Access reinstated for FCO 141 Record Series

We are pleased to announce that access to the record series, FCO 141 – Foreign and Commonwealth Office and predecessors: Records of Former Colonial Administrations: Migrated Archives, has now been restored.

Files can be ordered in advance from Monday 3 October and can be viewed in our Reading Rooms from Tuesday 11 October.  

Earlier this year, we temporarily withdrew the series because we found evidence of historical preservation treatment of these files indicating insecticide use. Testing confirmed the presence of historic pesticides.  

We consulted with occupational hygienists to carry out some further tests to assess the level of risk and to advise us of safe handling guidelines. 

The hygienists have now completed their work and risk to people has been assessed as minimal, with appropriate measures in place, allowing us to return the record series to the Reading Rooms. 

In keeping with the results and recommendations, we are implementing new guidelines for readers when using the documents from FCO 141. These measures have been put in place to prevent any potential transfer of these substances: 

  1. Records from the FCO 141 record series will be viewed in a separate room within the main Reading Room and must be ordered in advance to ensure you are allocated a seat on the day you wish to visit.
  2. We will provide disposable Nitrile Gloves for you to wear while using the FCO 141 documents.  
  3. If you are using mobile phones, cameras, laptops and any other objects while viewing the documents, they must be wiped down with the materials provided prior to leaving the Reading Room or after handling the documents. 
  4. Please refrain from touching your face, eyes or mouth whilst viewing the records, and wash your hands thoroughly with soap once finished.  

All other Reading Room rules should be followed. 

We will maintain our high levels of cleaning ensuring the areas where the series is handled are cleaned after use.  

Thank you for bearing with us throughout this time. We know that the lack of access has been frustrating but the safety of our staff and users is paramount. 

Please find more information below. 


Frequently Asked Questions

1. Why did you withdraw the record series FCO 141? 

Earlier this year while working with the records, staff observed that some documents had stickers stating that insecticides had been used in the binding of the documents. The whole series was temporarily withdrawn while we investigated if insecticides remained on the documents.  

2. What did the tests entail?  

The tests were carried out in two ways – non-invasive/non-destructive testing by X-ray fluorescence spectroscopy to detect heavy metals (mercury, lead, arsenic), and invasive/destructive testing using Gas Chromatography-Mass Spectroscopy to detect and identify organic insecticides (DDT, Lindane, dieldrin, and similar).   

3. What are the results? 

The results indicated that the items are contaminated with historic organic pesticides (DDT, Lindane, dieldrin, pentachlorophenol, and 1-chloronaphthalene). The glue of several items also tested positive for mercury.   

4. Who did the tests? 

X-ray fluorescence spectroscopy tests were carried out at The National Archives by our Heritage Science team. The Food and Environment Research Agency (FERA) carried out Gas Chromatography Mass Spectroscopy. These two techniques were also applied to a set of samples sent to Integrated Contamination Management (ICM), a private company specialising in the analysis of heritage items for contaminants. We worked with the company Synergy who measured the likelihood of inhaling the agents when readers or staff are working with the documents. Their report stated that the risk of inhaling any of the detected agents is negligible and that with certain safeguards, the documents can be viewed in our Reading Rooms.

5. What do these results mean for readers and those handling the documents?  

We can allow access once again to records in the FCO 141 series but there will be certain safety protocols to observe. You will have to wear gloves when looking at records from FCO 141. This is to protect you from any transfer of historic pesticides to your skin. Our current guidance, stating that gloves are not required when looking at all other documents, remains in place.  

6. I’ve handled the documents, should I be worried? 

The tests that we have carried out to identify the insecticides and to understand the risk to people handling the items indicate that the acute risk to health is minimal, assuming that readers have been following our Reading Room handling guidance. 

7. Where did the insecticides come from? 

Records indicate that insecticides were applied as a preservation method by bookbinders, staff, archives, and libraries historically. The insecticides were either directly sprayed on shelves and items or incorporated into the binding glue used to attach the covers to bound books, notebooks, and ledgers, to prevent insects from feeding on the paper. Some, though not all of the items in FCO141 contain stickers or stamps indicating treatment.  

8. Are any other record series likely to have been treated in the same way?  

We are not aware of any other record series being affected. However, it is possible that other items from the late nineteenth century to the 1970s may have been treated as a way to prevent documents being destroyed by insects. We are aware that in some parts of the world these types of preservation techniques may have been more prevalent. However, pesticides and insecticides have been used all around the world to prevent collections from being damaged by insects and mould. Historic records indicate that many libraries and archives were applying a variety of insecticides to their storage spaces in the past. Whether contaminants persist on other items, and at concentrations high enough to cause concern is a topic that requires further research. It is therefore important that readers always follow proper hygiene when handling documents: avoid touching the face and wash hands before and after handling of items, especially before consuming food or liquids.  

We are compiling a report on the testing and results which will be published on our website once complete. If you have any other questions on access to the records, please speak to a member of staff in the Reading Room.