All hazardous substances are hazardous wastes.

The statement is false because not all hazardous substances qualify as hazardous wastes. Hazardous substances are materials that can pose a risk to health or the environment due to their chemical properties, but they only become hazardous wastes when they are no longer usable and are discarded.

For example, a chemical in a laboratory may be classified as a hazardous substance due to its toxicity or reactivity. However, if that chemical is still in use or is being stored properly, it is not considered hazardous waste. It is only when that substance is disposed of, and it exhibits characteristics such as ignitability, corrosivity, reactivity, or toxicity, that it becomes classified as hazardous waste. This distinction is critical in understanding waste management protocols and regulatory compliance as outlined by the Resource Conservation and Recovery Act (RCRA) and other environmental regulations. Thus, while all hazardous wastes contain hazardous substances, the reverse is not true.