Chapter Two — Chemical Wastes
I. Requirements for the Accumulation Area
Containers holding waste must be in good condition, not leaking, and compatible with the waste being stored. The container must always be closed during storage, except when it is necessary to add waste. Hazardous waste must not be placed in unwashed containers that previously held an incompatible material (see Incompatibility chart in APPENDICES).
If a container holding hazardous waste is not in good condition or if it begins to leak, the generator must transfer the waste from this container to a container that is in good condition, overpack the container, or manage the waste in some other way that prevents a potential for a release or contamination. Please contact EHS Hazardous Materials Division, 512-471-3511, if assistance is required.
A storage container holding a hazardous waste that is incompatible with any waste or other materials stored nearby in other containers must be separated from the other materials or protected from them by means of a partition, wall or other device.
All waste containers must be:
- Clearly labeled, with their contents indicated. No container should be marked with the words "hazardous waste" or "non-hazardous waste". EHS tags may be used to list the contents. Paint over or remove any old labels.
- Kept at or near (immediate vicinity) the site of generation and under control of the generator.
- Compatible with contents (i.e. acid should not be stored in metal cans).
- Closed at all times except when waste is being added to container.
- Properly identified with completed waste tags before pickup is requested.
- Safe for transport with non-leaking screw-on caps.
- Filled to a safe level (not beyond the bottom of the neck of the container or a 2-inch head space for 55 gallon drums). Over-filled bottles are:
- hard to pour safely,
- inclined to burst,
- apt to leak, and
- capable of endangering the technician through splashing or shooting up into one's face upon opening or transporting.
Note: Do not use Red bags, Sharps containers (Biohazard), or Asbestos bags for hazardous chemical waste collection.
B. Accumulation Guidelines
A generator of possible hazardous waste may accumulate up to a total of 55 gallons of waste, which may be determined to be hazardous by the Office of Environmental Health and Safety, or one quart of "listed" acutely hazardous waste (see Appendix IV) at or near the point of generation. If a process will generate more than this volume at one time, the Office of Environmental Health and Safety should be contacted in advance to arrange a special waste pick up.
Whenever possible, keep different hazardous wastes separate so that disposal options remain clearer and more cost effective. In all cases, do not mix incompatible wastes or other materials (see Appendix III) in the same container or place wastes in an unwashed container that previously held an incompatible waste or material. However, if separation is not practical, collect waste in compatible containers and try to keep it segregated into the following categories:
- Miscellaneous solids, e.g., grossly contaminated gloves, rags or towels, and other grossly contaminated lab equipment should be collected separately from liquid wastes.
- Halogenated solvents, e.g., methylene chloride, chloroform, carbon tetrachloride.
- Note: Disposal of non-halogenated solvents contaminated with halogens costs 4-5 times as much as non-halogenated solvents.
- Non-halogenated solvents, e.g., xylene, toluene, alcohols.
- Waste oil must be kept as uncontaminated as possible in order to be recycled. You should keep oils separate from other chemicals, particularly solvents, pesticides, and PCB's.
- Metal-bearing waste whether dry, flammable, corrosive or other. Specific metals of concern are arsenic, barium, cadmium, chromium, lead, mercury, nickel, selenium, silver, and thallium.
- Accumulate waste that is both flammable and corrosive separately from waste that is either flammable or corrosive.
- Special wastes, e.g., cyanide, sulfide, pesticides, oxidizers, organic acids, explosives and peroxides, should be collected individually whenever possible.
- Mercury and mercury containing compounds. All mixtures containing mercury in any form must be disposed of as mercury contaminated waste.
II. Disposal Procedures for Regulated Wastes
A. Waste Tags and Request for Disposal Forms
Before chemical waste can be picked up by EHS, a waste tag is required. It should be filled out by the waste generator and attached to each container. The information on the tag is used to categorize and treat the waste. Please fill them out legibly, accurately and completely. Please include the following information:
- Generator — Name and telephone number of the individual responsible for supervising the process generating the waste.
