Why you don’t need to validate all of your PRP’s…

I’ve been asked several times now, how you should validate all of your pre-requisites (PRPs), so I thought it would be worthwhile writing a post about it.  You do not need to validate all of your PRPs, so I’m going to try to resolve some of the misunderstandings around this topic.  I’ve previously written a post on verification and validation for CCPs, which you may find useful…

Before we start, let’s just remember the difference between verification and validation:

Validation is – proving that it will work

One way to try to remember this, is that you carry out validation before you start doing something, for example before you launch a new product, you would check that production can make it to the correct specification, including the shelf life of the product.

Verification is proving that it is working

Verification you carry out after you have started doing something.  So, you would check (verify) that production continues to make the product to specification by carrying out checks on the line, or by carrying out shelf life tests.

In the same way, for CCPs – you validate the critical limits for the CCP before you implement the HACCP.  After you’ve implemented the CCP, you then check (verify) that you are meeting the critical limits for every batch of product made.

One other key point to remember about validation, is why you need to do it.  You need to do it because you need to prove that something is going to work (before you start doing it).  If there is no way of proving that it will work before its implemented, this is a good indicator that you’re trying to validate something that does not need validating.  What you’ll actually end up doing is verifying it instead.  I’ll explain this in more detail in the ‘Validation of PRP’s’ section later.

The misunderstanding around validating PRPs seems to be coming from a couple of sources:

  • Standards, such as BRC or SQF
  • Non-conformances raised during such audits

So, let’s tackle each one separately…

Validation requirements in the BRC standard

If you search for the word validation in the BRC standard, it appears in the following clauses:

2.7.3 The HACCP food safety team shall consider the control measures necessary to prevent or eliminate a food safety hazard or reduce it to an acceptable level. Where the control is achieved through existing prerequisite programmes, this shall be stated and the adequacy of the programme to control the specific hazard validated. Consideration may be given to using more than one control measure.

2.9.2 The HACCP food safety team shall validate each CCP. Documented evidence shall show that the control measures selected and critical limits identified are capable of consistently controlling the hazard to the specified acceptable level.

2.14.1 Appropriate changes resulting from the review shall be incorporated into the HACCP plan and/or prerequisite programmes, fully documented and validation recorded.

High-care Flow
4.3.6 Where high-care areas are part of the manufacturing site there should be physical segregation between these areas and other parts of the site. Segregation shall take into account the flow of product, nature of materials (including packaging), equipment, personnel, waste, airflow, air quality and utilities provision (including drains). Where physical barriers are not in place, the site shall have undertaken a documented risk assessment of the potential for cross-contamination, and effective, validated processes shall be in place to protect products from contamination.

Metal Detection … The location of the equipment or any other factors influencing the sensitivity of the equipment shall be validated and justified. Where in-line metal detectors are used the test piece shall be placed in the product flow wherever this is possible and the correct timing of the rejection system to remove identified contamination shall be validated.

4.11.3 … Where cleaning procedures are part of a defined prerequisite plan to control the risk of a specific hazard the cleaning and disinfection procedures and frequency shall be validated and records maintained. This shall include the risk from cleaning chemical residues on food contact surfaces.

CIP A schematic diagram of the layout of the CIP system including process piping circuits shall be available. There shall be an inspection report or other validation that:

  • systems are hygienically designed with no dead areas, limited interruptions to flow streams and good system drain ability
  • scavenge/return pumps are operated to ensure that there is no build-up of CIP solutions in the vessels
  • spray balls and rotating spray devices effectively clean vessels by providing full surface coverage and are periodically inspected for blockages
  • CIP equipment has adequate separation from active product lines (e.g. through the use of double seat valves, manually controlled links, blanks in pipework or make-or-break connections with proxy switches as interlocks) to prevent or safeguard against cross-contamination.

