributable to 
Consumption of All-Meat Commercial Dog Food or Treats Containing Excessive 
Thyroid Hormone: 14 Cases (20082013). Journal of the American Veterinary Medical 
Association 246 (1): 105-111. DOI: 10.2460/javma.246.1.105. 
 
51. Food and Drug Administration. 2017. Blue Buffalo Voluntarily Recalls One Lot of 
BLUE Wilderness Rocky Mountain Recipe TM Red Meat Dinner Wet Food for Adult 
Dogs Due to Potential Health Risk. Accessed April 22, 2022. 
https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/blue-buffalo-
voluntarily-recalls-one-lot-blue-wildernessr-rocky-mountain-recipe-tm-red-meat-
dinner?source=govdelivery 
 
52. Food and Drug Administration. 2017. Wellpet Voluntarily Recalls a Limited Amount of 
One Recipe of Canned Topper for Dogs Due to Potential Elevated Levels of Naturally 
Occurring Beef Thyroid Hormone. Accessed April 22, 2022. 
https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/wellpet-voluntarily-
recalls-limited-amount-one-recipe-canned-topper-dogs-due-potential-elevated 
 
53. New Zealand Food Safety Authority. 2018. Chapter 3: Supply, Slaughter and Dressing 
of Farmed Animals. In New Zealand Food Safety Authority Code of Practice for Petfood 
Processing. Accessed July 19, 2021. https://www.mpi.govt.nz/dmsdocument/23965-
operational-code-petfood-processing 
 
54. Food and Drug Administration. 2017. Exogenous Hyperthyroidism and Thyroid 
Hormones in Pet Food  Veterinarians. Accessed July 19, 2021.   
https://wayback.archive-it.org/7993/20201222185753/https://www.fda.gov/animal-
veterinary/product-safety-information/exogenous-hyperthyroidism-and-thyroid-
hormones-pet-food-veterinarians 
 
55. Food and Drug Administration. 2017. Thyroid Hormones in Pet Food  Pet Food 
Industry. Accessed July 19, 2021.  https://wayback.archive-
61 
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it.org/7993/20170404184730/https://www.fda.gov/AnimalVeterinary/ResourcesforYou/u
cm548914.htm 
 
56. Markus, C. K., et al. 1989. Pet Food-Derived Penicillin Residue as a Potential Cause of 
Hypersensitivity Myocarditis and Sudden Death. The America Journal of Cardiology. 
63 1154-1156. 
 
57. Food and Drug Administration. 2013. Milos Kitchen Voluntarily Recalls Chicken 
Jerky and Chicken Grillers Homestyle Dog Treats. Accessed July 19, 2021.  
http://wayback.archive-
it.org/7993/20161023032825/http://www.fda.gov/Safety/Recalls/ArchiveRecalls/2013/uc
m335621.htm 
 
58. Food and Drug Administration. 2016, updated 2020, 2022. Import Alert 72-07. 
Detention Without Physical Examination of Poultry Jerky-Type Pet Treats due to the 
Presence of Antibiotic and/or Antiviral Residue(s). Accessed June 2, 2022. 
https://www.accessdata.fda.gov/cms_ia/importalert_1140.html 
 
59. Peschka, M., et al. 2006. Occurrence and Fate of Barbiturates in the Aquatic 
Environment. Environmental Science & Technology 40 (23): 7200-7206. DOI: 
10.1021/es052567r. 
 
60. OConnor, J. J., et al. 1985. Fate of Sodium Pentobarbital in Rendered Products. 
American Journal of Veterinary Research 46 (8): 1721-1724. 
 
61. Kaiser, A. M., et al. 2010. Secondary Pentobarbital Poisoning in Two Dogs: A 
Cautionary Tale. Journal of Veterinary Diagnostic Investigation 22 (4): 632-634. DOI: 
10.1177/104063871002200423. 
 
62. Verster, A., et al. 1990. Accidental Pentobarbital Poisoning in a Lioness. Journal of the 
South African Veterinary Association 61 (1): 37-38. 
 
63. Jurczynski, K., and E. Zittlau. 2007. Pentobarbital Poisoning in Sumatran Tiger 
(Panthera Tigris Sumatrae). Journal of Zoo and Wildlife Medicine 38 (4): 583-584. DOI: 
10.1638/2006-0051R.1. 
 
64. Corona, M. 2015. Euthanized Horse Blamed for Contaminated Meat. In Reno Gazette 
Journal. Accessed July 19, 2021.  http://www.rgj.com/story/news/2015/03/12/animal-
ark-toxicology-results-shows-barbiturates-in-meat/70194788/ 
 
65. Food and Drug Administration. 2017. Evangers Voluntarily Recalls Hunk of Beef 
because of Pentobarbital Exposure in One Batch of Food. Accessed July 19, 2021. 
https://www.fda.gov/safety/recalls/ucm539900.htm 
 
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  Contains Nonbinding Recommendations 
 
66. Food and Drug Administration. 2016. Xylitol and Your Dog: Danger, Paws Off. 
Accessed July 19, 2021.  https://www.fda.gov/consumers/consumer-updates/paws-
xylitol-its-dangerous-dogs 
 
67. Food and Drug Administration. 2017. Melamine Pet Food Recall of 2007. Accessed 
April 22, 2022.  https://www.fda.gov/animal-veterinary/recalls-withdrawals/melamine-
pet-food-recall-2007 
 
68. United States Department of Agriculture. 2007. Interim Melamine and Analogues 
Safety/Risk Assessment. Washington, DC: United States Department of Agriculture. 
 
69. Food and Drug Administration. 2008. Dear Colleague Letter to the United States Food 
Manufacturing Industry, Regarding Melamine. Accessed July 19, 2021. 
https://wayback.archive-
it.org/7993/20170111170320/http://www.fda.gov/Food/FoodborneIllnessContaminants/C
hemicalContaminants/ucm164514.htm 
 
70. The United States Pharmacopeial Convention. 2016. Appendix XVII: Food Fraud 
Mitigation Guidance General Tests and Assays. In Food Chemicals Codex, 1586-1621. 
 
71. Congressional Research Service. 2014. Food Fraud and Economically Motivated 
Adulteration of Food and Food Ingredients. Accessed July 19, 2021. 
https://fas.org/sgp/crs/misc/R43358.pdf 
 
72. Ayotte, J. D., et al. 2007. Occurrence of Uranium and 222Radon in Glacial and Bedrock 
Aquifers in the Northern United States, 19932003. In U.S. Geological Survey Scientific 
Investigations Report 2007-5037. Accessed July 19, 2021. 
https://pubs.usgs.gov/sir/2007/5037/ 
 
73. Focazio, M. J., et al. 2001. Occurrence of Selected Radionuclides in Ground Water 
Used for Drinking Water in the United States: A Reconnaissance Survey, 1998. In U.S. 
Geological Survey Water-Resources Investigations Report 00-4273. Accessed July 19, 
2021.  https://pubs.usgs.gov/wri/wri004273/pdf/wri004273.pdf 
 
74. Food and Drug Administration. 2017. Chemical Hazards. Accessed July 19, 2021. 
https://www.fda.gov/animal-veterinary/biological-chemical-and-physical-contaminants-
animal-food/chemical-hazards#Industrial 
 
75. United States Environmental Protection Agency. 2017. Learn about Dioxin. Accessed 
July 19, 2021.  https://www.epa.gov/dioxin/learn-about-dioxin 
 
76. Food and Drug Administration. 2014. Burkmann Feeds, Danville, KY Recalls 656-
Layer Ration 20% Pellets Because of Possible Monensin Sodium Contamination. 
Accessed July 19, 2021.  http://wayback.archive-
it.org/7993/20170406075532/https://www.fda.gov/Safety/Recalls/ArchiveRecalls/2013/u
cm428401.htm 
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77. Food and Drug Administration. 2015. Western Milling LLC Voluntarily Recalls 
Western Blend Horse Feed, Lot 5251 Due To Potential Monensin Contamination. 
Accessed July 19, 2021.  http://wayback.archive-
it.org/7993/20170112071807/http://www.fda.gov/Safety/Recalls/ArchiveRecalls/2015/uc
m464436.htm 
 
78. Food and Drug Administration. 2016. The Reportable Food Registry: A Five-Year 
Overview of Targeting Inspection Resources and Identifying Patterns of Adulteration. 
Accessed April 22, 2022.  https://www.fda.gov/media/97862/download 
 
79. National Academies of Sciences, Engineering, and Medicine. 2016. Nutrient 
Requirement of Beef Cattle. In Nutrient Requirements of Beef Cattle, Washington, DC: 
The National Academies Press. 
 
80. Food and Drug Administration. 2012. Enforcement Report: Sirius Dog Treats. 
Accessed July 19, 2021. 
https://www.accessdata.fda.gov/scripts/ires/index.cfm?Product=112038. 
 
81. Wondra, K. J., et al. 1995. Effects of Particle Size and Pelleting on Growth 
Performance, Nutrient Digestibility, and Stomach Morphology in Finishing Pigs. 
Journal of Animal Science. 73 757-763. 
 
82. Constable, Peter D. 2015. Bloat in Ruminants. In Merck Veterinary Manual. Accessed 
July 19, 2021.  https://www.merckvetmanual.com/digestive-system/diseases-of-the-
ruminant-forestomach/bloat-in-ruminants 
 
83. Rasby, Rick J., et al. 2010. Bloat Prevention and Treatment in Cattle. University Of 
Nebraska-Lincoln, Institute of Agriculture and Natural Resources, Nebraska Extension 
Publications, G2018. Accessed July 19, 2021. 
https://extensionpublications.unl.edu/assets/html/g2018/build/g2018.htm 
 
84. Leib, M. S., and L. L. Sartor. 2008. Esophageal Foreign Body Obstruction Caused by a 
Dental Chew Treat in 31 Dogs (20002006). Journal of the American Veterinary 
Medical Association. 232 (7): 1021-1025. DOI: 10.2460/javma.232.7.1021. 
   
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CHAPTER 4  PREVENTIVE CONTROLS 
 
4.1  Purpose of this Chapter 
 
The guidance provided in this chapter is intended to help you identify and implement preventive 
controls for hazards you have determined require a preventive control.  This chapter provides an 
overview of common preventive controls that you could use to significantly minimize or prevent 
the occurrence of biological, chemical, and physical hazards in animal food and the animal food 
production environment when the outcome of your hazard analysis is that one or more known or 
reasonably foreseeable hazards requires a preventive control.  The guidance provided in this 
chapter also is intended to help you determine pertinent parameters to use when monitoring the 
preventive controls that you identify and implement.   
 
This chapter does not provide all the details needed for identifying and implementing preventive 
controls.  You have the flexibility to identify and implement preventive controls from among all 
procedures, practices, and processes that are available to you and that would provide assurances 
that the hazard is controlled (i.e., significantly minimized or prevented).   
 
4.2  Overview of Preventive Controls 
 
Preventive Controls 
 
The Preventive Controls for Animal Food (PCAF) regulation defines preventive 
controls as those risk-based, reasonably appropriate procedures, practices, and processes 
that a person knowledgeable about the safe manufacturing, processing, packing, or 
holding of animal food would employ to significantly minimize or prevent the hazards 
identified under the hazard analysis that are consistent with the current scientific 
understanding of safe food manufacturing, processing, packing, or holding at the time of 
the analysis (21 CFR 507.3).  Preventive controls include:  (1) controls at critical control 
points (CCPs), if there are any CCPs; and (2) controls, other than those at CCPs, that are 
also appropriate for animal food safety (21 CFR 507.34(a)(2)(i) and (ii)). 
 
The PCAF regulation requires that preventive controls must be written (21 CFR 507.34(b)).  The 
PCAF regulation also specifies that preventive controls include, as appropriate to the facility and 
the animal food:  (1) process controls; (2) sanitation controls; (3) supply-chain controls; (4) a 
recall plan; and (5) other preventive controls (see 21 CFR 507.34(c)).  The PCAF regulation also 
requires you to validate that the preventive controls that you identify and implement are adequate 
to control the hazard as appropriate to the nature of the preventive control and its role in the 
facilitys food safety system (see 21 CFR 507.47(a)), with some exceptions including sanitation 
controls in 21 CFR 507.34(c)(2) and the supply-chain program in subpart E of part 507 (see 21 
CFR 507.47(c)).  For information on validation and other preventive control management 
components, see Chapter 5.   
 
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4.3  Preventive Control Considerations 
 
When identifying preventive controls for your animal food hazards, you should consider:   
 
  The effect of the control on the targeted known or reasonably foreseeable animal food 
hazards.  For example:   
  Is the preventive control hazard-specific or does it control more than one hazard?   
o
  Does the control effectiveness depend upon other controls?   
o
  Can the preventive control be validated (as necessary)?   
o
  Will the product be exposed to the environment following the preventive control?   
o
 
  The feasibility of monitoring those controls.  For example:   
  Are the minimum or maximum parameter values for the preventive control 
o
measurable and practical?   
  Are you relying on parameter values or observations for your monitoring?   
o
  Can you obtain the results of monitoring quickly (i.e., real-time) to determine if 
o
the process is in control?   
  Are you monitoring a batch or continuous process?   
o
  Are you monitoring continuously or doing spot checks?   
o
  Can the parameters be monitored in-line or must the animal food be sampled?   
o
  Will the monitored parameters be indirectly linked to the minimum or maximum 
o
values (i.e., belt speed or pump flow rate for time of process)?   
 
  The location of the control with respect to other preventive control measures.  For 
example:   
  Is the application of the control measure at the last point in the process to ensure 
o
control of the targeted known or reasonably foreseeable hazard?   
  Will the failure of an upstream control result in the failure of a downstream 
o
control(s)?   
 
  Synergistic effects between control measures.  For example:   
  Consider whether one control measure can enhance the efficacy of another control 
o
measure, e.g., formulation process controls may combine the use of preservatives, 
acidification, and a  at levels that individually will not control pathogen growth, 
w
but they work together to do so.   
 
4.4  Process Controls 
 
Process controls include procedures, practices, and processes to ensure the control of parameters 
during operations such as heat processing, irradiating, and refrigerating animal food.  Process 
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controls must include, as appropriate to the nature of the applicable control and its role in the 
facilitys food safety system:  (1) parameters associated with the control of the hazard; and (2) 
the maximum or minimum value, or combination of values, to which any biological, chemical, or 
physical parameter must be controlled to significantly minimize or prevent a hazard requiring a 
process control.  See 21 CFR 507.34(c)(1).  Process controls do not include those procedures, 
practices, and processes that are not applied to the animal food itself, e.g., controls of personnel 
or the environment that may be used to significantly minimize or prevent hazards.   
 
4.4.1  Use of Parameter Values and Operating Limits in Process Controls 
 
Parameters are those properties that are controlled to ensure the hazard will be significantly 
minimized or prevented and the parameter value is the maximum or minimum value, or 
combination of values, to which any biological, chemical, or physical parameter must be 
controlled to significantly minimize or prevent a hazard requiring a process control.  Examples 
of process control parameters that can have a minimum or maximum parameter value (or 
combination of values) include time, temperature, flow rate, line speed, product bed depth, 
weight, product thickness or size, viscosity, moisture level, a , salt concentration, pH and others, 
w
depending upon the process.  During processing, if a process control parameter value does not 
meet your identified minimum or maximum parameter value (or combination of values) in your 
food safety plan, the process is not in control (i.e., a deviation has occurred) and there is a 
potential for producing a product that presents a human or animal health risk.   
 
Operating limits are criteria that may be more stringent than your minimum or maximum 
parameter values of your preventive control and are established for reasons other than animal 
food safety.  We recommend that you consider using operating limits to reduce the likelihood of 
a deviation from the established parameter value.  Operating limits may be established to avoid 
deviations from an allowed parameter value, to account for normal variation, and for quality 
reasons.  A benefit of using an operating limit is that such use may allow you to adjust your 
process if an operating limit is not met but the process does not deviate from your minimum or 
maximum parameter value.  An additional benefit of using an operating limit is to account for 
quality parameters and for normal variability of production processes.  Operating limits are not 
required under 21 CFR part 507 and we do not recommend you include them in your food safety 
plan (to avoid confusion with your required parameter values).   
 
For example, you are baking dog biscuits and your minimum temperature parameter value 
established for controlling Salmonella is 350F (177C) and your minimum time parameter value 
is 15 minutes.  In this example, we focus on the temperature parameter only and do not discuss 
time.  Your written procedure would need to include both time and temperature if they are both 
parameters with values established for control of Salmonella.  To achieve your desired quality 
specifications and to ensure safety, you bake the dog biscuits at 355F (179C) (i.e., the oven set 
temperature).  If your minimum parameter value is 350F (177C) to control Salmonella, you 
may have an operating limit of 352F (178C).  If you use an alarm system on your oven, you 
may set the alarm so if your oven temperature drops to 352F (178C), the alarm will sound and 
you can adjust the oven temperature to ensure that the temperature does not drop below the 
minimum parameter value of 350F (177C).  However, if you are finding that the alarm is 
sounding often because your oven temperature drops below your operating limit, you should 
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consider taking additional steps to ensure a more consistent oven temperature.  If the oven 
temperature drops below the minimum parameter value of 350F (177C), the hazard is not 
under control and a corrective action is required.   
 
See Figure 4-1 for an illustration on the use of operating limits to avoid a deviation from an 
established parameter value and Chapter 5 (section 5.7) for a discussion about corrective actions.  
One source of additional information on the use of operating limits is the FSPCA curriculum 
(Ref. 1).   
 
Fig ure 4-1:  The use of operating limits to avoid a deviation from an established parameter value 
 
360 
         
    358      
 
Oven Set Temperature 
355 
 
  352  Operating Limit 
  Adjustment 
Minimum Parameter Value 
  350 
  Deviation Began  Corrective Action Required 
 
 
Time (Minutes) 
 
 
 
 
4.5  Process Controls for Biological Hazards 
 
Many process controls, such as the application of heat to an animal food to adequately reduce 
pathogens, are applied in the same manner and for the same purpose as control measures 
established within Hazard Analysis and Critical Control Point (HACCP) plans for human food 
and applied at CCPs as recommended by the National Advisory Committee on Microbiological 
Criteria for Foods (Ref. 2) and the Codex Alimentarius Commission (Ref. 3).  No HACCP 
system has been mandated by FDA for any animal food.  HACCP principles have been 
voluntarily adopted by some segments of the animal food industry, such as some in the rendering 
industry and pet food industry.   
 
In addition to this guidance, a number of sources of scientific and technical information can be 
useful in establishing process control parameters and parameter values.  These sources may use 
the term critical limit as opposed to parameter value.  While these terms have a similar 
meaning, critical limit is more closely associated with HACCP.  Trade associations, process 
authorities, industry scientists, university and extension scientists, and consultants can be a 
resource for establishing process control parameters and parameter values.  The Consumer 
Brands Association, formerly known as the Grocery Manufacturers Association, has provided 
advice on control of Salmonella in low-moisture foods (Ref. 4), and the American Feed Industry 
Association has provided advice on control of Salmonella in animal food (Ref. 5).  Information 
also can be obtained from peer reviewed scientific literature.  For additional resources, see the 
training materials provided by the Food Safety Preventive Controls Alliance for human food and 
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animal food (Refs. 1 and 6).  In addition to information from such resources, you also can 
conduct scientific studies for specific products in-house, at a contract laboratory, or at a 
university to establish appropriate process control parameters and parameter values.   
 
Note that there may be differences between the application of process control parameters as 
discussed in these referenced sources and how you would apply the process control parameters to 
your specific animal food and manufacturing process.  For example, your animal food matrix 
may have a different particle size or composition than the reference source.  The process control 
parameters and/or minimum or maximum parameter values may need to be adjusted to account 
for those differences.  The process control parameter and parameter value(s) must be validated in 
accordance with 21 CFR 507.47.  For more information on validation see Chapter 5, section 
5.8.2.   
 
4.5.1  Use of Lethality Treatments as Process Controls 
 
The term lethality treatment refers to a treatment that is used to kill or inactivate 
microorganisms.  In general, when discussing bacterial pathogens in this document we use the 
terms kill or destroy when referring to treatments lethal to vegetative cells and inactivate 
when discussing treatments lethal to spores.  Protozoa may be killed or inactivated by common 
lethality treatments (Refs. 7, 8 and 9).  Common lethality treatments include:  (1) heat treatments 
(e.g., extrusion, cooking, pasteurizing, or baking); (2) high pressure processing (HPP); and (3) 
irradiation.  We discuss each of these in the following sections of this chapter.   
 
