This is an edited version of a lightning talk presented at the New Zealand Conservators of Cultural Materials conference, Wellington 17-19 October 2016.
I will first explain the logical, if somewhat tenuous, connection of this paper with the book – Plastic Fantastic: How the Biggest Fraud in Physics Shook the Scientific World. It is a book about a physicist who fabricated scientific results, duping many of the world’s top scientific journals and experts, including Nobel Prize-Winners. You will see that I have been dealing with a similar dearth of substantiated facts, starting with some misleading information in the innocuous-sounding Department of Internal Affairs file 158/67.
Some background first. Through 2015 and 16 myself and Peter Whitehead and Vicki-Anne Heikell have been collecting information for the conservation and preservation management plans for the Treaty documents, the Declaration of Independence, and the Women’s Suffrage Petition, in preparation for He Tohu Exhibition.
Historical data about previous storage conditions and treatments is important to inform our understanding of what happened in the past and what we can do in the future. The file 158/67 had information about the storage and conservation of He Whakapūtanga (which is the Maori name for the Declaration of Independence) and it mentioned the planned use of “non-flammable celluloid” or “non-flammable cellophane” loose-leaf sleeves within leather storage boxes.
In March this year I coincidentally discovered in the Lab store room three red leather-bound boxes, containing sleeves – two were empty, the third had documents stored in it. Of the two empty ones, one (see below) had sleeves, which were seriously degraded, to such an extent that they were barely recognisable as sleeves.
It also looked scorched and blackened around the box edges and on the inside of the lid, which was a cause for alarm. This was the box for IA 9-10, which contained the Rough Draft of the Treaty of Waitangi (see Appendix A, added post-conference as new evidence came to light).
I thought it prudent to check around the Archives to see if there were any more, and if they were in a similar state.
We found many more similar leather-bound boxes in the Object store room in the repository including a box entitled “Declaration of Independence” (Whakaputanga) (ref. IA 9-1) which had the two empty sleeves still intact inside being the same thick, yellowing plastic as the others.
Ah-ha, so is this the box referred to in file 158/67, supposedly made with non-flammable celluloid or cellophane? But what about the identical box, which had, scorch marks? It didn’t seem to make sense.
We therefore embarked rather hurriedly on a programme of managing the risk of there being potentially flammable plastic sleeves in the storage areas. First we removed all the sleeves from the boxes in the Object Store – all sleeves were intact except one. This one had degraded like the contents of our scorched box, but unlike that one, there was no scorching to be seen on the box edges and lid.
Once removed from the store, we retained the sleeves in a portfolio for appropriate disposal, and what with wanting to retain the Whakaputanga box complete with its, as yet, intact sleeves for documentation and historic reasons, it became important to know what exactly we were dealing with.
We had a few options. We could carry out a float test, a burn test, and FTIR analysis. We tried the float test, with help from our conservator colleagues at the Alexander Turnbull Library. This can help to distinguish between the three plastics commonly found in archives – cellulose acetate, cellulose nitrate and biaxially-oriented polyethylene terephthalate, otherwise known as polyester! Samples of sleeve from the scorched box were floated in trichloroethylene and they did float, which indicated that it was cellulose acetate. At the same time a sample of known cellulose nitrate film was tried and this sank. So from this we may deduce that our sample was indeed cellulose acetate. However, I had already tried a burn test, in my fireplace at home (as I didn’t want to burn the archives down…) and found it to burn extremely brightly and fiercely, even burning downwards, but it had gone out readily when I placed it in a cup of water. I also burnt a known acetate film sample and this was much more reluctant to burn and would not burn downwards.
So from the inconclusive results of the float and burn tests, I decided we needed a definitive answer by using FTIR testing. This was done off-site by Callaghan Innovation, and the results were surprisingly straightforward.
They tested two samples of the sleeve material, one from the Rough Draft of the Treaty of Waitangi box (the scorched box)(Sample A) and the other from the intact Whakaputanga box (Sample B). The test can identify peaks corresponding to the chemical composition of a material and in this case, even with slight differences between the two samples, both spectra showed characteristic nitrate peaks.
The difference between the two was explained by the fact that the burnt sample had exhibited a loss of nitrate on degradation, so its spectra was less intense. Cellulose nitrate degrades to produce acidic and oxidizing nitrogen oxide gases (including nitrous oxide, nitric oxide, and nitrogen dioxide). It was the release of these acidic gases that had caused the scorching on the box.
In the literature, including reports from the CCI, we have clear guidelines how to store cellulose nitrate material, including at what temperatures it can auto-ignite. This explains why our degraded sleeves are in the state they are in; quoting from a CCI report “Display and Storage of Museum Objects containing Cellulose Nitrate” “high concentrations of these gases build up that can embrittle and accelerate degradation of objects. In photographic film and objects in thin cross-section, the problem is less acute because the gases diffuse out of the object quickly and can be vented away. For objects of thick cross-section, diffusion is much slower. The gases are trapped for longer periods and have a greater chance to catalyse degradation. A vicious circle forms: faster decomposition increases the concentrations of nitrogen oxide gases, which in turn increases the rate of decomposition. The accompanying heating of the object can cause spontaneous ignition.” And “foul odours come from the nitrogen oxide gases.”
The sleeves in question were around 500microns thick, much thicker than photographic film, which is about 150microns, and there was an unpleasant smell, so all in all, I am happy that we have our diagnosis and reason for the current degraded state.
Finally, a note on future storage of the sleeves – back to the CCI report: “the changes mentioned are accompanied by progressive decreases in auto-ignition temperatures”. “Fresh, undegraded cellulose nitrate auto-ignites (or self-combusts) at 150°C, whereas the powdery or foamy mass of cellulose nitrate in the last stages of decomposition can auto-ignite at temperatures as low as 50°C. This temperature can easily be reached near light bulbs, radiators, attics in summer, etc.” So in our case, we are now storing the remaining box containing intact sleeves, the Whakapūtanga box, safely in our cold stores, and the disposal of the cleared-out sleeves languishing in the portfolio? – well, we tasked our friendly neighbourhood Army guys to take them away for “disposal”, that is, maybe for setting fire to them or blowing them up!
So for my conclusion: It was a happy chance that we found the reference to the “non-flammable celluloid” in file 158/67 when we did, and that the first three boxes presented themselves to us when they did. As a conservator you do question what you are told, and investigation is an exciting part of the job. We were able to extricate ourselves from the misleading statements of the past, and the misleading initial test results.
I will never be a Noble Prize winner, but I am happy that our plastic fantastic story has a transparent ending!
Past and present staff of Archives New Zealand and Alexander Turnbull Library
New information added in Dec 2016:
A photograph of archivist Ken Scadden holding the Rough Draft of the Treaty of Waitangi box came to light in November 2016. This was either taken or published in the Evening Post on 9/7/1988.
This means this badly deteriorated box was still intact in 1988. One can only wonder at the circumstances that have lead to the accelerated degradation to the degree we now see today.
Jonathan London commented on 7/10/16: “the Declaration of Independence – this may have been one of a suite of documents that were, until about 1989/1990 housed in leather-covered boxes made by the Government Printing Office back in the 50s/60s?, with post binding holding clear PVC pages in which were housed the smaller documents. I remember documents being removed from these as the PVC had become brittle and discoloured. I don’t remember any repairs being undertaken”.
This is useful information, especially about the dates of removing documents from the sleeves, as well as the reference to repairs.
All Photos: Anna Whitehead