8.B.2.1. Characterization for Off-Site Management

When waste is to be shipped off-site for recycling, reclamation, treatment, or disposal, the waste characterization information needed depends on the waste management facility's requirements and its permit. Analytical methods have been established by the U.S. Environmental Protection Agency (EPA), and environmental laboratories that use EPA methods are often certified or accredited. Most of these methods are for commercially available chemicals, and so approved analytical procedures may not be available for some laboratory chemicals. It is important to work with your waste disposal firm to determine how laboratory waste is to be categorized. To avoid redundant analysis for recurring waste streams (e.g., chlorinated solvents, labpacks of organic solids), waste disposal firms and off-site facilities often establish a waste-stream profile. In some cases, detailed analytical information is not necessary if waste containers fall within the profile's hazard classification.

8.B.2.2. Identification Responsibilities of All Laboratory Personnel

Because proper management and disposal of laboratory waste requires information about its properties, it is very important that laboratory personnel accurately and completely identify and clearly label all chemical and waste containers in their laboratory, as well as maintain the integrity of source material labels. It is recommended that supplementary information be kept in a separate, readily available record (e.g., laboratory information system, lab notebook), especially for very small containers or collections. In academic laboratories where student turnover is frequent, identification is particularly important for the materials used or generated. This practice is as important for small quantities as it is for large quantities.

8.B.2.3. Characterization of Unknowns

Establishing the hazardous characteristics and evaluating the potential listing of clearly identified waste is usually quite simple. Unidentified materials (unknowns) present a problem, however, because recycling, treatment, and disposal facilities need to know characteristics and hazards to manage waste safely. All chemicals must be characterized sufficiently for safe transportation off-site.

Analysis of laboratory unknowns is expensive, especially if EPA methods must be used, or the presence of a constituent must be ruled out, and handling unknowns is risky due to the possible presence of unstable, reactive, or highly toxic chemicals or byproducts. Although expensive, some waste disposal firms offer on-site services to categorize unknown laboratory waste to prepare it for shipment to their treatment facility.

8.B.2.4. In-Laboratory Test Procedures for Unknowns

When the identity of the material is not known, simple in-laboratory test procedures can be carried out to determine the hazard class into which the material should be categorized. Because the generator may be able to supply some general information, it may be beneficial to carry out the test procedures before the materials are removed from the laboratory. Perform these tests only if they can be done safely, and only if they facilitate the characterization of the waste required by your hazardous waste disposal firm. Understand that the following test procedures are only to provide additional information, and do not meet EPA regulatory requirements for waste analysis.

In general, precisely determining the molecular structure of the unknown material is not necessary. Hazard classification usually satisfies the regulatory requirements and those of the treatment disposal facility. However, it is important to establish which analytical data are required by the disposal facility.

Trained laboratory personnel who carry out the analytical procedures should be familiar with the characteristics of the waste and any necessary precautions. Because the hazards of the materials being tested are unknown, the use of proper personal protection and safety devices such as chemical hoods and shields is imperative. Older samples are particularly dangerous because they may have changed in composition, for example, through the formation of peroxides. (See Chapter 4, section 4.D.3.2, for information on the formation and identification of peroxides. See Chapter 6, section 6.G.3, for information on testing and disposal of peroxides.)

The following information is commonly required by treatment and disposal facilities before they agree to handle unknown materials:

• physical description,
• water reactivity,
• water solubility,
• pH,
• ignitability (flammability),
• presence of oxidizer,
• presence of sulfides or cyanides,
• presence of halogens,
• presence of radioactive materials,
• presence of biohazardous materials,
• presence of toxic constituents,
• presence of polychlorinated biphenyls (PCBs), and
• presence of high-odor compounds.

The following test procedures are readily accomplished by trained laboratory personnel. The overall sequence for testing is depicted in Figure 8.1 for liquid and solid materials.

FIGURE 8.1

Flowchart for categorizing unknown chemicals for waste disposal. This decision tree shows the sequence of tests to be performed to determine the appropriate hazard category of an unknown chemical. DWW, dangerous when wet; nos, not otherwise specified. (more...)

• Physical description. Include the state of the material (solid, liquid), the color, and the consistency (for solids) or viscosity (for liquids). For liquid materials, describe the clarity of the solution (transparent, translucent, or opaque). If an unknown material is a bi- or tri-layered liquid, describe each layer separately, giving an approximate percentage of the total for each layer. After taking appropriate safety precautions for handling the unknown, including the use of personal protection devices, remove a small sample for use in the following tests.
• Water reactivity. Carefully add a small quantity of the unknown to a few milliliters of water. Observe any changes, including heat evolution, gas evolution, and fame generation.
• Water solubility. Observe the solubility of the unknown in water. If it is an insoluble liquid, note whether it is less or more dense than water (i.e., does it float or sink?). Most nonhalogenated organic liquids are less dense than water.
• pH. Test the material with multirange pH paper. If the sample is water-soluble, test the pH of a 10% aqueous solution. Carrying out a neutralization titration may also be desirable or even required.
• Ignitability (flammability). Place a small sample of the material (<5 mL) in an aluminum test tray. Apply an ignition source, typically a propane torch, to the test sample for 0.5 second. If the material supports its own combustion, it is a flammable liquid with a flash point of less than 60 °C (140 ºF). If the sample does not ignite, apply the ignition source again for 1 second. If the material burns, it is combustible. Combustible materials have a flash point between 60 and 93 °C (140 and 200 ºF).
• Presence of oxidizer. Wet commercially available starch-iodide paper with 1 N hydrochloric acid, and place a small portion of the unknown on the wetted paper. A change in color of the paper to dark purple is a positive test for an oxidizer. The test can also be carried out by adding 0.1 to 0.2 g of sodium or potassium iodide to 1 mL of an acidic 10% solution of the unknown. Development of a yellow-brown color indicates an oxidizer. To test for hydroperoxides in water-insoluble organic solvents, dip the starch-iodine test paper into the solvent, and let it dry. Add a drop of water to the same section of the paper. Development of a dark color indicates the presence of hydroperoxides.
• Presence of peroxides. The following tests detect most (but not all) peroxy compounds, including all hydroperoxides. Please take care. (See Chapter 4, section 4.D.3.2, and Chapter 6, section 6.G.3, for information on the hazards of peroxides.)

  ◦

  Peroxide test strips, which turn to an indicative color in the presence of peroxides, are available commercially. Note that these strips must be air dried until the solvent evaporates and exposed to moisture for proper operation.

