3.3 Purchasing Chemicals
When ordering new chemicals, only order the amount of chemicals needed for the experiment being conducted. Do not order a larger size container for an experiment that will only last a semester or for an experiment that may occur in the future. Although chemicals usually cost less per unit when purchased in larger containers, when the actual usage, storage, and disposal are factored in, the cost savings diminishes significantly and may result in higher costs overall.
In addition, chemicals in large containers that are not used frequently can be rendered useless over time by contamination or degradation. In general, only order the minimum quantity of a chemical needed for the experiment, or one year’s worth of stock at the absolute most.