- Contact — Phone number of generator, building name, and room number for picking up the waste.
- Amount — Total volume or weight of the chemical in the container.
- Chemical Name — Specific, full chemical name, no formulas or abbreviations. Product names or trade names are acceptable if the manufacturer's name and address or a material safety data sheet can be supplied with the material. Vague statements such as "hydrocarbons", "organic waste", "various salts of ..." make it impossible to comply with EPA treatment standards and will delay the pick-up until sufficiently detailed information is submitted to EHS.
- Vol. % — Percentage of the total volume to which each chemical amount is equal (should add up to 100%) or the actual weight or volume of each constituent.
Note: Biological Waste and Sharps containers do not require waste tags.
When your container is ready for disposal and is properly tagged, contact the Hazardous Materials Division of the Office of Environmental Health & Safety by sending a Request for Disposal (see APPENDICES for examples of both a Chemical Waste and a Biological Waste or Sharps Request for Disposal form):
- via Campus Mail to:
Hazardous Materials Division
Office of Environmental Health & Safety
- hand deliver to:
Hazardous Materials Division
Office of Environmental Health & Safety Service Building, Room 221
- via Fax to Hazardous Materials Division Office of Environmental Health & Safety 512-471-6918
at least five working days prior to reaching the accumulation limits of 55 gallons of potentially hazardous waste or 1 quart of acutely hazardous waste. EHS makes pickups daily and will come to your site as quickly as possible. The information for each container listed on the form must be identical to the information on the waste disposal tag on the container. Please include the following information on a chemical waste Request for Disposal:
- Facility — Check the appropriate facility.
- Name — Name of the individual responsible for supervising the process of generating the waste. Must be a UT employee.
- Department — Name of department generating the waste.
- Mail Code — 5 character code for campus mail. See the front of the UT Phone Directory for listing.
- Phone Number — Phone number of person to contact regarding waste pickup.
- Alternate Contact — Name of individual to contact if primary contact is not available.
- Alternate Phone — Phone number of alternate contact.
- Location of Pickup — Building and room number where the waste is located. Use official 3-letter designation for building.
- Tag Number — Number that is pre-printed on the tag and corresponds to the waste that is described on the form.
- Contents — Specific, full chemical name, no formulas or abbreviations. Product names or trade names are acceptable if the manufacturer's name and address or a material safety data sheet can be supplied with the material. Vague statements such as "hydrocarbons", "organic waste", "various salts of ..." make it impossible to comply with EPA treatment standards and will delay the pick-up until sufficiently detailed information is submitted to EHS.
- Percentage % — Percentage of the total volume to which each chemical amount is equal (percentages for each tag number should add up to 100%).
- Amount — Total volume or weight of the chemical in the container.
- Physical State — Indicate if the material is a solid (S) or liquid (L).
- Signature — Signature of individual responsible for supervising the process of generating the waste, stating that the materials listed are fully and accurately described and are packaged and labeled according to EHS procedures. Must be a UT employee (e.g., faculty, staff, TA, or RA).
- Date — Date that the form was signed and routed to the Office of Environmental Health and Safety.
III. Disposal Procedures for Non-Regulated Wastes
The following checklist should be used in determining whether or not a waste may be disposed of in the sanitary sewer or municipal trash. This checklist does not apply to wastes which are radioactive or mixed in nature.
Does the material meet any of the following criteria?
_____ Is it ignitable? (see Chapter One A.1)
_____ Is it corrosive? (see Chapter One A.2)
_____ Is it reactive? (see Chapter One A.3)
_____ Is it toxic? (see Chapter One A.4)
_____ Is it an F listed waste? (see Chapter One B.1)
If the material has not been used, does it meet any of the following criteria?
_____ Is it a P listed waste? (see Appendix IV)
_____ Is it a U listed waste? (see Appendix V)
If the answer to any of the preceding questions is "yes," then the waste is regulated and must not be disposed of via sanitary sewer. Please refer to the disposal procedures outlined in Section II (Disposal Procedures for Regulated Wastes) of this chapter.