Heat treatment (thermal processing) 
 
Heat treatment is a common lethality process control.  Heat treatments generally fall into the 
following two categories:   
 
  Heat treatment that leads to commercial sterility:  heat processing at high temperatures 
(internal food temperature is > 212oF (100C)) under pressure with the objective of 
killing all forms of microorganisms, including the spores of bacteria.  The treated 
products are shelf-stable without refrigeration.   
  Heat treatment that reduces microbial pathogens but does not lead to commercial sterility:  
heat processing at lower temperatures (e.g., internal food temperature is 158F (70C) to 
212F (100C)), with the objective of killing the vegetative forms of microorganisms 
with little to no effect on the spores of bacteria.  The treated products may or may not be 
intended to be shelf-stable.  Pelleting and extrusion are examples of heat treatment 
processes that kill vegetative microbial pathogens and the resulting products are shelf- 
stable.  Pasteurization is an example of a heat treatment that reduces microbial pathogens 
but does not lead to a shelf-stable product.  Pelleting, extrusion, and pasteurization are 
typically applied to kill non-sporeformers such as Salmonella, L. monocytogenes, and 
pathogenic strains of E. coli.   
 
This chapter does not address heat treatments that lead to commercial sterility of low-acid 
canned foods.  Such treatments are subject to the requirements of 21 CFR 500.23 and 21 CFR 
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part 113 (Thermally Processed Low-Acid Foods Packaged in Hermetically Sealed Containers; 
commonly called Low-Acid Canned Foods (LACF)).  Microbiological hazards regulated under 
part 113 are not subject to the requirements for hazard analysis and risk-based preventive 
controls.  Note that although some hermetically sealed containers (e.g., pouches or trays) 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).   
 
Thermal destruction of microorganisms 
 
To design a lethal heat treatment for use as a preventive control, you should have a basic 
understanding of thermobacteriology (i.e., the relationship between bacteria and heat), including 
two key types of data and information:   
1.  The kinetics of thermal inactivation or destruction of microorganisms, known as 
thermal death time data; and,  
2.  The rate at which heating occurs within the animal food, also known as heat transfer 
or heat penetration.   
 
Immediately following, we describe basic concepts associated with thermal death time data and 
heat transfer/heat penetration.  A more extensive review of thermobacteriology, including 
graphical representations of the relationship of D-values and z-values to Thermal Death Time, is 
available (Ref. 10).   
 
Some terms and concepts used to describe the thermal destruction of microorganisms include:   
 
  F-value or TDT (Thermal Death Time) is the time required to kill a given population 
of microorganisms at a specified temperature  
  D-value or the decimal reduction time is the time required to kill 90% of a population 
of microorganisms at a constant temperature and under specified conditions  
  Z-value refers to the temperature increase required to reduce the D-value by a factor of 
10  
 
Food processing experts evaluate treatments intended to kill or inactivate pathogens in food in 
terms of logs of kill, where the term log is a shorthand expression of the mathematical term 
logarithm.  A logarithm is the exponent to which a base number must be raised to equal a given 
number.  In thermobacteriology, the base number is usually 10.  As an example, the number 100 
= 102 where the base number is 10 and the exponent is 2.  Because the exponent is 2, a 2-log 
reduction represents a 100-fold reduction.  Likewise, a 3-log reduction represents a 1000-fold 
reduction, 103.  The important thing to understand is that each log of kill is capable of causing a 
ten-fold reduction in the population of microorganisms that the treatment is designed to kill, i.e., 
the most resistant microorganism of public health significance.   
 
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The decimal reduction time (D) is used synonymously with log in the context of 
thermobacteriology.  A 1-log or 1-D process would be one that is capable of reducing the 
population of the most resistant microorganism of concern in the animal food ten-fold, e.g., from 
10,000 cells of the microorganism per gram of animal food to 1,000 cells of the microorganism 
per gram of animal food.  Importantly, it is not possible for a process to technically achieve a 
level of reduction equivalent to zero, or no microorganisms in animal food; instead, as a 
technical matter the probability of finding the organism becomes less likely as the number of log 
reduction increases.  Thus, a 5-log reduction process would be one that is capable of reducing the 
population by 100,000 fold, e.g., from 10,000 cells of the microorganism per gram of animal 
food to a probability of 1 cell in 10 grams of animal food, or 100,000 cells of the microorganism 
per gram of animal food to a probability of 1 cell per gram of animal food.  You should use a 
heat treatment that delivers a sufficient amount of log reduction to ensure the most resistant 
microorganism of concern is non-detectable when the animal food is tested using a validated 
method.   
 
Table 4-1 provides examples of the effect of lethal heat treatments on microorganisms in animal 
food using terms commonly associated with thermobacteriology.   
 
Table 4-1.  The Concept of Log Reductions of Microorganisms in Animal Food 
Final Number 
Initial Number of 
Decrease in Most  of Most 
the Most Resistant  Log 
Resistant  Percent  Resistent 
Microorganism of  Reduction 
Microorganism of  of  Microorganism 
Concern Per  (also known 
Concern Per Gram of  Change  of Concern Per 
Gram of Animal  as D) 
Animal Food  Gram of 
Food 
Animal Food 
10,000 or 4 log 1  1  10-fold  90%  1,000 or 3 log 
10,000 or 4 log  2  10 X 10 = 100-fold  99%  100 or 2 log 
10 X 10 X 10 = 1000- 99.9%  10 or 1 log 
10,000 or 4 log  3 
fold 
10 X 10 X 10 X 10 =  99.99%  1 or 0 log 
10,000 or 4 log  4 
10,000-fold 
10 X 10 X 10 X 10 X 10  99.999%  0.1 or -1 log 2 
10,000 or 4 log  5 
= 100,000-fold 
10 X 10 X 10 X 10 X 10  99.9999%  0.01 or -2 log 
10,000 or 4 log  6 
= 1,000,000-fold 
1 Additional equivalent ways to express 10,000 include 104, 10^4, and 10E4. 
2 Additional equivalent ways to express 0.1 include 10-1 or 1 in 10. 
 
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Relative heat resistance of microorganisms 
 
Some microorganisms are more resistant to heat than other microorganisms and, thus, require 
more stringent heating conditions to kill or inactivate them.  Table 4-2 shows the relative heat 
resistance of common types of microorganisms.   
 
Table 4-2.  Relative Heat Resistance of Microbial Forms 
Resistance to Heat  Microbial Form 
Highest  Bacterial Spores 
Some vegetative bacterial cells 
Moderate  Cysts of parasites 
Fungi, including fungal spores 
Some vegetative bacterial cells 
Least 
Viruses 
 
As already noted, this chapter addresses heat treatments that reduce pathogens in animal food but 
do not lead to commercial sterility.  These heat treatments are used to significantly minimize the 
number of vegetative cells of bacterial pathogens such as Salmonella, L. monocytogenes, and 
pathogenic E. coli.   
 
Factors affecting the heat resistance of microorganisms 
 
In addition to the inherent heat resistance of specific microorganisms (or life stages of 
microorganisms, such as the spore stage) other factors associated with animal food (such as a , 
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fat content, salt content, pH, and protein content) can affect the heat resistance of 
microorganisms.  Table 4-3 lists the most common factors that you should consider when 
designing a heat treatment as a process control for biological hazards.   
 
Table 4-3.  Factors that Influence the Heat Resistance of Microorganisms in Animal Food 
Factor  Effect on Microbial Heat Resistance 
As the a , humidity, or moisture goes down, in general the heat 
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Water 
resistance increases. 
As the fat content increases, there is a general increase in heat 
Fat 
resistance of some microorganisms. 
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Factor  Effect on Microbial Heat Resistance 
The effect of salt varies and depends on the kind of salt and its 
concentration.  Some salts that decrease a  appear to increase 
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Salts  heat resistance of microorganisms while other salts that may 
increase a (e.g., calcium and magnesium) appear to decrease 
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heat resistance. 
The presence of sugars can increase the heat resistance of 
Carbohydrates 
microorganisms due in part to the decrease in a . 
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Most microorganisms are more heat resistant near their 
optimum pH for growth.  Generally, as the pH increases or 
pH 
decreases relative to this optimum pH, the microorganisms 
become more sensitive to heat. 
Proteins have a protective effect and, thus, increase the heat 
Proteins 
resistance of microorganisms. 
 
Other factors that can influence the heat resistance of microorganisms include the number of 
microorganisms, the age of the microorganisms, the temperatures at which microbial growth 
occurs, the presence of inhibitory compounds, and the time-temperature combination used.   
 
Lethal heat treatments 
 
Lethal heat treatments (heat treatments) such as baking, rendering, roasting, pelleting, extrusion, 
and other conventional heating methods are used for processing a wide variety of animal food 
(e.g., cereal-grain products, pet food kibble, jerky treats, and fish food).  Heat treatments may be 
performed for a variety of reasons, such as to make animal food safe by significantly minimizing 
(which includes eliminating) foodborne pathogens such as Salmonella and L. monocytogenes, to 
improve palatability, to increase nutrient bioavailability, and to inactivate anti-nutrient factors.  
This discussion focuses on the heat treatment methods for biological hazards and animal food 
safety.   
 
There are a variety of ways to manage the application of these heat treatments depending upon 
the type of animal food and the method of heat application (e.g., rendering or extrusion).  You 
may obtain information from peer-review journals and extension white papers to determine 
appropriate heat treatment parameters for your facility and type of animal food.  Alternatively, 
you could establish the process scientifically and validate it through a scientific study 
demonstrating that if the minimum/maximum values are met for all the pertinent parameters 
(e.g., cooking temperature, time, and particle size) all particles will receive an adequate heat 
treatment.  For example, the processing time and temperature to significantly minimize 
pathogens in a homogeneous mixture of an ingredient with uniform particle size and density may 
be different than an animal food containing different size and density particles of various 
ingredients.  As another example, an all-dry kibble and a kibble with a semi-moist center would 
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be processed using different time-temperature combinations.  Besides time and temperature, 
other factors may impact process effectiveness.   
 
Normally, a study to validate a heat treatment is performed by a person or group knowledgeable 
in the design of heat treatments to determine the critical parameters required for the heat process 
being applied to ensure that it delivers the desired reduction level (logs of kill, as described 
earlier in this chapter).  If you do a study to validate the adequacy of your heat treatment 
preventive control(s), a preventive controls qualified individual (PCQI) must conduct (or 
oversee) your study.  See CFR 507.47(b)(1).  You may choose to seek assistance for your study 
from entities with special expertise in heat treatments.  Thus, for such studies, your PCQI will 
likely oversee, rather than conduct, the study.  Once that study has been completed, the person 
conducting the study will provide a time and temperature for the processor to monitor during 
processing, as well as any other parameters that are critical to delivery of an adequate heat 
treatment, such as maximum particle size.   
 
Emerging technologies based on thermal effects 
 
Microwave, radio frequency, ohmic heating, and inductive heating are heat-based processes that 
can kill microorganisms by thermal effects.  Microwave and radio frequency heating are based 
on the use of electromagnetic waves of certain frequencies to generate heat in a material through 
two mechanisms - dielectric and ionic.  Ohmic heating is the process of passing electric currents 
(primarily alternating) through animal food to heat it.  The heating occurs in the form of internal 
energy generation within the material.  Ohmic heating is distinguished from other electrical 
heating methods by the presence of electrodes contacting the animal food (as opposed to 
microwave heating, where electrodes are absent), and depends on frequency of the current and 
waveform (typically sinusoidal).  Inductive heating is a process of inducing electric currents 
within the animal food due to oscillating electromagnetic fields generated by electric coils.  
 
For any of these heat-based processes, the cumulative lethality delivered by the process (as 
represented in a heating curve which measures total time the food is exposed to the rising and 
falling temperatures) and the location of the cold points will determine the effect on 
microorganisms.  The effectiveness of these processes also depends on a  and pH of the product.  
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Although the shape of the destruction or inactivation curves is expected to be similar to those in 
conventional heating, the intricacies of each of the technologies need special attention if you plan 
to use them for microbial destruction or inactivation.  For instance, in microwave heating a 
number of factors influence the location of the cold points, such as the composition, shape, and 
size of the food, the microwave frequency, and the applicator design.  The location of the 
coldest-point and time/temperature history can be predicted through simulation software, and we 
expect that animal food manufacturers may be able to use these emerging technologies in the 
future.   
 
Additional information about these and other heat treatment technologies is available (Refs. 11, 
12, and 13).   
 
High pressure processing (HPP) 
 
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Microorganisms vary in their sensitivity to high pressure.  If you plan to use HPP, you should 
consider the target pathogen (e.g., Salmonella, L. monocytogenes, pathogenic E. coli, C. 
botulinum, and T. gondii), animal food characteristics, and whether the process is to result in 
animal food that will be frozen, refrigerated, or shelf-stable.  Destruction of the microorganism is 
primarily caused by changes in the structure and permeability of the cell wall, which causes 
fluids to be forced into the cell.   
 
Bacterial spores are the most pressure-resistant biological forms known.  Spores resist 
inactivation by high pressure alone and most require the addition of heat or some other 
mechanism to achieve appropriate levels of destruction.  C. botulinum is one of the most 
pressure-resistant microorganisms (Ref. 10).  Because of this, if C. botulinum is a known or 
reasonably foreseeable hazard in your animal food and the animal food is processed using HPP, 
you should refrigerate or freeze the animal food to provide control of sporeformers and toxin 
production.   
 
The unit of measure frequently used for HPP in the food industry is the pascal (Pa) or 
megapascal (MPa, 1,000,000 Pa).  High pressure processing of food requires pressures of 400 to 
700 MPa, or 4000-7000 bars (58,000-101,000 pounds per square inch gauge).  Most commercial 
human food industry applications use pressures in the range of 600 to 700 MPa (Ref. 10).   
 
High pressure processing requires very specialized and costly equipment.  Currently, the human 
and animal food industry uses HPP batch systems.  For batch processing, the food is packaged in 
a flexible or semi-flexible package, prior to placing the product in the HPP system, where the 
product is placed into a chamber and immersed in water or some other pressurizing fluid, then 
subjected to the high pressure for a time of 1-20 minutes, depending on the temperature and 
pressure.  The chamber is then depressurized, and the product removed.  Applications and the 
feasibility for commercialization for other HPP systems such as semi-continuous, continuous, 
and pulsed HPP have been described elsewhere (Ref. 10).   
 
The pressure-time combination sufficient to inactivate pathogens with the greatest resistance to 
inactivation by pressure is determined based on the estimated pathogen load (i.e., number of 
pathogens per gram of food) in the animal food.  Detailed reviews of the application and use of 
HPP as a process control in human food are available (Refs. 10 and 14).  Publicly available data 
on pressure ranges and corresponding retention times required for inactivating pathogens in 
animal food during HPP treatments are limited at this time.  If you rely on HPP to control 
pathogens in your animal food, you will likely need to conduct studies to validate your pressure-
time combinations for inactivating pathogens in that animal food (see 21 CFR 507.47).   
 
Irradiation 
 
Food is irradiated primarily to inactivate organisms that cause spoilage, quality deterioration, or 
are an animal food safety concern.   
 
The application of ionizing radiation damages DNA and very effectively inhibits DNA synthesis 
and further cell division in organisms exposed to these forms and levels of energy.  The amount 
of radiation energy used to control organisms varies according to the radiation resistance of the 
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particular organism, which is often specific to the number or load of the organisms present (Ref. 
15).   
 
In the United States, a source of radiation used to irradiate food is considered a food additive 
and, as such, the use of irradiation in producing food (including animal food) requires premarket 
approval by FDA.  See sections 201(s) and 409 of the FD&C Act and 21 CFR part 579, which 
incorporates part 179 (21 CFR 579.12).  The only sources of ionizing radiation approved for use 
on specific types of animal food are cobalt-60 or cesium-137 generated gamma rays, electron 
beams not exceeding 10 million electron volts (MeV), and X-rays not exceeding 5 MeV or 7.5 
MeV (except as otherwise permitted) depending on the source.  See 21 CFR 579.22 and 579.40.   
 
Some common terms used when describing the application of ionizing radiation in the treatment 
of animal food are:   
 
  Dose (absorbed)  The amount of energy absorbed per unit mass of irradiated material  
  D-value  Amount of radiation required to reduce the population of a specific 
microorganism by 90% (1-log) under the stated conditions  
  Gray (Gy)  A unit of absorbed dose of ionizing radiation, equal to 1 joule/kg of 
irradiated material (e.g., animal food)  
  Electron volt (eV)  A unit of energy.  One electron volt is the kinetic energy acquired by 
an electron in passing through a potential difference of one volt in a vacuum  
 
Food treated with ionizing radiation must receive the minimum radiation dose reasonably 
required to accomplish its intended technical effect and not more than the maximum dose 
specified by the applicable regulation for that use.  See 21 CFR 179.25(b).  Table 4-5 
summarizes maximum allowed doses of radiation for certain animal foods.  Doses below 10 
kiloGrays (kGy) have been used to inactivate pathogens such as Salmonella in dry cat, dog, and 
rodent food (Ref. 16).  Irradiation of dried chicken-breast meat at 10-25 kGy was studied for use 
as pet food and the study authors concluded that the irradiated chicken meat was safe for that use 
(Ref. 17).   
 
Table 4-4 provides a summary of compiled data on the ranges of decimal reduction doses (D-
values) for some non-spore-forming pathogenic bacteria determined in various human foods 
under various conditions (Ref. 15).  Only the pathogenic bacteria relevant to animal food are 
listed in the table.  If you use irradiation to control bacterial pathogens in your animal food, you 
should base your irradiation doses on D-values determined for pathogens under similar 
conditions (e.g., composition, physical state, atmospheric environment, and temperature of the 
animal food).   
 
 
 
 
 
 
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Table 4-4.  D-values (kGy) for Some Foodborne Pathogenic Bacteria 
Bacteria  Non-frozen food  Frozen food 
Salmonella spp.  0.18-0.92  0.37-1.28 
L. monocytogenes  0.20-1.0  0.52-1.4 
E. coli O157:H7  0.24-0.43  0.30-0.98 
 
Bacterial spores are more resistant to irradiation than non-spore-forming bacteria.  The spores of 
C. botulinum types A and B are particularly resistant.   
 
For illustrative purposes, Table 4-5 lists the FDA-approved uses of ionizing radiation for animal 
food as of 2022.  We created the table from the regulatory language in 21 CFR 579.22 and 
579.40, which specifies the limitations on the approved uses of ionizing radiation for the 
treatment of animal food.  You should refer to 21 CFR part 579 for the most current limitations 
on the approved uses for the treatment of animal food using ionizing radiation.   
 
Table 4-5.  FDA-Approved Uses for the Ionizing Radiation Treatment of Animal Food 
Animal Food  Use  Dose  Limitations 
Bagged complete  Microbial  Not to exceed 50  Animal food and animal 
diets, packaged  disinfection,  kiloGrays (kGy)  food ingredients treated 
feeds, feed  control or  by irradiation should be 
ingredients, bulk  elimination  formulated to account for 
feeds, animal treats  nutritional loss 
and chews 
Poultry feed and  Single treatment  Minimum dose 2.0  For poultry feed or feed 
poultry feed  for rendering  kGy; maximum dose  ingredients that do not 
ingredients  complete poultry  25 kGy.  The  contain drugs 
diets or poultry  absorbed dose of 
Feeds should be 
feed ingredients  irradiation is to be 
formulated to account for 
Salmonella  based on initial 
nutritional loss 
negative  concentration of 
Salmonella using the 
relationship that 1.0 
kGy reduces 
Salmonella 
concentration by one 
log cycle 
See 21 CFR part 579, subpart B  Radiation and Radiation Sources.   
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The regulation includes requirements to account for nutritional loss after irradiation.  This 
nutritional loss could result in a nutrient deficiency hazard that you determine requires a 
preventive control.  In dry cat, dog, and rodent food, gamma radiation within the approved dose 
is known to cause a significant reduction in Vitamin A (Ref. 16).  Irradiated cat food has been 
associated with the development of neurological disease in cats under certain circumstances 
(Ref. 18).   
 
4.5.2  Use of Time and Low Temperature as Process Controls 
 
Temperature is an essential factor that affects the growth of bacteria.  Bacterial growth can occur 
over a wide range of temperatures from about 23F (-5C) to 194F (90C).   
 
