Hazardous Waste Program fact sheet
Division of Environmental Quality Director: Ed Galbraith

This fact sheet provides general information to help pesticide applicators determine whether their leftover, un-wanted pesticide is solid waste or hazardous waste and how to properly dispose of each type. Disposal is an important part of responsible pesticide use, as improperly disposed pesticide wastes can create serious hazards for human health and the environment. Businesses should refer to this fact sheet and Making the Decision to Discard a Pesticide Decision Tree as general guidance only and should review appropriate state and federal laws and regulations before making the ultimate decision of how to manage waste pesticides.   

Keep these tips in mind to reduce the need for waste pesticide disposal:

Regulatory Citations
The federal hazardous waste regulations are in the Code of Federal Regulations, Title 40, Part 260 through Part 280 (40 CFR 260-280). The Missouri Hazardous Waste Law is in the Revised Statutes of Missouri (RSMo), Sections 260.350-260.575. The hazardous waste rules are in the Code of State Regulations, Title 10, Division 25 (10 CSR 25).

What is a pesticide waste?
Pesticide waste is any material which contains any concentration of pesticide which has been declared a waste or can no longer be used for its intended purpose. This includes such things as: rinse material from containers and spray equipment, left over spray solutions, excess pesticides, empty containers and banned, canceled or suspended pesticides. 

Are all pesticide wastes considered hazardous wastes?
Under federal regulations, commercial chemical products such as pesticides become "solid wastes" and thus, potentially hazardous wastes, at the point when the pesticide's holder (i.e., end-user, dealer, distributor, or registrant) decides to discard them. If a pesticide product or the active ingredient of the product is listed in 40 CFR 261.31 or 261.33 (Table 1) or exhibits a hazardous waste characteristic identified in 40 CFR 261.21 through 261.24, it then becomes a hazardous waste at the point when its holder decides to discard it. Parts 261.21 through 261.24 identify the following criteria:  ignitability, corrosivity, reactivity or toxicity characteristic. Most hazardous waste pesticides fall into the toxicity criteria due to the toxic organic properties.

An environmental consultant or licensed hazardous waste disposal contractor can help in making the determination if a waste is hazardous and can help dispose of the unwanted pesticide. The Missouri Department of Natural Resources maintains a list of Missouri licensed hazardous waste transporters. The department also provides a Missouri Commercial Hazardous Waste Facilities list (PUB 968) of companies with permits to accept hazardous waste. It is always recommended to call several consultants/contractors when obtaining bids for disposal. 

More ways to help determine if a pesticide is a hazardous waste include:

How to dispose of pesticide classified as hazardous waste?
Businesses generating hazardous waste must follow federal and state laws and regulations, depending on the type and amount of hazardous waste generated. Publications summarizing hazardous waste regulations include Handbook for Small-Quantity Generators (PUB 2174) and EPA’s guidance document, Typical Wastes Generated By Industry Sectors.

Determining how much hazardous waste pesticide is generated in any one month and accumulated at any one time is necessary information for determining generator requirements. Hazardous waste generator requirements can be found at 10 CSR 25-5.262 and a summary of the regulations can be found in a fact sheet titled Hazardous Waste Generator Status Guidance (PUB 2224). 

Disposal of a pesticide should be the last option remaining when dealing with unused pesticide. To avoid the problem of dealing with unused pesticide products, purchase only what can be used in one year. Also, before disposing of a pesticide try to give it to someone, provided the pesticide is in its original, fully labeled container, who can use it for its intended purpose or use up the product per label requirements – if the product is still legal to use. If you cannot find someone who can use the pesticide and you no longer have a use for the product, below are options for disposing of an unwanted hazardous waste pesticide. 

Pesticide Container Disposal
In addition to label requirements, some pesticide containers must meet the requirements set forth in 40 CFR 261.7, Residues of Hazardous Wastes in Empty Containers, to be considered empty. Empty containers that once stored pesticide classified as hazardous waste versus containers that stored pesticide not classified as hazardous waste may require different treatment methods for declaring the container empty. After the container is made empty according to 40 CFR 261.7 standards, the container can be punctured and then disposed of in a permitted solid waste landfill.

A viable option to disposing of empty pesticide containers (per 40 CFR 261.7) in a landfill is to recycle them. Some pesticide manufacturers may take back empty pesticide containers. Furthermore, some non-profit organizations receive money from pesticide manufacturers to provide free pesticide container recycling programs throughout the United States.       

Disposal of Pesticides Not Classified As Hazardous Waste
If you are absolutely certain the pesticide is not classified as a hazardous waste the pesticide may be solidified and placed into the sanitary landfill if the landfill chooses to accept it. However, because all pesticides are made to destroy insects or other organisms harmful to cultivated plants or to animals, disposal should be done in a professional manner preferably following the hazardous waste or universal waste laws and regulations.

