Excellence in research, education and environmental health and safety is of primary importance at University of Pennsylvania. In support of this activity, the Office of Environmental Health and Radiation Safety (EHRS) provides for the proper disposal of hazardous waste.
The University policy is zero tolerance for non-compliance with Environmental Regulations. The enclosed procedures must be followed to comply with rules from the U.S. Environmental Protection Agency (EPA) and the Pennsylvania Department of Environmental Protection (DEP) which regulate the disposal of hazardous wastes in a cradle-to-grave fashion.
Potentially Hazardous chemicals must be disposed of in accordance with federal and state regulations and procedures established by EHRS. Your department may also have procedures that you are required to follow. Contact your supervisor, instructor or EHRS before discarding of any potentially hazardous chemical.
The following guidelines will assist waste collection:
These are locations within laboratories where chemical wastes are collected and properly stored until they are picked up by EHRS.
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Hazardous materials have hazardous characteristics such as: flammable, corrosive, reactive, toxic, radioactive, poisonous, carcinogenic or infectious. In a general sense, these materials are considered hazardous because they present a potential risk to humans and/or the environment. A waste is a basically any discarded material. By law a hazardous waste is defined as a waste, or combination of wastes, that because of its quantity, concentration, or physical, chemical or infectious characteristics may cause or significantly contribute to an increase in serious irreversible, or incapacitating reversible illness or pose a substantial present or potential hazard to human health, safety or welfare or to the environment when improperly treated, stored, transported, used or disposed of or otherwise managed. Hazardous waste management plans generally separate waste into three broad groups: radioactive, chemical and biological. This guide addresses only chemical waste.
Hazardous waste includes a wide range of material such as discarded commercial chemical products, process wastes and wastewater. Some chemicals and chemical mixtures are hazardous wastes because they are specifically listed by the EPA. Most of the common laboratory solvents are listed wastes. A chemical waste that is not listed by the EPA is still a hazardous waste if it has one or more of EPA's four hazardous characteristics: ignitablity, corrosivity, reactivity or toxicity.
A chemical waste is considered to be a hazardous waste if it is specifically listed by the EPA or DEP as a hazardous waste or if it meets any of the four hazardous characteristics below. If a chemical waste is not on the EPA list of hazardous wastes, and does not meet any of the hazardous waste characteristics, it is a nonhazardous waste. For complete definitions of hazardous characteristics of waste see the EPA regulation 40 CFR 261-Identification and Listing of Hazardous Waste.
A liquid which has a flash point of less than 60°C is an ignitable waste (e. g. Acetone, Methanol). A solid is an ignitable waste if it is capable of causing fire through friction or absorption of moisture, or can undergo spontaneous chemical change which can result in vigorous and persistent burning under standard temperature and pressure (e. g. Benzoyl Peroxide). A substance which is an ignitable compressed gas or oxidizer is an ignitable waste (e. g. Propane, Hydrogen Peroxide).
An aqueous solution which has a pH less than or equal to 2 or greater than or equal to 12.5 (e.g. Hydrochloric Acid, Ammonium Hydroxide),or is a liquid and corrodes steel at a rate greater than 6.35 mm per year at a test temperature of 55°C, is a corrosive waste.
A reactive waste is a material that is normally unstable and undergoes violent chemical change without detonating, can react violently with water to form potentially explosive mixtures or can generate dangerous or possibly toxic gases, vapors or fumes in a quantity sufficient to present a danger to public safety, health or welfare or to the environment; or a material that is capable of detonation or explosive decomposition or reaction at standard temperature (e. g. Picric Acid, Potassium Cyanide, Lithium Aluminum Hydride).
A waste that contains one of the constituents in concentrations equal to or greater than the values listed in EPA regulation 40 CFR 261-Identification and Listing of Hazardous Waste is a toxic waste.
A hazardous waste can also be classified as either a process waste or a discarded commercial chemical product. This distinction is important when manifesting and labeling. A process waste is any waste that, by virtue of some use, process or procedure, no longer meets the manufacturer's original product specifications. Examples of process wastes are chromatography effluents, diluted chemicals, reaction mixtures, contaminated paper, etc.
A discarded commercial chemical product is the original (virgin) material, in the original container. Examples are small bottles of unused or outdated chemicals from laboratories, darkrooms, or service areas.
Laboratories and other areas that generate hazardous waste are required to comply with the generator requirements of the Resource Conservation and Recovery Act (RCRA, CFR Title 40) and Pennsylvania Hazardous Waste Management Regulations (25 PA Code ß 260-270). Every generator site (laboratory) is subject to inspection by the EPA and DEP. The steps necessary for compliance are summarized below.
Reagents in their original containers with legible manufacturer's labels require no additional labeling or packaging.