Thermophiles grow at temperatures above 131F (55C).  Mesophiles (e.g., Salmonella spp. and 
E. coli) grow at or near room temperatures.  Psychrophiles grow at or near refrigeration 
temperatures.  Psychrotrophs (e.g., L. monocytogenes) are capable of growth at refrigeration 
temperatures, but their optimal growth temperature is in the mesophilic range.  Table 4-6 lists 
four types of bacteria based on their temperature growth ranges.   
 
Table 4-6.  Temperature Ranges for the Growth of Microorganisms 
Minimum  Optimum  Maximum 
Group  Temperature for  Temperature for  Temperature for 
Growth F (C )  Growth F (C )  Growth F (C ) 
Thermophiles  104 - 113 (40 - 45)  131 - 167 (55 - 75)  140 - 194 (60 - 90) 
Mesophiles  41 - 59 (5 - 15)  86 - 113 (30 - 45)  95 - 117 (35 - 47) 
Psychrophiles  23 - 41 (-5 - +5)  54 - 59 (12 - 15)  59 - 68 (15 - 20) 
Psychrotrophs  23 - 41 (-5 - +5)  77 - 86 (25 - 30)  86 - 95 (30 - 35) 
 
Typically, the higher the temperature (within the normal growth range), the more rapid the 
growth of the microorganism.  It is not only the temperature that is of concern; it is the total time 
of exposure at temperatures that allows growth that needs to be minimized.  The most general 
recommendation is to hold refrigerated food below 41F (5C).   
 
Refrigeration 
 
Refrigeration works well for controlling the growth of most pathogenic bacteria.  However, some 
pathogens, like L. monocytogenes can grow at temperatures close to freezing.  Refrigeration has 
the added advantage of slowing down biological and chemical processes that result in spoilage 
and oxidative rancidity.   
 
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Maintaining cold temperatures during storage can be accomplished in several ways, such as ice, 
chemical coolant gel packs, and mechanical dry refrigeration (e.g., in a cooler).  You should 
ensure an adequate amount of ice or gel packs is present on the animal food at all times and 
monitor the temperature with a thermometer or temperature recording device.   
 
For mechanical dry refrigerated storage in a cooler, if the ambient temperature can be related to 
the product temperature, monitoring the temperature of the storage area will ensure that the 
product temperature is maintained.  Monitoring of the cooler is ordinarily done using continuous 
monitoring instruments such as recorder thermometer charts, maximum-indicating thermometers, 
and high temperature alarms.   
 
Time/Temperature 
 
When food that is intended to be stored under refrigeration is removed from refrigeration, the 
temperature of the food gradually increases and can reach the temperature associated with the 
growth range specific to particular pathogens.  Bacterial pathogens go through a lag phase, where 
little or no growth occurs as the microorganisms adjust to their new environment.  As the product 
temperature approaches the growth range, pathogens enter what is called the log phase where 
their numbers increase logarithmically.  For animal food intended to be refrigerated, the 
objective is to prevent the log phase from happening, ideally keeping pathogens in their lag 
phase.  We call the temperature range of concern (41F (5C) to 135F (57C)) the danger zone 
(Ref. 19).  Different pathogens have different rates of growth at different temperatures, and the 
rate of growth will be affected by the type of animal food and its inherent properties.  Therefore, 
the actual maximum time that an animal food may be safely held in the danger zone depends on 
a number of factors, including the type of pathogens that are present and the ability of the animal 
food to support their growth.   
 
Management of time and temperature during processing may be more complicated than during 
storage, because it involves information about the time and temperature exposure of the animal 
food (including raw materials and ingredients) during production.  You can manage time and 
temperature during processing in a variety of ways, such as marking units of animal food and 
tracking how long they remain at unrefrigerated temperatures; monitoring the temperature in a 
chilled processing room; or monitoring animal food temperatures during different phases of 
production.   
 
Cooling after cooking 
 
Cooling after cooking can be a critical function influencing the safety of human food (Ref. 19).  
Cooling after cooking may be important for animal food that is cooked but still requires 
refrigeration (e.g., pet food that is not shelf-stable).  Depending upon the animal food type and 
raw materials and ingredients, cooked animal food can still have viable pathogenic bacteria 
present.  Pathogens that are particularly heat tolerant (such as L. monocytogenes and the spores 
of C. botulinum) can sometimes survive the cooking process; however, this should not be the 
case if you selected the appropriate target pathogen for control by the applied process and you 
validated the control.   
 
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The spores of spore-forming pathogens (such as C. botulinum), if they are present, can survive 
the cooking process because temperatures that can only be achieved under pressure are usually 
needed to inactivate spores.  These spores will begin to germinate when the product temperature 
drops to a temperature at which they can grow (usually below 135F (57C)).  If the animal food 
is temperature-abused, pathogenic spores could germinate, grow, and the resulting cells can 
possibly produce toxin due to the fact that most spoilage bacteria (which may otherwise compete 
for growth) have been eliminated by the cooking process (Ref. 19).   
 
If the cooking process is adequate (i.e., heat and pressure) to inactivate spores, the cooling step 
will not be critical.  However, the animal food can be recontaminated during the cooling process 
as a result of improper handling, condensate or drip, or contact with other animal food.   
 
Freezing 
 
During frozen storage, populations of viable microorganisms in most animal food will decrease; 
however, some microorganisms remain viable for long periods of time during frozen storage.  
Most viruses, bacterial spores, and some bacterial cells survive freezing unchanged.  Some other 
microorganisms (e.g., parasitic protozoa such as T. gondii), are generally more sensitive than 
viruses and bacteria to the freezing and thawing process (i.e., freezing, frozen storage, or 
thawing).  For this reason, freezing and frozen storage are good methods for inactivating 
protozoa in various animal food (Ref. 7). This is especially important if animals are likely to eat 
the animal food raw, after thawing.  However, freezing should not be considered a preventive 
control to significantly minimize pathogens such as Salmonella spp., L. monocytogenes, and 
pathogenic E. coli.   
 
4.5.3  Use of Product Formulation as Process Controls 
 
In this section of this chapter, we discuss two key factors, a  and pH, that are frequently used as 
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a formulation process control.  We also discuss the use of preservatives as a formulation process 
control.   
 
Water activity (a ) 
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Microorganisms need water to survive as well as to grow.  Two measurements relevant to safety 
of animal food are equilibrium relative humidity (ERH) and a .  The a  refers to the availability 
w w
of water to the organism.  In general, microorganisms survive and grow better when the a  is 
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high than when the a is low.   
w 
 
If you have a closed container of pure water, the air above the water becomes saturated with 
water vapor over time.  The ERH of the air at saturation is 100%, which is equivalent to an a  of 
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the water of 1.0.  Thus, pure water has an a  of 1.0 (Ref. 20).   
w
 
Animal food represents more complex systems than water, and the water can bind to components 
of the animal food so not all the water in the animal food is available to microorganisms; thus, 
the a  of animal food is less than 1.0.   
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The a  is directly related to the vapor pressure of the water in a solution.  You can determine a  
w w
by measuring the ERH of the air over the solution in a closed container.  Equilibrium relative 
humidity, expressed as a percentage, divided by 100 equals the a :   
w
 
a  = ERH/100 
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or the partial pressure of water vapor above the animal food (p) divided by the partial pressure of 
water vapor above pure water (p ) at the same temperature:  (Ref. 21).   
o
 
a   = p/p
w o 
 
Animal food types vary in their a  and can be classified into three categories based on a :  moist 
w w
animal food (a above 0.85), intermediate-moisture animal food (a between 0.60 and 0.85), and 
w  w 
low-moisture animal food (a  below 0.60).  Depending on a , animal food may require 
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additional preventive controls to significantly minimize pathogens.  Moist animal food would 
require refrigeration or another control such as heat treatment, acid pH, or preservatives to 
control the growth of pathogens.  Intermediate-moisture animal food would not require 
refrigeration to control pathogens but may have a limited shelf life because of spoilage, primarily 
by yeast and mold.  The microbiological stability of intermediate-moisture animal food may 
depend on factors other than a , such as reduced pH, chemical preservatives, heat treatments, or 
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combinations of these, even though the reduced a  is of major importance.  Low-moisture animal 
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food has an extended shelf life, even without refrigeration when stored properly.  Table 4-7 
classifies animal food into three categories based on a  and provides examples of animal food 
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types.   
 
Table 4-7.  Examples of Animal Food Types Based on Water Activity (a ) 
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Water Activity 
Categories  Animal Food Types 
(a ) 
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Refrigerated and frozen pet food 
Moist Animal 
Above 0.85  Fresh meats and fish 
Food 
Fresh fruits and vegetables 
Soft or semi-moist pet food 
Dry pet food (e.g., kibble) 
Intermediate-
Between 0.60 and 
Moisture Animal  Dog biscuit treat 
0.85 
Food 
Dried distillers grains 
Molasses 
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Water Activity 
Categories  Animal Food Types 
(a ) 
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Corn syrup solids 
Low-Moisture 
Below 0.60  Extruded wheat pellet 
Animal Food 
Whole egg powder 
 
Some of the intermediate and low a  animal food types have naturally low a  (e.g., molasses).  
w w
We do not discuss those animal food types because a  does not have to be controlled during 
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processing.  Other intermediate and low a  animal food types, like dry pet food (kibble), pelleted 
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livestock food, and distillers grains start with a high a  and, through processing, end up with a 
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reduced a .  This section of this chapter focuses on these types of animal food.   
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Control of water activity (a ) 
w
 
There are two primary ways of reducing a  in animal food:  (1) product formulation (e.g., by 
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adding humectants such as propylene glycol (except in cat food) and salt); and (2) dehydration 
(drying).  In this section of this chapter, we discuss reducing a  by product formulation.  See 
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section 4.5.4 for more information on dehydration/drying.   
 
Every organism has a minimum, optimum, and maximum a  for growth (see Table 4-8 for the 
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minimum a for growth of certain pathogens (Ref. 22)).  Yeasts and molds can grow at low a ; 
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however, 0.85 is generally considered the safe cutoff level for bacterial pathogen growth (Ref. 
23).   
 
Table 4-8.  Minimum Water Activity (a ) for Bacterial Pathogen Growth 
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Minimum 
Pathogen 
a  (using salt) 
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Salmonella spp.  0.94 
L. monocytogenes  0.92 
Pathogenic E. coli  0.95 
C. botulinum (depending on type)  0.935-0.97 
 
There are two basic ways for how you can approach product formulation that uses management 
of a for animal food safety.  One approach is to closely follow a scientifically established 
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process control for animal food that ensures a sufficiently low a .  The other approach is to 
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develop your own process control capable of achieving the desired a  and to ensure its adequacy 
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by taking finished product samples and testing them for a .   
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Exposure to a moist environment will impact the ability of a  to serve as a preventive control.  If 
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you rely on a , consider your storage conditions; specifically, protection from water in the 
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environment.  For example, a leaking roof could cause stored plant protein meal to become wet, 
resulting in a meal with a  that could support the growth of pathogens.   
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Acidity (pH) 
 
The term pH refers to a numeric scale used to describe acidity and alkalinity.  The pH reflects 
the concentration of hydrogen ions and is expressed mathematically as the negative logarithm of 
the hydrogen ion concentration in moles per liter.  The pH scale ranges from 0 to14 with pH less 
than 7 being acidic, pH equal to 7 neutral, and pH greater than 7 alkaline:   
 
pH = -log[H+] 
 
Microorganisms can grow only at certain pH levels.  Lowering the pH is a method of inhibiting 
the growth of bacteria rather than a method of killing bacteria.  Although many microorganisms 
held at low pH for an extended period of time will be killed, some pathogenic bacteria, and in 
particular pathogenic E. coli, can survive acidic conditions for an extended period of time, even 
if their growth is inhibited.  For details on the pH values for limiting growth of certain bacterial 
pathogens, see Table 4-9 (Ref. 24).   
 
Table 4-9.  pH Values for Limiting Pathogen Growth 
Pathogen  pH Less Than 
Salmonella spp.  3.8 
L. monocytogenes  4.39 
Pathogenic E. coli  4.4 
C. botulinum  4.6 
 
Acidification 
 
Because an acid pH can inhibit the growth of many bacteria, acidification of animal food could 
be used as a formulation process control.  Acidification is the direct addition of acid to a low-
acid animal food (i.e., food with a pH above 4.6).  There are a variety of acids (such as acetic 
acid, lactic acid, and citric acid) that can be used to acidify animal food.   
 
There are several different methods you might use to add acid to the animal food.  One method is 
called direct acidification, where predetermined amounts of acid and the low-acid animal food 
are added to individual finished product containers during production.  In this method, it is 
important that the processor control the acid-to-animal food ratio.  Another method of 
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acidification is batch acidification.  As the name implies, acid and animal food are combined in 
large batches and allowed to equilibrate.  The acidified animal food is then packaged.  If you use 
acidification to significantly minimize pathogenic microorganisms in your animal food, you must 
validate the process for acidifying that animal food (see 21 CFR 507.47).   
 
Fermentation 
 
During bacterial fermentation of animal food, acid-producing bacteria produce lactic acid, which 
reduces the pH of the food.  Examples of animal food fermented by bacterial fermentation to a 
pH below 4.6 include haylage and silage.  Many of these fermentation activities occur on-farm 
and operations meeting the farm definition in 21 CFR 1.227 are exempt from the PCAF 
regulation (see 21 CFR 507.5(a)).   
 
Preservatives 
 
Preservatives can be used to prevent the growth of microorganisms  e.g., when used in an 
animal food that is not thermally processed or not thermally processed to an extent that is 
sufficient to kill the vegetative cells of non-pathogenic microorganisms (such as spoilage 
microorganisms) that are capable of reproducing in the animal food under the conditions in 
which the animal food is stored, distributed, retailed, and held by the user.  Preservatives work 
by denaturing protein, inhibiting enzymes, or altering or destroying the cell walls or cell 
membranes of microorganisms.  A listing of some substances that are generally recognized as 
safe (GRAS) for use as chemical preservatives is available in 21 CFR part 582, subpart D.   
 
4.5.4  Use of Dehydration/Drying as Process Controls 
 
In the United States, there are three primary methods of dehydration as a process control for 
biological hazards:   
  Forced air drying  used for solid animal food like grains and legumes  
  Spray drying  used for liquids and semi-liquids like milk, blood, and blood plasma  
  Freeze-drying  used for a limited selection of animal food like some raw pet food  
 
Dehydrated/dried animal food is usually considered shelf-stable due to its low a  and, therefore, 
w
is often stored and distributed unrefrigerated.  Examples of shelf-stable dehydrated/dried animal 
food include freeze-dried raw pet food, milk powders, spray dried animal blood, and dried grains 
and soybeans.   
 
If you use dehydration/drying as a process control, you should determine if the animal food will 
require a packaging material that will prevent rehydration of the animal food under the expected 
conditions of storage and distribution.  Additionally, finished animal food packaging and 
package closures should be free of gross defects that could expose the animal food to moisture 
during storage and distribution.   
 
Use of the dehydration process can be an effective method for preventing or significantly 
minimizing deterioration of animal food.  Deterioration of animal food includes the loss of 
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palatability or nutritive value typically associated with the animal food.  This deterioration could 
be a safety concern because animals are often fed the same food containing the same ingredients 
for prolonged periods of time.  Food refusal or consumption of animal food containing 
inadequate amounts of nutrients may result in poor productivity or health issues.   
 
4.6  Preventive Controls for Chemical Hazards 
 
4.6.1  Preventive Controls for Nutrient Deficiencies and Toxicities 
 
As discussed in Chapter 3, nutrient deficiencies or toxicities are considered chemical hazards for 
animal food and FDA has a history of recalls of animal food due to this type of chemical hazard.  
Depending on your facility, the type of animal food, and the intended species (and life stage) of 
animals, you may determine that a nutrient deficiency or toxicity hazard is a known or 
reasonably foreseeable hazard that requires a preventive control.   
 
Many nutrient deficiency or toxicity hazards occur before or during processing, for example, due 
to a miscalculation in the initial recipe/formulation of an animal food for an intended species or 
life stage, inadvertent addition of the wrong mineral mix to a batch of animal food, or failure to 
account for the effects some processing procedures (such as LACF thermal processing or 
irradiation of animal food) have on certain nutrients.  Implementation of process controls would 
be appropriate for many nutrient deficiency or toxicity hazards.  Though preventive controls for 
nutrient deficiencies or toxicities can vary, we describe a few examples.   
 
Essential nutrients in your animal food need to be present at the levels needed by the intended 
animal species (and life stage) and cannot be present in low or excessive levels if the levels could 
result in a nutrient deficiency or toxicity hazard.  For example, vitamin D is a known or 
reasonably foreseeable nutrient deficiency or toxicity chemical hazard for some types of animal 
food.  Past recalls of animal food include both those for vitamin D excess and vitamin D 
deficiencies (see section 3.4.2 in Chapter 3).  If you identify vitamin D deficiency or toxicity in 
your animal food as a hazard requiring a preventive control, your preventive control will depend 
on your manufacturing procedures and could include several types of controls.  Ensuring you 
have the proper nutrient recipe/formulation for a specific species (and life stage) could be one 
control.  An animal nutritionist or similarly trained individual should prepare the 
recipe/formulation.  Confirming you receive the correct ingredient from your supplier, e.g., by 
performing a visual check of the label or certificate of analysis to ensure receipt of the 
appropriate ingredient/component and concentration level, may also be a control.  Another 
control could be one to ensure that the animal food manufacturing equipment is capable of 
producing a homogeneous animal food.  For example, a large mixer that is not filled with the 
minimum volume of ingredients recommended by the manufacturer may not mix a small batch 
of animal food adequately, which could result in the vitamin D not being uniformly distributed 
throughout the animal food (i.e., deficient in some parts, excessive in others).   
 
You should regard thiamine deficiency as known or reasonably foreseeable chemical hazard for 
cat food that is thermally processed as an LACF product.  If you are manufacturing a cat food 
that will undergo LACF thermal processing, you would likely determine that thiamine deficiency 
is a chemical hazard requiring a preventive control.  One process control could include the 
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addition of extra thiamine to the cat food to account for the loss during processing.  Testing 
thiamine levels of processed cat food, at a frequency deemed necessary and appropriate, could be 
an additional process control, or a verification activity to ensure the addition of extra thiamine is 
effective.   
 
You should regard copper excess as a known or reasonably foreseeable chemical hazard for 
sheep food.  If you are manufacturing food for cattle that requires copper at levels that would be 
toxic to sheep, and you manufacture food for sheep on the same equipment, you would likely 
determine that copper excess is a known or reasonably foreseeable nutrient toxicity hazard 
requiring a preventive control.  A preventive control you could implement is a combination of 
sequencing of animal food production and proper flushing of equipment after cattle food 
production.  Sequencing would ensure any food for sheep is manufactured prior to any food for 
cattle.  You could implement additional controls so there is not an inadvertent mix up by an 
employee, to ensure the proper mineral supplement containing copper is added to the appropriate 
animal food (cattle versus sheep).  And, you could add control procedures for labeling of 
finished animal food to ensure a bag of food for cattle (with higher levels of copper) is not 
mistakenly labeled as sheep food.   
 
The following is an example of preventive controls for a nutrient deficiency or toxicity hazard.  
You are manufacturing animal food using a mineral premix received from a supplier and you 
have identified a nutrient deficiency or toxicity hazard.  During your hazard evaluation, you find 
there is a reasonable probability that exposure to the nutrient deficiency or toxicity hazard from 
that premix will result in serious adverse health consequences or death to humans or animals.  
You determine nutrient deficiency or toxicity is a hazard requiring a preventive control.  You 
could implement a preventive control to analyze the premix to ensure it meets your 
specifications.  If you are a receiving facility that relies on your supplier to control the nutrient 
deficiency or toxicity hazard you have determined requires a preventive control, you must 
establish and implement a risk-based supply-chain program (see 21 CFR 507.105).  Because 
there is a reasonable probability that exposure to a nutrient deficiency or toxicity hazard from 
that premix will result in serious adverse health consequences or death to humans or animals, 
your supplier verification activity must be an onsite audit of your supplier (conducted before 
using the raw materials or other ingredients and at least annually after your initial onsite audit), 
unless you can provide a written determination that other verification activities and/or less 
frequent onsite audits of the supplier provide adequate assurance that the nutrient deficiency or 
toxicity hazard is controlled.  (See 21 CFR 507.130(b)(1) and (2)).  For example, you may make 
a written determination that your approved supplier can test each lot of premix for the hazard and 
provide you with a Certificate of Analysis or other documentation for you to review and assess, 
in addition to quarterly testing that you conduct to verify the analytical results.   
 
