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Hazardous Waste

Hazardous Waste Disposal Guide

Once a material is deemed no longer useful and is ready for disposal it is necessary to consider whether it can be safely and legally put in a dumpster for landfilling, poured down the drain or set aside as a hazardous waste for special disposal.

Campus employees have a responsibility to manage their wastes appropriately not only because of the desire to protect our natural resources but also because of legal restrictions which control disposal. This guide is intended to provide you with the information you need to dispose of waste materials properly.

If you are unsure of correct disposal methods or have additional questions please call the University Safety Manager at 920-465-2273.

What is Hazardous Waste?

The Wisconsin statutes define waste as any liquid, solid, or gaseous material that can no longer be used for its originally intended purpose because it has become contaminated or has been used in some process. A waste is also any material which is still usable for its originally intended purpose but which you decide to discard. Regulations (Wisconsin Administrative Code Chapter NR 600) define a hazardous waste in two ways: listed hazardous waste and characteristic hazardous waste.

Listed Hazardous Wastes

These are specific wastes that are classified as hazardous in the regulations. These listed wastes are found in the four tables which have been reprinted in the appendix. Each listed waste has a hazardous waste number which starts with the letter "F", "K", "P", or "U."

  • "F" Waste - waste that results from production or waste treatment process, are discarded chemical products or are contaminated with a specific chemical.
  • "K" Waste - waste that results from specific production or waste treatment processes. The campus rarely has this type of waste.
  • "P" Waste - waste chemicals that are considered acutely hazardous when discarded because they can be extremely dangerous to human health or the environment. Cyanides and arsenic as well as some pesticides are found in this table. "P" wastes are of particular concern on the UWGB campus since a small quantity of this waste can make the difference between our classification as a large quantity generator versus a small quantity generator.
  • "U" Waste - waste which is considered toxic but not acutely hazardous. Examples include phenol, formalin, chlorobenzene, aniline dyes and carbon tetrachloride.

Characteristic Hazardous Waste

The majority of hazardous waste which the campus generates is characteristic hazardous waste. It is not included on any of the lists mentioned above but is considered hazardous because it exhibits one of the four characteristics mentioned below.

  • Ignitable - a liquid with a flash point less than 140 Fahrenheit, an ignitable compressed gas or oxidizer, or other material that can cause fire through friction absorption of moisture or spontaneous chemical changes, Common examples include used oil-based paint, used paint thinner, adhesives and mineral spirits.
  • Corrosive - a water containing liquid with a pH less than or equal to 2.0 or greater than or equal to 12.5, or a liquid that corrodes plain carbon steel at a rate greater than 6.35 mm per year. Examples include waste rust removers and waste battery acids.
  • Reactive - a waste that is normally unstable, readily undergoes violent changes without detonating, reacts violently with water, forms a potentially explosive mixture with water, or generates toxic gases or fumes when mixed with water or noncorrosive materials, is incapable of detonation or explosive reaction, or is a forbidden Class A or Class B explosive.
  • Toxic - A waste is TC hazardous if (according to the Toxicity Characteristic Leaching Procedure) it exceeds the regulatory levels for any of the eight metals, six pesticides or 25 organic chemicals listed in the appendix under toxic substances. This list includes metals like chromium, lead, mercury, silver and organic chemicals like benzene, chloroform, methyl ethyl ketone, and butadiene.

If you have a waste which is listed in one of the tables or exhibits one of the characteristics mentioned above, do not place it in a dumpster for landfill. Hazardous waste must be shipped with the campus hazardous waste shipment. Contact the University Safety Manager, ext. 2273, for proper disposal.

Empty Containers

Empty containers that formerly contained hazardous waste can be put in the dumpster for landfill. A container is empty if all waste has been removed by the methods commonly used to empty that type of container (e.g. pouring or pumping).In addition, the container must have less than one inch of waste remaining, or 3% or less by weight of waste remaining if the container holds 110 gallons or less or .3% or less by weight or waste remaining if the container holds more than 110 gallons. Containers that held acutely hazardous waste ("P" wastes) must be triple rinsed to be considered empty. Rinse water is considered hazardous if it has any of the characteristics mentioned above.


If you mix one gallon of a hazardous waste with one gallon of a nonhazardous waste you now have two gallons of hazardous waste and you have doubled the disposal costs. According to the mixture rule, nonhazardous waste that is mixed with listed hazardous waste is automatically hazardous waste. Therefore, do not mix your wastes. Dilution of characteristic hazardous waste to make it nonhazardous is considered treatment and is subject to regulatory requirements. The campus does not have a license to treat hazardous wastes. The only exception to the treatment restriction is simple neutralization which is discussed under sewer disposal.