Melanie is working in a laboratory and spills a bottle of reagent which sources would most likely tell her how to clean the spilled regeant

The lab teacher would be one resource that could be asked, since they are likely experienced in the use and disposal of the reagent. Also, in other instances, the Material Safety Data Sheets could be accessed, since they will have all the steps required for handling, disposal, and cleaning of the reagent, and any hazards that need to be accounted for in the cleaning-up process.