Good Laboratory Practice: Frequently asked questions

These FAQs are published for information only to assist facilities in their application of the GLP principles. The topics have been selected because questions surrounding these issues are frequently received into the GLP mailbox.

Raised hand1. What is the recommended archive period for GLP (Good Laboratory Practice) study records and materials?
2. Our lab is accredited by UKAS to ISO 17025. Does this mean we will meet the requirements for GLP?
3. How much information must we have on a test item and does it have to have been generated in a GLP environment?
4. Our laboratory performs analysis of samples from clinical and pre-clinical studies. Should we work to GLP or GCP (Good Clinical Practice)?
5. Our laboratory is located outside of the UK. Can we become members of the UK GLP Compliance Monitoring Programme and will the UK GLPMA (GLP Monitoring Authority) inspect us?
6. Do we need to conduct formulations analysis where there is no specific requirement for it in the test guideline (OECD, ICH etc)?
7. Can formulation analysis be performed in a GMP (Good Manufacturing Practice) compliant laboratory?
8. How do we issue a final report amendment?
9. Why is there a need for us to inspect our quality assurance (QA) activities?
10. Who should conduct inspections of our QA activities?
11. Does an inspection of the QA activities by either the GLPMA or a sponsor satisfy the requirement to inspect our QA activities?
12. Do we have to use an external consultant to inspect our QA activities?
13. If we use an external consultant are there any specific points we should consider?
14. As part of our GLP study, the sponsor wants to perform some analysis in house at their facility.  The sponsor’s facility is not a member of a compliance monitoring programme is it acceptable to exclude this work from the study director’s claim of compliance?
15. When considering use of a non-GLP facility to perform part of a GLP study, who decides what is critical to the study outcome and objectives?
16. When conducting some field trials it will usually be necessary to use agricultural facilities such as field plots, orchards, horticultural facilities such as greenhouses, polytunnels, or farming units such as cattle sheds and fish farms etc. When should the GLPMA be notified of the intention to use such facilities?



1. What is the recommended archive period for GLP (Good Laboratory Practice) study records and materials?
The GLP Principles specify the manner in which study materials should be archived but do not specify for how long these items should be retained. For some types of test items, the legislation relating to that type of chemical or product may specify a required archiving period and this should be complied with.

Supporting records should be retained for as long as they may be required in order to support study data.

Items that have a limited shelf-life are not expected to be retained beyond their likely usefulness.

The UK GLPMA (GLP Monitoring Authority) requires that study specific records be maintained for a period of two years or one inspection cycle, which ever is longer. In order that sufficient records are available to facilitate a thorough and complete inspection of a test facility.

Further guidance is available in the published MHRA guidance document below:
Guidance on archivingPDF file (opens in new window) (63Kb)

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2. Our lab is accredited by UKAS (United Kingdom Accreditation Service) to ISO 17025. Does this mean we will meet the requirements for GLP (Good Laboratory Practice)?
The first fundamental difference between any accreditation scheme and GLP is that accreditations serve to demonstrate technical competence, impartiality and performance capability. GLP is a legal requirement in the UK for laboratories that are conducting regulatory studies and embodies a set of principles that provides a framework within which laboratory studies are planned, performed, monitored, recorded, reported and archived.
GLP studies usually evaluate the properties of a test item to either determine its characteristics or to evaluate the effect that it has upon a test system, for example, the potential of a new agrochemical active ingredient to persist in soil.

ISO 17025 is a standard for laboratory competence that accreditation bodies use and is concerned with the technical competence of a laboratory. Accreditations usually serve to demonstrate impartiality and performance capability.

Tests conducted to ISO 17025 are usually performed to evaluate a specific property of a sample, for example, the analysis of a sample of soil to determine the metal content using ICP-MS (inductively coupled plasma mass spectrometry).

Both GLP and ISO 17025 require documented management systems and verification that activities are conducted in a controlled and consistent manner. The GLP Principles also describe specific roles and responsibilities that do not directly correlate to (but are compatible with) those within ISO 17025. Consequently, whilst accreditation to ISO 17025 will have addressed many of the elements required for GLP compliance, it is unlikely that a quality system designed to meet the requirements of ISO 17025 will satisfy the requirements of GLP.

