Material and evidence management (collection, retention and disposal)


This Operational Circular should be read in conjunction with the relevant sections of the Enforcement Guide - Work-related deaths and inquests (England and Wales) and the Enforcement Guide - Fatal accident inquiries (Scotland). It provides guidance on the collection, retention and disposal of material gathered and generated by HSE staff whilst exercising their statutory functions.



The purpose of this Operational Guidance is to provide  practical guidance to Inspectors, Visiting Officers (VOs), Regulatory Compliance Officers (RCOs), Litigations Officers (LOs) and others on material and evidence management. It advises on the collection, retention (including recording), and disposal of material gathered and generated by HSE staff. It does not provide guidance on exhibiting material as specific guidance is provided in the Enforcement Guide (England and Wales): Collecting physical evidence - Preparing evidence for court, and Enforcement Guide (Scotland): Preparing evidence for use in court.

It does not aim to replicate guidance provided elsewhere and should therefore be read in conjunction with Enforcement Guide (England and Wales) and the Enforcement Guide (Scotland). Reference is made to the appropriate sections of the Enforcement Guides throughout this OG.

Definition of relevant material

The definition of material is widely interpreted in law. In England and Wales, material is defined under the Criminal Procedure Investigation Act 1996 Code of Practice as 'material of any kind, including information and objects, which is obtained in the course of a criminal investigation and which may be relevant to the investigation'. This includes not only material taken into possession such as physical items and/or documents, but also material generated, eg photographs, e:mails and/or interview records. In Scotland, reference is made in law to 'information' which is defined as 'material of any kind given to or obtained by the prosecutor in connection with the proceedings'. However, given the above definition, and for simplification, reference is only made to 'material' in this OG, but includes 'information' as defined by Scots Law.

Material will be relevant regardless of whether it benefits or weakens the prosecution case, or assists the defence. It is not only evidential material (ie used material) that should be considered as relevant:  any information, record or thing which may have a bearing on the case, whether used or unused, should be considered relevant material.

For simplicity this OG only refers to 'inspectors', however other HSE staff, in particular, Visiting Officers (VO's) and Regulatory Compliance Officers (RCO's), should implement this guidance as required.

Whilst it is hoped the guidance provided in this OG and in the Enforcement Guides for England & Wales, and Scotland will assist in most scenarios, inspectors should consult their line manager if uncertain.


Gathering material (including taking material into possession)

Although inspectors frequently gather significant amounts of material during the course of their work, not all of it will become evidence. However to comply with the Criminal Procedure Investigations Act 1996 (CPIA) and the Attorney General's (AG) Guidelines on Disclosure in England and Wales; and the Criminal Justice and Licensing (Scotland) Act (CJLA) 2010 in Scotland, inspectors should ensure all relevant material is retained and recorded as either used or unused material.

Inspectors must therefore collect all material properly and in accordance with current operational guidance provided by the Enforcement Guides for England & Wales, and Scotland. Inspectors should:

  • always carefully consider what evidence that they need to collect and how this is to be done, ie is it require for a particular line of enquiry;
  • seek, whenever possible, to obtain the 'best evidence' available;
  • ensure the material is not subject to legal privilege;
  • where material has been relinquished voluntarily by a relevant person ie  the owner or responsible person, record the relevant details in their notebook eg details of person relinquishing material and that it was done voluntarily;
  • if formally taking material into possession, clearly explain to the relevant person the powers they are exercising under section 20 of the Health and Safety at Work Act 1974, and record that this was done in their notebook;
  • use the most relevant forms with the appropriate s20 HSWA power specified;
  • use and complete the most appropriate bag, tag, or label; and,
  • record in their notebook all material taken. 

In addition to considering whether there is an evidential need to take items of material into possession, inspectors should also consider whether the original material needs to be taken into possession and retained, or whether it can be demonstrated in another way eg a photocopy, photograph or electronic copy.