  ◦

  Add 1 to 3 mL of the liquid to be tested to an equal volume of acetic acid, add a few drops of 5% aqueous potassium iodide solution, and shake. The appearance of a yellow to brown color indicates the presence of peroxides. Alternatively, addition of 1 mL of a freshly prepared 10% solution of potassium iodide to 10 mL of an organic liquid in a 25-mL glass cylinder produces a yellow color if peroxides are present.

  ◦

  Add 0.5 mL of the liquid to be tested to a mixture of 1 mL of 10% aqueous potassium iodide solution and 0.5 mL of dilute hydrochloric acid to which has been added a few drops of starch solution just prior to the test. The appearance of a blue or blue-black color within 1 minute indicates the presence of peroxides.

  None of these tests should be applied to materials (such as metallic potassium) that may be contaminated with inorganic peroxides. (See Chapter 6, section 6.G.3, for more information about peroxide testing.)
• Presence of sulfide. Commercial test strips for the presence of sulfide are available, and their use is recommended. If the test strips are not available in the laboratory, the following test can be performed. Warning: This test produces hazardous and odiferous vapors. Use only small quantities of solution for the test and use appropriate ventilation. The test for inorganic sulfides is carried out only when the pH of an aqueous solution of the unknown is greater than 10. Add a few drops of concentrated hydrochloric acid to a sample of the unknown while holding a piece of commercial lead acetate paper, wet with distilled water, over the sample. Development of a brown-black color on the paper indicates generation of hydrogen sulfide.
• Presence of cyanide. Commercial test strips for the presence of cyanide are available, and their use is strongly recommended.
• Presence of halogen. Heat a piece of copper wire until red in a flame. Cool the wire in distilled or deionized water, and dip it into the unknown. Again heat the wire in the flame. The presence of halogen is indicated by a green color around the wire in the flame.

8.B.3.1. Definition of Characteristic Waste

According to federal law, the properties of chemical waste that pose hazards are as follows. Note that these definitions are unique, especially the definition of waste having the characteristic of toxicity.

1. Ignitability. Ignitable materials are defined as having one or more of the following characteristics:
   1. liquids that have a flash point of less than 60 °C (140 °F) or some other characteristic that has the potential to cause fire;
   2. materials other than liquids that are capable, under standard temperature and pressure, of causing fire by friction, adsorption of moisture, or spontaneous chemical changes and, when ignited, burn so vigorously and persistently that they create a hazard;
   3. flammable compressed gases, including those that form flammable mixtures;
   4. oxidizers that stimulate combustion of organic materials.
   Ignitable materials include most common organic solvents, gases such as hydrogen and hydrocarbons, and certain nitrate salts.
2. Corrosivity. Corrosive liquids have a pH ≤ 2 or pH ≥ 12.5 or corrode certain grades of steel. Most common laboratory acids and bases are corrosive. Solid corrosives, such as sodium hydroxide pellets and powders, are not legally considered by RCRA to be corrosive. However, trained laboratory personnel must recognize that such materials are extremely dangerous to skin and eyes and must be handled accordingly.
3. Reactivity. The reactivity classification includes substances that are unstable, react violently with water, detonate if exposed to some initiating source, or produce toxic gases. Alkali metals, peroxides and compounds that have peroxidized, and cyanide or sulfide compounds are classed as reactive.
4. Toxicity. Toxicity is established through the toxicity characteristic leaching procedure (TCLP) test, which measures the tendency of certain toxic materials to be leached (extracted) from the waste material under circumstances assumed to reproduce conditions of a landfill. The TCLP list includes a relatively small number of industrially important toxic chemicals and is based on the leachate concentration, above which a waste is considered hazardous. Failure to pass the TCLP results in classification of a material as a toxic waste. The TCLP test is primarily for solid materials; liquids are typically evaluated on a straight concentration basis. TCLP analyses are usually performed by environmental testing laboratories.

8.B.3.2. Definition of Listed Waste

A chemical waste that does not exhibit one of the above characteristics may still be regulated if it is a listed waste. Although EPA has developed several lists of hazardous waste, three regulatory lists are of most interest to trained laboratory personnel:

• F list: waste from nonspecific sources (e.g., spent solvents and process or reaction waste);
• U list: hazardous waste (e.g., toxic laboratory chemicals); and
• P list: acutely hazardous waste [e.g., highly toxic laboratory chemicals, that is, chemicals having a lethal dose (LD₅₀) of <50 mg/kg (oral, rat)].

Of the listed wastes, the most common for laboratories are the F wastes, which include many laboratory solvents. These include halogenated solvents (methyl-ene chloride, tetrachloroethylene, and chlorinated fluorocarbons) and nonhalogenated solvents (xylene, acetone, ethyl acetate, ethyl benzene, ethyl ether, methyl isobutyl ketone, methanol, and n-butyl alcohol). Note that these are regulated under this listing only if they have been used (spent).

The other categories of listed waste common to laboratories are the U and P lists, which include many chemicals frequently found in laboratories. U and P lists pertain to

• waste chemicals that have not been used, because once used, the U or P listing does not apply;
• spills and spill cleanup material from U- or P-listed compounds; and
• rinsate from triple rinsing of empty containers of P compounds (described below), which is collected and handled as hazardous.

8.B.3.3. Determining the Regulatory Status of a Waste

The EPA regulations place the burden of determining whether a waste is regulated as hazardous and in what hazard classification it falls on the waste generator. Most laboratories rely on their EHS staff or their waste disposal firm to determine EPA and DOT regulatory categories (such as EPA ID numbers and transportation classes), as well as waste characterization information needed by the recycling, treatment, or disposal facility.

Testing is not necessarily required, and in most cases trained laboratory personnel are able to provide sufficient information about the waste to categorize it by general hazard categories. If the waste is not a common chemical with known characteristics, enough information about it must be supplied to satisfy the regulatory requirements and to ensure that it can be handled and disposed of safely. The information needed to characterize a waste also depends on the method of ultimate disposal. (See the discussion of disposal methods in sections 8.B.6 to 8.B.7, below.)

8.B.3.4. Empty Containers

The rules for disposal of empty hazardous waste containers, and cleaning the empty containers, are complex. A container or inner liner of a container that contained hazardous waste is “empty” under federal regulations if all waste has been removed by standard practice and no more than 2.5 cm (1 in.) of residue, or 3% by weight of containers less than 110 gal, remains. If the container held acute hazardous waste, triple rinsing or equivalent measures are required before the container is “empty” within the federal regulations. The rinsate must be collected and handled as acutely hazardous waste. “Empty” containers are no longer subject to federal regulation.

