Inert gases such as nitrogen and argon are commonly used in our laboratories. If the contents of a cylinder were suddenly released into the laboratory atmosphere, the oxygen content of the air could be reduced below the safe 19.5% level necessary to avoid hypoxia in lab occupants.
Find out how to determine if a worst-case release of inert gas can reduce oxygen concentrations below safe levels and what you can do about the risk in this Safety Note: Inert Gas Safety.
Do you dispose of different types of chemicals? If so, you run the risk of mixing incompatible chemicals together in your waste containers. Refer to this chart (EPAChemicalCompatibilityChart) to help determine what you can put in the same waste container. The chart is fairly complex, but the topic is also fairly complex. Always be sure to use secondary references such as Safety Data Sheets to verify that your chemicals are compatible–the EPA chart is general, not specific.