Correct Response: C. Excess chemicals need to be disposed of properly according to state, federal, and science safety guidelines. Chemicals not disposed of properly may be hazardous to the people in the laboratory and the environment. If the chemical is returned to the original stock (A), it has the potential of contaminating the entire stock. The Material Safety Data Sheet (B) provides information about the chemical, including the proper method of storage and disposal, but it is not a reporting form. Setting a chemical substance aside (D), even if properly labeled, is not an appropriate method of dealing with the excess chemical since it can become contaminated with other substances used in the laboratory or can react with the air while exposed.