These are minimum standards. If empty containers are to be recycled or disposed of in the normal trash, it is recommended that labels be removed from empty hazardous waste containers, and that they be emptied as much as possible. Consider rinsing emptied containers with water or a detergent solution. Resulting rinsate from containers previously holding acutely hazardous waste are hazardous waste and must be disposed of accordingly. Rinsate resulting from cleaning of other hazardous waste containers is hazardous waste if it exhibits EPA's hazardous waste characteristics of ignitability, corrosivity, reactivity, or toxicity. It is prudent to follow these guidelines for disposing of empty containers of nonhazardous and nonregulated laboratory chemicals.

Properly cleaning containers as described above, and recycling or disposing of them with the normal trash, reduces costs as well as the volume of hazardous waste generated. Alternatively, some firms and institutions decide that it is more convenient to handle all empty chemical containers from laboratories as hazardous waste and dispose of them accordingly. This especially makes sense if the rinsate is hazardous.

8.B.4.1. Accumulation of Waste at the Location of Generation

Laboratory experiments generate a great variety of waste, including used disposable laboratory ware, filter media and similar materials, aqueous solutions, and hazardous and nonhazardous chemicals. As stated in the introduction to this chapter, begin no activity unless a plan for disposal of all waste, hazardous and nonhazardous, has been formulated.

The accumulation and temporary storage of waste in the laboratory is called satellite accumulation. The legal standards for satellite accumulation are included in this section; they are also good practices for the management of nonregulated waste. To ensure security and management oversight, chemical waste should be accumulated at or near the point of generation, and under control of laboratory personnel. Note that there is an optional alternative federal standard for the accumulation of waste within laboratories of colleges, universities, teaching hospitals, and certain nonprofit research facilities associated with colleges or universities. This is described in section 8.B.4.3, below.

Each category of waste has certain precautions and appropriate disposal methods. Below is a list of requirements and good practices for accumulating chemical waste in the laboratory:

• Collect hazardous or flammable waste solvents in an appropriate container pending transfer to the institution's central facility or satellite site for chemical waste handling or pickup by commercial disposal firm. Often, different kinds of waste are accumulated within a common container.
• Take care not to mix incompatible waste. This is a special concern with commingled waste solvents, which must be chemically compatible to ensure that heat generation, gas evolution, or another reaction does not occur. (See the discussion of commingling in section 8.B.4.2, below.) For example, waste solvents can usually be mixed for disposal, with due regard for the compatibility of the components.
• Keep wastes segregated by how they will be managed. For example, because nonhalogenated solvents are more suitable for fuel blending, many laboratories collect halogenated and nonhalogenated solvent wastes separately.
• Collect waste in dependable containers that are compatible with their contents. Keep containers closed except when adding or subtracting waste. Separate containers of incompatible materials physically or otherwise stored in a protective manner. (See Chapter 5, section 5.E.2, for storing chemicals according to their compatibility.)
• Use an appropriate container for the collection of liquid waste. Glass bottles are impervious to most chemicals but present a breakage hazard, and narrow-neck bottles are difficult to empty. The use of plastic (e.g., polyethylene jerry cans) or metal (galvanized or stainless steel) safety containers for the collection of liquid waste is strongly encouraged. Note that fame arresters in safety containers can easily become plugged if there is sediment and may need to be cleaned occasionally. Do not store amines or corrosive materials in metal containers.
• Do not use galvanized steel safety cans for halogenated waste solvents because they tend to corrode and leak.
• As detailed below, clearly and securely label waste containers with their contents.
• Securely cap waste containers when not in immediate use. To minimize releases to the atmosphere, when a funnel is used either immediately reclose the container or use a capped waste funnel. Do not use the same funnel for containers containing incompatible waste types.
• Collect aqueous waste separately from organic solvent waste. Some laboratories may be served by a wastewater treatment facility that allows the disposal of aqueous waste to the sanitary sewer if it falls within a narrow range of acceptable waste types. Thus, solutions of nonhazardous salts or water-miscible organic materials may be acceptable in some localities. Solutions containing flammable or hazardous waste, even if water-miscible, are almost never allowed, and water-immiscible substances must never be put down the drain. Collect aqueous waste for nonsewer disposal in a container selected for resistance to corrosion. Do not use glass for aqueous waste if there is danger of freezing. Depending on the requirements of the disposal facility, adjustment of the pH of aqueous waste may be required. Such adjustment requires consideration of the possible consequences of the neutralization reaction that might take place: gas evolution, heat generation, or precipitation.
• Place solid chemical waste, such as reaction byproducts or contaminated filter or chromatography media, in an appropriately labeled container to await disposal or pickup. Segregate unwanted reagents for disposal in their original containers, if possible. If original containers are used, labels should be intact and fully legible. Make every effort to use, share, or recycle unwanted reagents rather than commit them to disposal. (See Chapter 5, sections 5.D and 5.E, for a discussion of labeling alternatives.)
• Consider how to dispose of nonhazardous solid waste in laboratory trash or segregate it for recycling. Check the laboratory chemical safety summary, material safety data sheet, or other appropriate reference to determine toxicity. Consult institutional policy on nonhazardous solid waste disposal.

Trained laboratory personnel, who are most familiar with the waste and its generation, need to be actively involved in waste identification and management decisions, so that the waste is managed safely and efficiently. Often the appropriate time to decide to recycle or reuse surplus materials is shortly after the waste is generated, rather than when they are sent for disposal. Once combined with other waste materials, recycling or reuse may be more difficult. Evaluate all the costs and benefits of either decision at this time.

Safety considerations must be of primary concern. Store waste in clearly labeled containers in a designated location that does not interfere with normal laboratory operations. Ventilated storage may be appropriate. Use secondary containment such as trays, for spills or leakage from the primary containers. Many states require the use of secondary containment for wastes in satellite accumulation areas.

Federal regulations allow the indefinite accumulation of up to 55 gal of hazardous waste or 1 qt of acutely hazardous waste at or near the point of generation. However, prudence dictates that the quantities accumulated are consistent with good safety practices. Furthermore, satellite accumulation time must be consistent with the stability of the material. The general recommendation is that waste not be held for more than 1 year; some states specifically set this limit for satellite accumulation time. Within 3 days of the time that the amount of waste exceeds the 55-gal (or 1-qt) limit, manage it under the storage and accumulation time limits required at a central accumulation area, as described below.