Inspectors should take extra care when taking into possession digital material held on computer hard drives, laptops and other data / media storage devices (eg portable hard drives, pdas, mobile phones, secure digital cards, USB flash drives). These devices can store enormous amounts of material which can result in significant disclosure issues in the event of a prosecution. There may also be material classed as legally privileged held on such devices. Guidance on this issue is contained in the Enforcement Guide (E&W): Documents from Computers and Enforcement Guide (Scotland): Documents from Computers. In addition the Association of Chief Police Officers (ACPO) has produced guidance entitled Good Practice Guide for Computer-Based Electronic Evidence.

If Inspectors are gathering material digitally eg saving to a USB flash drive, they should save the material in a suitable format which counteracts any accusations that the material has been modified or changed eg portable document format (pdf).

To become evidence, inspectors must ensure that relevant material is in a form that can be used in court, eg exhibited or produced by a witness statement. Guidance on this issue is contained in the Preparing Evidence for Court sections of the Enforcement Guide (E&W) and Enforcement Guide - Collecting physical evidence (Scotland). In Scotland, inspectors should ensure compliance with the additional requirements in relation to admissibility of 'business documents' and the authentication of copy documents, ie by the use of docquets and certificates of authentication. Guidance is provided on the Enforcement Guide (Scotland): Collecting physical evidence.

Inspectors must also be able to account for the integrity and continuity of evidence relied upon in court. This not only includes how material was taken into possession, but also its handling, storage, and movement, including any testing and/or examination undertaken while it is in possession. 

Specific guidance on gathering certain types of material is provided in Appendix 3.

Taking material into possession using either s20 HSWA powers or with the consent of the duty holder or material owner

When gathering material inspectors should:

  • attempt to obtain the material with the co-operation of the responsible person, ie without using their powers under section 20 of the Health and Safety at Work etc. Act (HSWA) 1974; or,
  • where co-operation from the responsible person is not forthcoming, use their powers under section 20 of the Health and Safety at Work etc. Act 1974.

When powers under section 20 of HSWA powers are used, Inspectors should fully explain the process and the specific power to the responsible person, and record that they have done so in their notebook. Further guidance can be found in the Enforcement Guide (E&W): Obtaining evidence using section 20 powers, and Enforcement Guide (Scotland): Evidence using section S20 powers.

HSE staff who do not possess section 20 HSWA powers, such as Visiting Officers (VOs) or Regulatory Compliance Officers (RCOs) should ensure that the duty holder and/or material owner fully understands that they have no formal powers to take material into possession, and that they can only do so if possession of the material is relinquished voluntarily.

Use of powers under Section 20 of the Health and Safety at Work etc Act 1974

Inspectors should be sure as to which s20 HSWA power they are using when taking into possession different types of material. Inspectors should use the correct form ie LP6 or LP25, when using these powers. All the relevant boxes should be completed and the form signed and dated.

When it is not possible to give this form to the responsible person, Inspectors should leave the form at the premises in a conspicuous position. If possible the form should be placed in a plastic wallet to ensure it remains in good condition.  A photograph should if possible be taken to record its location on site.

LP6: Notice to identify articles or substances taken into possession which have caused or are likely to cause danger to health or safety

Inspectors should use power s20(2)(i) HSWA where the material being taken into possession has caused or is likely to cause danger and complete a form LP6 (as required by s20(6) HSWA). 

LP25: Notice to identify material taken away / into possession using powers under Section 20 of Health and Safety at Work etc Act 1974

Where the material being taken into possession has not caused or is not likely to cause danger, inspectors should use:

  • s20(2)(k) for books or documents taken away for copying and return; or,
  • s20(2)(m) for any other material, whether that be for copying and return (eg imaging of computer hard drives or other digital media), or to retain for any reason deemed necessary for the purposes of carrying into effect any of the relevant statutory provisions (eg material which may become evidence in any subsequent prosecution).

Material taken into possession with the consent of the owner / duty holder

When material is relinquished voluntarily, inspectors should record this in their notebook and list all the material taken into possession. They should record the name of the person from whom they received the material and ask that person to sign and date their notebook.

LP12: Notice to Leave Undisturbed

Where due to the nature, size, condition, weight etc. of the material, it is not appropriate to physically remove an item from a location, inspectors should consider serving a Notice to Leave Undisturbed using Form LP12. Discretion should be used when serving such a Notice. A Notice to Leave Undisturbed could be used to instruct that an accident scene remains undisturbed, or just a specified item of plant or machinery.