If the material is not a hazardous waste, please answer the following questions:
_____ Is the material miscible in all proportions with water?
If the answer to the preceding question is "no," then the waste is prohibited by the City of Austin POTW and must not be disposed of via sanitary sewer. Please refer to the disposal procedures outlined in section II of this chapter (Disposal Procedures for Regulated Wastes).
_____ Does the sum of the concentrations of the following constituents in the waste exceed 2 ppm?
|Carbon tetrachloride||Methylene chloride|
_____ Does the waste contain any of the following constituents at levels greater than the specified amount?
_____ Is it extremely toxic or a known carcinogen or mutagen?
If the answers to the two preceding questions are "yes," then the waste is prohibited by the City of Austin POTW and must not be disposed of via sanitary sewer. Please refer to the disposal procedures outlined in section II of this chapter (Disposal Procedures for Regulated Wastes). Otherwise, the material is acceptable for sanitary sewer disposal if it is a liquid or for trash disposal if it is a solid. The discharge of wastes to the sanitary sewer should be accompanied with copious amounts of water — a good rule of thumb is to use a 100-fold excess of water when discharging wastes to the sanitary sewer.
Examples of Non-Regulated Chemicals
The following are examples of nonhazardous chemicals which may be disposed of either in the general trash (for solids) or the sanitary sewer (for liquids). For a more complete list, please consult Appendix I.
|Adenosine 3'-monophosphate, sodium salt|
|Albumin, bovine, methylated|
|Bacto peptone; Peptone|
IV. Disposal Procedures for Empty Containers
Disposal procedures for empty containers depends on the previous contents and the efficiency of emptying them. Containers of pourable contents must be completely emptied. Containers of thick or solidified materials must be scraped out or drained until no more than one inch of material remains in the bottom of the container or no more than 3% of the original weight of the contents remains, whichever is less. Chemical containers that meet these criteria are considered empty and may be disposed of by placing the container in the hallway, next to the lab door after 5:00 p.m., given the following provisions:
- if the container labels are made unreadable by affixing an "Empty" sticker over the previous label (stickers are available from EHS),
- if the container cap is removed and discarded in the normal trash, and
- if the sole active ingredient of the previous contents was not acutely hazardous (see list of acutely hazardous waste in Appendix IV).
Note: 55 gallon drums must be rendered unusable to be disposed of through the normal trash collection procedures. To render a drum unusable it should either be crushed or the sides should be obviously punctured.
If containers are not or cannot be emptied or if they contained acutely hazardous waste, submit them to EHS Hazardous Materials Division as waste in accordance with the procedures described in this manual. You can also utilize a used container to hold waste for pick up if the waste is compatible with the residue in the container, the label is defaced, and the container is in good condition and not leaking.
Containers that held compressed gases are to be picked up intact by EHS. Empty cylinders should be tagged in the same manner as other waste, with the previous contents listed and the notation (EMPTY) on both the tag and the RFD.
V. Waste Minimization
A. Methods for Treating Hazardous Wastes in the Laboratory
Scientific and engineering research and teaching activities in academic institutions can result in the generation of relatively small quantities of a wide variety of waste and surplus chemicals. The small-scale treatment and deactivation of these sorts of chemical products and by-products as part of the experimental plan (i.e., as part of the routine procedure) is one approach that can be used to address the problem of waste minimization at the laboratory level. Several texts have been published that deal with this issue — two particularly good examples are:
- George Lunn and Eric Sansone. 1994. Destruction of Hazardous Chemicals in the Laboratory, 2nd Edition. Frederick, Maryland: Wiley-Interscience Publications.
- Margaret A. Armour. 1991. Hazardous Laboratory Chemicals — A Disposal Guide. Edmonton, Alberta, Canada: CRC Press.