Packaging and labeling are key parts of this initial in-laboratory operation. Label every container of hazardous waste with the material's identity and its hazard (e.g., flammable, corrosive) and the words “hazardous waste.” Although the identity need not be a complete listing of all chemical constituents, knowledgeable laboratory professionals or waste handlers should be able to evaluate the hazard. However, when compatible wastes are collected in a common container, keep a list of the components to aid in later disposal decisions. Labeling must be clear and permanent. Although federal regulations do not require posting the date when satellite accumulation begins, some states do require this. The institution may suggest that this information be recorded as part of its chemical management plan.

8.B.4.2. Accumulation of Waste in a Central Area

The central accumulation area is an important component in the organization's chemical management plan. In addition to being the primary location where waste management occurs, it may also be the location where excess chemicals are held for possible redistribution. Along with the laboratory, the central accumulation area is often where hazard reduction of waste takes place through allowable on-site treatment processes.

The central accumulation area is often the appropriate place to accomplish considerable cost savings by commingling (i.e., combining) similar waste materials. This is the process where compatible wastes from various sources are combined prior to disposal. Commingling is particularly suitable for waste solvents because disposal of liquid in a 55-gal drum is generally much less expensive than disposal of the same volume of liquid in small containers. Because mixing waste requires transfer of waste between containers, the identity of all materials must be known and their compatibility understood. Although these procedures are very cost-effective, they require additional safety precautions, including the use of personal protective equipment and special and engineering controls. In addition to the facility needs described below, commingling areas require non-explosive electrical systems, grounding and bonding between floors and containers, nonsparking conductive floors and containers, and specialized ventilation systems. A walk-in fume hood is often used for both solvent commingling and the storage of commingling equipment. It is important to design the process to minimize lifting, awkward procedures that may cause injury, and the handling of heavy drums and equipment.

In some cases the disposal method and ultimate fate of the waste require that different wastes not be accumulated together. For example, if commingled waste contains significant amounts of halogenated solvents (usually >1%), disposing of the mixture can be considerably more expensive. In such cases segregation of halogenated and nonhalogenated solvents is economically favorable.

According to federal regulations, storage at a central accumulation area is normally limited to 90 days, although more time is allowed for small-quantity generators or other special situations (180 or 270 days). The count begins when the waste is brought to the central accumulation area from the laboratory or satellite accumulation area. A special permit is required for storage beyond the above limits. Obtaining such a permit is usually too expensive and too time-consuming for most laboratory operations. (See RCRA and Chapter 11, section 11.E.1, for more information.)

Store waste materials within a central accumulation area in appropriate and clearly labeled containers and separate them according to chemical compatibility as noted in Chapter 5, section 5.E.2. The label must include the accumulation start date and the words “hazardous waste.”

Central accumulation areas should have fire suppression systems, ventilation, and dikes to avoid sewer contamination in case of a spill. Employees must be trained in correct handling of the materials as well as contingency planning and emergency response. The area should be secure, and employees should be encouraged to report any suspicious activity. Employees should know how to activate alarms, how to use fire extinguishers and other emergency response equipment, how to exit, and the location of the exterior assembly point. Be sure to document training and provide periodic refreshers.

Transportation of waste from laboratories (satellite accumulation areas) to the central accumulation area also requires specific attention to safety. Transport materials in appropriate and clearly labeled containers. Make provision for spill control in case of an accident during transportation and handling. Larger institutions are advised to have an internal tracking system to follow the movement of waste. If public roads are used to transport laboratory waste, additional DOT packaging, marking, labeling, and manifesting regulations may apply, as described below.

Final preparations for off-site disposal usually occur at the central accumulation area. Decisions on disposal options are best made here as larger quantities of waste are gathered. Identification of unknown materials not carried out within the laboratory must be completed at this point because unidentified waste cannot be shipped to a disposal site.

Your hazardous waste disposal firm is frequently involved with this phase of waste management. The decision of whether to involve a hazardous waste disposal firm, how, and when is largely based on logistics and economics. Table 8.1 describes the tasks involved in initiating off-site disposal and provides recommendations for what should be done in-house by staff and what should be contracted to professional service companies.

TABLE 8.1

Assignment of Tasks for Waste Handling.

Laboratory waste typically leaves the generator's facility commingled in drums as compatible wastes or within a labpack. Labpacks are containers, often 55-gal drums, in which small containers of waste are packed with an absorbent material. Labpacks had been used as the principal method for disposing of laboratory waste within a landfill. However, recent landfill disposal restrictions severely limit landfill disposal of hazardous materials. Thus, the labpack has become principally a shipping container. The labpack is taken to a permitted treatment, storage, and disposal facility (TSDF), where it is either incinerated or unpacked and the contents redistributed for safe, efficient, and legal treatment and disposal.

If chemical hazardous waste is being accumulated for recycling (e.g., waste lead, solvents for redistillation), federal law requires 75% or more of these materials to be recycled or disposed of in each calendar year. This figure does not apply to surplus chemicals held for redistribution to other laboratories.

8.B.4.3. Special Regulations for Laboratories at Academic Institutions

Although laboratories are generally required to comply with the same regulations as industrial facilities, regulations promulgated in 2008 provide limited relief for academic institutions from some of the requirements associated with on-site management. When adopted by the state in which the laboratory is located, these alternative standards are available to colleges, universities, teaching hospitals, and certain nonprofit research facilities associated with colleges or universities. These standards are completely optional, at the discretion of the educational or research institution. To take advantage of these provisions, academic facilities must implement a performance-oriented laboratory management plan. This facility-specific plan must provide for seven required elements:

1. labeling standards,
2. container standards,
3. training requirements,
4. removal frequency of unwanted chemicals,
5. hazardous waste determinations,
6. laboratory cleanouts, and
7. prevention of emergencies.

The provisions allow academic facilities additional time to move waste from laboratories to central accumulation areas and additional time and flexibility in making waste determinations, and encourage laboratory cleanouts by providing relief from some time limits and generator classification provisions. However, these alternative standards require semiannual removal of all laboratory hazardous waste, whereas the standard satellite accumulation rule has no time limit for the accumulation of laboratory waste in unfilled containers smaller than 55 gal.

The academic waste rule does not apply in states with primacy over RCRA regulations until promulgated by the state. Check with your state environmental agency to see if the rule has been implemented. The entire text of the rule is available at the EPA Web site, www.epa.gov.

