Amount of substance in use in chemical engineering in the United States is the pound-mole, having the symbol lb-mol. One pound-mole is . When quoting an amount of substance, it is necessary to specify the entity involved, unless there is no risk of ambiguity. One mole of chlorine could refer either to chlorine atoms, as in 58.44 g of sodium chloride, or to chlorine molecules, as in 22.711 liters of chlorine gas at STP. The simplest way to avoid ambiguity is to replace the term "substance" by the name of the entity or to quote the empirical formula. For example: Amount of substance
Aroma compound substance is not safe on the EPA. The EPA, however, does not conduct independent safety testing but relies on data provided by the manufacturer. In 2010 the International Fragrance Association published a list of 3,059 chemicals used in 2011 based on a voluntary survey of its members. It was estimated to represent about 90% of the world's production volume of fragrances. Aroma compound An aroma compound, also known as an odorant, aroma, fragrance, or flavor, is a chemical compound that has a smell or odor. A chemical compound has a smell or odor when it is sufficiently volatile to be