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Review your hazardous waste

Permit Primer

Review all of your wastes to determine if any of your wastes are exempt. Please click on "Some exempt wastes" below to review a list of common exempt wastes. If appropriate, check the Exempt box on your waste inventory sheets.

Some exempt wastes

Some businesses may generate wastes that are exempt or conditionally exempt from regulation as hazardous waste. Please review the following list of materials and refer to the specific code citations to determine if your waste is eligible for an exemption from the hazardous waste rules or reduced regulation.

Exempt or conditionally exempt

  • Empty containers that previously held non–acute hazardous waste. See s. NR 661.0007, Wis. Adm. Code.
  • Wastes that are discharged directly to a publicly owned treatment works (POTW) without being stored or accumulated first. The POTW must be notified of this discharge and the requirements of the POTW must be complied with. Wastes which are trucked to a POTW are not excluded. See s. NR 661.0004(1), Wis. Adm. Code.
  • Non–terne–plated used oil filters that have been gravity hot-drained. See s. NR 661.0004(2)(m), Wis. Adm. Code.

Reduced regulations

Is your waste listed?

There are specific wastes that are classified as hazardous in the regulations. The listed hazardous wastes can be found in four tables in section NR 661 Subchapter D, Wis. Adm. Code (see link below). Tables I and II list hazardous wastes that differ in terms of their sources (the processes that generate them). In contrast, Tables IV and V list unused chemicals that differ in terms of their toxicity.

The following list contains known hazardous wastes. Compare the listed wastes below with those on your inventory sheets. Then check the Hazardous Waste box on your waste inventory sheets.

Refer to section NR NR 661 Subchapter D — Lists of Hazardous Wastes for more information.

Is your waste ignitable?

Ignitable means a liquid with a flash point less than 140 degrees Fahrenheit (check the MSDS or lab analysis report), an ignitable compressed gas or oxidizer, or other material that can cause fire through friction, absorption of moisture or spontaneous chemical changes. For example, many solvents and some paint filters are ignitable.

Even if your waste is not on a list, it may be hazardous because it exhibits one of four characteristics: ignitability, corrosivity, reactivity, or toxicity. Review all of your wastes to determine if they are ignitable. If they are ignitable, then check the Hazardous Waste box on your waste inventory sheets. Examples include paint wastes, certain nonchlorinated degreasers or other solvents, adhesives, thinners, and mineral spirits.

Note: Solvents with higher flash points (>140 degrees F) or aqueous alkaline cleaning solutions (detergents) have become available for small parts washers as an alternative to mineral spirits. If appropriate, this substitution could reduce your hazardous waste disposal fees.

Check your MSDS, the product's label or contact your supplier to help you make a determination. Check out the NIOSH Guide to Chemical Hazards to assist in determining the flash point of chemicals you have at your business.

Is your waste corrosive?

Corrosive means a water containing liquid with a pH of 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 millimeters per year. Examples include waste rust removers, waste acid or alkaline cleaning fluids, and waste battery acids.

Review all of your wastes to determine if they are corrosive. If they are corrosive, then check the Hazardous Waste box on your waste inventory sheets.

Consult the SDS, the product's label or your supplier to help you make a determination. Check out the NIOSH Guide to Chemical Hazards to assist in determining the corrosivity of chemicals you have at your business.

Is your waste reactive?

Reactive means a waste that is normally unstable, readily undergoes violent changes without detonating, reacts violently with water, forms potentially explosive mixtures with water, or generates toxic gases or fumes when mixed with water or noncorrosive materials, is capable of detonation or explosive reaction, or is a forbidden Class A or Class B explosive. Examples include cyanide plating wastes, sulfide containing wastes and waste toluene disocyanate.

Review all of your wastes to determine if they are reactive. If they are reactive, then check the Hazardous Waste box on your waste inventory sheets.

Consult the SDS, the product's label or your supplier to help you make a determination. Check out the NIOSH Guide to Chemical Hazards to assist in determining the reactivity of chemicals you may have at your business.

Is your waste toxic?

Toxic means a waste that EPA has determined has toxic characteristics. A waste is toxic if it exceeds the regulatory levels for any of the eight metals, six pesticides or 25 organic compounds listed below.

Review all of your wastes to determine if they are toxic. If they are toxic, then check the Hazardous Waste box on your waste inventory sheets.

Toxicity is determined using a test called the toxicity characteristic leaching procedure (TCLP) which simulates how a chemical would act if deposited in a landfill. If your wastes contain an unknown concentration of any of the following contaminants you should review your records, contact similar businesses or contact the manufacturer to determine if TCLP data exists on the waste in question. If no data is available, you may need to have a TCLP test conducted by a laboratory.

There are specific wastes that are classified as hazardous in the regulations. There are criteria that establish whether your waste is hazardous. It is either listed or it meets one of four characteristics: ignitable, corrosive, reactive and toxic. Review those criteria in the drop downs below.

Contaminant Regulatory level (mg/L) Contaminant Regulatory level (mg/L)
Metals
arsenic 5.0 barium 100.0
cadmium 1.0 chromium 5.0
lead 5.0 mercury 0.2
selenium 1.0 silver 5.0
Pesticides
chlordane 0.03 2,4–D 10.0
endrin 0.02 heptachlor (and its epoxide) 0.008
lindane 0.4 methoxychlor 10.0
toxaphene 0.5 2,4,5–TP (silvex) 1.0
Semi–volatiles
o–cresol 200.0 m–cresol 200.0
p–cresol 200.0 cresol 200.0
1,4–dichlorobenzene 7.5 2,4–dinitrotoluene 0.13
hexachlorobenzene 0.13 hexachlorobutadiene 0.5
hexachloroethane 3.0 nitrobenzene 2.0
pentachlorophenol 100.0 pyridine 5.0
2,4,5–trichlorophenol 400.0 2,4,6–trichlorophenol 2.0
Volatiles
benzene 0.5 carbon tetrachloride 0.5
chlorobenzene 100.0 chloroform 6.0
1,2-dichloroethane 0.5 1,1-dichloroethylene 0.7
methyl ethyl ketone 200.0 tetrachloroethylene 0.7
trichloroethylene 0.5 vinyl chloride 0.2

If you do need laboratory services, please refer to the Wisconsin Lists of Accredited Laboratories.

When finished, continue on to the next page for the interactive questionnaire to help you learn whether your wastes might be hazardous.

Contact information
DNR Hazardous waste staff