8.B.6.1. Treatment and Recycling

There are various methods for physical and chemical treatment of hazardous wastes, as well as methods for recycling, reclamation, and recovery of valuable materials contained in the waste. These methods include neutralization, oxidation-reduction, distillation, digestion, encapsulation, and several forms of thermal treatment. While the expense and practicality of these technologies is largely based on the specific nature and volume of the material, treatment or recycling is preferable to incineration for some hazardous wastes. For example, high- and low-pH wastes may be neutralized, resulting in treatable wastewater and salts. Incineration of mercury and other toxic metals is restricted; recycling, recovery, or encapsulation is environmentally preferred. Filtration of aqueous-based wastes may also significantly decrease volumes and result in wastewaters suitable for treatment in a sewage treatment facility. Note that recycling and reclamation extend to reclamation of energy as well as materials, and flammable waste liquids from laboratory operations are almost universally consolidated and used in fuel blending operations, typically to power cement plants. These liquids may also be used as a fuel source for rotary kilns.

8.B.6.2. Disposal in the Sanitary Sewer

Disposal in the sewer system (down the drain) had been a common method of waste disposal until recent years. However, environmental concerns, the viability of publicly owned treatment works (POTW), and a changing disposal culture have changed that custom markedly. In fact, many industrial and academic laboratory facilities have completely eliminated sewer disposal. Most sewer disposal is controlled locally, and it is therefore advisable to consult with the POTW to determine what is allowed. Yet, if permitted by the sewer facility, it is often reasonable to consider disposal of some chemical waste materials in the sanitary sewer. These include substances that are water-soluble and those that do not violate the federal prohibitions on disposal of waste materials that interfere with POTW operations or pose a hazard.

Chemicals that may be permissible for sewer disposal include aqueous solutions that readily biodegrade and low-toxicity solutions of inorganic substances. When allowed by law, liquid laboratory wastes that are commonly disposed of in the sanitary sewer include spent buffer solutions, neutralized mineral acids and caustics, and very dilute aqueous solutions of water-soluble organic solvents (e.g., methanol, ethanol). After checking with authorities, some laboratories flush small amounts of water-soluble nontoxic solids into the sanitary sewer with excess water. Examples of potentially sewer-disposable solids include sodium or potassium chloride, nutrients, and other chemicals generally regarded as safe. Disposal of water-miscible flammable liquids in the sewer system is usually severely limited. Water-immiscible chemicals should never go down the drain.

Under federal, state, and local law, there are various exemptions, exclusions, effluent limits, and permitting requirements that may apply to laboratory wastewaters. For most labs, there are allowances for disposing of aqueous waste, rinsate, and certain hazardous and other laboratory wastes (within limits) via the sanitary sewer. Requirements vary by state, locale, and the individual laboratory's plumbing and sewer system, as well as other facility discharges and treatment systems that the laboratory is part of. Be aware that there are notification requirements for sewer discharges of any acute hazardous waste to a POTW (and more than 15 kg per month of other hazardous waste), and a one-time notification requirement for discharges that fall within the federal domestic sewage exclusion.

In general, if laboratory wastes are discharged via a sanitary sewer to a POTW, follow the advice above to contact your POTW as to permitting and notification requirements and effluent limits. If not, contact your state water pollution control office to determine permitting and notification requirements and effluent limits.

Waste approved for drain disposal should be disposed of only in drains that flow to a POTW, never into a storm drain or septic system. Waste should be flushed with at least a 100-fold excess of water, and the facility's wastewater effluent should be checked periodically to ensure that concentration limits are not being exceeded.

8.B.6.3. Release to the Atmosphere

The release of vapors to the atmosphere, via, for example, open evaporation or laboratory chemical hood effluent, is not an acceptable disposal method. Apparatus for operations expected to release vapors should be equipped with appropriate trapping devices. Although laboratory emissions are not considered a major source under the Clean Air Act, deliberate disposal of materials via evaporation of vapors is strictly prohibited under RCRA.

Chemical hoods, the most common source of laboratory releases to the atmosphere, are designed as safety devices to transport vapors away from laboratory personnel, not as a routine means for volatile waste disposal. Units containing absorbent filters have been introduced into some laboratories, but have limited absorbing capacity. Redirection of hood vapors to a common trapping device can completely eliminate discharge into the atmosphere. (See Chapter 9, for more details.)

8.B.6.4. Incineration

Incineration is the most common disposal method for laboratory wastes. Incineration is normally performed in rotary kilns at high temperatures (1200–1400 °F). This technology provides for complete destruction of most organic materials and significantly reduces the volume of residual material which must be disposed of by landfill. However, it is an expensive option, generally requiring the use of significant volumes of fuel to generate the required temperatures. Also, some materials, such as mercury and mercury salts, may not be incinerated because of regulations and limitations of the destruction capability. (For information about reducing the use of mercury in laboratories, see Chapter 5, section 5.B.8.)

8.B.7.1. Preparation for Off-Site Treatment or Disposal of Waste

Transportation and packaging requirements dictate how waste is prepared for shipment to a transfer, treatment, or disposal facility. Laboratory waste is often placed into DOT-compliant 1- to 55-gal overpacks. Reactives, gases, and highly incompatible and some highly toxic chemicals must be packaged separately.

Using labpacks is quite simple. As described above, small containers of compatible waste materials are placed in a larger container, usually a 30- to 55-gal drum, along with appropriate packing materials, as they are collected. When a drum is filled and ready for shipping, an inventory list of the contents of the labpack is prepared.

For certain similar and compatible liquid wastes, however, collecting containers of waste in a labpack is usually much more expensive than commingling (i.e., mixing) the wastes, partly because a 55-gal lab-pack only holds about 16 gal of waste in its individual containers. Most often, nonhalogenated solvents are ideally suited for commingling in bulk, because the best disposal strategies for flammable liquids are fuel blending or recycling. Commingling requires opening of containers and transferring their contents from the smaller laboratory containers to a larger drum. Furthermore, the containers should be rinsed before they are considered nonhazardous, and the rinsate must be treated as a hazardous waste.

Safety precautions and facility requirements for commingling are described above. See section 8.B.3.4, above, for information on rinsing and disposal of empty containers. Drums of commingled waste usually require an analysis or listing of their contents.

Commingling does not make sense if safe facilities are not available, or when insufficient amounts of compatible waste are generated within storage time limits.

8.B.7.2. Choice of Transporter and Disposal Facility

Because the long-term liability for the waste remains with the generator, it is imperative that the generator be thoroughly familiar with the experience and record of the transporter and TSDF. Economic factors alone should not govern choices, because the long-term consequences can be significant. The generator must obtain assurance, in terms of documentation, permits, records, insurance and liability coverage, and regulatory compliance history, that the chosen service provider is reliable.

There is often an advantage, particularly for smaller facilities, to contracting for all of the hazardous waste disposal operations. These include the packing and appropriate labeling of waste for off-site transportation and disposal, preparation of the shipping manifest, and arranging for the transporter and disposal facility. Again, the liability remains with the generator, and so the choice of such a waste disposal firm is critical.