See section 4.9 for a summary of the supply-chain controls found in 21 CFR part 507, subpart E.  
For more information and our current thinking about supply-chain programs see our draft GFI 
#246, entitled Hazard Analysis and Risk-Based Preventive Controls for Food for Animals: 
Supply-Chain Program.17   
 
 
17 https://www.fda.gov/media/113923/download.  
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You might identify specific CGMPs as your preventive control for certain nutrient deficiencies 
or toxicities.  If you do this, the specific CGMP must be included in your food safety plan as 
your written preventive control (see 21 CFR 507.31) along with the required preventive control 
management components (see 21 CFR 507.39).   
 
4.6.2  Drying and Storage Conditions as Preventive Controls for Mycotoxins 
 
Mycotoxins are toxic metabolites produced by certain fungi (e.g., molds) that can infect and 
proliferate on raw agricultural commodities (e.g., grains such as wheat and corn, peanuts, fruits, 
and tree nuts) in the field and during storage (see Chapter 3, section 3.4.1).  Growth of toxigenic 
fungi during storage and transportation can be enhanced by improper drying or rewetting of the 
crop from rain or condensation.  Thus, proper drying and maintaining appropriate storage 
conditions could be used as preventive controls that can significantly minimize or prevent the 
growth of mold and production of mycotoxins in storage.   
 
By far the most critical environmental factors determining whether a raw agricultural commodity 
will support mold growth are temperature, moisture content, and time.  In storage, each of these 
parameters can be manipulated to prevent mold growth in a raw agricultural commodity.  The 
control of moisture is the principal preventive control for preventing mold growth.  Although 
low-temperature storage can help inhibit mold growth in some conditions, large-scale storage of 
raw agricultural commodities generally takes place in structures that do not provide for 
temperature control.  Thus, low-temperature storage generally is not a viable preventive control 
for mycotoxins during the storage of raw agricultural commodities.   
 
4.6.3  Sequencing and Flushing as Preventive Controls for Drug Carryover 
 
If a facility does not have dedicated equipment for manufacturing certain types of animal food, 
then sequencing and flushing are procedures that could be used to prevent or significantly 
minimize a drug carryover hazard.   
 
Sequencing involves scheduling the production of animal food containing certain drugs (e.g., 
ionophores or other antimicrobials) to occur after the production of nonmedicated animal food to 
minimize the potential for cross-contamination.   
 
Flushing is a method to help remove drugs or animal food that may be left in or on the 
equipment after production.  Flushing is the process of running an ingredient through the 
manufacturing equipment and associated handling equipment (e.g., conveyors) after the 
production of a batch of medicated animal food, for the purpose of removing any drug left in or 
on the equipment.  Abrasive flushing material such as corn, soybean meal, and peanut hulls, is 
helpful after manufacturing a medicated animal food with high fat content or containing 
molasses that may stick to equipment.  Depending on the facility and the animal food 
manufactured, flushing may need to be conducted more often than at the end or start of the day.  
Any flushing method used as a preventive control must be validated as required by 21 CFR 
507.47.   
 
In a medicated feed mill, required employee training in the principles of animal food hygiene and 
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animal food safety (see 21 CFR 507.4(b)(2)) should include information about the drugs used by 
the facility and the potential for illness or injury to animals when those drugs cross-contaminate 
nonmedicated animal food.  See 21 CFR part 225 for additional medicated feed regulations.   
 
4.7  Preventive Controls for Physical Hazards 
 
4.7.1  Preventive Controls for Metal Hazards 
 
Metal-to-metal contact during processing can introduce metal fragments into products.  For 
example, metal fragments can break off during mechanical cutting and blending operations.  
Some metal equipment has parts that can break or fall off, such as wire-mesh belts.  You can 
control metal hazards by using physical separation techniques (e.g., magnets, sieves, screens), 
electronic or X-ray metal detection devices, and by regularly inspecting at-risk equipment for 
signs of damage.   
 
The effectiveness of physical separation techniques depends on the nature of the animal food.  
For example, these measures are more likely to be effective in liquids, powders, and similar 
animal food ingredients and finished animal food in which the metal fragment will not become 
imbedded.   
 
The use of electronic metal detectors is complex, especially with regard to stainless steel, which 
is difficult to detect.  The orientation of the metal object in the animal food affects the ability of 
the equipment to detect it.  For example, if a detector is not properly calibrated and is set to 
detect a sphere 0.08 inch (2 mm) in diameter, it may fail to detect a stainless steel wire that is 
smaller in diameter but up to 0.9 inch (24 mm) long, depending on the orientation of the wire as 
it travels through the detector.  Processing conditions, such as ambient humidity or product 
acidity, may affect the conductivity of the product and create an interference signal that may 
mask metal inclusion unless the detector is properly calibrated.  You should consider these 
factors when calibrating and using such equipment.   
 
X-ray devices can also be used for metal detection.  One advantage of using an X-ray device is 
that the device can also detect non-metal foreign objects such as glass fragments.   
 
Also, preventive controls can include scheduled maintenance of equipment and periodic 
examination of your processing equipment for damage that can cause the introduction of metal 
fragments into the animal food.  You should particularly look at equipment that is prone to 
breaking, such as saw blades, or equipment that has metal-to-metal contact.  The success of this 
strategy depends in large part on the nature of the equipment inspected and the frequency of the 
inspection.  However, this approach will not necessarily prevent metal fragments from being 
incorporated into the product in all cases but may enable you to separate products that may have 
been exposed to metal fragments.  Visually inspecting equipment for damaged or missing parts 
may only be feasible with relatively simple equipment, such as band saws, small orbital blenders, 
and wire-mesh belts.  More complex equipment that contains many parts, some of which may 
not be readily visible, may not be suitable for visual inspection and you should use controls such 
as metal detection or physical separation techniques.   
 
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4.7.2  Preventive Controls for Glass Hazards 
 
Glass fragments can be introduced into animal food when processing occurs under overhead 
light fixtures and light bulbs made of glass that can fracture.  Animals may ingest these glass 
fragments which can cause serious injury (e.g., laceration or perforation of the gastrointestinal 
tract and choking).  Light bulbs, fixtures, skylights, or other glass items suspended over exposed 
animal food in any step of preparation must be shatter-resistant to protect against the 
contamination of animal food from glass breakage (see 21 CFR 507.17(b)(5)).   
 
4.7.3  Preventive Controls for Hard Plastic Hazards 
 
Hard plastic can be introduced into animal food at any time during processing when tools and 
equipment (e.g., scoops, buckets, paddles, sieves, and screens) wear down.  Normal use and 
processing may wear down these tools or equipment over time resulting in fatigue, cracking, and 
breaking.  As a preventive measure, it is important to regularly examine plastics for cracks 
throughout your facility.  Plastic can also be present in incoming ingredients (e.g., animal 
identification tags in rendered products, or packaging material from products originally intended 
for human food used for animal food).  Preventive controls that can be used to significantly 
minimize or prevent hard plastics in animal food at receiving or during manufacturing include 
visually inspecting animal food and using physical separation techniques (e.g., sieves and 
screens).   
 
4.7.4  Preventive Controls for Conditions of Animal Food That Can be Hazards 
 
Conditions of the animal food that can cause illness or injury in animals include physical, 
mechanical, and other characteristics of animal food (e.g., particle size, hardness, surface 
roughness, digestibility, and ability to soften when moistened).  Preventive controls will vary 
depending on the type of animal food and the specific condition of the animal food that you have 
determined requires a preventive control.   
 
If you determine particle size (e.g., too small or too large) is a condition of animal food hazard 
that requires a preventive control, you could address particle size through process controls.  If 
you are reducing the particle size during manufacturing, your process controls would ensure the 
process is achieving the desired particle size, for example, through selection of the hammer-mill 
screen size.   
 
Another condition of animal food hazard you might identify is excessive hardness or poor 
digestibility.  Recipe/formulations and manufacturing processes could impact the hardness 
and/or digestibility of animal food.  For example, starch is used in animal food for nutritive value 
and as a thickening agent.  When starch is gelatinized, the chemical structure of the starch is 
changed, providing digestive enzymes in saliva access to the glycosidic linkages in the starch.  
The enzymes soften the animal food during chewing and make it easier for the animal to 
swallow.  If you have identified the inability to soften when moistened as a condition of animal 
food hazard that requires a preventive control for your animal food, you might use a supply-
chain program to ensure starch meets your specifications (e.g., iodine value, solubility, and 
viscosity).  You also may rely on your manufacturing process to gelatinize the starch.  In this 
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situation, you may determine that you need to implement a process control to ensure acceptable 
gelatinization of the starch to significantly minimize or prevent indigestible animal food.  Your 
process control would include parameters for the processing (e.g., temperature, time, pressure, 
and moisture content) necessary to gelatinize the starch in your food.   
 
4.8  Sanitation Controls 
 
Sanitation controls include procedures, practices, and processes to ensure that the facility is 
maintained in a sanitary condition adequate to significantly minimize or prevent hazards such as 
environmental pathogens and biological hazards due to employee handling.  Sanitation controls 
must include, as appropriate to the facility and the animal food, procedures, practices, and 
processes for the:  (1) cleanliness of animal food-contact surfaces, including animal food-contact 
surfaces of utensils and equipment; and (2) prevention of cross-contamination from insanitary 
objects and from personnel to animal food, animal food-packaging material, and other animal 
food-contact surfaces and from raw product to processed product.  See 21 CFR 507.34(c)(2).   
 
Animal food CGMPs include requirements for sanitation of the plant (see 21 CFR 507.19).  
These requirements are applicable to the cleanliness of equipment, utensils, buildings, structures, 
and fixtures.  To comply with these CGMP requirements, cleaning procedures should take place 
routinely, often daily, in your facility.  To facilitate sanitation, there are requirements for the 
design and construction of equipment and utensils (see 21 CFR 507.22(a)).   
 
Some of your sanitation procedures, practices, and processes used in your facility for general 
cleaning and sanitation may be performed to comply with CGMP requirements.  Other sanitation 
procedures, practices, and processes may be sanitation controls if used to significantly minimize 
or prevent a biological hazard.  You determine which hazards require a sanitation control 
through your hazard analysis.  For example, you may determine a sanitation control is needed in 
addition to the general facility cleaning if there is a biological hazard such as L. monocytogenes 
that you determined requires a preventive control.  The sanitation control is the cleaning and 
sanitizing you conduct on animal food-contact surfaces of utensils and equipment to significantly 
minimize or prevent L. monocytogenes.  Because the cleaning and sanitizing are used as a 
sanitation control, they are subject to the preventive control management components in 21 CFR 
507.39.   
 
For your sanitation controls to be effective, you should first assess the cleaning procedures, 
practices, and processes that you have in place to comply with the CGMP requirements.  See our 
GFI #235 entitled Current Good Manufacturing Practice Requirements for Food for 
Animals.18  Equipment design that ensures that all surfaces can be accessed and cleaned (see 21 
CFR 507.22(a)(1)) is essential for the effective application of sanitation controls.  For 
clarification of the terms cleaning and sanitize, see section 4.8.1.  Considerations for 
equipment design include factors such as whether equipment includes hollow bodies or poorly 
developed welds and seams, as well as whether ease of disassembly allows adequate access to all 
animal food-contact surfaces to ensure thorough cleaning and sanitation.  Design considerations 
also apply to animal food facility structures (e.g., floors, walls, piping, and ceilings) to facilitate 
 
18 https://www.fda.gov/media/97464/download.  
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cleaning and sanitation practices.  Sources of scientific and technical information also can be 
useful in establishing sanitation controls (Refs. 25, 26, and 27).   
 
4.8.1  Cleaning Strategies and Sanitation Controls 
 
The PCAF regulation does not define the term cleaning.  In this guidance, we use the term 
cleaning to mean the removal of soil, animal food residue, dirt, grease or other objectionable 
matter.  Cleaning procedures, practices, and processes are generally considered part of a 
facilitys general sanitation program.  The PCAF regulation defines sanitize to mean to 
adequately treat cleaned surfaces by a process that is effective in destroying vegetative cells of 
pathogens, and in substantially reducing numbers of other undesirable microorganisms, but 
without adversely affecting the product or its safety for animals or humans (21 CFR 507.3).  
Although cleaning operations and sanitizing operations often are conducted separately  and 
sequentially  some systems (such as steam systems) both clean and sanitize surfaces; we 
consider that such systems satisfy the definition of sanitize.   
 
The cleaning procedures and any sanitation controls you use will vary based on the nature of 
your facility, such as whether your facility has a dry or wet processing environment.   
 
Table 4-10 describes three types of cleaning strategies that you can use to remove soil, food 
residue, dirt, grease, or other objectionable matter depending upon the processing environment 
(wet or dry).  Table 4-10 also includes some recommendations when using these cleaning 
strategies.   
 
Table 4-10.  Types of Cleaning Strategies 
Cleaning 
Description  Recommendations 
Strategy 
When feasible, initially dry clean area or 
Wet Cleaning  Uses water-based and/or 
equipment 
wet chemical cleaning 
solutions  Use water on an as needed basis 
Typically used for wet  Use water only in required areas 
processing environments 
When feasible, avoid using water in a 
manner that could aerosolize (e.g., high 
pressure) 
When animal food-contact surfaces are 
wet-cleaned, the surfaces must, when 
necessary, be thoroughly dried before 
subsequent use (see 21 CFR 507.19(b)(1)) 
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Cleaning 
Description  Recommendations 
Strategy 
When feasible, initially dry clean area or 
Controlled  Uses a limited amount of 
equipment 
Wet Cleaning  water 
Use only as much water as is necessary 
Typically used for dry 
processing environments  Move specific pieces of equipment to a 
designated area for cleaning and sanitizing 
and dry them prior to returning them to the 
dry manufacturing area 
When animal food-contact surfaces are 
wet-cleaned, the surfaces must, when 
necessary, be thoroughly dried before 
subsequent use (see 21 CFR 507.19(b)(1)), 
and complete drying should immediately 
follow after the controlled wet cleaning 
Remove animal food residues by actions 
Dry Cleaning  The physical removal of 
such as sweeping, brushing, scraping, 
residues (e.g., animal 
flushing or vacuuming the residues from 
food particles and dust) 
equipment surfaces and the facility 
without water 
environment 
Typically used for dry 
Be careful to not distribute animal food 
processing environments 
particles to other equipment or areas 
during removal 
Compressed air must be used in a way that 
protects against the contamination of 
animal food (see 21 CFR 507.22(e)) (e.g., 
does not blow dirt, debris, or other 
contaminants into the animal food or onto 
animal food-contact surfaces) 
 
Moisture control is important in preventing contamination with undesirable microorganisms.  For 
example, water in a dry processing environment is one of the most significant risk factors for 
Salmonella contamination because the presence of water allows for pathogen growth leading to 
product contamination from the environment or from insanitary food contact surfaces.  You 
should maintain dry conditions at all times when you determine that Salmonella in the 
environment is a hazard requiring a preventive control, except for the occasions when you decide 
that controlled wet cleaning is necessary.  Potential problems arise when there is visible water 
present in the dry areas or when there are areas in which standing water has dried.  Salmonella 
may be found both in wet spots and in spots where standing water has dried.  Therefore, dry 
cleaning or controlled wet cleaning practices should be considered for use as a component of 
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sanitation controls in a dry processing environment.   
 
Wet processing operations are typically cleaned using wet cleaning practices.  However, the use 
of water should be minimized even in facilities that are wet cleaned.  Wet floors can serve as 
potential sources for L. monocytogenes via the movement of people and equipment and material 
handling items such as totes and pallets.  Cleaning and sanitizing floors, including drains, could 
help reduce the potential for L. monocytogenes to establish in the environment.  L. 
monocytogenes is not usually airborne; however, in wet environments, aerosols from high 
pressure water hoses used during cleaning operations help spread L. monocytogenes throughout 
the environment and from one surface (e.g., floors) to another surface (e.g., animal food-contact 
surfaces, such as conveyors, tables, and animal food containers).  Cleaning and sanitizing may be 
an important sanitation control for facilities that have determined they need to control L. 
monocytogenes because they are producing animal food such as raw pet food which may be 
exposed to the environment prior to packaging.   
 
If you determine sanitizing is necessary, you should sanitize animal food contact surfaces and 
other areas as appropriate after the surfaces are cleaned.  You should use all sanitizers in 
accordance with the EPA-registered (or similar registration in other countries) label use 
instructions, including approval for use in food establishments.   
 
For additional information on the impact of wet and dry processing environments on L. 
monocytogenes and Salmonella, see Chapter 3, section 3.3.4.   
 
4.8.2  Use of Sanitation Controls to Prevent Cross-Contamination 
 
As noted previously in this section, sanitation controls must include, as appropriate to the facility 
and the animal food, procedures, practices, and processes for the prevention of cross-
contamination from insanitary objects and from personnel to animal food, animal food packaging 
material, and other animal food-contact surfaces and from raw product to processed product.  See 
21 CFR 507.34(c)(2)(ii).   
 
Table 4-11 describes some practices that you can use to prevent cross-contamination of 
processed animal food from insanitary objects, personnel, and raw product.   
 
Table 4-11.  Practices to Prevent Cross-Contamination 
Practice  Description 
Hygienic zoning for separation and segregation of process operations 
Hygienic Zoning  such as raw vs. work-in-process vs. finished product; wet vs. dry; 
personnel and materials traffic flow; air balance 
Hygienic Zone  Dedicated cleaning and sanitation practices (including sanitizing) within 
Specific  hygiene zones 
Cleaning 
 
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The objective of hygienic zoning is to reduce the potential for transient pathogens to enter 
sensitive areas in your facility.  You should determine the need for, and scope of, a hygienic 
zoning program based on the outcome of your hazard analysis and considering your facility and 
type of animal food.  In determining the need for, and scope of, a hygienic zoning program, you 
should take into account the design of your plant, packaging, personnel and ingredient traffic 
flows, and any cross over areas.  You also should consider potential contaminants from raw 
materials, air flow, support areas, and other activities taking place in your facility.   
 
Hygienic zoning is more likely to have application in the production of pet food than in facilities 
producing livestock food.  For example, a facility that makes pet food might decide it needs to 
implement a hygienic zoning program to prevent cross-contamination with Salmonella spp. or L. 
monocytogenes since the pet food may be exposed to the environment prior to packaging.   
 
4.9  Supply-Chain Controls 
 
A supply-chain control is a type of preventive control (21 CFR 507.34(c)(3)).  The requirements 
for implementing a supply-chain program to control a hazard that must be controlled by a 
supplier are found in 21 CFR part 507, subpart E.   
 
The requirements for a supply-chain control differ from those for a process control or sanitation 
control.  If a supply-chain program is needed based on the outcome of your hazard analysis, you 
must be familiar with the requirements of the supply-chain program.  The sections in 21 CFR 
part 507, subpart E are as follows:   
  Requirement to establish and implement a supply-chain program (21 CFR 507.105)  
  General requirements applicable to a supply-chain program (21 CFR 507.110)  
  Responsibilities of the receiving facility (21 CFR 507.115)  
  Using approved suppliers (21 CFR 507.120)  
  Determining appropriate supplier verification activities (including determining the 
frequency of conducting the activity) (21 CFR 507.125)  
  Conducting supplier verification activities for raw materials and other ingredients (21 
CFR 507.130)  
  Onsite audit (21 CFR 507.135)  
  Records documenting the supply-chain program (21 CFR 507.175)  
We provide FDAs current thinking on the requirements of the supply-chain program in our draft 
GFI #246 entitled Hazard Analysis and Risk-Based Preventive Controls for Food for Animals: 
Supply-Chain Program.19   
 
4.10  Recall Plan 
 
 
19 https://www.fda.gov/media/113923/download. 
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For animal food with a hazard requiring a preventive control, you must establish a written recall 
plan for the animal food.  (See 21 CFR 507.38(a)(1).)  The written recall plan must include 
procedures that describe the steps to be taken, and assign responsibility for taking those steps, to 
perform the following actions as appropriate to the facility:   
  directly notify the direct consignees of the animal food being recalled, including how to 
return or dispose of the affected animal food (21 CFR 507.38(b)(1))  
  notify the public about any hazard presented by the animal food when appropriate to 
protect human and animal health (21 CFR 507.38(b)(2))  
  conduct effectiveness checks to verify that the recall is carried out (21 CFR 507.38(b)(3))  
  appropriately dispose of recalled animal food  e.g., through reprocessing, reworking, 
diverting to a use that does not present a safety concern, or destroying the animal food 
(21 CFR 507.38(b)(4))  
We recommend that you consult our general guidance on policy, procedures, and industry 
responsibilities regarding recalls in 21 CFR part 7, subpart C (sections 7.40 through 7.59) and on 
FDAs website, Industry Guidance for Recalls.20  
 
Careful planning when developing a recall plan can increase recall efficiency.  You must assign 
responsibility for performing all procedures in your recall plan (21 CFR 507.38(a)(2)).  You may 
consider assigning responsibilities to a position rather than specifying an individual by name.  
Assigning responsibilities to a position would not require you to update the recall section of your 
food safety plan if you have a change in personnel.  For facilities that have multiple shifts, this 
may allow you to initiate a recall faster since you would not have to wait for an individual who 
may work on a different shift.  However, we also recommend you ensure each person in that 
position, to which the responsibility is assigned, understands the steps to be taken during a recall.   
 
