Additional Recommendations from Other Organizations

All present industrial catalyst systems are based on silver deposited on a slightly porous solid. The most widely used support is x-alumina, but silica-alumina and carborundum can also be employed. The specific surface area of the support, its porosity, and the pore size exert a considerable influence on the metal distribution at the surface, and consequently on catalytic activity. Several techniques are also available for fixing the silver, either by impregnation from a solution, or by deposition from a suspension. An initiator, usually consisting of alkaline earth or alkaline metals, can be added to the catalyst, but other metallic additions have also been recommended. Certain halogenated organic derivatives, such as dichloropropane, may increase selectivity in trace amounts (10 ppm in the feed), by reducing combustion side reactions. 

Although the US is one of the few countries to have a formal system for monitoring adverse reactions from food additives as part of its regulatory structure, other countries also periodically review additives. In addition, the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO) also monitors food additives. Since 1956, the Joint FAO/WHO Expert Committee on Food Additives has developed specifications for the purity of additives, evaluated toxicological data, and recommended safe levels of use. 

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