In some states, Minnesota and Montana, for example, arrangements have been developed with local regulators to allow a large laboratory waste generator to handle the waste from very small laboratories such as those at small colleges and public schools. This plan results in informed assistance and cost savings for the smaller units. In Wisconsin, a statewide commercial contract that can be accessed by all state educational systems has been arranged. There is usually significant advantage to working with local and state agencies to develop acceptable plans for disposal methods that are environmentally and economically favorable for both large and small generators.

8.C.1.1. Minimization of Mixed Waste

Rigorous application of waste minimization principles can often solve the problems of managing mixed waste. Such efforts are most successful when scientists and EHS staff work together to evaluate laboratory processes. A successful collaborative minimization initiative undertaken by the NIH Mixed Waste Minimization Program demonstrated that the ultraviolet peroxidation treatment of aqueous mixed waste could reduce or eliminate a large portion of the mixed waste generated in the NIH research laboratories. This treatment method degrades hazardous organic compounds in high-volume aqueous mixed waste streams. The removal efficiency for a number of volatile and semi-volatile compounds is in excess of 99.99%. The treated waste can be discharged to the sanitary sewer (Rau, 1997).

Modifying laboratory processes, improving operations, or using substitute materials are approaches that can achieve minimization of mixed waste. Examples of these approaches include the following:

• Use 2.5-mL scintillation vials (“minivials”) rather than 10-mL vials. Adapters are available for scintillation counters with 10-mL vial racks.
• Count phosphorus-32 (³²P) without scintillation fluid by the Cerenkov method on the tritium (³H) setting of a liquid scintillation counter (approximately 40% efficiency); iodine-125 (¹²⁵I) can be counted without scintillation fluid in a gamma counter.
• Use microscale chemistry techniques.
• Eliminate the methanol/acetic acid (chemical) and radioactive mixed hazards in gel electrophoresis work by skipping the gel-fixing step if it is not required.
• Line lead containers with disposable plastic or use alternative shielding materials to prevent lead contamination by radioactivity.
• Reduce the volume of dry waste by compaction of contaminated waste gloves, absorbent pads, and glassware.

Some simple operational improvements can help minimize mixed waste. Purchase chemicals and radioactive materials in quantities necessary for a planned experiment to avoid creating surplus materials that may end up as waste. Establish procedures that will prevent commingling radioactive waste with noncontaminated materials and trash.

Consider substituting a less-hazardous constituent for either the chemical or the radioactive source of the mixed waste. The experimenter should use the minimum activity necessary and select the radionuclide with the most appropriate decay characteristics. Examples include the following:

• Use nonignitable scintillation fluid (e.g., phenylxylylethane, linear alkylbenzenes, and diisopropylnaphthalene) instead of flammable scintillation fluid (e.g., toluene, xylene, and pseudocumene). LSF that is sold as being “biodegradable” or “sewer disposable” is more appropriately labeled as “nonignitable” because biodegradability in the sanitary sewer can vary considerably with the local treatment facility.
• Use nonradioactive substitutes such as scintillation proximity assays for phosphorus-32 (³²P) or sulfur-35 (³⁵S) sequencing studies or ³H cation assays, and enhanced chemiluminescence as a substitute for ³²P and ³⁵S DNA probe labeling and Southern blot analysis.
• Substitute enriched stable isotopes for radionuclides in some cases. Mass spectrometry (MS) techniques, such as inductively coupled plasma-MS, are beginning to rival the sensitivity of some counting methods. Examples include use of oxygen-18 (¹⁸O) and deuterium (²H) with mass spectrometry detection as substitutes for oxygen-19 (¹⁹O) and ³H.
• Substitution of shorter-half-life radionuclides such as ³²P (t_1/2 = 14 days) for phosphorus-33 (³³P) (t_1/2 = 25 days) in orthophosphate studies, or ³³P or ³²P for ³⁵S (t_1/2 = 87 days) in nucleotides and deoxynucleotides. In many uses, iodine-131 (¹³¹I) (t_1/2 = 8 days) can be substituted for ¹²⁵I (t_1/2 = 60 days). Additional exposure precautions may be required.

8.C.1.2. Safe Storage of Mixed Waste

Store waste containing short-half-life radionuclides for decay prior to subsequent waste management processing and disposal. On-site decay-in-storage of LLW is very efficient and minimizes handling and transportation risks. Most institutions designate a room or facility equipped with good ventilation, effluent trapping, and fire suppression to contain and manage on-site decay-in-storage. Laboratory decay-in-storage space can provide safe storage for low-risk mixed wastes. Laboratory storage is not appropriate for storage of putrescent or reactive materials.

The specific USNRC requirements for decay-in-storage of radioactive waste are usually detailed in the institution's license. Decay-in-storage is usually limited to half-lives of less than 65 days. When the short-half-life radionuclides have decayed to background levels (the length of time depending on the initial radioactivity level but typically defined as a storage period of at least 10 half-lives), the chemical–radioactive waste can be managed as a chemical waste. After the decay period, USNRC licenses usually require that the mixed waste be surveyed for external radiation prior to releasing it to the chemical waste stream.

Storage of mixed waste for decay for more than 90 days may require the approval of the state chemical hazardous waste authority. In permitted storage facilities, storage may be limited to 1 year for some types of mixed waste. Workers should contact their institution's EHS staff or local hazardous waste agency to determine their regulatory status and requirements for storing mixed waste for decay.

8.C.1.3. Hazard Reduction of Mixed Waste

Chemical hazards can be reduced by carrying out various common chemical reactions with the waste in the laboratory. However, “treatment” of chemical hazardous waste has regulatory implications that must be considered. Many of the same considerations apply to treatment of mixed waste.