A recall can be disruptive to your operation and business, but there are steps you can take in 
advance to minimize this disruptive effect:   
 
  Adequately code animal food to make possible positive lot identification and to facilitate 
effective recall of all violative lots.   
  Maintain such animal food distribution records as are necessary to facilitate location of 
products that are being recalled.  You may wish to maintain such records for a period of 
time that exceeds the shelf life and expected use of the product as a matter of business 
practice.   
4.11  References for Chapter 4 
 
1.  Food Safety Preventive Controls Alliance. 2016. Preventive Controls for Animal Food 
Participant Manual. First Edition v.1.0.  
 
 
20 https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/industry-guidance-recalls  
95 
  Contains Nonbinding Recommendations 
 
2.  National Advisory Committee on Microbiological Criteria for Foods. 1998. Hazard 
Analysis and Critical Control Point Principles and Application Guidelines. Journal of 
Food Protection 61 (9): 1246-1259.  
 
3.  Codex Alimentarius Commission. 2003. Recommended International Code of Practice 
General Principles of Food Hygiene CAC/RCP1-1969, Rev. 4-20031. Accessed July 
19, 2021.  http://www.mhlw.go.jp/english/topics/importedfoods/guideline/dl/04.pdf.  
 
4.  Grocery Manufacturers Association. 2009. Control of Salmonella in Low-Moisture 
Foods. Accessed July 19, 2021. 
http://graphics8.nytimes.com/packages/pdf/business/20090515_moss_ingredients/Salm
onellaControlGuidance.pdf.  
 
5.  American Feed Industry Association. 2010. Salmonella Control Guidelines. Accessed 
July 19, 2021.  http://ucfoodsafety.ucdavis.edu/files/172958.pdf.  
 
6.  Food Safety Preventive Controls Alliance. 2016. Preventive Controls for Human 
Food. First Edition v.1.2.  
 
7.  Kijlstra, A., and E. Jongert. 2008. Control of the Risk of Human Toxoplasmosis 
Transmitted by Meat. International Journal for Parasitology 38 (12): 1359-1370. 
DOI:10.1016/j.ijpara.2008.06.002.  
 
8.  Lindsay, D. S., et al. 2006. Effects of High-Pressure Processing on Toxoplasma gondii 
Tissue Cysts in Ground Pork. Journal of Parasitology 92 (1): 195-196. DOI: 
10.1645/GE-631R.1.  
 
9.  Jones, J. L., and J. P. Dubey. 2012. Foodborne Toxoplasmosis. Clinical Infectious 
Diseases 55 (6): 845-851. DOI: 10.1093/cid/cis508.  
 
10.  Food and Drug Administration. 2000. Kinetics of Microbial Inactivation for 
Alternative Food Processing Technologies  Overarching Principles: Kinetics and 
Pathogens of Concern for all Technologies.  Accessed June 2, 2022.  
https://www.fda.gov/media/103619/download.  
 
11.  Lacroix, M. 2014. Chapter 16: Irradiation. In Emerging Technologies for Food 
Processing, edited by Sun, D. W., 293312. London: Elsevier Academic Press.  
 
12.  Tiwari, B. K. 2014. Chapter 17: New Chemical and Biochemical Hurdles. In 
Emerging Technologies for Food Processing, edited by Sun, D. W., 313-325. London: 
Elsevier Academic Press.  
 
13.  Niemira, B. A. 2014. Chapter 18: Decontamination of Foods by Cold Plasma. In 
Emerging Technologies for Food Processing, edited by Sun, D. W., London: Elsevier 
Academic Press.  
 
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  Contains Nonbinding Recommendations 
 
14.  Tao, Y., et al. 2014. Chapter 1: High-Pressure Processing of Foods: An Overview. In 
Emerging Technologies for Food Processing, edited by Sun, D.W., 3-24. London: 
Elsevier Academic Press.  
 
15.  Farkas, J., et al. 2014. Chapter 27: Food Technologies: Food Irradiation. In 
Encyclopedia of Food Safety, edited by Motarjemi, Y., Moy, G., and Tood E., 178-186. 
Waltham: Elsevier.  
 
16.  Caulfield, C. D., et al. 2008. Effects of Gamma Irradiation and Pasteurization on the 
Nutritive Composition of Commercially Available Animal Diets. Journal of the 
American Association for Laboratory Animal Science 47 (6): 61-66.  
 
17.  Zhu, J. T, et al. 2012. Toxicological Evaluation of Chicken-Breast Meat with High-
Dose Irradiation. Journal of Integrative Agriculture 11 (12): 2088-2096. DOI:  
10.1016/S2095-3119(12)60467-5.  
 
18.  Child, G., et al. 2009. Ataxia and Paralysis in Cats in Australia Associated with 
Exposure to an Imported Gamma-Irradiated Commercial Dry Pet Food. Australian 
Veterinary Journal 87 (9): 349-351. DOI: 10.1111/j.1751-0813.2009.00475.x.  
 
19.  Food and Drug Administration. 2017. Food Code. Accessed July 19, 2021. 
https://www.fda.gov/food/fda-food-code/food-code-2017.  
 
20.  Cauvain, S.P., and L.S. Young. 2011. Equilibrium Relative Humidity (Water Activity). 
In Food and Beverage Stability and Shelf Life, edited by Kilcast, D. and Subramaniam, 
P., 667. Cambridge: Woodhead Publishing.  
 
21.  Padua, G.W. 2014. Water Activity. In Encyclopedia of Agricultural, Food, and 
Biological Engineering, edited by Heldman, D.R. and Moraru, C.I., 1837-1839. Boca 
Raton: CRC Press.  
 
22.  International Commission on Microbiological Specification. 1996. Microorganisms in 
Foods 5: Characteristics of microbial pathogens. Blackie Academic & Professional.   
 
23.  Food and Drug Administration. 2015. Water Activity (a ) in Foods. Accessed July 
w
19, 2021.  
https://www.fda.gov/ICECI/Inspections/InspectionGuides/InspectionTechnicalGuides/u
cm072916.htm.  
 
24.  United States Department of Agriculture. 2012. Introduction to the Microbiology of 
Food Processing. In Small Plant News Guidebook Series, 40.  
 
25.  Holah, J. T. 2014. Chapter 9: Cleaning and Disinfection Practices in Food Processing. 
In Hygiene in Food Processing - Principles and Practice, edited by Lelieveld, H. L. M., 
J. T. Holah and Napper D., Cambridge: Elsevier Publishing.  
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  Contains Nonbinding Recommendations 
 
 
26.  Marriott, N. G., and R. B. Gravani. 2010. Chapter 8: Quality Assurance for 
Sanitation. In Principles of Food Sanitation, 116-140. New York: Springer.  
 
27.  Marriott, N. G., and R. B. Gravani. 2010. Chapter 9: Cleaning Compounds. In 
Principles of Food Sanitation, 141-164. New York: Springer.  
 
   
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CHAPTER 5  OVERVIEW OF PREVENTIVE CONTROL MANAGEMENT 
COMPONENTS 
 
5.1  Purpose of this Chapter 
 
The guidance provided in this chapter is intended to help you implement the preventive control 
management components (PC management components) that are part of your food safety plan. 
See 21 CFR 507.39.  If you have determined there are no hazards requiring preventive controls 
for your animal food, you would not need to establish PC management components.   
 
5.2  Overview of Preventive Control Management Components 
 
The PC management components include monitoring, corrective actions and corrections, 
verification activities (including validation and verification of implementation and effectiveness), 
and their associated records.  You must apply appropriate PC management components to ensure 
the effectiveness of your preventive control(s) identified in your food safety plan, taking into 
account the nature of the preventive control and its role in your facilitys animal food safety 
system.  See 21 CFR 507.39.  This chapter will focus on PC management components associated 
with process controls, sanitation controls, and other preventive controls.   
 
5.3  Who is Responsible for Conducting Preventive Control Management Component 
Activities? 
 
In this Chapter, we discuss two types of individuals who are responsible for conducting PC 
management components, a preventive controls qualified individual (PCQI) and a qualified 
individual (QI) (see Box 5-1).  As discussed in Chapter 1, your PCQI is a qualified individual 
who successfully completed training in the development and application of risk-based preventive 
controls or is otherwise qualified through job experience to develop and apply a food safety 
system.  The PCQI must prepare (or oversee the preparation of) your food safety plan.  
Specifically, for PC management components, PCQIs must conduct or oversee validation of 
preventive controls and some verification of implementation and effectiveness activities (see 21 
CFR 507.53(a)).  The PCQI may designate another individual to conduct these activities 
provided the individual is a QI and the PCQI maintains oversight.   
 
Box 5-1.  Definition of Qualified Individual 
Qualified Individual (QI) 
 
A person who has the education, training, or experience (or a combination thereof) 
necessary to manufacture, process, pack, or hold safe animal food as appropriate to the 
individuals assigned duties.  A qualified individual may be, but is not required to be, an 
employee of the establishment.  (21 CFR 507.3) 
 
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In many cases, a QI may be assigned the responsibility for conducting the PC management 
component activities.  The individual(s) who conducts and generates records for monitoring, 
corrective actions and corrections, and other activities must be qualified to perform these 
assigned duties.  See 21 CFR 507.4(b)(1).  For a discussion of training required for a QI, see our 
GFI #235 entitled Current Good Manufacturing Practice Requirements for Food for 
Animals.21   
 
5.4  Recordkeeping Requirements for Preventive Control Management Components 
 
The specific records required for each PC management component are found in their respective 
sections of the PCAF regulation:   
  21 CFR 507.40  Monitoring  
  21 CFR 507.42  Corrective actions and corrections  
  21 CFR 507.45  Verification (including validation and verification of implementation 
and effectiveness)  
 
These records are subject to the recordkeeping requirements in 21 CFR part 507, subpart F  
Requirements Applying to Records That Must Be Established and Maintained.  The records must 
meet the various requirements in 21 CFR 507.202.  For example, the records must contain the 
actual values and observations obtained during monitoring and as appropriate during 
verification; be created concurrently with the activity documented including the date and if 
necessary the time; and, be signed or initialed by the individual performing the activity (see 21 
CFR 507.202(a) and (b)).   
 
In general, records must be retained for at least two years (see 21 CFR 507.208(a)(1)).  Some 
records are required to be retained longer, such as those related to the general adequacy of the 
equipment or processes being used at the facility (see 21 CFR 507.208(b)).  Results of scientific 
studies and evaluations (i.e., used for validation) must be retained for at least two years after 
their use is discontinued (e.g., discontinued because you have updated the records documenting 
validation).  See 21 CFR 507.208(b).  The recordkeeping requirements are discussed further in 
each PC management component section of this chapter.   
 
5.5  Preventive Control Management Components Examples 
 
We use two animal food scenarios throughout this chapter to help illustrate the requirements we 
describe in this chapter.  The scenarios are simplified for purposes of this guidance and focus on 
a single hazard and preventive control for each facility.  We use different employee position 
titles in the examples, but all individuals are QIs.  See Boxes 5-3a and b through 5-12a and b for 
the two example scenarios.   
 
Boxes 5-2a and 5-2b provide an introduction to the two scenarios.   
 
 
 
21 https://www.fda.gov/media/97464/download.  
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Box 5-2a.  PC Management Components Example  Introduction 
Salmonella in dog biscuit treats:  At your facility, you bake dog biscuits containing chicken 
by-products.  Based on your hazard analysis, you identify Salmonella as a known or 
reasonably foreseeable biological hazard and determine that this hazard requires a preventive 
control.  The preventive control you identify is thermal processing (time and temperature 
preventive control) implemented by baking the biscuits in an oven to significantly minimize 
Salmonella.  You set the minimum parameter value for temperature at 350F (177C) and the 
minimum parameter value for baking time at 15 minutes.  In order to ensure the safety of the 
dog biscuits, you bake them at a temperature of 355F (179C).  The preventive control is 
validated by your PCQI before you begin initial production (see Box 5-5a).  These 
procedures (i.e., your preventive control) are written in your food safety plan.  Your facility 
runs 3 shifts daily, 8 hours each, and every seventh day shuts down during the last shift for 
cleaning.  Immediately after exiting the baking chamber, the biscuits are gently cooled down 
to ambient temperature on an enclosed cooling conveyor that delivers the biscuits to the 
bagging/packaging machine where they are packaged 20 biscuits per sealed poly bag.   
 
Box 5-2b.  PC Management Components Example  Introduction 
Monensin in horse food:  At your feed mill, you manufacture food for cattle containing the 
animal drug monensin.  You also manufacture horse food using the same equipment.  Based 
on your hazard analysis, you identify monensin in horse food as a known or reasonably 
foreseeable chemical hazard and determine that this hazard requires a preventive control.  
You identify and implement as your preventive control daily sequencing and flushing 
procedures.  Your sequencing procedure specifies that horse food must be manufactured prior 
to animal food containing monensin (e.g., food for beef cattle).  Your flushing procedure 
specifies the amount and type of flush material to use and that flushing must be performed at 
the end of each day.  The preventive control is validated by your PCQI before you begin 
initial production of horse food (see Box 5-5b).  These procedures (i.e., your preventive 
control) are written in your food safety plan.   
 
5.6  Monitoring 
 
Monitor means to conduct a planned sequence of observations or measurements to assess 
whether control measures are operating as intended (21 CFR 507.3).  You must establish and 
implement written procedures for monitoring preventive controls, including the frequency with 
which they are to be performed (as appropriate to the nature of the preventive control and its role 
in your animal food safety system).  See 21 CFR 507.40.   
 
Your monitoring procedures should answer five questions:   
1.  What will be monitored?  
2.  How will monitoring be done?  
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3.  How often will monitoring be done (frequency)?  
4.  Who will do the monitoring?  
5.  What records do I need to document monitoring?  
 
5.6.1  What Will Be Monitored? 
 
What you monitor should be directly related to control of the hazard.  For example, for a process 
control you monitor parameters to ensure the maximum or minimum parameter values, or a 
combination of parameter values used to control the hazard, are met.   
 
For preventive controls other than process controls, what you monitor depends on the type of 
preventive control.  For example, for sanitation controls, you may monitor that the sanitizer is 
prepared and applied according to your written procedures.   
 
5.6.2  How Will Monitoring Be Done? 
 
The type of monitoring method you choose will depend on the preventive control you are 
implementing.  You may monitor by using a variety of instruments, laboratory analyses, or 
visual checks.   
 
Instrumentation may be appropriate for a preventive control that has a parameter that can be 
measured during processing.  For example, you would use instruments to monitor parameters 
such as pH, a , temperature, or pressure.   
w
 
Laboratory analysis may be conducted using an onsite rapid testing method or conducted off-site 
by an outside laboratory.  For example, if you are controlling the level of aflatoxin in your raw 
corn, you may use a rapid test to monitor for the presence of aflatoxin.   
 
Visual checks also may be an appropriate monitoring activity, such as observing package 
integrity to ensure a finished pet food will not be exposed to contaminants from the environment 
(e.g., looking for broken bags or containers).   
 
5.6.3  How Often Will Monitoring Be Done (Frequency)? 
 
You must monitor the preventive controls with adequate frequency to provide assurance that 
they are consistently performed (21 CFR 507.40(b)).  The frequency of monitoring depends upon 
the hazard you identify, your preventive control, and the animal food.  You may determine that 
some preventive controls require continuous monitoring while others can be adequately 
monitored on a less frequent basis.   
 
Continuous monitoring is typically performed by an instrument that produces a continuous 
record, for example a temperature-chart recorder on an oven.  Continuous monitoring is desirable 
and, in some cases, you may decide it is necessary.  Even with continuous monitoring, you 
should check the paper or electronic record of the continuous monitoring instrument (device) 
with adequate frequency to provide assurance that the preventive control is being consistently 
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performed, for example, by determining if there are deviations from the control parameter 
values.   
 
In some situations, you may decide that continuous monitoring is not necessary.  Non-continuous 
monitoring might include temperature checks at designated points in the production process or 
samples taken for pH analysis at designated time points during the day.  When determining the 
frequency for non-continuous monitoring, you should consider the variation during normal 
processing, how close your operating limits are to your parameter values (if appropriate), and 
how much animal food could be impacted if a deviation occurs.  See Chapter 4, section 4.4.1, for 
more information about operating limits.   
 
You should monitor often enough:  (1) to determine the normal variability in what you are 
measuring or observing, and (2) to detect a deviation.  Generally, the greater the time span 
between measurements, or between checks that procedures are being followed, the more animal 
food you put at risk.  If a measurement or observation shows that a deviation occurred, you 
should assume that the preventive control was not effective or not implemented correctly 
following the most recent acceptable measurement or observation.   
 
5.6.4  Who Will Do the Monitoring? 
 
The person conducting the monitoring must be a QI for their assigned duties.  See 21 CFR 
507.4(b)(1).   
 
5.6.5  What Records Do I Need to Document Monitoring? 
 
You must document your monitoring of preventive controls in records that are subject to 
verification and records review by a PCQI (see 21 CFR 507.40(c)(1) and 507.49(a)(4)(i)).  
Records include the documents that are generated during continuous or periodic monitoring.   
 
Records for monitoring refrigeration temperature may be affirmative or exception records.  
Affirmative monitoring records demonstrate that refrigeration temperature (your preventive 
control) is under control.  See 21 CFR 507.40(c)(2)(i).  For example, an affirmative record is the 
record on which your QI records your refrigerator temperature demonstrating the temperature is 
controlled or the chart recorder record from the continuous monitoring system.   
 
A continuous monitoring system of refrigeration temperature may generate an exception record 
if there is a loss of temperature control.  Exception records may be adequate in circumstances 
other than monitoring of refrigeration temperature.  See 21 CFR 507.40(c)(2)(ii).  When using 
exception records, a record is generated only when a deviation occurs.  For example, if your 
freezer temperature rises above your parameter value, your computer system generates an 
exception record demonstrating the rise of temperature and time of deviation.  If you use an 
exception record, you must have evidence that your system is working as intended (see 21 CFR 
507.49), such as a record that the system has been challenged by increasing the temperature to a 
point at which an exception record is generated.   
 
Boxes 5-3a and 5-3b provide examples of monitoring.   
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Box 5-3a.  PC Management Component Example  Monitoring 
Salmonella in dog biscuit treats:  According to your time and temperature preventive 
control, you bake your biscuits in a conveyor oven set at a speed to give a 15-minute baking 
time at 355F (179C) to ensure you stay above your minimum parameter value of 350F 
(177C).  Your conveyor oven is equipped with a thermocouple probe, a temperature chart 
recorder, and alarm system that continuously measures oven temperature. 
 
Per your written preventive control procedures, the designated operator does a visual check of 
the chart recorder every hour to ensure the oven temperature remains at 355F (179C) (your 
1st monitoring procedure) and documents this in the monitoring record.  In addition, the 
operator uses a stopwatch to check conveyor speed every 2 hours to ensure a 15-minute 
baking time (your 2nd monitoring procedure) and records the results in the monitoring record.   
 