B. Five Examples of Reagent Substitutions that Result in Less Hazardous and/or Less Costly Waste
To enhance safety and minimize the environmental consequences of an experiment, careful thought should be given to the materials to be used and the scale of the experiment. Traditionally, chemists have chosen reagents and materials for experiments to meet scientific criteria without always giving careful consideration to waste minimization or environmental objectives. In synthetic procedures, overall yield and purity of the desired product were usually regarded as the most important factors. Material substitution emerged as an important consideration in manufacturing process design because of the large quantities of chemicals involved. The following questions should now be considered when choosing a material to be used as a reagent or solvent in an experimental procedure:
- Can this material be replaced by one that will expose the experimenter, and others who handle it, to a lower order of potential hazard?
- Can this material be replaced by one that will reduce or eliminate the generation of hazardous waste and the consequent cost of waste disposal?
The following examples illustrate applications of these principles to common laboratory procedures:
- Phosgene is a highly toxic gas used as a reagent in many organic transformations. Its use requires proper precautions to deal with the containment of the gas and the handling and disposal of cylinders. Commercially available substitutes such as diphosgene (trichloro-methyl)chloroformate, a liquid, or triphosgene bis(trichloromethyl)carbonate, a low-melting solid, can often be substituted for phosgene by appropriate adjustment of experimental conditions or can be used to generate phosgene only on demand. Both chemicals are highly toxic themselves, but they offer a means to avoid the problems associated with handling a toxic gas.
- Many widely used reagents contain toxic heavy metals, such as chromium and mercury. Waste containing these materials cannot be incinerated and must be handled separately for disposal. Thus, substitution of other reagents for heavy metal reagents will almost always be beneficial with respect to hazard and waste minimization. Chromic acid cleaning solutions for glassware can be replaced by proprietary detergents used in conjunction with ultrasonic baths. Various chromium (VI) oxidants have been important in synthetic organic chemistry, but their use can often be avoided through the substitution of organic oxidants. The Swern oxidation of alcohols (oxalyl chloride/DMSO) produces relatively innocuous byproducts, which can be handled with other organic waste. Other oxidation reagents tailored to the specific needs of a given transformation are available.
- Fluorine and fluorinating reagents such as perchloryl fluoride are among the most demanding of reagents to handle because of their high reactivity and toxicity. Accordingly, there has been considerable incentive to develop substitutes for these materials. One example is F-TEDA-BF4, or 1-chloromethyl-4-fluoro-1,4-diazonia[2.2.2]bicycloctane bis(tetrafluoroborate). This reagent can be substituted for more hazardous reagents in many fluorination procedures.
- Organic solvents for liquid-liquid extraction or chromatography can often be replaced by other solvents with significant benefit. Benzene, once a widely used solvent, is now recognized as a human carcinogen and must be handled accordingly. Toluene can often serve as a satisfactory substitute. Diethyl ether is a flammable solvent whose handling must take into account its tendency to form explosive peroxides. Methyl t-butyl ether offers only slight advantages over diethyl ether with respect to flammability, but its greatly reduced tendency to form peroxides eliminates the need to monitor peroxide formation during handling and storage.
- The technology for handling supercritical fluids has developed rapidly in recent years. Supercritical carbon dioxide can replace organic solvents for high-performance chromatography and is beginning to find use as a reaction medium. While supercritical solvents require specialized equipment for handling, they offer the potential benefit of large reductions in organic solvent waste.
- Mercury thermometers are widely used and easily broken, which results in worker exposure to mercury, release of the vapors to the environment, and increased waste disposal costs as all of the cleanup material must be disposed of as mercury contaminated waste. Substitution of alcohol thermometers for mercury thermometers eliminates these problems. Thermometers containing alcohol are as accurate and have as wide a temperature range as mercury thermometers, and the waste from the cleanup of broken alcohol thermometers can be thrown in the regular trash. Moreover, the breakage of alcohol thermometers does not expose the lab personnel to poisonous vapors.