A listing of the pesticides from 40 CFR 261.31 through 40 CFR 261.33 is provided below in Table 1. Please note the table may not include all hazardous waste pesticides. Table 1 includes various Hazardous Waste Codes (RCRA #) that have special meanings and are defined as follows:

F-List hazardous wastes from nonspecific sources (40 CFR 261.31)
P-List acutely toxic hazardous wastes from specific sources (40 CFR 261.33(e))
U-List toxic hazardous wastes and other commercial chemical products (40 CFR 261.33(f))
Toxicity characteristic hazardous wastes that meet or exceed the regulatory level listed in the table (as shown by laboratory analysis)

Table 1.  Pesticides in parts 261.31 and 261.33

Pesticide/Chemical CAS # RCRA # Toxicity Characteristic # Regulatory Level (mg/L)
1,1,1-Trichloroethane 71-55-6 U226    
2,4-D, Salts, Esters and Acids Various U240 D016 200.00
2,4,5-T, Salts, Esters and Acids Various F027
A-Naphthylthiourea (ANTU) 86-88-4 P072
Acrolein 107-02-8 P003
Aldicarb 116-06-3 P070
Aldrin 309-00-2 P004
Allyl Alcohol 107-18-6 P005
Aluminum Phosphide 1302-45-0 P006
Aluminum Phosphide 20859-73-8 P006
Aluminum Phosphide 1302-45-0 P006
Amitrole 61-82-5 U011
Arsenic Trioxide 1327-53-3 P012
Arsenic Acid 7778-39-4 P010
Arsenic Pentoxide 1303-28-2 P011
Avitrol 504-24-5 P008
Cacodylic Acid 75-60-5 U136
Calcium Cyanide 592-01-8 P021
Carbon Tetrachloride 56-23-5 U211
Carbon Disulfide 75-15-0 P022
Chlordane 57-74-9 U036 D020 0.03
Chlordecone 143-50-0 U142
Chlorobenzene 108-90-7 U037 D021 100.00
Chlorobenzilate 510-15-6 U038
D-D (1,2-Dichloropropane) 8003-19-8 U083
DDD 72-54-8 U060
DDT 50-29-3 U061
Diallate 2303-16-4 U062
Dibromochloropropane (DBCP) 96-12-8 U066
Dieldrin 60-57-1 P037
Dimethoate 60-51-5 P044
Dinoseb 88-85-7 P020
Disulfoton 298-04-4 P039
Endosulfan 115-29-7 P050
Endothall Disodium 129-67-9 P088
Endrin 72-20-8 P051 D012 0.02
Erbon 136-25-4 F027
Ethylene Dibromide 106-93-4 U067
Famphur 52-85-7 P097
Fluoracetamide/1081 640-19-7 P057
Fluoracetamide 640-19-7 P057
Formaldehyde 50-00-0 U122
Furfural 98-01-1 U125
Heptachlor 76-48-8 P059 D031 0.008
Hexachlorobenzene 118-74-1 U127
Isodrin 465-73-6 P069
Kepone 143-50-0 U142
Lead Acetate 301-04-2 U144
Lindane 58-89-9 U129 D013 0.4
Maleic Hydrazide 123-33-1 U148
Methomyl 16752-77-5 P066
Methoxychlor 72-43-5 U247 D014 10.0
Methyl Bromide 74-83-9 U029
Methyl Parathion 298-00-0 P071
Nicotine 54-11-5 P075
Nitrobenzene 98-95-3 U169
OMPA, Schradan 152-16-9 P085
Orthodichlorobenzene 95-50-1 U070
Paradichlorobenzene 106-46-7 U072
Parathion 56-38-2 P089
Pentachlorophenol, Salts 7778-73-6 F027
Pentachlorophenol 87-86-5 U242 D037 100.00
Phenylmercuric Acetate (PMA) 62-38-4 P092
Phorate 298-02-2 P094
PMA 62-38-4 P092
Potassium Cyanide 151-50-8 P098
Procytox 50-18-0 U058
Pronamide 23950-58-5 U192
Safrole 94-59-7 U203
Silvex, Salts, Acids and Esters Various F027
Sodium Cyanide 143-33-9 P106
Sodium Pentachlorophenate 131-52-2 F027
Sodium Fluoroacetate 62-74-8 P058
Strychnine And Salts 60-41-3 P108
Strychnine Alkaloid 57-24-9 P108
Sulfotepp 3689-24-5 P109
Thallium Sulfate 7446-18-6 P115
Thiofanox 39196-18-4 P045
Thiram 137-26-8 U244
Toxaphene 8001-35-2 P123 D015 0.5
Warfarin 81-81-2 U248
Wood Creosote 8021-39-4 U051
Zinc Phosphide (<10%) 1314-84-7 U249
Zinc Pentachlorophenate 2917-32-0 F027
Zinophos 297-97-2 P040    

Additional Information
EPA Guidance document, Typical Wastes Generated by Industry Sectors
Handbook for Small-Quantity Generatory* (PUB 2174)
Hazardous Waste Generator Registration, Reporting and Waste Fees* (PUB 2254)
Hazardous Waste Generator Status Guidance* (PUB 2224)
Licensed Hazardous and Infectious Waste Transporter List*
Make the Decision to Discard a Pesticide Decision Tree Z:\env\hwp\docs\16.01 HWP - Decision Tree 3.pdf
Making a Hazardous Waste Determination (PUB 919)
Managing Conditionally Exempt Small Quantities of Hazardous Waste* (PUB 128)
Missouri Commercial Hazardous Waste Facilities List* (PUB 968)
The Universal Waste Rule in Missouri* (PUB 2058)
Pesticide Collection Web page
Code of Federal Regulations  
Missouri Code of State Regulations for Department of Natural Resources
Missouri Revised Statutes