Once the investigation work associated with a particular item of material is complete (examination, testing, measurements, photographing etc.), the notice should be withdrawn, thereby returning the material to the responsible person.

Bags, tags and labels

To ensure material items are clearly identified and the chain of continuity is maintained, inspectors and other staff should use, when appropriate, the bags, tags, and labels (each with its own unique number) made available by HSE.

Inspectors should use their judgement when considering whether, or which bag, tag or label should be used. In selecting the appropriate bag, tag or label to use, they should consider factors such as the type of material (eg its size, condition, weight, shape, any sharp edges, etc.) and the risk of cross contamination with other materials, from the item being gathered.

Inspectors should complete as much information in each of the boxes on the bag, tag or label as soon as possible after gathering the material item. Inspectors should use a ballpoint or waterproof pen and complete wherever possible the following details:

  • the exhibit number assigned to the material item;
  • a clear description of the material item(s);
  • the time/date obtained;
  • the location from which it was obtained;
  • from whom it was obtained (in specific box or in description);
  • who obtained it;
  • the signature field;
  • any additional information deemed important (health and safety information).

Inspectors gathering or generating material will need to comply with the requirements of the CPIA and the CJLA and so should ensure that the description of each item accurately makes clear the nature of the item, and contains sufficient detail to enable relevant persons to decide whether they wish to inspect the material, or to request a copy of it.

The continuity boxes should be completed and signed where the material item is passed from one person to another. In addition, inspectors should record in their notebook when the item is passed to another, including a note of the exhibit number or if one has not yet been assigned, the unique reference number (URN) associated with the bag, tag or label.

The following bags tags and labels should be used as appropriate when gathering material:

  1. Evidence Bags - Inspectors should consider the use of an evidence bag when gathering evidence when it is essential to demonstrate that an item has not been altered, tampered with or cross contaminated in any way. The label on the bag should be completed as far as possible, the item placed, and then secured within the bag by use of the tamper-proof seal.

    The material item should remain within the bag until it is opened in court, should that be required, or until it is opened to undergo any testing or examination.

    If the evidence bag does need to be opened to examine an item, this should be in the presence of a witness. Both the person opening the bag and witness should complete and sign the relevant section of the bag label ie 'Bag Opened by' and 'Witness' accordingly. The opened bag should be retained and on completion of the examination, the material item and previous evidence bag(s) should be placed and sealed in a new completed evidence bag. Inspectors and others should perform this process each time an evidence bag is opened.

    The use of bags should not only be considered for small pieces of plant and other equipment, but also for original documents where it is necessary. In such cases, inspectors and others should make a copy of the document (working copy), and seal the original within the completed evidence bag.

    Every time an evidence bag is passed to another person, the receiver should complete the continuity box on the bag label to record receipt of the item.

  2. Evidence Labels - Inspectors and others should not alter in any way material items gathered during an investigation eg original documents, or an authenticated copy of an original document should not be written on, or damaged in any way. Inspectors should therefore use an evidence label which can be secured to a document eg stapled.

    (i)       Material Label (LPMat1)
    To comply with the Criminal Procedure Rules [Rule 27.3 (a) & (b)] in England and Wales, documents used as evidence in a prosecution must not only be exhibited in a statement (which must contain such a description of that exhibit as to identify it clearly), but must also be labelled or marked accordingly, and the label or mark signed by the maker of the statement. 

    Inspectors should consider using the material label for documentary material. The label does not have an URN, and therefore the Exhibit Reference field on the label should be completed as soon as possible after the item is obtained.

    The 'Subsequently Identified Boxes' should be completed and the label signed and dated by witnesses who refer to the document in their witness statement.

    (ii)       Luggage Type Label
    Inspectors and others should consider using the smaller luggage type labels (similar in format to the A4 sized label above), where the best option is to tie a label to the material item. The label should be signed by witnesses who subsequently identify and refer to the item of material in their witness statement etc.  The label should also be completed, for chain of continuity purposes should the material item be passed from one person to another during an investigation.

