According to the EPA, a hazardous waste is either listed in one of the several lists prepared by the EPA, or, it exhibits one or more of the following characteristics: ignitable, reactive, corrosive, or toxic. If wastes exhibit any of these characteristics, they are regulated as hazardous, and arrangements for disposal must be made with EHSO. The two lists that are most likely to contain names of chemicals found on Miami's campuses are the P-list and the U-list, both are provided in this appendix. Many chemicals are not considered hazardous waste using the "Listed Waste" or "Characteristic Waste" criteria. However, these chemicals may be at least moderately toxic, moderately corrosive or combustible and should be collected by EHSO to ensure safe handling and disposal. No chemical or chemical mixture should be poured down the drain or thrown in the trash unless the user is sure that the material is inert or innocuous and has approval for the disposal from EHSO.

Ignitable Waste

Any liquid waste having a flashpoint of less than 140o F is considered an ignitable hazardous waste. A flashpoint can generally be determined by reference to the container label, a material safety data sheet, a chemical reference manual, or testing. The following are examples of ignitable wastes: ethyl ether, methanol, ethanol, acetone, toluene, benzene, pentane, hexane, and xylene. Solids are also regulated as ignitable waste if the material is capable of ignition through friction, moisture absorption, or spontaneous chemical changes and burns so vigorously and persistently as to create a hazard. Many commercial products may also exhibit the characteristic of ignitability. Oxidizers are also considered ignitable hazardous wastes.

Corrosive Waste

Any waste with a pH less than 2.0 or greater than 12.5 or which corrodes steel at a rate greater than 6 mm per year is regulated as a corrosive waste. Wastes in this category include many acids and bases. The following are examples of corrosive wastes: sulfuric acid, ammonium hydroxide, nitric acid, sodium hydroxide, and hydrofluoric acid.

Reactive Waste

Any waste that is shock-sensitive, violently unstable, reacts violently with air or water, or generates cyanide or sulfide gases is regulated as a reactive waste. Some common chemicals which are classified reactive are: picric acid and other polynitroaromatics, old ethers and other peroxide forming organics, organic peroxides, ammonium perchlorate and metal perchlorates, and metal amides and azides.

Toxic Waste

Any waste, which equals or exceeds a designated concentration of certain toxic compounds is regulated as a characteristically toxic hazardous waste. The test to determine these concentrations is known as the TCLP (Toxicity Characteristic Leaching Procedure). It determines the amount of the toxic compound that leaches from the waste, simulating what could leach into the environment from an improperly disposed waste. The extraction procedure is a standardized laboratory test that requires specialized equipment. Therefore wastes with any of the TCLP compounds are assumed to be toxic. These compounds include the heavy metals such as lead, chromium, and barium as well as many organic materials and a group of pesticides. Some commercial products may exhibit the characteristic of toxicity through the TCLP testing procedure.