Box 5-3b.  PC Management Component Example  Monitoring 
Monensin in horse food:  To monitor your sequencing and flushing preventive control, 
your written procedures state that the designated operator(s) must record the order of each 
batch of animal food produced that day to document horse food is produced prior to any 
animal food containing monensin, and to document the flushing of equipment at the end of 
the day.  To accomplish this, the designated operator completes a real-time sequencing 
production record (your 1st monitoring record) for each batch of animal food produced and a 
flushing record (your 2nd monitoring record) at the end of the day.  Per your written 
procedures, your sequencing production record contains:  the date, the type of animal food 
produced, the order in which the animal food is to be produced, the time the batch was 
produced, the name of any drugs used in the batch, the quantity produced, and the batch lot 
number.  Per your written procedures, your flushing record contains:  the date, the time the 
flushing occurred, and the type and amount of material used for flushing.   
 
5.7  Corrective Actions and Corrections 
 
When your preventive control is not properly implemented, you must conduct a corrective action 
or correction.  See 21 CFR 507.42.  The purpose of corrective actions is to prevent adulterated 
animal food from entering commerce.  When minor, isolated problems occur that do not directly 
impact animal food safety, corrections may be appropriate instead of corrective actions.   
 
5.7.1  Corrective Actions 
 
As appropriate to the nature of the hazard and the nature of the preventive control, you must 
establish and implement written corrective action procedures you must take if preventive 
controls are not properly implemented (21 CFR 507.42(a)(1)).  As appropriate, your written 
corrective action procedures also must include procedures to address the presence of a pathogen 
or appropriate indicator organism in an animal food detected as a result of your product testing 
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(see 21 CFR 507.42(a)(1)(i)), and the presence of an environmental pathogen or appropriate 
indicator organism detected through your environmental monitoring (21 CFR 507.42(a)(1)(ii)).   
 
Specifically, the corrective action procedures must describe the steps to be taken to ensure that:   
  appropriate action is taken to identify and correct the problem that has occurred with the 
implementation of a preventive control (21 CFR 507.42(a)(2)(i))  
  appropriate action is taken when necessary to reduce the likelihood that the problem will 
recur (21 CFR 507.42(a)(2)(ii)) 
  all affected animal food is evaluated for safety (21 CFR 507.42(a)(2)(iii))  
  all affected animal food is prevented from entering into commerce if you cannot ensure 
the affected animal food is not adulterated (21 CFR 507.42(a)(2)(iv))  
A predetermined corrective action procedure has advantages.  For example, the written 
procedure provides detailed instructions for an employee to follow in the event of a deviation in 
applying a preventive control and is prepared at a time when an emergency situation is not 
calling for an immediate decision.   
 
You may not be able to anticipate all the problems that could happen and include them in your 
written corrective action procedures; however, you still must take corrective actions when an 
unanticipated problem occurs.  You must take appropriate corrective actions if:   
 
  you do not properly implement a preventive control and you have not established a 
written corrective action procedure (see 21 CFR 507.42(b)(1)(i));  
  your preventive contol (or combination of controls) or your food safety plan as a whole is 
ineffective (see 21 CFR 507.42(b)(1)(ii)); or  
  a review of your records (as required in 21 CFR 507.49(a)(4)) finds that your records are 
not complete, the activities you conducted did not follow your food safety plan, or you 
did not make appropriate decisions about corrective actions (see 21 CFR 
507.42(b)(1)(iii)).   
 
The corrective actions for the problems in the bulleted list immediately above include standard 
corrective action procedures (i.e., identify and correct the problem, take steps to reduce the 
likelihood the problem will recur, evaluate all affected animal food for safety, and prevent 
adulterated animal food from entering commerce).  See 21 CFR 507.42(b)(2)(i)-(iv).  In addition, 
when appropriate, you must reanalyze your food safety plan (or the applicable portion of your 
food safety plan) to determine whether you need to modify your plan.  See 21 CFR 
507.42(b)(2)(v).   
 
Finally, all corrective actions taken must be documented in records that are subject to 
verification and records review by (or under the oversight of) a PCQI.  See 21 CFR 507.42(d).   
 
5.7.2  Corrections 
 
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Corrections may be appropriate instead of corrective actions when minor, isolated problems 
occur that do not directly impact animal food safety.  A correction is an action to identify and 
correct a problem that occurred during the production of animal food, without other actions 
associated with a corrective action procedure (such as actions to reduce the likelihood that the 
problem will recur, evaluate all affected animal food for safety, and prevent affected animal food 
from entering commerce).  See 21 CFR 507.3.  The term correction focuses on the first step in 
a corrective action procedure (i.e., identify and correct the problem).   
 
For example, the following scenario illustrates when a correction may be appropriate instead of a 
corrective action.  At production start-up, you observe pet food residue on cleaned equipment.  
Before using the equipment, you correct the pet food residue problem by re-cleaning and 
sanitizing the equipment.  Because you correct the pet food residue problem before production, 
no pet food is affected, and no corrective actions are needed.  You are not required to document 
this particular correction (see 21 CFR 507.42(d)).   
 
If the correction was not made prior to production start-up, then you would need to follow your 
corrective action procedures because the sanitation preventive control was not properly 
implemented (see 21 CFR 507.42(a)(1)).  In addition, if the problem is not isolated, such as you 
repeatedly find pet food residue on cleaned equipment, you would need to take corrective action 
to reduce the likelihood the problem will recur (see 21 CFR 507.42(b)(2)).   
 
5.7.3  Corrective Action and Correction Records 
 
You must document all corrective actions taken (and, when appropriate, corrections) in records 
that are subject to verification and records review.  See 21 CFR 507.42(d).  One way to comply 
with this requirement is to document the corrective action steps you have taken:   
 
1.  Document the actions taken to identify and correct the problem with implementation of 
the preventive control.  For example, explain how you identified what went wrong with a 
process control and how you restored the process control.   
2.  Document what you did to reduce the likelihood that the problem will recur.  Evaluation 
of historical corrective action records can help you identify recurring problems.  When a 
deviation from a preventive control procedure recurs frequently and you find that the 
preventive control is ineffective, you must reanalyze the food safety plan (see 21 CFR 
507.50(b)(4)).   
3.  Document how you evaluated the safety of all affected animal food.  Depending on the 
nature of the deviation, you may need someone with specific technical expertise to 
conduct the evaluation.   
4.  Document what you did with any affected animal food, including identifying the specific 
animal food involved (e.g., lot numbers or batches, if applicable), the amount of animal 
food involved, and the disposition of the affected animal food (e.g., destroyed, 
reprocessed, or diverted to another use).   
 
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You are only required to document corrections in records when appropriate.  See 21 CFR 
507.42(d).  However, we recommend documenting some corrections because they provide a 
record of both the problem and the steps you took to correct the problem.  If the problem recurs 
on a frequent basis, such documentation also can be helpful in determining if a corrective action 
is needed (e.g., repairing or replacing equipment).   
 
Boxes 5-4a and 5-4b provide examples of corrective actions.   
 
Box 5-4a.  PC Management Component Example  Corrective Actions 
Salmonella in dog biscuit treats:  If your oven temperature drops below 352F (178C) 
(your operating limit), an alarm sounds.  If the alarm sounds, the designated operator checks 
the oven to determine the problem and makes an adjustment if the problem is minor.  If the 
temperature drops below 350F (177C) (i.e., deviates from your established minimum 
parameter value), incoming biscuits are stopped from entering the oven and biscuits within 
the oven are diverted and held to determine appropriate disposition.  The designated 
operator immediately initiates a corrective action per your written corrective action 
procedures.   
 
During production, an oven alarm sounds indicating that the oven temperature fell below 
352F (178C).  The designated operator conducts an initial inspection of the oven to see 
whether a minor adjustment will correct the temperature.  While he is examining the oven, 
the temperature drops below 350F (177C) (the established minimum parameter value for 
temperature).  Incoming biscuits are stopped from entering the oven, and biscuits within the 
oven are diverted and held to determine appropriate disposition.  Per your written corrective 
action procedures, the designated operator promptly informs the shift manager, who 
oversees corrective actions.  The shift manager then contacts the maintenance department.  
The maintenance individual determines the oven air recirculation fan was not operating 
properly and installs a new fan.  The shift manager documents this repair in the corrective 
action records, along with her signature and date.   
 
The shift manager also documents the lot number for the batch of biscuits that was in the 
oven when the oven temperature was below 350F (177C).  All biscuits that were in the 
oven when the parameter value was not met are separated from other ingredients and 
products and set aside for destruction.  To destroy the diverted biscuits, an employee puts 
the diverted biscuits in trash bags, adds a denaturing agent, and places the diverted biscuits 
in the dumpster.  The shift manager observes the destruction and documents, in the 
corrective action record, the diverted biscuits lot number.   
 
Once the replacement parts are installed, the designated operator confirms that the oven 
temperature is at 355F (179C) prior to resuming production.  To reduce the likelihood of a 
future preventive control failure, the maintenance department schedules more frequent 
checks to ensure that all parts of the oven are functioning properly.   
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Box 5-4b.  PC Management Component Example  Corrective Actions 
Monensin in horse food:  Per your verification of monitoring procedures (see Box 5-5b), 
the plant manager conducts a review of sequencing and flushing records at the end of each 
day.  One day he finds that a batch of horse food was manufactured directly after a batch of 
beef cattle food containing monensin.  The plant manager is the individual assigned 
responsibility for identifying the cause of the improper implementation of the sequencing 
and flushing preventive control.  The plant manager determines that failure to follow the 
established sequencing procedures is due to human error.   
 
The plant manager records the lot code of the affected horse food and labels the container to 
identify that the batch must be kept from entering commerce until the affected horse food 
can be evaluated for safety.  According to your corrective action procedures, when your 
sequencing plan is not properly executed you may either rework the batch of affected food 
for beef cattle or destroy the batch to ensure the food is not fed to susceptible animals (i.e., 
horses).   
 
When you determine that the affected horse food is safe to be reworked for food for beef 
cattle, you reformulate the batch to be nutritionally adequate for beef cattle.  You generate a 
rework record to document your corrective action that the affected horse food is being 
reworked and reformulated for beef cattle, and that the reworked horse food is safe for beef 
cattle.   
 
To reduce the likelihood of a recurrence of the human error problem, all designated 
operators are immediately retrained on the sequencing and flushing preventive control 
procedures and their importance.  This retraining is part of your corrective action and is 
documented in a record in your facility files.   
 
 
5.8  Verification Activities 
 
5.8.1  Verification 
 
Verification means the application of methods, procedures, tests and other evaluations, in 
addition to monitoring, to determine whether a control measure or combination of control 
measures is or has been operating as intended and to establish the validity of the food safety plan 
(21 CFR 507.3).  Verification answers the question:  Can I affirm that the preventive controls in 
my food safety plan are effective and being properly implemented to control the hazard(s)?   
 
To implement your preventive control, you are required to conduct several verification activities 
as appropriate to the nature of the preventive control and its role in your facilitys food safety 
system.  Your verification activities must be documented in records.  See 21 CFR 507.45(b).  A 
complete list of the verification activities is in 21 CFR 507.45, and summarized below and in 
Figure 5.1:   
  validation in accordance with 21 CFR 507.47  Validation  
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  verification that monitoring is being conducted in accordance with 21 CFR 507.40  
Monitoring  
  verification that appropriate decisions about corrective actions are being made in 
accordance with 21 CFR 507.42  Corrective Actions and Corrections  
  verification of implementation and effectiveness of your preventive controls in 
accordance with 21 CFR 507.49  Verification of Implementation and Effectiveness  
  reanalysis of your food safety plan in accordance with 21 CFR 507.50  Reanalysis  
 
Figure 5-1.  Verification Activities 
VERIFICATION
Verification 
that 
Verification 
Appropriate  Verification of 
that  Reanalysis of 
Decisions  Implementation 
Validation Monitoring is  the Food 
about  and 
Being  Safety Plan
Corrective  Effectiveness
Conducted
Actions are 
Being Made
 
5.8.2  Validation 
 
Validation means obtaining and evaluating scientific and technical evidence that a control 
measure, combination of control measures, or the food safety plan as a whole, when properly 
implemented, is capable of effectively controlling the identified hazards (21 CFR 507.3).  You 
must validate that the preventive controls you identify and implement are adequate to control the 
hazard as appropriate to the nature of the preventive control and the role of the preventive control 
in your facilitys food safety system.  See 21 CFR 507.47(a).  In general, validation answers the 
question:  Can I provide scientific, technical, or study data evidence that my preventive 
control(s) can adequately control the hazard(s)?   
 
Validation is a verification activity that has its own requirements in 21 CFR 507.47.  Validation 
must be performed or overseen by a PCQI (21 CFR 507.47(b)(1)).   
 
Your PCQI must use or oversee the use of scientific and technical evidence to determine that the 
preventive controls you are implementing are adequate to control the biological, chemical, or 
physical hazards.  See 21 CFR 507.47(b)(2).  This evidence may come from various sources, 
such as peer-reviewed scientific articles, university extension whitepapers, government 
documents, predictive mathematical models and other risk-based models, and technical 
information from equipment manufacturers and trade associations.  When using these resources 
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as evidence to validate your preventive controls, you should ensure that the evidence is 
applicable to your animal food and facility (e.g., processing equipment, manufacturing 
procedures, or storage conditions).   
 
Sometimes, evidence may not exist; existing evidence is not applicable to your animal food and 
facility; or, the evidence is not sufficient to validate your preventive control.  In these 
circumstances, you must conduct studies to determine that your preventive control, when 
properly implemented, is adequate to control the hazards.  See 21 CFR 507.47(b)(2).  We 
recommend that you consult with a food safety expert with knowledge of developing and 
conducting studies.  The study must be conducted or overseen by a PCQI (21 CFR 507.47(b)(1)).   
 
Validation must be documented in your records.  See 21 CFR 507.45(b).  You must retain 
records that document validation of your food safety plan for at least 2 years after their use is 
discontinued.  See 21 CFR 507.208(b).   
 
Validation must be completed within specific timeframes:   
  prior to implementation of the food safety plan (see 21 CFR 507.47(b)(1)(i)(A))  
  when necessary to demonstrate the preventive control can be implemented as designed:   
  within 90 calendar days after production of the applicable animal food first begins 
o
(21 CFR 507.47(b)(1)(i)(B)(1)), or  
  within a reasonable timeframe, provided that the PCQI prepares or oversees the 
o
preparation of a written justification for a timeframe that exceeds 90 calendar 
days after production of the applicable animal food first begins (21 CFR 
507.47(b)(1)(i)(B)(2))  
  whenever a change to a preventive control or combination of preventive controls could 
impact whether the preventive control or combination of preventive controls, when 
properly implemented, will effectively control the hazards (21 CFR 507.47(b)(1)(ii))  
  whenever a reanalysis of the food safety plan reveals the need to do so (21 CFR 
507.47(b)(1)(iii))  
 
Although validation is appropriate for a variety of preventive controls, validation is not required 
for sanitation controls, your recall plan, the supply-chain program (in 21 CFR part 507, subpart 
E), and other preventive controls if a PCQI prepares a written justification that validation is not 
applicable (see 21 CFR 507.47(c)).   
 
Boxes 5-5a and 5-5b provide examples of validation.   
 
 
 
 
 
 
 
 
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Box 5-5a.  PC Management Component Example  Validation 
Salmonella in dog biscuit treats:  Before you begin initial production of your dog biscuit 
treats, your PCQI searches peer-reviewed journals and extension white papers to find 
scientific literature on the time and temperature needed to significantly minimize Salmonella 
in dog biscuits.  After evaluating the types of biscuits (including size, ingredients, and 
shape), processing equipment, and the manufacturing processes found in the literature 
review, your PCQI determines the time and temperature found in the literature (a minimum 
of 15 minutes at 350F (177C) or higher) are effective as a preventive control for 
Salmonella in biscuits baked at your facility.  In order to ensure the safety of the dog 
biscuits, you bake your dog biscuits at 355F (179C).  You maintain the scientific literature 
(i.e., evidence) your PCQI uses to validate the preventive control, and her determination that 
the preventive control is adequate to control the Salmonella hazard, as part of your facilitys 
records.   
 
Box 5-5b.  PC Management Component Example  Validation 
Monensin in horse food:  Your PCQI obtains scientific literature and extension white 
papers to document the historical use by the animal food industry of sequencing and flushing 
procedures to prevent the occurrence of unsafe monensin levels in food for horses.  Your 
PCQI evaluates the information and determines that the sequencing and flushing procedures 
described in the published literature and commonly practiced by the animal food industry 
can be appropriately implemented at your facility and will adequately control the hazard.  
You maintain, as part of your facilitys records, the scientific literature (i.e., evidence) your 
PCQI uses to validate the preventive control and his determination that the preventive 
control is adequate.   
 
5.8.3  Verification of Monitoring 
 
You are required to verify that monitoring is being conducted in accordance with 21 CFR 507.40 
(see 21 CFR 507.45(a)(2)).  Verification relies, in part, on review of monitoring records to 
ensure that the preventive controls you have established are being implemented according to 
your food safety plan.  Verification that monitoring is being conducted as required must be done 
in a way that is appropriate to the nature of the preventive control and its role in your facilitys 
food safety system (see 21 CFR 507.45(a)(2)).  You could determine, based on your preventive 
controls, that verification of monitoring can be accomplished by reviewing monitoring records, 
e.g., a review by a manager at the end of the operating day, or just the review by the PCQI 
required under 21 CFR 507.49(a)(4)(i).  In addition, you may choose to actually observe the 
monitoring, e.g., a manager can periodically observe the equipment operator as the operator 
conducts the monitoring.  Verification of monitoring must be documented in your records (see 
21 CFR 507.45(b)).   
 
Boxes 5-6a and 5-6b provide examples of verification of monitoring. 
 
 
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Box 5-6a.  PC Management Component Example  Verification of Monitoring 
Salmonella in dog biscuit treats:  Once during each shift, the shift manager checks the 
monitoring record for the oven temperature (the chart recorder printout and the record of the 
operators check of the printout) and conveyor belt speed (the record of the operators 
stopwatch timing results) to ensure the designated operator is monitoring at your specified 
frequency.  At the end of each shift, the shift manager reviews the monitoring record and 
verifies that monitoring is being conducted according to your written procedures.  The shift 
manager documents her verification of monitoring, including verification that there were no 
deviations from set parameter values, by initialing and dating a logbook kept with the oven 
monitoring records.   
 
Box 5-6b.  PC Management Component Example  Verification of Monitoring 
Monensin in horse food:  At the end of each day, the plant manager confirms that the 
sequencing production record for each batch of animal food (the 1st monitoring record) and 
the flushing record (the 2nd monitoring record) are generated and complete.  He then 
compares the sequencing production records and flushing records to the written sequencing 
and flushing procedures.  The plant manager signs and dates the monitoring records to show 
that he verified that the monitoring took place according to the sequencing and flushing 
procedures.   
 
5.8.4  Verification of Decisions about Corrective Actions 
 
You are required to verify that appropriate decisions about corrective actions are being made in 
accordance with 21 CFR 507.42 (see 21 CFR 507.45(a)(3)).  The regulation allows flexibility for 
you to determine the activities you can use to verify that appropriate decisions were made about 
your corrective actions.  You could determine, based on your preventive controls, that 
verification of decisions regarding corrective actions can be accomplished by reviewing 
corrective action records, e.g., a review by a manager after a corrective action, or just the review 
by the PCQI required under 21 CFR 507.49(a)(4)(i).  In addition, you may choose to actually 
observe the corrective actions, e.g., a manager can observe the QI as he conducts the corrective 
action.   
 
Boxes 5-7a and 5-7b provide examples of verification of decisions about corrective actions. 
 
Box 5-7a.  PC Management Component Example  Verification of Decisions about 
Corrective Actions 
 
Salmonella in dog biscuit treats:  The shift manager verifies that appropriate decisions were 
made about corrective actions, confirming that the steps taken are consistent with your 
written corrective action procedures in your food safety plan.  (See Box 5-11a for PCQI 
verification of corrective actions).   
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Box 5-7b.  PC Management Component Example  Verification of Decisions about 
Corrective Actions 
Monensin in horse food:  The plant manager verifies that appropriate decisions were made 
about corrective actions, confirming that the steps taken are consistent with your written 
corrective action procedures in your food safety plan.  (See Box 5-11b for PCQI verification 
of corrective actions).   
 