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3. How much information must we have on a test item and does it have to have been generated in a GLP (Good Laboratory Practice) environment?
To conduct a GLP study on a test item where no information has been provided is not acceptable. The GLP Principles state that information relating to a test item’s identity (code, CAS number, name etc) and characteristics (batch, purity, composition etc) should be known and that records relating to expiry date and quantities received and used should be maintained (Schedule 1, Part VI 1.- and 2.-).
To conduct a GLP study on a test item where the study director and their facility take no responsibility for verifying the identity and nature of the test item is not acceptable. For example, a claim in either the study plan or the report that “The Sponsor is responsible for the characterisation of the test item” is not acceptable. The GLP Principles state that the study director and their test facility management have a responsibility to establish a mechanism by which the identity of the test item can be verified (Schedule 1, Part VI, 2.-(3)). If the sponsor is determining the test item characteristics, this information should be made available to the study director.

There is no requirement to characterise the test item in a GLP compliant test facility. However, the study director should be satisfied that the information has been generated in a facility where the results obtained are considered to be accurate and reliable.

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4. Our laboratory performs analysis of samples from clinical and pre-clinical studies. Should we work to GLP(Good Laboratory Practice) or GCP (Good Clinical Practice)?
If the UK laboratory is performing work which is in support of a clinical trial, then this work should be performed in compliance with GCP - The Medicines for Human Use (Clinical Trials) Regulations 2004 as amended.
Compliance with the principles of GLP is a legal requirement for test facilities that undertake non-clinical regulatory studies (Regulation 4 of the UK GLP regulations (external link)). GLP does not extend to the analysis of any samples that have been collected as part of a human clinical trial.

If a facility is performing clinical analysis in support of clinical trials and non-clinical regulatory studies, then the facility will need to ensure that the requirements of GLP and GCP are met. There is a degree of overlap between the two standards and if the facility is already operating in compliance with the principles of GLP, it is likely that the facility will also be meeting many of the GCP requirements. However, there are some important aspects within GCP that will need to be considered, such as patient safety, confidentiality and consent. A guidance document on the conduct of clinical analysis is available below:

Guidance on the maintenance of regulatory compliance in laboratories that perform the analysis or evaluation of clinical trial samplesPDF file (opens in new window) (316Kb)

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5. Our laboratory is located outside of the UK. Can we become members of the UK GLP Compliance Monitoring Programme and will the UK GLPMA (GLP Monitoring Authority) inspect us?
The UK GLP Compliance Monitoring Programme is only open to laboratories that are located within the United Kingdom. Laboratories in other countries fall outside of the scope of the UK GLP regulations, and the regulatory remit of the UK GLPMA, and so will not be admitted to the UK GLP Compliance Monitoring Programme.

The UK GLPMA will not inspect laboratories outside of the UK for the purposes of assessing their compliance with the principles of GLP unless we are requested to do so by a UK receiving authority. Any verification of the GLP compliance status of laboratories should be undertaken by the regulatory body responsible for GLP compliance in the country concerned.

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6. Do we need to conduct formulations analysis where there is no specific requirement for it in the test guideline (OECD, ICH etc)?
The OECD (Organisation for Economic Co-operation and Development) Principles of GLP (Good Laboratory Practice) require that if a test item is administered or applied in a vehicle the homogeneity, stability and concentration of the test item in the vehicle should be determined. Consequently, this information should be generated as part of a GLP study if the study director intends to make a full claim of GLP compliance, regardless of whether or not it is specifically required by a test guideline.
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7. Can formulation analysis be performed in a GMP (Good Manufacturing Practice) compliant laboratory?
In some instances, and particularly when testing pharmaceuticals, a study director may receive a formulated test item that has been supplied by a facility that works in compliance with the principles of GMP. In these cases it would be acceptable for the GMP facility’s own laboratory or an associated GMP contract laboratory to determine the homogeneity, concentration and stability of the formulation. In such circumstances, the study director has a responsibility to ensure that the laboratory used to perform the analysis has been subject to a GMP inspection by the appropriate regulatory body. The study director must also indicate in their statement within the final report that the work was performed in accordance with the principles of GMP.
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8. How do we issue a final report amendment?
Part IX of Schedule 1 of the GLP Regulations 1999 requires that amendments to the final report of a study should clearly specify the reason for the correction or addition to the final report and also requires that the amendment should be signed and dated by the study director. The form of the amendment itself is not dictated by the Regulations.