  3. Tags - Inspectors and other staff should consider using evidence tags for gathering larger or more unusual items of material. The tags have no or only a minimal label but they do possess a URN. Relevant notes ie material description and the date, location and the person from whom it was obtained, should be recorded in a notebook to ensure that the chain of continuity has been maintained for evidence identified in this way.

    If necessary and where they can be applied, tags should also be used to secure material items, machinery or locations eg to a crate containing a number of material items, an electrical enclosure or machinery locking off point, or a latch or clasp on a door or cupboard.

Retention and recording of material

Inspectors are responsible for the security of material items until the time of their disposal. This means that material items must be stored securely and in compliance with the Government Security Classifications scheme. Guidance is provided on the intranet at 'Protective marking and secure handling of information'.

Inspectors should ordinarily ensure that real evidence (material objects) are stored in a secure evidence facility such as a dedicated evidence room or an evidence cabinet in a HSE office. Guidance on dedicated evidence storage facilities in HSE offices is provided in Appendix 1. However and depending upon local arrangements inspectors may also wish to store other material, such as documentary evidence (eg key witness statements, permits to work, etc.) in that same, dedicated facility. 

Inspectors should ensure material that is not stored in a dedicated storage facility (eg documents, witness statements) is kept secure elsewhere in the office such as in secure FMU cabinets or their own lockable tambour unit.

Where material is stored at an inspector's residence (which should only happen when necessary and for short periods only), the inspector should ensure that appropriate measures are taken to ensure its security.

Material not subject to HSL analysis may, by exception and where all the following conditions are met, be stored at HSL's evidence storage facility:

  • 'live' cases only;
  • it is an ongoing investigation and there is a realistic prospect of enforcement action;
  • the item is bulky;
  • a reason can be provided to justify why the Inspector cannot store it elsewhere; and,
  • an end-date for the storage period can be identified.  

A HSE reactive support request form should be completed and submitted to HSL.    

Recording of material on HSE's Material and Evidence Management Tool

All relevant material should be recorded on the Material and Evidence Management Tool (MEMT) as soon as possible after it is gathered or generated, and a decision has been made by the relevant Principal Inspector that an incident warrants a full investigation.  

MEMT can also be used to record non-relevant material, although only significant non-relevant material items should be recorded, for example, material gathered or generated which is not currently relevant to the investigation but which has the  potential to impact on any future  prosecution.

Storing a digital copy of material in dedicated TRIM investigation folders

Documentary material should be scanned either by using dedicated scanners or the printer/photocopying machines. Material gathered in a digital format, or generated electronically (eg documents saved to a USB flash drive in pdf format, or emails) can be saved directly to TRIM.

The material should then be named in accordance with HSE'S TRIM Business Rules for FOD and HID and saved as a pdf in the dedicated TRIM folder for the investigation. The URL for the TRIM record for the material item should be copied and pasted into the TRIM Record Number field in the appropriate material record on MEMT.

When there is a significant amount of material to be scanned and saved into TRIM, this can be carried out by HSE Print Unit at Redgrave Court. Guidance on the scanning of material by Print Unit can be obtained by contacting Print Unit on 0151 951 4403 (VPN 523).

Transportation of material during office moves

All material stored in dedicated evidence storage facilities should be recorded in an Evidence Room log. Prior to transporting material to a new office, and new dedicated evidence storage facility, material should be placed in a suitable, labelled container and the appropriate details ie container number, should be recorded in the Evidence Log.

Where material items have been placed in sealed evidence bags, the evidence bag should suffice in demonstrating that the material item has not been tampered with anyway. However, smaller loose items not placed in sealed evidence bags should be placed in a suitable container with a lid eg transportation crate. An evidence tag should be used to seal the container. The tag should remain in place until the container is received at the new dedicated evidence storage facility, at which point it can be removed and the material logged into the new facility accordingly.

The transportation of larger material items, which are not in a sealed evidence bag, or cannot be placed in a container should be carefully considered. Appropriate measures should be taken if necessary eg wrapping material item, to ensure that it is not damaged or tampered with in anyway.

