Handbook of Solvents - George Wypych - ChemTech - Ventech!

14.15 Medical applications 955
Solventborne wood preservatives contain mainly nonpolar, organic solvents apart
from other substances such as fungicides and insecticides. 1 These solvents are classified as
VOCs.
14.14.2.2 Technical and environmental aspects
Solvent-based wood preservatives show several advantages, especially in their application
and technical effectiveness. 1 They can be applied repeatedly and do not alter the structure of
the wood products. Application is faster and the characteristics of the final product are improved,
e.g., visual appearance of surface.
Nevertheless, there are some disadvantages, especially environmental ones. Most solvents
are released quickly (VOCs) and can cause severe environmental effects. This is especially
true if toxic solvents are employed.
Emissions of solvents from wood products are described under various conditions,
e.g. indoor air emissions from furniture or emissions in test chambers. 3,4 Solvents can be
emitted as primary or reactive products of the wood product or the coating system; solvents
can also be investigated as secondary emission products. 3,5 The emission characteristics depend
on solvent properties and surrounding conditions, e.g., air velocity and air exchange
rate. 6
In the indoor air, solvents from wood products follow various pathways. Examples of
interactions are possible reactions of solvents (e.g., styrene) with air components (e.g.,
hydroxy radicals), 3 transport into and through indoor materials 7 or sorption processes. 5 The
emitted solvents can be reduced by ventilation processes or they may be absorbed by organisms.
For humans, absorption of the wood preservatives or ingredients (e.g., solvents) can
cause various toxic effects. It is often difficult to pinpoint the causative agents (see Chapter
20).
REFERENCES
1 Ullmann`s Encyclopedia of Industrial Chemistry, 1998.
2 DIBt (Deutsches Institut für Bautechnik). Holzschutzmittelverzeichnis. Index of wood preservatives (1999).
3 T. Salthammer, A. Schwarz, F. Fuhrmann, Atmospher. Environ., 33, 75 (1999).
4 T. Salthammer, Atmospher. Environ., 7, 189 (1997).
5 M. Wensing, H.J. Moriske, T. Salthammer, Gefahrstoffe Reinhaltung der Luft, 58, 463 (1998).
6 E. Uhde, A. Borgschulte, T. Salthammer, Atmospher. Environ., 32, 773 (1998).
7 R. Meininghaus, T. Salthammer, H. Knoppel, Atmospher. Environ., 33, 2395 (1999).
14.15 MEDICAL APPLICATIONS
George Wypych
ChemTec Laboratories, Inc., Toronto, Canada
Industries manufacturing medical devices use a wide variety of technological processes
which most likely take advantage of most of the available solvents. The range of solvent use
is so wide that a complete description of each solvent and its application is not possible in
this book. It is questionable if such analysis is possible given that many processes are
guarded by trade secrets where there is no patent disclosure. Some examples are given,