The responsibilities of the study director and QA apply to a final report amendment in the same manner they would apply to a final report. Consequently, any amendment to a final report should:

  • Be signed by the study director to indicate acceptance of responsibility for the validity of the data and to indicate the extent of compliance with GLP (if the original study director is no longer available, this should be stated and the amendment signed by management).
  • Be inspected by QA to confirm that the reported results reflect the raw data.
  • Contain a signed QA statement detailing the inspections conducted (for example, review of the amended final report and data pertinent to it) and confirming that the amendment reflects the raw data.
  • Be retained in the facility archive.

In deciding how best to deal with amendments to a final report , it is useful to consider the extent of the addition or correction, and whether it affects a discrete part of the final report, or affects multiple parts of the final report requiring changes to be made to many of its pages.

Should the amendment affect only a discrete part of the final report it is possible to issue a short document detailing the following:

  • the correction to be made and/or the text to be added to a specific section
  • the reason why the change is being made
  • a signed statement by the study director
  • a signed QA statement.

Should the amendment affect multiple sections of the final report (for example, where amendment of a data point affects derived data, tabulated data and statistical analysis) it may be more appropriate to issue an amended final report that replaces the original final report in its entirety. In this instance, the amended final report should clearly state that it replaces the original version and detail the reason why the changes or additions have been made.

Sponsors should be informed as soon as possible that a final report amendment or amended final report is required to ensure that any regulatory authorities that have received the original final report can be informed. Test facilities should request confirmation from the sponsor that the amended final report has been received and circulated appropriately.

It is advisable to sequentially number final report amendments.

If a final report is to be reformatted to meet the specific requirements of a regulatory authority, this is not considered to constitute either a correction or addition to the final report provided that:

  • No changes are made to the detailed information presented and the narrative text of the final report remains identical
  • Any changes in wording relate only to those required for formal statements (for example, addition of a statement of no data confidentiality within a final report reformatted for submission to the United States Environmental Protection Agency).

If the issue of a final report amendment is required to correct information within the original final report, test facility management should investigate the root cause of the error.

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9. Why is there a need for us to inspect our quality assurance (QA) activities?
All elements of a test facility’s quality system should be inspected; QA is a key part of the GLP quality system. The inspection of QA activities should be used to determine the extent to which the QA programme meets the requirements of GLP and the extent to which it complies with the requirements of the test facility’s own processes and procedures.

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10. Who should conduct inspections of our QA activities?
Inspections should be performed by a person(s) independent of the work/activities they are assessing and who are accountable to test facility management. Inspections should be undertaken by persons who are suitably trained and experienced and are familiar with the test facility’s QA processes and procedures.

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11. Does an inspection of the QA activities by either the GLPMA or a sponsor satisfy the requirement to inspect our QA activities?
No, the GLP Regulations state that 'the quality assurance programme should be carried out by an individual or individuals designated by and directly responsible to management and who are familiar with the test procedures'. Neither the GLPMA nor the sponsor is responsible to test facility management. However, departures from GLP identified during such inspections should be considered by test facility management and may contribute to the overall assessment of QA.

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12. Do we have to use an external consultant to inspect our QA activities?
No, the assessment of QA activities can be performed by any member of staff that is independent of the activities they are inspecting and has been appropriately trained.

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13. If we use an external consultant are there any specific points we should consider?
Test facility management should ensure that external consultants are suitably trained and experienced. There should be a formal agreement between test facility management and the consultant(s). The test facility should retain documentary evidence to support the appointment of the consultant.

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14. As part of our GLP study, the sponsor wants to perform some analysis in house at their facility. The sponsor’s facility is not a member of a compliance monitoring programme is it acceptable to exclude this work from the study director’s claim of compliance?

If the analysis is deemed to be critical to the study outcome or the study objectives then it would not be acceptable to exclude work from the study director’s claim of compliance and this work should be done in compliance with GLP. There is an exception to this regarding formulation analysis that is answered separately.

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15. When considering use of a non-GLP facility to perform part of a GLP study, who decides what is critical to the study outcome and objectives?
Since the study director has overall responsibility for the GLP compliance of the study he/she should ultimately make the decision.  

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16. When conducting some field trials it will usually be necessary to use agricultural facilities such as field plots, orchards, horticultural facilities such as greenhouses, polytunnels, or farming units such as cattle sheds and fish farms etc. When should the GLPMA be notified of the intention to use such facilities?