The system shall be re-validated following alterations or additions to the CIP equipment. A log of changes to the CIP system shall be maintained. The CIP equipment shall be operated to ensure effective cleaning is carried out:

  • The process parameters, time, detergent concentrations, flow rate and temperatures shall be defined to ensure removal of the appropriate target hazard (e.g. soil, allergens, vegetative microorganisms, spores). This shall be validated and records of the validation maintained.

5.1.3 Trials using production equipment shall be carried out where it is necessary to validate that product formulation and manufacturing processes are capable of producing a safe product of the required quality.

5.2.3 Where a product is designed to enable a claim to be made to satisfy a consumer group (e.g. a nutritional claim, reduced sugar), the company shall ensure that the product formulation and production process is fully validated to meet the stated claim.

Management of Allergens
5.3.7 Where a claim is made regarding the suitability of a food for allergy or food sensitivity sufferers, the site shall ensure that the production process is fully validated to meet the stated claim and the effectiveness of the process is routinely verified. This shall be documented.

5.3.8 Equipment or area cleaning procedures shall be designed to remove or reduce to acceptable levels any potential cross-contamination by allergens. The cleaning methods shall be validated to ensure they are effective and the effectiveness of the procedure routinely verified. Cleaning equipment used to clean allergenic materials shall either be identifiable and specific for allergen use, single use, or effectively cleaned after use.

Controls of Operations
6.1.4 Where variation in processing conditions may occur within equipment critical to the safety or quality of products, the processing characteristics shall be validated and verified at a frequency based on risk and performance of equipment (e.g. heat distribution in retorts, ovens and processing vessels; temperature distribution in freezers and cold stores).

Protective Clothing
7.4.3 Laundering of protective clothing shall take place by an approved contracted or in-house laundry using defined criteria to validate the effectiveness of the laundering process.

Summary of the Requirements

In the BRC the standard states that validation is required for:

  • Specific food safety hazards which are managed by PRPs (2.7.3), and when they change following a review, they are re-validated (2.14.1)
  • CCPs (2.9.2), and when they change following a review, they are re-validated (2.14.1)
  • Where high-care barriers are not in place
  • Metal detector location, sensitivity and reject timing (,
  • Cleaning procedures and frequency for cleaning tasks which control food safety hazards (4.11.3 & 5.3.8)
  • CIP systems ( &
  • NPD factory trials (5.1.3)
  • Nutritional claims (5.2.3)
  • Intolerance or allergy claims (e.g. free from) (5.3.7)
  • In-house laundry procedures (7.4.3)

Validation requirements in the SQF standard (Level 2)

If you search SQF Level 2 for validation, it appears in the following clauses:

2.1.4 Management Review Changes to food safety fundamentals and food safety plans that have an impact on the supplier’s ability to deliver safe food are to be validated. Records of all reviews and reasons for amending documents, validations and changes to the SQF System shall be maintained.

2.3.1 Product Development and Realization Product formulation, manufacturing processes and the fulfilment of product requirements shall be validated by facility trials, shelf life trials and product testing. Shelf life trials where necessary shall be conducted to establish and validate a product’s:

  1. Handling, storage requirements including the establishment of “use by” or “best before dates”;
  2. Microbiological criteria; and
  3. Consumer preparation, storage and handling requirements. A food safety plan shall be validated and verified for each new product and its associated process through conversion to commercial production and distribution, or where a change to ingredients, process, or packaging occurs that may impact food safety.

2.3.2 Raw and Packaging Materials Raw and packaging materials and ingredients shall be validated to ensure product safety is not compromised and the material is fit for its intended purpose. Validation of raw materials and ingredients shall include Certificate of conformance; or certificate of analysis; or sampling and testing. Validation of packaging materials shall include:

  1. Certification that all packaging that comes into direct contact with food meets either regulatory acceptance or approval criteria. Documentation shall either be in the form of a declaration of continued guarantee of compliance, a certificate of conformance, or a certificate from the applicable regulatory agency.
  2. In the absence of a certificate of conformance, certificate of analysis, or letter of guarantee, tests and analyses to confirm the absence of potential chemical migration from the packaging to the food contents shall be conducted and records maintained.

