Paper Conservation: Decisions & Compromises

Two different analytical methods were chosen
to detect the off gassing ethylene oxide, a digital
handheld device, Dräger X-am 5000, which
turned out to be too rough (measuring range 0
- 200 ppm, resolution 0.5 ppm, smallest possible
detection 1 ppm; expected concentration below)
and a GC/FID. For the later the measurement was
passive with ORSA-tubes filled with activated
carbon. The measurement lasted for 336 hours.
Then the tubes were taken out, closed and sent
to gas chromatography. The analysis was made
with GC/FID with retention time catalogues and
quantification via external calibration function.
This standard working instruction is a modified
NIOSH 1612. Working conditions: Gaschromatograph
“Doppelsäulengerät Sichromat 1-4”; Injektion:
split/splitless; 2.5 µL splitted auf 2 wide-bore
colums, 250°C, Colums: 30 m OPTIMA-WAX; 0.53
mm * 1.0 µm and 30 m OPTIMA 1; 0.53 mm *1.0
µm, Both detectors FID (250°C), Carrier gas Nitrogen:
2.5 mL/min, burning gas synth. air: 300 mL/
min, Hydrogen: 25 mL/min, stove temperature
45°C isotherm 10 min, 45°C to 180°C in 5°C/
min; 180°C isotherm 13 min, 180°C to 200°C in
10°C/min, 200°C isotherm 13 min.
Fig. 2: Sampling of books by cellulose nitrate membranes.
the book. The books for ethylene oxide measurement
were chosen aiming to get a representative
average of all these features. This is especially
important when it comes to transfer data into
application Europe-wide and on an “average
archive” at the end of the project. 28 volumes
bound in leather, parchment, paper and textiles,
dating from the 18 th , 19 th and 20 th century, thus
representing also different sorts of paper as book
block, ranging from folio to quart were selected
by the Parish in Swidnica and brought to the
European Research Centre for Book and Paper
Conservation-Restoration in Horn. There these
books were put into a chamber of inert synthetic
material of 1 m 3 volume and stored under closed
conditions for 60 days at 20°C and 50% R. H.
Results and conclusions
The books in Swidnica were fumigated with
ethylene oxide in the 1990s. Nowadays, after 20
years, no ethylene oxide could be detected with
the methods described above. A risk for human
heath is thus rather improbable.
The results of the fungal sampling are shown in
Table 1. From some samples, especially from the
inner part of the books, no fungi could be isolated.
Only very few fungi that are directly related
to the destruction of the materials where isolated
(Sterflinger, 2010; Sterflinger & Pinzari, 2011):
Nigrospora and Alternaria are known to degrade
cellulose and Scedosporium is a keratinolytic
fungus, able to degrade leather. Species of Scedosporium
are known to be pathogenic for humans,
causing a skin infection called phyaeohyphomycosis
(de Hoog et al., 2000). Most abundant
were species of the genus Cladosporium which
were isolated from nearly all samples except for
some inner parts of books. Cladosporium, however,
is not regarded a true contaminant of books
and cannot be related to the phenomenology of
the sampled areas. Cladosporium rather is an environmental
fungus which is extremely common
in the air and spores of which settle down in dirt
and dust. Thus, these fungi are isolated readily
from the materials because of the spore load
and not because they are actively growing and
established on the books. Typical contaminants
of humid paper, like species of Chaetomium or
Trichoderma are missing.
As a preliminary conclusion from the project it
can be stated that the fungal community isolated
15-20 years after fumigation can only to a small
extend be related to the biogenic fungal phenomena
like white and dark floccose spots and areas
visible on and in the books. It can be concluded
that this is due to the ethylene oxide treatment
that killed especially those fungi that formed
ICOM-CC Graphic Documents Working Group Interim Meeting | Vienna 17 – 19 April 2013
110