Hazardous Waste Defined

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.

Classification of Chemical Waste

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.

Ignitable

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).

Corrosive

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.

Reactive

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).

Toxic

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.

Process wastes and discarded commercial chemical products

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.

Requirements for Hazardous Waste Management in the Laboratory

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.

• Weekly Inspections - items to be inspected are listed on the Satellite Accumulation Area poster. The Principal Investigator/Supervisor is responsible for assuring this inspection is done weekly.
  
• Segregation and Containment - the wastes must be separated by chemical compatibility groups. Each group of containers must be provided with appropriate secondary containment. Containment trays and tubs are available from EHRS. Additional information on compatibility is provided below.
  
• Storage - only one container per waste stream (type of waste) is allowed in a lab, i.e., one container for halogenated solvents, one container for non-halogenated solvents.
  
• Closed Containers - all containers must be closed at all times except when actually adding waste.

Labeling -

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.

Liquids (Small Quantities)

• You must provide your own collection container if you generate small quantities (<1 L a week) of hazardous liquid waste.
  
• Collect this waste in a labeled, plastic screw top container. Do not use glass bottles.
  
• Fill out the Penn Chemical Disposal Label (see Figure 2) when this container is full. Use chemical names on the label. Do not use formulas or abbreviations.
  
• Percentage concentrations are preferred to volumes.

Figure 2

Liquids (Large Quantities)

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.

• Always attach a chemical waste label and circle the appropriate waste stream before using the container. This tag identifies the contents of the container.
  
• Do not write on 19 L carboys with markers. Containers are reused and the markings cannot be removed.
  
• Leave two inches of empty space in the top of the 19 liter container and ensure that the rubber gasket inside the lid is in place. This will prevent leaks during transportation.
  
• Fill out the mixed-waste chemical disposal label - Penn Chemical Disposal Label (see Figure 2) when the container is full and attach it to the container.
  
• When the container is full complete the waste label by listing each chemical and its approximate concentration.

Figure 3: 19 liter carboy with chemical waste label

Chemical Compatibility

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.

Chemical Compatibility Chart

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.

Waste Minimization

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.

Training

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.

Disposal of Unknowns

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.

Empty Containers

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:

• Acrolein
• Allyl alcohol
• Compounds containing Arsenic
• Carbon Disulfide
• Compounds containing Cyanide
• 2,4, Dinitrophenol
• Nitric oxide
• Nitrogen dioxide
• p-Nitroaniline
• Osmium Tetroxide
• Phosgene
• Phosphine
• Sodium Azide
• Vanadium pentoxide

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.

Mutagen Carcinogen Policy

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:

1. Solutions:
   Small quantities of aqueous solutions containing < 10 ug/ml (10 ppm) may be flushed down the drain. Do not discard non-aqueous solutions down the drain. If you generate larger volumes of liquid waste you must store it in a leak proof, sealable polyethylene container for disposal as chemical waste. If organic solvents are used, note their names on the container. EHRS will provide five gallon containers for labs that generate large quantities of liquid waste. Do not mix solids or gels with solutions.
   
   
2. Contaminated sharps (needles, syringes, slides, broken glass, etc.)
   which contain mutagen/carcinogen residue must be discarded into an infectious waste sharps container clearly labeled "MUTAGEN/CARCINOGEN SHARPS -- DO NOT AUTOCLAVE." Discard the sharps container as infectious waste without autoclaving when it is 2/3 to 3/4 full. (Labels for sharps containers are available from EHRS.)
   
   
3. Solids: (gloves, centrifuge tubes, towels, etc.) that are contaminated.
   Store in a translucent polyethylene container for disposal as chemical waste. The generator must provide this container. Do not use glass containers for waste collection under any circumstances.
   
   Solids that are used with but are not contaminated with a carcinogen or mutagen may be discarded as trash.
   
   
4. Gels:
   Ethidium bromide gel waste (low concentration, < 10 ug/ml) may be wrapped in plastic wrap and discarded in the trash. For disposal information on other mutagen/carcinogen gel waste, call EHRS.