2.5 SQF System Verification Validation and verification activities shall be conducted. The frequency and methods used to validate and verify food safety fundamentals, critical limits, and other food safety controls identified in food safety plans shall be documented and implemented and meet their intended purpose.

2.5.2 Validation & Effectiveness (M) The methods, responsibility and criteria for ensuring the effectiveness of pre-requisite programs, and validating critical food safety limits to ensure they achieve their intended purpose shall be documented and implemented. The methods applied shall ensure that:

  1. Pre-requisite programs are confirmed to ensure they achieve the required result.
  2. Critical limits are selected to achieve the designated level of control of the identified food safety hazard(s); and
  3. All critical limits and control measures individually or in combination effectively provide the level of control required.
  4. Changes to the processes or procedures are assessed to ensure controls are still effective.
  5. Critical food safety limits are re-validated at least annually. Records of all validation activities shall be maintained.

2.5.6 Product Sampling, Inspection and Analysis The methods, responsibility and criteria for sampling, inspecting and/or analyzing raw materials, finished product and work in progress shall be documented and implemented. The methods applied shall ensure:

…iii. All analyses are conducted to nationally recognized methods or alternative methods which are validated as equivalent to the nationally recognized methods.

2.8.2 Allergen Management The responsibility and methods used to control allergens and to prevent sources of allergens from contaminating product shall be documented and implemented. The allergen management program shall include:

…viii. Based on risk assessment, procedures for validation and verification of the effectiveness of the cleaning and sanitation of areas and equipment in which allergens are used shall be effectively implemented.

Depending on the module topic, there are then additional validations required.  I won’t list all of these, as they are very specific to the topic and those already detailed are sufficient to explain.

Summary of the Requirements

The SQF standard requires validation for:

  • Any controls which are fundamental to food safety, including CCPs (,,, & section 2.5.2)
  • NPD factory trials (
  • Shelf life (
  • New product safety (
  • New ingredients and packaging ( &
  • Testing methods for raw materials, finished product and work-in-progress product (
  • Cleaning procedures to control allergens (

Validation of PRPs

Although there are elements of PRPs shown in both the BRC list and the SQF list, the first most important point to make is that not all PRPs need validating. Neither the BRC nor SQF standard say that PRPs must be validated. What they do say, is where a PRP controls food safety, the specific control that ensures the safety of the food should be validated.  But, not the whole PRP.

BRC have even clarified this in the interpretation guideline under clause 2.7.3, which says:

“Where control is achieved via the prerequisite programme, reference must be made, in the HACCP plan, to the specific prerequisite that controls the hazard. While the prerequisite programme is expected to be effective in achieving the level of control required to ensure food safety, it is not a requirement that a documented validation of every prerequisite is undertaken, as prerequisite programmes typically cover a wide range of general environmental controls, often with results which are not quantifiable. However, where a prerequisite programme is used to manage a specific hazard (e.g. cleaning regimes used to prevent allergen cross-contamination) there needs to be a documented validation that the prerequisite controls the identified hazard. Examples of prerequisites that require validation include:

  • Control of allergen cross-contamination by cleaning of the production equipment – evidence is required that the cleaning regime can effectively remove the presence of the allergen (examples of how this might be achieved are given in the guidance to clause 5.3.8).
  • Chilled storage conditions – the defined storage temperature must be validated by reference to technical literature, confirming the control of growth of relevant spoilage or food poisoning organisms, and it must be validated that the storage facility is capable of consistently delivering the defined temperature.”
Note that the BRC say “it is not a requirement that a documented validation of every prerequisite is undertaken”. Basically any specific elements of the PRPs that has a black and white, pass or fail result can be validated.

