What is a hazardous waste?
A hazardous waste is a waste that poses a potential hazard to human health or the environment when improperly handled. The most commonly used solvents in the dry cleaning industry are:
• perchloroethylene (also known as tetrachloroethylene or "perc"');
• petroleum solvents; and
• trichloroethane.
During the cleaning, extraction and drying process, dry cleaners may produce one or more of the following wastes:
• filters and filter media;
• separator water;
• spent solvents and solvent containing rags (from spill cleanup);
• spent carbon and cartridges from carbon adsorbers; and
• still residues and muck.
Most dry cleaners generate hazardous waste. Hazardous wastes are classified into two types: listed and characteristic.
Listed hazardous wastes are listed by name or process in the Code of Federal Regulations Chapter 261, and in Ohio's Hazardous Waste Management Rules, Ohio Administrative Code Chapter 3745-51. For example, perc used in dry cleaning is a listed hazardous waste with a hazardous waste code of F002 when spent. Perc has the waste code U210 as a pure commercial chemical product if discarded prior to use. Spill residues from the cleanup of perc product spills are also considered to be U210 hazardous waste.
Any other waste coming in contact with a listed waste also becomes a listed waste by virtue of the "mixture rule." This includes wastes such as filters, filter media, still residue (sludge), and filter powder (muck) containing perc.
A characteristic waste exhibits one or more of the four hazardous characteristics (ignitability, reactivity, corrosivity and toxicity). For example, a waste solvent exhibits the characteristic of ignitability if it has a flashpoint below 140 degrees F.
The characteristic of toxicity is determined by use of the Toxicity Characteristic Leaching Procedure (TCLP). This analytical test simulates the acidic conditions found in a landfill and determines how much of certain regulated substances would leach from the waste if placed in a landfill. Regulatory levels are set for 39 hazardous constituents in terms of parts per million, and any waste exceeding these levels is a toxic hazardous waste.
Perc, for example, is one of the 39 hazardous constituents. Any waste which contains 0.7 parts per million or more of perc is considered to be a D039 toxic hazardous waste.