Nevertheless, there are still justifiable and legal reasons to carry out such operations in the laboratory when hazards can be minimized safely. Neutralization, oxidation, reduction, and various other chemical conversions as well as physical methods of separation and concentration can be applied prudently to many laboratory-scale mixed wastes. However, the dual character of the hazard, chemical and radioactive, requires that additional precautions be exercised. Treatment for the chemical hazard must not create a radioactivity risk for personnel or the environment. For example, vapors or aerosols from a reaction, distillation, or evaporation must not lead to escape of unsafe levels of radioactive materials into the atmosphere. Laboratory chemical hoods appropriate for such operations should be designed to trap any radioactive effluent. When mixed waste is made chemically safe for disposal into the sanitary sewer, the laboratory must ensure that the radioactivity hazard is below the standards set by the POTW. Several examples for reducing the hazard of mixed waste are described below:

• The worker can reduce the chemical hazard to a safe level and then handle the material as only a radioactive hazardous waste. Many low-level radiation materials can then be allowed to decay to a safe level, following which simple disposal is allowable.
• Some radioactive methanol–acetic acid solutions from gel electrophoresis can be recycled via distillation and the methanol reused. The solution is neutralized prior to distillation to protect the distillation equipment from corrosion and to reduce the level of methyl acetate formed during the process.
• The volume of waste phenol, chloroform, methanol, and water containing radionuclides can be reduced by separating the nonaqueous portion using a separatory funnel. After separation, the organic phase can be distilled to produce chloroform waste, which may contain levels of radioactivity below license limits for radioactive waste. The still bottom and aqueous phase must be handled as a mixed waste.
• High-performance liquid chromatography, used to purify radiolabeled proteins and lipids, can generate a waste radioactive solution of acetonitrile, water, methanol, acetic acid, and often a small amount of dimethylformamide. When the solution is distilled by rotary flash evaporation, the distillate of acetonitrile, methanol, and water is nonradioactive and can be handled as a chemical hazardous waste. The radioactive still bottom, containing 1 to 5% methanol and acetic acid, can usually be neutralized, diluted, and disposed of in the sanitary sewer.
• Aqueous solutions containing uranyl or thorium compounds can be evaporated to dryness and the residues disposed of as radioactive waste. Because of their toxicity, solidification may be necessary prior to burial at a LLRW site.
• Activated carbon, Molecular Sieves^®, synthetic resins, and ion-exchange resins have been used with varying success in the separation of chemical and radioactive waste constituents. Activated carbon has been used to remove low concentrations of chloroform (less than 150 ppm) from aqueous mixed waste solutions. However, activated carbon is not suitable for high concentrations of phenol–chloroform or acetonitrile–water mixed waste. Amberlite^® XAD resin, a series of Amberlite^® polymeric absorbent resins used in chromatography, has been shown to be effective in removing the organic constituents from aqueous phenol, chloroform, and methanol solutions, leaving an aqueous solution that can be managed as a radioactive waste. Chemical constituents can be separated from mixed waste by using supercritical fluid extraction (e.g., carbon dioxide), which is now available commercially.
• Surface contamination from radioactively contaminated lead can be removed by dipping the contaminated lead into a solution of 1 M hydrochloric acid. After rinsing the lead with water, it usually can be documented as nonradioactive. The acidic wash and rinse solutions contain radionuclides and lead and must be handled as mixed waste. However, decontaminating the lead results in a smaller mass of mixed waste and allows the decontaminated lead to be reused or recycled. Commercial rinse products are also available for this purpose.
• Incineration is advantageous as a treatment for many types of chemical–radioactive waste, especially those that contain toxic or flammable organic chemicals. Incineration can destroy oxidizable organic chemicals in the waste. To comply with radionuclide release limits, USNRC licensees need to control emissions and may need to restrict the incinerator's waste feed. Radioactive ash is typically managed as a radioactive waste. It is important to keep toxic metals (e.g., lead, mercury) out of the incinerable waste so that the ash is not chemically hazardous according to the TCLP test. On-site incineration minimizes handling and transportation risks; however, incineration of chemical waste is regulated by EPA and requires a permit, which is beyond the resources of most laboratory waste generators.

8.C.1.4. Commercial Disposal Services for Mixed Waste

Because of the great variety of laboratory mixed waste, it is often difficult to find a facility that can manage both the radioactive and the chemical hazards of the waste. In general, existing commercial disposal facilities are in business to manage mixed waste from the nuclear power industry, not waste from laboratories. Several commercial disposal facilities that accept mixed waste from off-site generators do exist in the United States. These sites have the capacity to manage LSF, halogenated organics, and other organic waste. Treatment capacity exists for stabilization, neutralization, decontamination/macroencapsulation of lead, and reduction of chromium waste.

In spite of this capacity, many types of laboratory mixed waste have no commercial repository. No commercial mixed-waste disposal facilities exist for waste contaminated with most toxic metals (such as mercury) or for lead-contaminated oils. Commercial disposal capacity likewise does not exist for high concentrations of halogen-containing organics and other TCLP waste, such as waste that contains chloroform.

8.C.2.1. Disposal of Chemically Contaminated Animal Tissue

Animal carcasses and tissues that contain a toxic chemical may be the most prominent chemical–biological laboratory waste. Such waste includes biological specimens preserved in formalin and rodents that have been fed lead, mercury, or PCBs in toxicity studies. If storage of such putrescible waste is necessary, refrigeration is usually advisable. Infectious waste should be stored separately in a secure area.

Incineration, which destroys potential infectious agents, is the most appropriate disposal method for putrescible waste. Large research institutions are likely to have an on-site animal incinerator. Medical waste incineration is also available through commercial waste haulers.

(If animal or commercial incineration is unavailable, methods in section 8.C.3.3, below, may be adaptable to chemical–biological waste.)

8.C.2.2. Sewer Disposal of Chemical–Biological Liquids

Laboratories that manipulate infectious agents, blood, or body fluids may generate waste that is contaminated with these materials and toxic chemicals. In most cases, blood and body fluids that contain toxic chemicals can be disposed of safely in a sanitary sewer, which is designed to accept biological waste. Approval for such disposal should be requested from the local wastewater treatment works. Chemical concentrations in such waste are typically low enough to be accepted by a local treatment works. OSHA recommends that a separate sink be used exclusively for disposal of human blood, body fluids, and infectious waste. It may be prudent to treat blood and body fluids with bleach (usually a 1:10 aqueous dilution of household bleach) prior to disposal in the sanitary sewer. Laboratory personnel should take care to prevent personal exposure while waste is being discharged into the sewer.

8.C.2.3. Disinfection and Autoclaving of Contaminated Labware

Contaminated labware may include cultures, stocks, petri plates, and other disposable laboratory items (e.g., gloves, pipettes, and tips). In many cases, the small quantities of infectious waste on labware can be disinfected safely with bleach or other chemical disinfectant (e.g., by soaking overnight). Once disinfected, the labware can be treated as a chemical waste. Laboratory personnel must check with the state or regional EPA office to determine if a treatment permit is required for chemical disinfection of chemical–biological waste.

