The use of ‘poisonous insecticidal solutions’ in bookbinding: coping with historic pesticide treatments in the archive

Abstract Records from a popular series at The National Archives were found to bear warning labels that they have been bound using a ‘poisonous insecticidal solution’. Research into historic sources suggested that the agents used by bookbinders in the early twentieth century were mercuric chloride, copper sulphate, and beechwood creosote; these may have been replaced by organochlorine pesticides (OCPs) such as dichlorodiphenyltrichloroethane (DDT) mid-century. Analysis by X-ray fluorescence (XRF) spectroscopy confirmed the presence of mercury in labelled, bound items. A number of OCPs were detected using gas chromatography/mass spectrometry (GCMS) including DDT, gamma-hexachlorocyclohexane (Lindane, γ-HCH), Dieldrin, pentachlorophenol (PCP), dichlorodiphenyldichloroethylene (DDE), and 1-chloronaphthalene (1-CP). Tests confirmed the presence of these agents on all items tested regardless of format (e.g. tagged files and bound volumes) or period of creation, suggesting the OCPs were introduced to the items after the binding process. An occupational hygienist (OH) consultancy was engaged to carry out in-situ air monitoring during production, digitisation, and general handling of the items. Risk assessments were developed based on the results, allowing readers and staff to once again access the collection with safety measures including the use of personal protective equipment (PPE)