Testing to see if a new product will meet the required shelf life, either by sending it away for micro testing or by putting it through a taste panel – has a specific pass or fail result.  The method used (micro or taste panel), to establish the pass or fail result can also be validated to prove that the method actually works. In both cases, the key point is that you can prove it – you can prove that the method produces the right result and also the method is capable of producing the right result.

Take this theory, that validation is proving that something will work. Now, let’s apply it to a very general PRP – such as waste disposal…

How would you validate the PRP of waste disposal? How can you prove that the waste disposal system you are going to put in place, will work, before you implement it?  You can approve your waste disposal contractor – this will help you to ensure that you’re using a contractor that has all the right licences, but this doesn’t prove that it will work.  You can audit your waste system – but you can’t do that before you start.  An audit is verification, because it is a check that takes place after the system has been implemented, to ensure that it is working.  So, you can’t validate the general PRP of waste disposal.

If you had your own waste disposal system, such as your own on-site effluent treatment plan – this, you could validate.  You could validate it, because it has a very black and white, pass or fail result.  The treatment plant must treat the waste, so that it meets a specific result.  You could validate what the result needs to be, and you could run trials to establish if the treatment plant could achieve this result consistently.  You could do all of this, to prove it will work, before you put the treatment plant into use – this is validation.  Once you’ve then put the plant into use, you would check it routinely to make sure it was working – these checks would be the verification.

I hope you can see, that when you look at the list of validation requirements from both the BRC and the SQF standard, they only require validation of certain aspects of PRP’s.  They do not ask you to validate all PRP’s.

Non-conformances from audits

Many sites that I’ve spoke to about validating their PRP’s feel that they are being pushed into doing this, because they’ve had a non-conformance on an audit, or their auditor has told them that they must do it.

The first thing to say about this point, is that if you are given a non-conformance on an audit, where your auditor is asking you to do something that does not meet the standard – you do have a right to contest it. However – you must do this straight away. You cannot contest it once you’ve had your non-conformances signed off as complete and been issued with your certificate.  Please, do not try to close out the non-conformance to get rid of it, and then contest it.

If you’re not sure about a non-conformance – please get in touch with us.  We would be happy to look at it for you and help you to establish if it was a valid non-conformance.

If you think your auditor wants you to put validation in place for your PRP’s, it is quite likely that you’ve misunderstood one another.  If you go ahead and try to put validation in place, it is possible that you’ll get another non-conformance in next years audit – because you’ve not actually closed out what the auditor really wanted, because of the misunderstanding.  Again, please get in touch with us, we’re happy to talk through your non-conformance over the phone, so you can be assured that the corrective and preventive action that you put in place satisfies the auditor.

I know this has been a long one, but I really hope you’ve found it useful.  If you’ve got experience of this issue, it would be great if you could share it with everyone, by telling us about it in the comments section below.  Hearing about what happened to others helps us all. Or if you would like clarification on any NCN’s – add them to the comments or email me directly for help.

Have your say…

5 thoughts on “Why you don’t need to validate all your PRP’s

  1. Hi Kassy

    I always have to go back to HACCP training material for the definitions of validation and verification I can never be sure of the difference – I think your will it work, is it working explanation will save me that job in future – Thank you!

  2. Hi Kassy,

    Thks for your interesting insights.

    Two comments relating to SQF.

    The text of SQF version 7 (released 2012) was adjusted to avoid stating that PRPs are required to be “validated”. The SQF website FAQ explains the reasons for this change.

    SQF does not require the (haccp) chronological differentiation between validation and verification as detailed in Codex (2008). It appears to more follow the Codex (2009) (haccp) definition that validation is “Obtaining evidence that the elements of the HACCP plan are effective”.

    1. Hi,
      It’s really useful to know that the SQF have included that explaination in their FAQ – I’ve added a link of this below for others to read if they would like to.
      Thank you for adding your comments to the post, it’s great to share this information as it will help others that read this post in the future.


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