The Effect of Disinfection with Quarternary Ammonium Salt Solution on Paper

In the conservation treatment of paper antiquities infected with mold, disinfection is of primary importance. Many methods have been used for this purpose. Fumigation with ethylene oxide and with other fungicidal vapors, such as p-chlor-m-cresol or dichlorophen has been employed. Disinfection with ethylene oxide of single prints, maps or books requires expensive vacuum chambers, which are usually not available in small conservation laboratories. Therefore a simple chemical treatment, which can disinfect paper artifacts without degrading them, would fill a long-felt conservation need. Such a method of disinfection by a quarternary ammonium salt (quas) solution bath was performed in our laboratory. In this method, Sterinol (10% water solution of dimethylLaurylbenzyI ammonium bromide, POLFA, Poland) is used. It was found that a 15 min warm bath containing 0.75-1.0% of the above mentioned pure ammonium salt causes effective disinfection of the most badly molded paper objects (black/white) such as book sheets, prints, maps, etc. This technique easily removes dirt and fungal deposits from paper. The surface active properties of this compound were considered. After the disinfecting bath in the above ammonium salt solution the disinfected material should be thoroughly washed with tap water and subsequently 3 times with distilled water. It was mentioned by Browning that quarternary ammonium compounds are used for disinfection of paper pulp during milling and also for protection of the final product against the development of microorganisms. The concentration of these compounds in the paper may reach 0.5%. Sykes found that these salts are especially easily adsorbed by materials of well developed surfaces like paper, charcoal, etc. Triolo et al. studied the effect of Cequartyl BE (lauryldimethylcarbetoxymethyl ammonium bromide) on paper. They stated that the above compound induces a dangerous acidity of the paper (pH 4.8). Cequartyl BE introduced into the paper in a concentration of 3% caused an unfavorable decrease in the degree of cellulose polymerization, although it did not appreciably affect its brightness. The neutralization of a Cequartyl BE solution with sodium hydroxide diminished this harmful effect. The above authors are of the opinion that the com-