Vacuum storage bags: an inexpensive and convenient tool for temporary storage of items infested with pests and mould

As an accredited book and archives conservator running a commercial practice, I am regularly called upon to offer professional advice on items that have been affected by insect infestation, flood or mould. By the time a client reaches out for help, the problem may be severe; isolating infestations and preventing their spread is the first step in effective management of the problem. In this article, I discuss how I have recently used vacuum storage bags as a means of temporarily housing infested objects and why they have proved so effective.

The use of vacuum packing instruments in larger collections to isolate damaged collection items and dry out flood-damaged materials is well documented. These machines are incredibly useful in preventing life-giving air flow to mould spores, fungi and insects. Their use is a crucial means of pausing the devastation of collection items until they can be seen by a conservation professional. These machines, adapted from the food-packaging industry by incorporating conservation-grade plastics, have been rigorously tested for off-gassing and other ageing characteristics; yet they can be prohibitively expensive to a small library or archive. For these organisations, good relationships with larger institutions who might be willing to share their resources can be extremely helpful; but such an arrangement could take significant planning and management.

Over the last couple of decades, the application of vacuum storage and anoxic environments in conservation has led to the production of various means of ensuring the effectiveness of these methods of isolation. Oxygen-absorbing scavengers that decrease the amount of oxygen present in the storage have been developed and are readily available. Oxygen indicator tablets change colour when the levels of oxygen have effectively been reduced, and silica gel packs can also be used to absorb available moisture. This is now a measurable and controllable process.

My first application of the use of vacuum storage bags was for a library with an active conservation programme run by an extremely engaged librarian. She is experienced at fundraising, using a book sponsorship programme to promote the collection and direct funds specifically to where they are needed most. The collection is housed in a historic building in central London and is actively managed for environmental risk factors, including mould.

Following a flood within the collection, several items had been identified as having been affected by mould. A professional alliance with a national museum meant that these items had all been photographed and vacuum-packed in 2009. Given that they were now “at-risk” items which were a conservation priority, our librarian needed to know how much conservation treatment would cost; but this meant breaking the vacuum seal. I needed to provide a safe means of storing the vulnerable, potentially infested items after opening up the existing vacuum packaging, as I had been asked to provide a condition assessment and quotation for the treatment required. I suggested the use of domestic vacuum storage bags, which could then be sealed with the Museum Vac, which has a HEPA filter to contain mould spores. Oxygen-absorbing scavengers and indicator tablets would tell how effective the seal was. It must be cautioned that this is a temporary method of storage, as the bags are of indeterminate make-up and are likely to contain PVC or other unsuitable plastics.

Title page of mould-damaged book

This book from the collection, Allen’s A True, Sincere and Modest Defense (1532), was extremely degraded, with no boards or spine. It was first wrapped in blotter, to minimise the effect of pull of the storage bag on the fragile, damaged edges, and then sealed. It will either have its mould safely removed and treated as part of the conservation programme, or be re-sealed by the friendly national museum. Until that time, it is wrapped, labelled and stored safely, with both oxygen scavengers and indicator tablets so that it can be clearly seen how effective the storage bag is performing.

Blocking from mould damage

Blocking from mould damage

Mould-damaged book in vaccum bag showing seal

Mould-damaged book in vacuum bag showing seal

Mould damaged Book with Oxygen Scavenger, Detector Tablet and Silica

Mould-damaged book with oxygen scavenger, detector tablet and silica

My second opportunity to use this technique was for a private client for whom I had conserved a particularly valuable and interesting family relic. I first treated and bound this folio after it had been severely affected by mould. It contained beautifully rendered watercolours of a family textile mill, complete with fabric samples on each page. It is therefore a complex, mixed-media item with various “edible”, by both mould and insects, constituents. The earlier treatment had included controlled removal and dehydration of the mould and repairs prior to binding, and it had been very successful. The mould-damaged areas had been repaired using methylcellulose in water as an adhesive and resizing agent, alongside various handmade wove and Japanese papers. I provided clear guidance on the long-term storage of the folio as a means of preventing further damage.

Five years later, however, I was contacted again about this folio. It had been not only affected by a leak in the cupboard where it had been stored, but also infested with silverfish. The life cycle of silverfish is comprised of several stages, so it was important to eradicate all eggs, larvae and mature adults. Silverfish are extremely resilient and adaptable insects and can survive for up to two years, often with long periods without food.

I needed to safely examine the folio while preventing it from infesting anything else it might come into the proximity of. I sealed it in a vacuum storage bag before bringing it into my workshop, where I was able to examine and then re-seal it without it coming into contact with any other items. After approval from the client, the item was safely treated and repaired. When I expressed to the client my concern about its long-term protection, she informed me that it was to be donated to a local museum, where it would be stored in a safe and monitored environment. The vacuum storage bag would ensure that it could be safely returned to her without the risk of further infestation, until the arrangements with the museum could be made.

Naish album vacuum packing

Folio of watercolours, vacuum packing

Folio of watercolours - silverfish

Folio of watercolours, silverfish

Folio of watercolours - after treatment

Folio of watercolours – after treatment

The use of vacuum storage bags has proved to be a practical, inexpensive method of managing vulnerable items. Safely isolating them in this way allows them to be assessed professionally and prevents the risk of further damage not only to the objects themselves, but also to the wider collections that house them. Further potential applications of the use of these bags may include the isolation of suspect donations to collections or even loans which may suffer from suspected active infestations that require isolation from collection storage areas. As heritage professionals we plan for disasters, but this method is particularly suited to individual items that require a quick, temporary solution to prevent further damage.

Ann-Marie Miller ACR is an accredited book and archives conservator based in London. She works for a broad range of institutional clients and private collectors, from national museums to corporate archives. Previously, she worked for seven years at the British Library, achieving accredited status in 2007. She earned a post-graduate diploma and a master’s degree in conservation at Camberwell College of Arts, after studying the History of Art at the Courtauld Institute of Art.

Codex Conservation, Unit 2, Print Village Chadwick Road SE15 4PU

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