To ensure continuity of material is maintained, the movement of all evidential material should be witnessed and recorded by an appropriate member(s) of staff, both at the point of leaving the office being vacated to arrival at the new office and dedicated evidence storage facility.

Disposal of material

Material not owned by HSE, should be returned to the rightful owner when there is no longer any legal or business need to retain it. All other material should be retained in accordance with HSE's Business Classification Scheme and Disposal Schedule.

Material associated with investigations not resulting in prosecution

Material should be returned to the relevant owner as soon as possible where a decision is made not to prosecute. However, decisions made by HSE, including those in relation to prosecution can be the subject of challenge, including judicial review. Therefore prior to returning material, inspectors should satisfy themselves that persons with 'sufficient interest' are:

  • fully aware of the decision not to prosecute; and,
  • not proposing to challenge the decision.  

Persons with 'sufficient interest' are those deemed to have a direct, personal interest in the decision or action under challenge; for example, the injured person or the bereaved.  However, the definition could extend, for example, to trade unions or relevant public interest groups).

All material should therefore be retained until the time limit for an application has expired. Material not owned by HSE should be returned after this period has expired. In England and Wales, this is three months after the grounds to make the judicial review application first arose ie three months after the person with 'sufficient interest' was informed of the decision not to prosecute. In Scotland, there is no time limit for a judicial review application, and therefore inspectors should satisfy themselves that there is unlikely to be such an application before returning any material to its owners.

Non-relevant material

Inspectors should consider the need to retain material which has been gathered during an investigation, but on review is deemed to be non-relevant and so unlikely to have any impact on any future prosecution. Inspectors should consider returning non-relevant material as soon as possible and before the investigation, or any proposed prosecution is complete. Inspectors should record the reasons for an early return of material in the Location History field in MEMT.

However, inspectors should exercise caution before returning non-relevant material early as non-relevant material may become relevant in an investigation as existing or new lines of enquiry are investigated, and therefore the material:

  • could become evidence which is required to confirm, supplement or disprove a reasonable lines of enquiry; or,
  • must be disclosed to the defence as it 'might reasonably be considered capable of undermining the case for the prosecution or of assisting the case for the accused'.

Where non-relevant material is retained, it should be kept securely, but in the case of documentary material, there is no requirement to scan it and save it in the TRIM folder.

Material associated with investigations resulting in prosecution

Material associated with a prosecution should be retained until:

On completion of the prosecution, the following action should be carried out;

  • material should be weeded to remove duplicates;
  • any material which HSE wishes to retain for business purposes in the longer term should be identified at this stage and copied into a relevant TRIM folder (for example, a  generic investigation TRIM folder for the relevant FMU). Such material might include that which is useful for future training purposes or presentations. 
  •  an initial retention review date should be recorded on MEMT, usually 6 months post sentence, although in prosecutions resulting in a custodial sentence this may be longer ie the date any custodial sentence has been completed.  

As soon as possible after the expiry of the initial review date, original material not owned by HSE should be returned to its owner. Guidance is provided in Appendix 2.  Only one copy of HSE owned material needs to be retained following expiry of the initial review date; this means that where digital copies of material exist in the TRIM investigation folder, the corresponding physical copies can be discarded. A further retention review date should then be recorded on MEMT, at which date consideration can be given to disposing all material associated with an investigation, unless it is to be retained for possible transfer to The National Archives (TNA) in accordance with HSE's Business Classification Scheme and Disposal Schedule.


Not applicable.



Not applicable.


All investigations.


Guidance on the use of relevant equipment and forms / notices is contained within the Bags, Tag and Labels section of this OG.

Recording and reporting

Not applicable.

Health and Safety

Inspectors should consider if there are any health and safety risks associated with gathering material eg hazardous substances such as asbestos. Where appropriate, inspectors should procure the services  of HSE Occupational Hygiene Specialists or HSL. Guidance on Hazardous substances, including asbestos can be found on the intranet at Your Health and Safety: Health.


Not applicable.

Further references


Legal and Enforcement Team.


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Updated 2022-11-14