Toxicity, general relative

Use of Sodium Amalgam. Reductive desulfonylation with metal amalgams, and particularly Na/Hg (5-6%), is the most widely employed and general method for all types of sulfones even though it requires the handling of substantial quantities of mercury, which is toxic and relatively expensive. 

Waterborne dispersions containing poly(vinyl acetate) are widely used as adhesives for wood or wood-based materials. Their success can be attributed to several factors such as easy application, non-flammability, low toxicity and relatively low cost. In fact, high temperatures are generally not required to dry these adhesives, their shelf-life is long and water can be used to remove the residual product from tools. Furthermore, these adhesives show an extremely low toxicity profile due to the presence of water as dispersing medium and to the very low content of volatile organic compounds (VOCs). 

The toxic nature of mercury and its compounds has caused concern over environmental pollution, and governmental agencies have imposed severe restrictions on release of mercury compounds to waterways and the air (see Mercury). Methods of precipitation and agglomeration of mercurial wastes from process water have been developed. These methods generally depend on the formation of relatively insoluble compounds such as mercury sulfides, oxides, and thiocarbamates. MetaUic mercury is invariably formed as a by-product. The use of coprecipitants, which adsorb mercury on their surfaces facihtating removal, is frequent. 

Chemical Toxicity. Radiopharmaceuticals are subject to the same requirements for safety as are other pharmaceuticals, and are tested for chemical toxicity in much the same manner. It is generally understood, however, that patients are likely to receive relatively few doses of any given radiopharmaceutical so that the effects of long-term chronic exposure to the compound rarely need be assessed. Safety margins, that is, the ratio of the adininistered dose to the lowest dose that produces an observable effect, are usually on the order of 100 or more. 

---