Each container must be labeled with Penn Chemical Disposal Label. When the container is full place the date when full on the label. Plan ahead and contact EHRS to arrange for a waste pick-up.
Figure 2

EHRS provides white polyethylene 19 liter waste containers for labs that produce large volumes of compatible liquid wastes (See Figure 3). If your lab produces more than eight liters of any solvent mixture per month, call EHRS to request a container.
Figure 3: 19 liter carboy with chemical waste label

The following chart is provided as a guide to segregating hazardous waste containers, it is not to be used for mixing chemicals. Containers of incompatible wastes must be stored in separate areas. Tubs are available from EHRS. Call (215) 898-4453 for any questions or assistance.
Many hazardous wastes, when mixed with other waste or material, can produce effects which are harmful to human health and the environment, such as (1) heat or pressure, (2) fire or explosion, (3) violent reaction, (4) toxic dusts; mists, fumes, or gases, or (5) flammable fumes or gases.
Below are examples of potentially incompatible wastes, waste components, and materials, along with the harmful consequences which might result from mixing material in one group with material in another group. The list is intended only as a guide to indicate the need for special precautions when managing these potentially incompatible waste materials or components.
This list is not intended to be exhaustive. A laboratory director shall, as regulations require, adequately analyze his or her wastes so that he can prevent creating uncontrolled substances or reactions of the type listed below, whether they are listed below or not. In the lists below, the mixing of a Group A material with a Group B material might have the potential consequences as noted.
| Group 1-A | Group 1-B |
|---|---|
|
Alkaline Liquids |
Acid Liquids |
Potential consequences: Heat generation, violent reaction
| Group 2-A | Group 2-B |
|---|---|
|
Aluminum |
Wastes in Group 1-A or 1-B |
|
Beryllium |
|
|
Calcium |
|
|
Magnesium |
|
|
Sodium |
|
|
Other reactive metals and metal hydrides |
|
Potential consequences: Fire or explosion generation of flammable hydrogen gas
| Group 3-A | Group 3-B |
|---|---|
|
Alcohols |
Concentrated waste in Groups 1-A or 1-B |
|
Water |
Calcium |
|
|
Lithium |
|
|
Metal hydrides |
|
|
Potassium |
|
|
SO2Cl2, SOCl2, PCl3, CH3SiCl3 |
|
|
Other water-reactive wastes |
Potential consequences: Fire, explosion, or heat generation; generation of flammable or toxic gases.
| Group 4-A | Group 4-B |
|---|---|
|
Alcohols |
Concentrated Group 1-A or 1-B wastes |
|
Aldehydes |
Group 2-A wastes |
|
Halogenated hydrocarbons |
|
|
Nitrated hydrocarbons |
|
|
Unsaturated hydrocarbons |
|
|
Other reactive organic compounds and solvents |
|
Potential consequences: Fire, explosion, or violent reaction.
| Group 5-A | Group 5-B |
|---|---|
|
Spent cyanide and sulfide solutions |
Group 1-B wastes |
|
|
|
Potential consequences: Generation of toxic hydrogen cyanide or hydrogen sulfide gas
| Group 6-A | Group 6-B |
|---|---|
|
Chlorates |
Acetic acid and other organic acids |
|
Chlorine |
Concentrated mineral acids |
|
Chlorites |
Group 2-A wastes |
|
Chromic acid |
Group 4-A wastes |
|
Hypochlorites |
Other flammable and combustible wastes |
|
Nitrates |
|
|
Nitric acid, fuming |
|
|
Perchlorates |
|
|
Permanganates |
|
|
Peroxides |
|
Potential consequences: Fire, explosion, or violent reaction.
Each principal investigator or supervisor should evaluate methods to reduce waste volume and toxicity. You are to substitute non-hazardous or less toxic materials whenever possible. You are to purchase only the amount of chemical that is actually needed. Excess chemicals often become waste and any purchase savings are outweighed by disposal costs. Check with other laboratories in your department to see if they may be able to use any chemicals that you no longer need.
All personnel who handle hazardous waste in laboratories will receive training on proper waste handling procedures and emergency response procedures. Initial training must be completed during the first six months of employment; refresher training is provided annually thereafter. Hazardous waste training will be conducted as part of the annual laboratory safety training. Additional training sessions can be arranged by calling EHRS.
All chemicals must be identified and containers properly labeled at all times. Each laboratory director is responsible for seeing that this requirement is met in their laboratories.
If an unknown chemical is discovered, label it as "unknown" and attach a note detailing any information about what the chemical may be or what experiment it may have been used for and where it was found. Contact EHRS for disposal.
If you find any unlabeled chemical that has crystallized or there is any other indication that it may be unstable, DO NOT TOUCH IT! Contact EHRS (215) 898-4453 immediately.