5.8.5  Verification of Implementation and Effectiveness 
 
You are required to verify that you are consistently implementing your preventive controls, and 
that your preventive controls are effective in significantly minimizing or preventing the hazard.  
See 21 CFR 507.49(a).   
 
Various activities are required, as appropriate, to verify implementation and effectiveness of your 
preventive controls.  Those activities must include, as appropriate to your facility, animal food, 
and the nature of the preventive control and its role in your facilitys food safety system, 
calibration of instruments, product testing, environmental monitoring, and review of records. 
There may be additional activities you include based on your facility, animal food, and the nature 
of the preventive control and its role in your facilitys food safety system.  If you determine in 
your food safety plan that calibration of instruments, product testing, or environmental 
monitoring are appropriate for your facility, animal food, the nature of your preventive control, 
and the role of your preventive control in your facilitys food safety system, then you must 
conduct these verification activities.  See 21 CFR 507.49(a).   
 
Calibration 
 
You are required to calibrate, or check for accuracy, your instruments used for process 
monitoring and verification.  See 21 CFR 507.49(a)(1).  You must establish and implement 
written procedures for the method and frequency of the calibration (or accuracy check).  See 21 
CFR 507.49(b)(1).   
 
By calibrate we mean compare to a standard, with adjustment to correct error as necessary.  By 
accuracy check we mean simply comparison to a standard.  An example of an accuracy check is 
using test weights to compare the weights shown on a small weight scale with the known weights 
of the test weights.  Calibration as recommended by the instruments manufacturer is important 
to ensure that the preventive control dependent on the instrument can be accurately monitored 
and verified.  You may perform checks for accuracy on a more frequent basis than what is 
recommended by the instruments manufacturer.  If the outcome of the accuracy check shows 
your instrument is not accurate, we expect you to calibrate or replace the instrument.   
 
When calibration or an accuracy check of a process monitoring or verification instrument shows 
that the instrument is not accurate, you should evaluate the monitoring records since the last 
instrument calibration or accuracy check to determine whether the inaccuracy would have 
contributed to a deviation.  This deviation could indicate a failure of your preventive control, 
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meaning a corrective action is needed, including evaluation of the affected animal food.  Food 
safety plans with infrequent calibration or accuracy checks can place more products at risk than 
those with more frequent checks if a problem with instrument accuracy occurs.   
 
Boxes 5-8a and 5-8b provide examples of calibration, a component of verification of 
implementation and effectiveness.   
 
Box 5-8a.  PC Management Component Example  Verification of Implementation and 
Effectiveness, Calibration 
Salmonella in dog biscuit treats:  Based on the recommendation of your PCQI, you use 
calibration of the thermocouple and conveyor speed as activities for verification of 
implementation and effectiveness of the time and temperature preventive control. The oven 
thermocouple is calibrated every six months based on the recommended maintenance 
schedule provided by the oven manufacturer.  Thermocouple accuracy checks are conducted 
daily by comparing the readings to a separate temperature-indicating device.  The separate 
temperature-indicating device is calibrated yearly.  The conveyor speed also is calibrated 
every six months to coincide with the thermocouple calibration to ensure the retention time 
of the biscuit treats in the oven is accurate.  You document in records all accuracy checks 
and calibrations for review by your PCQI.  You have included written procedures for the 
method and frequency of calibration and accuracy checks in your written food safety plan.   
 
Box 5-8b.  PC Management Component Example  Verification of Implementation and 
Effectiveness, Calibration 
Monensin in horse food:  Based on the recommendation of your PCQI, you use calibration 
of the weighing system to ensure an accurate amount of flushing material is added to the 
system as the activity for the verification of implementation and effectiveness of flushing as a 
preventive control in your facility.  Your PCQI determines that an annual calibration is a 
sufficient frequency.  You have included a written procedure for the method and frequency of 
calibration in your written food safety plan.   
 
Product testing 
 
In your facility, you may use product testing as a verification of implementation and 
effectiveness of your preventive controls.  Product testing is often considered an effective way to 
verify the control of a biological hazard.  Also, you may use product testing to verify the control 
of other hazards, such as nutrient deficiencies or toxicities.  Product testing is not required for all 
facilities that identify pathogens or other hazards requiring a preventive control.  While product 
testing is a way to verify the implementation and effectiveness of your preventive controls for 
the purposes of 21 CFR 507.49, product testing does not prevent or significantly minimize the 
hazard.  Therefore, product testing is not a preventive control.   
 
If you use product testing to verify that your preventive control is consistently implemented and 
effective, you must establish and implement written procedures for the product testing.  See 21 
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CFR 507.49(b).  The following requirements in 21 CFR 507.49(b)(2) apply to the procedures for 
product testing.  The procedures must:   
  be scientifically valid  
  identify the test microorganisms or other analytes  
  specify the procedures for identifying samples, including their relationship to specific lots 
of product  
  include the procedures for sampling, including the number of samples and sampling 
frequency  
  identify the tests conducted including the analytical methods used  
  identify the laboratory conducting the testing  
  include the corrective action procedures required by 21 CFR 507.42(a)(1)  
 
Boxes 5-9a and 5-9b provide examples of product testing, a component of verification of 
implementation and effectiveness of preventive controls.   
 
Box 5-9a.  PC Management Component Example  Verification of Implementation and 
Effectiveness, Product Testing 
Salmonella in dog biscuit treats:  Your PCQI determines that product testing for Salmonella 
is an appropriate activity for verification of implementation and effectiveness of your time 
and temperature preventive control.  Your written procedures specify that once a week, a 
sample will be randomly collected from each batch during the selected shift (which alternates 
each week).  Each sample of biscuits collected consists of 10 sub-samples with each sub-
sample weighing about 200 grams and labeled with the corresponding batch number(s).  The 
samples are analyzed in-house using a validated method from the most recent edition of the 
Bacteriological Analytical Manual, chapter 5.  If a laboratory sample is found to contain 
Salmonella, your shift manager follows corrective action procedures found in your food 
safety plan to address the presence of a pathogen detected upon product testing.   
 
Box 5-9b.  PC Management Component Example  Verification of Implementation and  
Effectiveness, Product Testing 
Monensin in horse food:  The PCQI did not identify product testing as an activity for 
verification of implementation and effectiveness for your sequencing and flushing preventive 
control.   
 
Environmental monitoring 
 
Environmental monitoring, for an environmental pathogen or for an appropriate indicator 
organism, may be used when your hazard analysis determines that contamination of animal food 
with an environmental pathogen (or appropriate indicator organism) is a hazard requiring a 
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preventive control.  You determine (based on your facility, your animal food, and the nature of 
the preventive control and its role in your facilitys food safety system) if environmental 
monitoring is appropriate to verify the adequacy of your preventive control.  For example, you 
could decide that environmental monitoring is necessary to verify that your sanitation controls 
are implemented properly and working effectively to control Salmonella in the environment.   
 
The presence of an indicator organism indicates conditions may be suitable for the presence and 
growth of an environmental pathogen.  FDAs current thinking is that Listeria spp. may be an 
appropriate indicator organism for L. monocytogenes, because tests for Listeria spp. will detect 
multiple species of Listeria, including L. monocytogenes.  Though data are available to support 
the use of Enterobacteriaceae for environmental monitoring, we are not aware of any data or 
information supporting the use of an indicator organism by itself for the purpose of 
environmental monitoring for Salmonella spp. (Ref. 1).   
 
If you use environmental monitoring to verify that your preventive controls are consistently 
implemented and effective, you must establish and implement written procedures for the 
environmental monitoring.  See 21 CFR 507.49(b).  The following requirements in 21 CFR 
507.49(b)(3) apply to the procedures for environmental monitoring.  The procedures must:   
  be scientifically valid  
  identify the test microorganisms  
  identify the locations from which samples will be collected and the number of sites to be 
tested during routine environmental monitoring (the number and location of sampling 
sites must be adequate to determine whether preventive controls are effective)  
  identify the timing and frequency for collecting and testing samples (the timing and 
frequency for collecting and testing samples must be adequate to determine whether 
preventive controls are effective)  
  identify the tests conducted, including the analytical methods used  
  identify the laboratory conducting the testing 
  include the corrective action procedures required by 21 CFR 507.42(a)(1)(ii)  
 
Environmental monitoring involves collecting samples for environmental pathogen analysis from 
areas in your facility where animal food is manufactured, processed, packed or held.  You 
determine where and how often environmental samples are taken in your facility and include this 
in your written procedures.  An effective environmental monitoring program diligently tries to 
find the pathogen.  To be effective, the sampling is conducted with sufficient frequency and 
samples are taken in places in the facility where the pathogen is likely found, such as areas that 
may have been contaminated with raw animal food ingredients, or areas that are frequently wet.  
For additional information on environmental monitoring see (Ref. 2).   
 
Boxes 5-10a and 5-10b provide examples of decisions about environmental monitoring, a 
component of verification of implementation and effectiveness of preventive controls.   
 
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Box 5-10a.  PC Management Component Example  Verification of Implementation and 
Effectiveness, Environmental Monitoring 
Salmonella in dog biscuit treats:  The PCQI did not identify environmental monitoring as a 
verification of implementation and effectiveness activity for your time and temperature 
preventive control since the dog biscuits are not exposed to the environment prior to 
packaging.   
 
Box 5-10b.  PC Management Component Example  Verification of Implementation and 
Effectiveness, Environmental Monitoring 
Monensin in horse food:  The PCQI did not identify environmental monitoring as a 
verification of implementation and effectiveness activity for your sequencing and flushing 
preventive control.   
 
Record review 
 
Verification of implementation and effectiveness includes the review of certain records within 
specified timeframes.  This review must be conducted by, or under the oversight of, a PCQI (see 
21 CFR 507.49(a)(4)).  Monitoring and corrective action records must be reviewed within seven 
working days after the records are created or within a reasonable timeframe, provided the PCQI 
prepares (or oversees the preparation of) a written justification for a timeframe that exceeds 
seven working days.  See 21 CFR 507.49(a)(4)(i).  Records of calibration, product testing, 
environmental monitoring, supplier and supply-chain verification activities, and other 
verification activities must be reviewed within a reasonable timeframe after they are created.  
See 21 CFR 507.49(a)(4)(ii).   
 
Record review by, or under the oversight of, a PCQI must ensure the following:   
  records are complete  
  activities reflected in the records occurred in accordance with the food safety plan  
  preventive controls are effective  
  appropriate decisions were made about corrective actions 
See 21 CFR 507.49(a)(4).   
 
Record review conducted in accordance with 21 CFR 507.49 must be documented in records 
(see 21 CFR 507.45(b)).   
 
Boxes 5-11a and 5-11b provide examples of record review, a component of verification of 
implementation and effectiveness.   
 
 
 
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Box 5-11a.  PC Management Component Example  Verification of Implementation and 
Effectiveness, Record Review 
Salmonella in dog biscuit treats:  You determine that the monitoring records (your 
temperature chart recorder printout and record of the operators check of the printout and 
conveyor speed record) will be verified at the end of each shift by the shift manager (see Box 
5-6a).  Your plant manager will conduct a review of the monitoring records every Monday.  
Since the shift manager is reviewing monitoring records at the end of each shift, and the plant 
manager is reviewing weekly, your PCQI writes a justification that she only needs to review 
the monitoring records once a month.  During her monthly review, your PCQI signs that she 
verified the monitoring records.   
 
Within one week after the calibration is performed (see Box 5-8a), your PCQI reviews the 
calibration records of the oven thermocouple, temperature indicating device, and conveyor 
speed to complete record review for verification of implementation and effectiveness of the 
time and temperature preventive control.  The PCQI reviews the daily thermocouple accuracy 
check during her monthly review of the monitoring records.  She documents her review of 
the calibration and accuracy check records at the time she performs these verification 
activities.   
 
When a corrective action is taken, your corrective action procedures require the PCQI to 
review associated records within five working days.  Your PCQI reviews the corrective 
action records generated after the failure of your time and temperature preventive control (see 
Box 5-4a).  The corrective action records she reviews are:   
 
1.  the temperature chart recorder record that identified the problem  
2.  documentation of the lot number of the diverted biscuits  
3.  diverted biscuit destruction record  
4.  oven repair record  
5.  maintenance schedule update  
 
Through the corrective action record review, she also ensures that the outcome of the safety 
evaluation, destruction of the biscuits, and increase in the oven maintenance schedule were 
appropriate decisions for this corrective action.   
 
Once the corrective action records are reviewed and the PCQI determines that appropriate 
decisions were made about the corrective action, your PCQI signs the records and places 
them in the corrective action file.   
 
 
 
 
 
 
 
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Box 5-11b.  PC Management Component Example  Verification of Implementation and 
Effectiveness, Record Review 
Monensin in horse food:  Your facility determines that the two monitoring records 
(sequencing production record and flushing record) will be verified daily by the plant 
manager (see Boxes 5-3b and 5-6b) and reviewed weekly by the PCQI.  Your PCQI reviews 
and signs the two monitoring records.   
 
Your PCQI reviews the annual calibration record of the weighing system within one week 
after the weighing system is calibrated (see Box 5-8b).   
 
When a corrective action is taken, your facilitys procedures require your PCQI to review 
associated records within seven working days.  During the weekly record review, your PCQI 
reviews the corrective action records generated after the failure of your sequencing and 
flushing preventive control (see Box 5-4b).  He ensures the following records are complete 
and consistent with your corrective action procedures for the sequencing and flushing 
preventive control:   
 
1.  the sequencing and flushing records that identified the problem  
2.  documentation of the lot number of the affected horse food  
3.  rework record  
4.  employee retraining record  
 
Through the corrective action record review, he also ensures that the outcome of the safety 
evaluation, rework of the horse food for beef cattle food, and retraining of the designated 
operators are appropriate decisions for this corrective action.   
 
Once the corrective action records are reviewed and the PCQI determines appropriate 
decisions were made about the corrective action, your PCQI signs the records and places 
them in the corrective action file.   
 
5.8.6  Reanalysis 
 
You must conduct a reanalysis of your food safety plan (see 21 CFR 507.50).  Reanalysis is a 
verification activity and must be documented (see 21 CFR 507.45(b)).  Your required reanalysis 
must be conducted by, or overseen by, your PCQI (see 21 CFR 507.50(e)).   
 
At least once every 3 years, you must conduct a reanalysis of your food safety plan as a whole.  
See 21 CFR 507.50(a).  A reanalysis of the plan or the applicable portion of the plan is also 
required whenever:   
  a significant change in the activities conducted at your facility creates a reasonable 
potential for a new hazard or creates a significant increase in a previously identified 
hazard (see 21 CFR 507.50(b)(1))  
  you become aware of new information about potential hazards associated with the animal 
food (see 21 CFR 507.50(b)(2))  
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  appropriate after an unanticipated animal food safety problem (see 21 CFR 507.50(b)(3))  
  you find that a preventive control, combination of preventive controls, or the food safety 
plan as a whole is ineffective (see 21 CFR 507.50(b)(4))  
  FDA determines a reanalysis is necessary to respond to new hazards and developments in 
scientific understanding (see 21 CFR 507.50(f))  
 
The need for a reanalysis of your food safety plan sooner than 3 years (i.e., a for-cause 
reanalysis) will vary by facility and animal food and on a case-by-case basis. We recommend 
you consult your PCQI about when to conduct a for-cause reanalysis. Depending on the cause for 
the reanalysis, you may need to reanalyze your whole food safety plan, or just the applicable 
portion of your food safety plan (see 21 CFR 507.50(b)).   
 
The following are examples of some circumstances that would or would not require a for-cause 
reanalysis of your food safety plan, or an applicable portion of your food safety plan.   
 
Significant change in activities conducted at your facility that creates a reasonable potential for a 
new hazard or creates a significant increase in a previously identified hazard (see 21 CFR 
507.50(b)(1)):   
 
  You currently manufacture food for cattle and swine but are expanding your operation to 
start manufacturing poultry food.  You reanalyze your food safety plan to include poultry 
food.  Your hazard analysis may determine that there are additional hazards requiring a 
preventive control. If so, you would revise your preventive controls and management 
components to control these hazards.   
  You start using a different corn by-product as an ingredient in your animal food.  Your 
hazard analysis already considers the known or reasonably foreseeable hazards associated 
with using corn and corn by-products in your animal food.  You do not need to reanalyze 
your food safety plan because the hazards associated with using corn by-products are 
already covered in your hazard analysis and the new ingredient does not create a 
significant increase in the identified hazards.   
 
You become aware of new information about potential hazards associated with the animal food 
(see 21 CFR 507.50(b)(2)):   
 
  At the conclusion of an inspection, you receive a Form FDA 483, Inspectional 
Observations, observing that your facility uses corn as an ingredient, and you have not 
identified aflatoxin as a known or reasonably foreseeable hazard in your hazard analysis.  
You would reanalyze the applicable portion(s) of your food safety plan, including 
performing an evaluation of aflatoxin as a known or reasonably foreseeable hazard 
associated with the use of corn as an ingredient.   
  You manufacture food for horses and in reading a trade magazine learn that horses are 
very sensitive to monensin.  Your facility does not manufacture medicated feed.  As a 
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result, you would not reanalyze your food safety plan because monensin is not used in 
your facility.   
 
Unanticipated animal food safety problem (see 21 CFR 507.50(b)(3)):   
 
  You manufacture cattle food and horse food. Your current food safety plan identifies 
non-protein nitrogen (NPN) nutrient toxicity from urea as a known or reasonably 
foreseeable hazard in your cattle food because you use urea in your cattle food.  But you 
had determined that NPN toxicity was not a hazard requiring a preventive control 
because your batching and mixing procedures have historically resulted in appropriate 
amounts of urea in your cattle food.  You did not identify NPN toxicity as a known or 
reasonably foreseeable hazard in your horse food because urea is not used as an 
ingredient in horse food.  Later, you receive several complaints about NPN toxicity in 
horses consuming your horse food and you initiate a recall.  You perform an investigation 
and find the urea was added to horse food due to employee error.  Because of the 
unanticipated animal food safety problem (nutrient toxicity from urea), you reanalyze 
your food safety plan to consider NPN toxicity for your horse food.  
  You initiate a market withdrawal of your packaged animal food because your printer 
malfunctioned and as a result, your package label does not include the required net 
quantity of contents as outlined in 21 CFR 501.105.  You would not reanalyze your food 
safety plan as a result of this market withdrawal.  You initiated the market withdrawal to 
address a misbranding issue; however, the market withdrawal is not related to a food 
safety issue.   
 
You find that your preventive control, combination of preventive controls, or the food safety plan 
as a whole is ineffective (see 21 CFR 507.50(b)(4)):    
 
  You manufacture dog food and, based on your hazard evaluation, conclude that the 
probability of a vitamin D toxicity occurring is low at your facility due to your existing 
prerequisite programs.  As a result, you determine vitamin D toxicity is not a hazard 
requiring a preventive control.  You later receive consumer complaints with 
accompanying veterinary records indicating possible vitamin D toxicity in dogs.  You do 
a root cause investigation and determine your prerequisite programs were not followed, 
which resulted in finished dog food with toxic levels of vitamin D.  Because your food 
safety plan as a whole was ineffective, you reanalyze your food safety plan to reconsider 
the vitamin D toxicity hazard.   
  You receive a complaint from one customer who suspects that the chicken food they 
received for laying hens was deficient in calcium.  You request the customer provide a 
sample of the food. You have their sample and a portion of your retained food for that lot 
analyzed for calcium.  The analysis results show that each sample was in the range 
appropriate for laying hens.  You would not need to reanalyze your food safety plan.   
 
You must complete reanalysis of your food safety plan and validate any additional preventive 
controls:  (1) before any change in activity is in effect; or, (2) when necessary to demonstrate the 
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control measure can be implemented as designed, within 90 calendar days after production of 
animal food begins, or within a reasonable timeframe that exceeds 90 days as outlined in a 
written justification from your PCQI.  See 21 CFR 507.50(c).   
 
If a significant change in the activities conducted at your facility creates a reasonable potential 
for a new hazard or creates a significant increase in a previously identified hazard, you must 
revise your food safety plan or document the basis for your conclusion that no revisions are 
needed.  See 21 CFR 507.50(d).   
 
The documentation of reanalysis must include the date the reanalysis was conducted and the 
signature or initials of the individual conducting the reanalysis.  See 21 CFR 507.202(b)(2) and 
(3).   
 
Boxes 5-12a and 5-12b provide examples of reanalysis.   
 