Autoclaves can be used to steam-sterilize infectious waste but should be tested routinely for efficacy. Autoclaving does not require an EPA permit. Care must be taken because autoclaving of chemical–biological waste at 120 to 130 °C may result in the volatilization or release of the chemical constituent. Additional waste containment may be needed to minimize chemical releases, but it can interfere with steam penetration into the waste load and sterilization. Before autoclaving, evaluate the waste to verify that the heat and pressure of autoclaving do not create unsafe conditions.

Autoclaving waste containing flammable liquids may result in a fire or explosion. Note also that steam sterilization of waste that contains bleach may harm an autoclave. To autoclave voluminous chemical–biological waste streams, it may be appropriate to dedicate an autoclave room with ample ventilation and to restrict access.

8.C.2.4. Disposal of Chemically Contaminated Medical Waste and Sharps

Laboratories that work with human blood must adhere to OSHA's Standard for Occupational Exposure to Bloodborne Pathogens (29 CFR § 1910.1030), which requires waste containment, marking, and labeling. The OSHA standard also regulates waste disposal from laboratories that manipulate HIV or HBV. In general, such waste that has chemical contamination can be incinerated with other medical waste.

Waste hypodermic needles and other “sharps” (e.g., scalpels and razor blades) need to be contained in a puncture-resistant waste collection container. Sharps should be destroyed by incineration or by grinding as part of the disinfection treatment. Incineration of chemical- or drug-contaminated needles in a medical waste incinerator is appropriate if the waste is not an EPA-regulated chemical waste and if the chemical's toxicity or contamination is low. Needles and other sharps that are contaminated with toxic chemicals and infectious agents or blood can be autoclaved or disinfected on-site (see the precautions above), and then managed as a chemical waste. The waste container's biohazard symbol and markings should be defaced after autoclaving or disinfection to indicate that the waste has been sterilized. Noninfectious needles and sharps with high chemical toxicity or contamination are accepted by chemical incinerators.

Some biomedical research generates materials contaminated with blood and cytotoxic antineoplastic drugs or other highly potent drugs. Incineration of these materials as medical waste is appropriate. In some cases, chemical disinfection and treatment can be combined to destroy both infectious agents and the drug. Note that unemptied source containers of some drugs are EPA-listed hazardous waste and must be managed as a regulated chemical waste.

8.C.2.5. Minimization Methods for Chemical– Biological Waste

Waste minimization methods used for chemical waste can be used to reduce or eliminate the chemical hazard of chemical–biological waste. Some laboratories that generate biohazardous waste have replaced disposable items with reusable supplies, which are disinfected between uses.

For biological waste, waste minimization can be accomplished best through careful source separation of biological waste from other waste streams. When state guidelines for defining infectious waste do not exist, it is important for laboratories to define carefully those biological wastes that can be disposed of safely as non-infectious within the framework of the CDC and NIH guidelines (HHS/CDC/NIH, 2007a). Training workers to identify and separate biological waste will prevent its inadvertent mixing with other waste streams and normal trash.

8.C.3.1. Off-Site Management of Low-Level Radioactive Waste

Many laboratories do not have an on-site incinerator for radioactive–biological waste. Communities tend to oppose waste incinerators, and on-site incineration is prohibitively costly for some radioactive–biological waste generators. Even institutions that have incinerators must usually rely on off-site disposal for some of their radioactive waste. For radioactive putrescible waste, off-site disposal requires special packaging, storage, and transport considerations.

8.C.3.2. Disposal of Radioactive Animal Carcasses and Tissue

Waste radioactive animal carcasses and tissue generated from biomedical research typically pose no significant infectious hazard, but they are putrescible. USNRC regulations allow animal carcasses and tissue with less than 1.85 kBq/g of ³H or ¹⁴C to be disposed of without regard to radioactivity. Thus animal carcasses and tissue below this limit need not be managed as a radioactive–biological waste but only as a biological waste.

Animal tissue with higher levels of activity or other radionuclides must be managed as a radioactive waste. As with all putrescible waste, waste should be refrigerated, frozen, or otherwise preserved during accumulation, transport, and storage.

Although on-site incineration is the preferred method of managing radioactive animal carcasses and tissue, several alternatives exist. Alkaline digestion of animal carcasses containing ³H, ¹⁴C, and formaldehyde, followed by neutralization, results in an aqueous radioactive stream that can usually be disposed of in the sanitary sewer. The process uses 1 M potassium hydroxide at 300 °C and pressures up to 150 psi. Commercial units are available for this process. Radioactive animal carcasses may be accepted at a LLRW site when packed in lime.

Some institutions grind radioactive animal tissue for disposal in the sanitary sewer. USNRC requires that all such sewer-disposable waste be dispersible within the liquid effluent. Preventing contamination and exposure of waste handlers to dust or particles is an important safety measure in this operation.

Autoclaving of infectious animal carcasses is difficult because of the waste's high heat capacity and poor heat conductivity, and often unproductive because treated waste remains putrescible.

8.C.3.3. Disposal of Radioactive–Biological Contaminated Labware

Radioactive–biological contaminated labware (e.g., gloves and disposable laboratory articles) is generated from biomedical research using radioactive materials with infectious agents, blood, and body fluids. On-site incineration, autoclaving, and off-site disposal are the management options for this waste. Chemical decontamination (e.g., soaking in bleach) may be appropriate if it can be done without risking personal exposure, increasing waste volumes, or creating a waste that is difficult to handle (e.g., wet waste). After disinfection, radioactive–biological waste can be managed as radioactive waste.

Infectious waste and sharps containers that contain radionuclides can be autoclaved safely if the following precautions are satisfied:

• Monitor the air emissions of a test load to determine if the release of radioactive material is in compliance with USNRC license limits.
• Wipe-test the autoclave interior for surface contamination regularly.
• For ongoing treatment of this waste, dedicate an autoclave or autoclave room for this purpose. The room should have ample ventilation.
• Restrict access during autoclaving.
• Test the autoclave efficacy regularly using biological and chemical indicators.

Radioactive needles contaminated with infectious agents or blood should be autoclaved as described above, and then incinerated on-site or shipped to a LLRW site. To prevent injuries, it is important that hypodermic needles and other sharps be kept in waste containers that are puncture-resistant, leakproof, and closable from the point of discard through ultimate disposal. To prevent generation of radioactive aerosols, destruction of needles by grinding or a similar means is not recommended.

8.C.3.4. Sewer Disposal of Radioactive–Biological Liquids

Radioactive blood, body fluids, and other sewer-compatible liquids may be disposed of in the sanitary sewer if quantities are within USNRC license and treatment work limits. Precautions must be taken to prevent exposure of waste handlers. OSHA recommends that disposal of human blood and body fluids be done in a dedicated sink.