Generally empty chemical containers are not considered hazardous waste. The container must be completely empty, that is all of the contents that can be removed by normal means must be removed and the residue must be less than 1%. The word "empty" must be written across the label. The container may then be disposed of in the regular trash.
An exception to the above applies to containers that held chemicals listed by the EPA and PADEP as "Acutely Hazardous Wastes". The most common laboratory chemicals found on this list are:
A complete list of the Acutely Hazardous Wastes can be found the EPA regulation 40 CFR 261-Identification and Listing of Hazardous Waste. Empty containers that formerly held any of these Acutely Hazardous Wastes in the pure unused form, not mixtures or spent material, must be disposed of as hazardous waste.
Mutagens and carcinogens are used extensively in laboratories. A list of the most commonly used chemicals in this category is provided in the following table. (Remember this is not a comprehensive list.) Mutagen or carcinogen waste in solid form or concentrated solution is hazardous chemical waste and must not be thrown in the trash or down the drain. Call or email the Office of Environmental Health and Radiation Safety (ehrs@ehrs.upenn.edu) to arrange for pick-up of your hazardous waste or if you need more information.
Segregate and store your waste as follows:
| Chemical | CAS Number | Chemical | CAS Number |
|---|---|---|---|
| 1,2-Dibromo-3-chloropropane | 96-12-8 | 2-Aminofluorene | 153-78-6 |
| 1,1-Dimethylethylenimine | Benz[a]anthracene | 56-55-3 | |
| Ethylenedibromide | 106-93-4 | Benzo[a]pyrene | 50-32-8 |
| Propylenimine | 75-55-8 | Chlorambucil | 305-03-3 |
| Ethionine | 67-21-0 | Cycasin | 14901-08-7 |
| 3'-methyl-4-amino-azobenzene | Diazomethane | 334-88-3 | |
| Urethane | 51-79-6 | Dibenz[a,h]anthracene | 53-70-3 |
| Bromoethylmethanesulfonate | 7,12-Dimethylbenz[a]anthracene | 57-97-6 | |
| Chloromethylmethylether | 107-30-2 | 4-Dimethylaminazobenzene | 60-11-7 |
| Diepoxybutane | 1464-53-5 | 3-3'-Dimethylbenzidine | 612-82-8 |
| Dimethyleaminobezene | 60-11-7 | 1,4-Dinitrosopiperazine | 140-79-4 |
| 1,1-Dimethylhydrazine | 57-14-7 | N-Hydroxy-2-acetylaminofluorene | |
| 1,2-Dimethylhydrazine | 540-73-8 | 3-Methylcholanthrene | 56-49-5 |
| Ethidium Bromide | 1239-45-8 | 4,4'-Methylenebis(2-chloroaniline) | 101-14-4 |
| Ethylmethanesulfonate | 62-50-0 | Methyazomethyl acetate | 5926-62-1 |
| Hydrazine | 302-01-2 | 1-Methyl-3-nitro-1-nitrosoguanidine | 70-25-7 |
| Methylhydrazine | 60-34-4 | 1-Naphthylamine | |
| Methylmethanesulfonate | 66-27-3 | N-[4-(5-Nitro-2-furyl)-2-thiazoyl]-formamide | |
| N-Nitorsodiethylamine | 55-18-5 | N-Nitroso-N-ethylurea | |
| N-Nitrosodimethylamine | 62-75-9 | N-Nitroso-N-methylurea | 684-93-5 |
| N-Nitrosodi-n-butylamine | 924-16-3 | 4-Nitroquinoline-1-oxide | 56-57-5 |
| N-Nitrosodi-n-propylamine | 621-64-7 | Procarbazine | 366-70-1 |
| N-Nitroso-N-ethylurethane | 1,3-Propanesultone | 1120-71-4 | |
| N-Nitroso-N-methylurethane | 615-53-2 | m-Toluenediamine | 95-80-7 |
| N-Nitrosopiperidine | 100-75-4 | Uracil mustard | 66-75-1 |
| Polychlorinatedbiphenyls | 11141-16-5 | 4-Aminobiphenyl | 92-67-1 |
| β-Propiolactone | 57-57-8 | Benzidine | 92-87-5 |
| N-Acetoxy-2-acetylaminofluorene | 3,3'-Dichlorobenzidine | 91-94-1 | |
| 2-Acetylaminofluorene | 53-96-3 | 3,3'-Dimethoxy-benzidine | 20325-40-0 |
| Aflatoxins- | 1162-65-8 | 2-Naphthylamine | 91-59-8 |
| Methylnitrosourea | |||
| 17β-estradiol | |||
| ø-Aminoazotoluene | 97-56-3 | 4-Nitro-biphenyl |