Box 5-12a.  PC Management Component Example  Reanalysis 
Salmonella in dog biscuit treats:  The oven fan was replaced with the same model fan, 
confirmed to be operating properly by the designated operator, and there is no change in the 
process.  Your PCQI determines that a reanalysis of the food safety plan for the preventive 
control of Salmonella in your dog biscuit treats is not necessary.   
 
You decide to install an additional production line to make miniature size dog biscuit treats.  
This is a significant change in your production that creates a significant increase in the 
Salmonella hazard, which requires a reanalysis of your food safety plan.  Prior to beginning 
production of the miniature biscuits, your PCQI validates the time and temperature 
preventive control required to significantly minimize Salmonella in the smaller size biscuit.  
The new preventive control, procedures for monitoring the preventive control, and corrective 
action procedures are added to your revised food safety plan.   
 
Box 5-12b.  PC Management Component Example  Reanalysis 
Monensin in horse food:  Your PCQI determines that a reanalysis of the food safety plan is 
appropriate because it has been three years since the last reanalysis.  Your PCQI conducts the 
reanalysis and concludes that no changes are needed for the sequencing and flushing 
preventive control.   
 
5.9  References for Chapter 5 
 
1.  Food and Drug Administration. 2014. FDA Memorandum Environmental Monitoring. 
   
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APPENDIX A  Glossary of Terms 
 
Definitions Established in 21 CFR 507.3:   
 
Adequate means that which is needed to accomplish the intended purpose in keeping with good 
public (human and animal) health practice.   
 
Animal food means food for animals other than man and includes pet food, animal feed, and raw 
materials and ingredients.   
 
Correction means an action to identify and correct a problem that occurred during the production 
of animal food, without other actions associated with a corrective action procedure (such as 
actions to reduce the likelihood that the problem will recur, evaluate all affected animal food for 
safety, and prevent affected animal food from entering commerce).   
 
Critical control point means a point, step, or procedure in a food process at which control can be 
applied and is essential to prevent or eliminate a food safety hazard or reduce such hazard to an 
acceptable level.   
 
Environmental pathogen means a pathogen capable of surviving and persisting within the 
manufacturing, processing, packing, or holding environment such that food for animals may be 
contaminated and may result in foodborne illness if that animal food is not treated to 
significantly minimize or prevent the environmental pathogen.  Examples of environmental 
pathogens for the purposes of this part include Listeria monocytogenes and Salmonella spp. But 
do not include the spores of pathogenic spore-forming bacteria.   
 
Facility means a domestic facility or a foreign facility that is required to register under section 
415 of the Federal Food, Drug, and Cosmetic Act, in accordance with the requirements of 21 
CFR part 1, subpart H.   
 
Farm means farm as defined in 21 CFR 1.227.   
 
Food-contact surfaces are those surfaces that contact animal food and those surfaces from which 
drainage, or other transfer, onto the animal food or onto surfaces that contact the animal food 
ordinarily occurs during the normal course of operations.  Food-contact surfaces includes 
utensils and animal food-contact surfaces of equipment.   
 
Hazard means any biological, chemical (including radiological), or physical agent that has the 
potential to cause illness or injury in humans or animals.   
 
Hazard requiring a preventive control means a known or reasonably foreseeable hazard for 
which a person knowledgeable about the safe manufacturing, processing, packing, or holding of 
animal food would, based on the outcome of a hazard analysis (which includes an assessment of 
the severity of the illness or injury to humans or animals if the hazard were to occur and the 
probability that the hazard will occur in the absence of preventive controls), establish one or 
more preventive controls to significantly minimize or prevent the hazard in an animal food and 
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components to manage those controls (such as monitoring, corrections or corrective actions, 
verification, and records) as appropriate to the animal food, the facility, and the nature of the 
preventive control and its role in the facilitys food safety system.   
 
Holding means storage of animal food and also includes activities performed incidental to 
storage of an animal food (e.g., activities performed for the safe or effective storage of that 
animal food, such as fumigating animal food during storage, and drying/dehydrating raw 
agricultural commodities when the drying/dehydrating does not create a distinct commodity 
(such as drying/dehydrating hay or alfalfa)).  Holding also includes activities performed as a 
practical necessity for the distribution of that animal food (such as blending of the same raw 
agricultural commodity and breaking down pallets), but does not include activities that transform 
a raw agricultural commodity into a processed food as defined in section 201(gg) of the Federal 
Food, Drug, and Cosmetic Act.  Holding facilities could include warehouses, cold storage 
facilities, storage silos, grain elevators, and liquid-storage tanks.   
 
Known or reasonably foreseeable hazard means a biological, chemical (including radiological), 
or physical hazard that is known to be, or has the potential to be, associated with the facility or 
the animal food.   
 
Lot means the animal food produced during a period of time and identified by an establishments 
specific code.   
 
Manufacturing/processing means making animal food from one or more ingredients, or 
synthesizing, preparing, treating, modifying, or manipulating animal food, including food crops 
or ingredients.  Examples of manufacturing/processing activities include:  Baking, boiling, 
bottling, canning, cooking, cooling, cutting, distilling, drying/dehydrating raw agricultural 
commodities to create a distinct commodity (such as drying/dehydrating grapes to produce 
raisins), evaporating, eviscerating, extracting juice, extruding, formulating, freezing, grinding, 
homogenizing, irradiating, labeling, milling, mixing, packaging (including modified atmosphere 
packaging), pasteurizing, peeling, pelleting, rendering, treating to manipulate ripening, trimming, 
washing, or waxing.  For farms and farm mixed-type facilities, manufacturing/processing does 
not include activities that are part of harvesting, packing, or holding.   
 
Microorganisms means yeasts, molds, bacteria, viruses, protozoa, and microscopic parasites and 
includes species that are pathogens.  The term undesirable microorganisms includes those 
microorganisms that are pathogens, that subject animal food to decomposition, that indicate that 
animal food is contaminated with filth, or that otherwise may cause animal food to be 
adulterated.   
 
Monitor means to conduct a planned sequence of observations or measurements to assess 
whether control measures are operating as intended.   
 
Packing means placing animal food into a container other than packaging the animal food and 
also includes repacking and activities performed incidental to packing or repacking an animal 
food (e.g., activities performed for the safe or effective packing or repacking of that animal food 
(such as sorting, culling, grading, and weighing or conveying incidental to packing or 
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repacking)), but does not include activities that transform a raw agricultural commodity into a 
processed food as defined in section 201(gg) of the Federal Food, Drug, and Cosmetic Act.   
 
Pathogen means a microorganism of public (human or animal) health significance.   
 
Pest refers to any objectionable animals or insects including birds, rodents, flies, and larvae.   
 
Plant means the building or structure, or parts thereof, used for or in connection with the 
manufacturing, processing, packing, or holding of animal food.   
 
Preventive controls means those risk-based, reasonably appropriate procedures, practices, and 
processes that a person knowledgeable about the safe manufacturing, processing, packing, or 
holding of animal food would employ to significantly minimize or prevent the hazards identified 
under the hazard analysis that are consistent with the current scientific understanding of safe 
food manufacturing, processing, packing, or holding at the time of the analysis.   
 
Preventive controls qualified individual means a qualified individual who has successfully 
completed training in the development and application of risk-based preventive controls at least 
equivalent to that received under a standardized curriculum recognized as adequate by FDA, or 
is otherwise qualified through job experience to develop and apply a food safety system.   
 
Qualified individual means a person who has the education, training, or experience (or a 
combination thereof) necessary to manufacture, process, pack, or hold safe animal food as 
appropriate to the individuals assigned duties.  A qualified individual may be, but is not required 
to be, an employee of the establishment.   
 
Raw agricultural commodity has the meaning given in section 201(r) of the Federal Food, Drug, 
and Cosmetic Act.   
 
Receiving facility means a facility that is subject to subparts C and E of this part [part 507] and 
that manufactures/processes a raw material or other ingredient that it receives from a supplier.   
 
Rework means clean, unadulterated animal food that has been removed from processing for 
reasons other than insanitary conditions or that has been successfully reconditioned by 
reprocessing and that is suitable for use as animal food.   
 
Sanitize means to adequately treat cleaned surfaces by a process that is effective in destroying 
vegetative cells of pathogens, and in substantially reducing numbers of other undesirable 
microorganisms, but without adversely affecting the product or its safety for animals or humans.   
 
Significantly minimize means to reduce to an acceptable level, including to eliminate.   
 
Supplier means the establishment that manufactures/processes the animal food, raises the animal, 
or grows the food that is provided to a receiving facility without further manufacturing/ 
processing by another establishment, except for further manufacturing/ processing that consists 
solely of the addition of labeling or similar activity of a de minimis nature.   
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Supply-chain-applied control means a preventive control for a hazard in a raw material or other 
ingredient when the hazard in the raw material or other ingredient is controlled before its receipt.   
 
Unexposed packaged animal food means packaged animal food that is not exposed to the 
environment.   
 
Validation means obtaining and evaluating scientific and technical evidence that a control 
measure, combination of control measures, or the food safety plan as a whole, when properly 
implemented, is capable of effectively controlling the identified hazards.   
 
Verification means the application of methods, procedures, tests and other evaluations, in 
addition to monitoring, to determine whether a control measure or combination of control 
measures is or has been operating as intended and to establish the validity of the food safety plan.   
 
Water activity (a ) means a measure of the free moisture in an animal food and is the quotient of 
w
the water vapor pressure of the substance divided by the vapor pressure of pure water at the same 
temperature.   
 
You means, for purposes of 21 CFR part 507, the owner, operator, or agent in charge of a facility.   
 
Other Terms Used in this Guidance:   
 
Clean in place (CIP):  A system used to clean process piping, bins, tanks, mixing equipment, or 
larger pieces of equipment without disassembly, where interior product zones are fully exposed 
and soil can be readily washed away by the flow of the cleaning solution.   
 
Cleaning:  The removal of soil, animal food residue, dirt, grease or other objectionable matter.   
 
Corrective action:  An action to identify and correct specific problems, including failure to 
properly implement a preventive control, that occur during the production of animal food.   
 
A corrective action must include certain elements, such as identification and correction of the 
problem, reducing the likelihood of recurrence, evaluating the animal food for safety, and 
preventing adulterated animal food from entering commerce.  The requirements for corrective 
actions are found in 21 CFR 507.42(a) and (b).   
 
Deviation:  Failure to meet a parameter value (e.g., by being above or below the parameter 
value).   
 
Environmental sample:  A sample that is collected from a surface or area of the plant for the 
purpose of testing the surface or area for the presence of an environmental pathogen or 
appropriate indicator organism.   
 
HACCP (Hazard Analysis and Critical Control Point):  A systematic approach to the 
identification, evaluation, and control of food safety hazards.   
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Hazard analysis:  The process of identifying and evaluating known or reasonably foreseeable 
hazards to determine whether there are any hazards requiring a preventive control.   
 
Operating limits:  Criteria that may be more stringent than the minimum or maximum 
parameter values and are established for reasons other than animal food safety.   
 
Parameter value:  The maximum or minimum value, or combination of values, to which any 
biological, chemical, or physical parameter must be controlled to significantly minimize or 
prevent a hazard requiring a process control.   
 
PCAF regulation:  Part 507 of title 21 of the Code of Federal Regulations, established by the 
final rule entitled Current Good Manufacturing Practice, Hazard Analysis, and Risk-Based 
Preventive Controls for Food for Animals.   
 
PCAF requirements:  The requirements of subparts A, C, D, E, and F of part 507 of Title 21 of 
the Code of Federal Regulations.   
   
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APPENDIX B  Table of Abbreviations and Acronyms Used in this Guidance 
 
ABBREVIATION 
WHAT IT MEANS 
OR ACRONYM 
AAFCO  Association of American Feed Control Officials 
a   water activity 
w
BSE  Bovine Spongiform Encephalopathy 
C. botulinum  Clostridium botulinum 
CCP  critical control point 
CDC  Centers for Disease Control and Prevention 
CFR  Code of Federal Regulations 
CGMP  current good manufacturing practice 
CGMP  current good manufacturing practice requirements in 21 CFR part 
requirements  507, subparts A, B, and F 
CIP  clean in place 
Codex  Codex Alimentarius Commission 
CWD  Chronic Wasting Disease 
D-value  decimal reduction time 
DNA  deoxyribonucleic acid 
E. coli  Escherichia coli 
EPA  U.S. Environmental Protection Agency 
ERH  equilibrium relative humidity 
eV  electron volt 
FDA  U.S. Food and Drug Administration 
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ABBREVIATION 
WHAT IT MEANS 
OR ACRONYM 
FD&C Act  Federal Food, Drug, and Cosmetic Act 
Food Safety and Inspection Service of the U.S. Department of 
FSIS 
Agriculture 
FSMA  FDA Food Safety Modernization Act 
FSPCA  Food Safety Preventive Controls Alliance  
GRAS  generally recognized as safe 
Gray (a unit of absorbed dose of ionizing radiation, equal to 1 
Gy 
joule/kg of irradiated material) 
HACCP  Hazard Analysis and Critical Control Point 
HA worksheet  Hazard Analysis worksheet 
HPP  high pressure processing 
kGy  kiloGray 
Kg  kilogram 
LACF  low-acid canned food 
L. monocytogenes  Listeria monocytogenes 
MBM  meat and bone meal 
MeV  million electron volts 
mm  millimeter 
MPa  megapascal 
ng  nanogram 
NRC  National Research Council 
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ABBREVIATION 
WHAT IT MEANS 
OR ACRONYM 
Pa  pascal 
PAH  polyaromatic hydrocarbon 
Current Good Manufacturing Practice, Hazard Analysis, and 
PCAF regulation  Risk-Based Preventive Controls for Food for Animals regulation 
in 21 CFR part 507 
PCB  polychlorinated biphenyl 
PC management 
preventive control management components 
components 
PCQI  preventive controls qualified individual 
Preventive control requirements in 21 CFR part 507, subparts A, 
PC requirements 
C, D, E, and F 
pH  refers to a numeric scale used to describe acidity and alkalinity 
ppb  parts per billion 
QI  qualified individual 
RFR  Reportable Food Registry 
ROP  reduced oxygen packaging 
SOP  standard operating procedure 
TDT  thermal death time 
T. gondii  Toxoplasma gondii 
USDA  U.S. Department of Agriculture 
refers to the temperature increase required to reduce the D-value 
z-value 
by a factor of 10 
 
   
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APPENDIX C  Flowchart  Hazard Analysis 
(21 CFR 507.33) 
 
My facility is subject to the hazard analysis and preventive controls requirements.  My required 
written Food Safety Plan must be prepared by a preventive controls qualified individual and 
include a written Hazard Analysis.   
 
 
   
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APPENDIX C  Hazard Analysis 
(21 CFR 507.33) 
 
My facility is subject to the hazard analysis and preventive controls requirements.  My required 
written Food Safety Plan must be prepared by, or under the oversight of, a preventive controls 
qualified individual and include a written Hazard Analysis.   
 
Step 1  FOR EACH TYPE OF ANIMAL FOOD AT MY FACILITY, ARE THERE KNOWN 
OR REASONABLY FORESEEABLE HAZARDS?  See 21 CFR 507.33(a)(1) and (b).   
 
NO  There are NO known or reasonably foreseeable hazards.  I must document in my written 
Hazard Analysis this determination.  See 21 CFR 507.33(a)(2).  I must reanalyze my Hazard 
Analysis in accordance with 21 CFR 507.50.   
 
YES  Step 2  Evaluate the known or reasonably foreseeable hazards for each type of animal 
food at my facility by assessing:   
 
  The severity of illness or injury if the hazard were to occur; and,  
  The probability that the hazard will occur in the absence of preventive controls. 
(21 CFR 507.33(c)(1))   
 
Also, I must include the evaluation in 21 CFR 507.33(c)(2), if applicable; and, consider the 
effect of the items listed in 21 CFR 507.33(d)(1) through (10) on the safety of the finished 
animal food for the intended animal.   
 
ARE THERE ANY HAZARDS REQUIRING A PREVENTIVE CONTROL? 
See 21 CFR 507.33.   
 
NO  The known or reasonably foreseeable hazards do NOT require a preventive control.  I must 
include in my written Hazard Analysis an evaluation of the hazards.  See 21 CFR 507.33(a)(2).  I 
must reanalyze my Hazard Analysis in accordance with 21 CFR 507.50.   
 
YES  The known or reasonably foreseeable hazard(s) in my written Hazard Analysis requires a 
preventive control.  I must reanalyze my Hazard Analysis in accordance with 21 CFR 507.50. (I 
must also identify and implement preventive controls and appropriate preventive control 
management components in accordance with 21 CFR 507.34 and 507.39).   
   
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APPENDIX D  Example Hazard Analysis Worksheet 
 
The example Hazard Analysis worksheet is organized by column.  Chapters 2 and 3 provide 
information that can be used to complete columns one through four.  Chapter 4 provides 
information that can be used to complete columns five and six.   
 
Note:  A typical worksheet may include multiple pages.  Also, you may need to attach additional 
information or documentation, such as when you determine that a hazard does not require a 
preventive control.  You may use any method that results in a written hazard analysis.  The 
FSPCA curriculum for animal food provides another example of a hazard analysis worksheet.   
 
PLANT NAME:  ____________________________________________________________ 
ADDRESS:  ________________________________________________________________ 
ANIMAL FOOD:   __________________________________________________________ 
INTENDED SPECIES:  ______________________________________________________ 
LIFE STAGE/PRODUCTION CLASS:  ________________________________________ 
DATE (MM/DD/YY):  _______________________________________________________ 
(Column 1)  (Column 2)  (Column 3)  (Column 4)  (Column 5)  (Column 6) 
           
Ingredient  Known or  Does the  Explanation/  Preventive  Is the 
and  Reasonably  Known or  Justification  Control(s)  Preventive 
Processing  Foreseeable  Reasonably  Applied  Control 
Step  Hazard  Foreseeable  Applied at 
Hazard  this Step? 
Require a   
Preventive   
Control?   
Yes or No  Yes or 
No 
           
           
 
   
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APPENDIX D 
 
How to Use the Hazard Analysis Worksheet 
 
Column 1  Ingredient and Processing Step:  List: (1) the receipt of ingredients used in your 
process as a way of identifying hazards associated with an ingredient (you may group similar 
ingredients such as grains); and (2) the processing steps.  A process flow diagram and detailed 
process description (see Chapter 2, Box 2-2) can help you identify the processing steps included 
in your hazard analysis.   
 
Column 2  Known or Reasonably Foreseeable Hazard:  List the results of your identification 
of the known or reasonably foreseeable hazards from your hazard analysis.  Include biological, 
chemical, or physical hazards that could be introduced or increased from ingredients, your 
process, or the environment.  See Chapter 2, section 2.4.1.   
 
Column 3  Does the Known or Reasonably Foreseeable Hazard Require a Preventive 
Control:  For each known or reasonably foreseeable hazard identified in column 2, record the 
conclusions of your hazard analysis  i.e., the determinations you make whether each known or 
reasonably foreseeable hazard requires a preventive control (Yes or No).  See Chapter 2, 
section 2.4.2.   
 
Column 4  Explanation/Justification:  You should justify, or explain, your Yes or No 
conclusion for column 3 based on your evaluation of the hazard.  Record the key factors or a 
summary of the evaluation that led to the determination for each hazard of whether a preventive 
control is required.  Explaining your reasons for a No conclusion can be just as important as 
explaining your reasons for a Yes conclusion.  See Chapter 2, section 2.5.   
 
Column 5  Preventive Control(s) Applied:  Identify the preventive control(s) you will apply 
to significantly minimize or prevent the hazard requiring a preventive control (indicated by 
Yes in column 3).  You might list, for example, the type of preventive control (e.g., process, 
sanitation, or supply-chain-applied controls), or list the specific preventive control you select 
(e.g., irradiation, time and temperature, or a ).  See Chapter 2, section 2.6, and Chapter 4.   
w
 
If the identified hazard does not require a preventive control (indicated by No in column 3), 
you can leave the corresponding cell blank or put in N/A for not applicable.   
 
Column 6  Is the Preventive Control Applied at this Step:  The Hazard Analysis worksheet 
allows you to break your production process into multiple steps (such as receiving or 
processing), and you may apply your preventive control at a step in the process other than the 
step where you list the hazard.  Specify whether the preventive control will be applied at the 
specific processing step (i.e., Yes or No).  See Chapter 2, section 2.7.   
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