The following examples should assist in determining whether or not the GLPMA should be notified.

Scenario 1:  A pesticide residue study using defined plots within a larger field of a commercially grown crop.  Key study activities will be performed by (GLP) test facility personnel.

This is the most common type of field trial. The whole field of commercial crop, including the test plots, will be subject to normal pesticide and fertiliser application by the farmer. All applications of test item to the test plots, and subsequent harvesting of the agricultural commodity is performed by personnel from the GLP compliant test facility.  In this situation, all key study activities are performed by personnel from the GLP test facility using their own equipment. The GLPMA does not need to be notified of the use of such field sites.  The situation is the same when using a number of fruit trees or bushes within a larger commercial stand, or the use of test plots within normal commercial greenhouses or 'polytunnels'.

Scenario 2:  A pesticide residue study using defined plots within a larger field of commercially grown crop. Some key study activities (eg application or sampling) will be undertaken by persons not working for the test facility.

In contrast to scenario 1 above, the GLP compliant test facility will need to extend its compliance to cover the critical study activities undertaken by these 'non-GLP' persons. This would include eg appropriate training and monitoring by the study director and/or quality assurance. In these circumstances the GLPMA should be informed of the work to be performed by such persons.

Scenario 3: A pesticide residue study using defined plots within a larger field of commercially grown crop. Key study activities will be performed by (GLP) test facility personnel, but additional processing of the raw agricultural commodity will be conducted by persons not working for the test facility.

The use of the field plots would not need to be notified to the GLPMA, but the use of processing facilities where harvested commodities are treated to prepare other items such as juice, sauce etc. would normally need to be notified.  This is because the premises, equipment (and possibly staff) at a non-GLP facility will be used to conduct important study activities that could affect study outcome.

Scenario 4: Veterinary residue trial in farm animals

Such trials are usually conducted in animal facilities belonging to the GLP compliant test facility. However, there may be studies that require a larger number of animals than can be accommodated in their own animal facilities, and therefore it becomes necessary to utilise the premises of commercial farms.  The intended use of these premises should normally be notified to the GLPMA since the design, construction and use of the cowsheds could impact on the conduct of the study. Also, it is likely that in these situations farm staff will be undertaking routine husbandry activities such as feeding and so will be responsible for generating data that will be used in the final study report.

The situation would be the same if using commercial fish farms when it is necessary to house a large number of fish, or to use fish of larger sizes that cannot be handled in a GLP compliant laboratory.

Scenario 5: Trials requiring the use of specialised facilities

Where specialised facilities are necessary to conduct a field study, these will usually need to be notified to the GLPMA since they will consist of premises and equipment belonging to another organisation, and due to the specialised nature of the work, it will often be performed by staff from the non-GLP organisation.  Examples of specialised facilities notified to the GLPMA have concerned potato fogging, chestnut fumigation and seed treatment.

Scenario 6: Operator exposure studies

In these studies, operators at commercial farms conduct routine pesticide applications using their own (farm) equipment and following normal (farm) procedures.  Indicators, including cloth samples or swabs from the clothing or skin of the operator, are taken by the GLP compliant test facility for subsequent pesticide analysis.  Sampling is performed by test facility personnel, and subsequent analyses are conducted within the GLP test facility, and so the GLP compliance status of this work is clear.

The intention of the study is to obtain representative exposure data from 'ordinary' farm hands following standard agricultural practice; making them follow more defined (GLP) procedures would compromise the validity of the results obtained.  For this reason the actual pesticide preparation and application procedures must be conducted by farm staff using farm equipment and according to their established practice.  This requirement should be clearly stated in the study plan, and should be verified by the study director during their monitoring of the work.

The GLPMA would usually expect to be notified of the use of a non-GLP facility (a commercial farm) to perform critical study activities such as the preparation and application of pesticides. However, given the intended purpose of these studies, the GLPMA has adopted the position that it does not need to be notified of the use of non-GLP facilities when they are engaged solely in the preparation and application of pesticides as part of operator exposure studies. The final report should provide additional information concerning how these activities were conducted (and controlled) and the study director should provide a justification why they consider that the data obtained are valid for the purposes of risk assessment.

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Page last modified: 20 December 2011