Infectious Waste Management, Treatment, and Disposal

Infectious Waste Management, Treatment, and Disposal

Lawrence G. Doucet

In the modern era, for well over 200 years, medical waste management and disposal were of minor concern to most hospitals and health care facilities. Medical waste was essentially not covered in any particular regulations, and ample, low cost disposal options were readily available. Except for pathologic waste, such as body parts, almost all medical wastes were routinely disposed in local municipal landfills, with no special treatment, and with minimal concerns for segregation or special handling. Over this entire period, there were no documented or reported epidemics or public health impacts associated with medical waste disposal practices. However, that all changed dramatically in the early 1980s shortly after the Centers for Disease Control and Prevention (CDC) released its first report about the disease now known as AIDS, which led to rampant fears of a possible worldwide epidemic. At the time of CDC’s first AIDS report, little was known about what caused the disease or how it was spread which fostered confusion, consternation, and great concern among health care providers about how best to protect against transmission of the disease. The supposition among many experts, regulators, and most of the general public was that just about any waste generated at hospitals and other health care facilities was a likely source of the AIDS pathogen contamination and posed substantial threats to anyone that could be possibly exposed to it. Such suppositions, in turn, led to overreactions and panic-based decisions that sparked the promulgation of increasingly stringent infectious waste regulations, tremendous increases in “infectious waste” generation rates, launching of the commercial infectious waste disposal industry, and the development and promotion of countless alternative medical waste treatment technologies.

This chapter provides an overview of infectious waste regulations and standards with a particular focus on the United States as well as the basis and background of their development and promulgation. It also provides a general overview of recommended policies and procedures for managing infectious waste as well currently available systems and technologies for infectious waste treatment and disposal.


Health care institutions are obviously the predominant generators of infectious or medical waste. These are categorized by the North American Industry Classification System (NAICS) under the sector entitled Health Care and Social Assistance, and facilities in the health care industry are identified under NAICS Code 62. This code comprises four subsectors that include ambulatory health care services, hospitals, nursing and residential care facilities, and social assistance. The facilities included within each of these subsectors and respective NAICS code numbers are shown on Table 54.1.

In addition to health care facilities, other generators or sources of infectious or medical waste include academic, industrial, and governmental research laboratories; microbiological production facilities; biotechnology and pharmaceutical laboratory; and production facilities. Veterinary facilities including veterinarians’ offices, veterinary hospitals, and animal pharmaceutical research and production facilities are also generators. The following is a list of known and potential sources of medical waste:

  • Hospitals, medical centers, and polyclinics

  • Clinics, diagnostic facilities, dialysis centers, and other specialized outpatient treatment facilities

  • Primary health centers, rural health stations, basic health units, or health posts

  • Maternity centers or birthing facilities

  • Physicians’ offices

  • Dental clinics and offices

  • Medical laboratories, biomedical laboratories, research centers, and biotechnology laboratories

  • Blood banks, blood collection centers, and blood transfusion centers

  • Nursing homes for the elderly and long-term residential care facilities

  • Facilities and hospices for the chronically and terminally ill

  • Pharmacies and dispensaries, drug stores, and pharmaceutical manufacturing facilities

  • Alternative medicine treatment facilities such as acupuncture centers

  • Veterinary hospitals, veterinarians’ clinics, and veterinary offices

  • Animal research and testing centers and animal quarantine stations

  • Home health care settings

    TABLE 54.1 Health care industry classifications Code 62 for the North American Industry Classification System (NAICS) under the Health Care and Social Assistance sector

    NAICS Sectors

    NAICS Nos.

    Ambulatory health care services subsector

    NAICS 621

    Offices of physicians

    NAICS 6211

    Offices of dentists

    NAICS 6212

    Offices of other health practitioners

    NAICS 6213

    Outpatient care centers

    NAICS 6214

    Medical and diagnostic laboratories

    NAICS 6215

    Home health care services

    NAICS 6216

    Other ambulatory health care services

    NAICS 6219

    Hospitals subsector

    NAICS 622

    General medical and surgical hospitals

    NAICS 6221

    Psychiatric and substance abuse hospitals

    NAICS 6222

    Specialty hospitals

    NAICS 6223

    Nursing and residential care facilities subsector

    NAICS 623

    Nursing care facilities

    NAICS 6231

    Mental retardation, mental health, and substance abuse facilities

    NAICS 6232

    Community care facilities for the elderly

    NAICS 6233

    Social assistance subsector

    NAICS 624

    Individual and family services

    NAICS 6241

    Community food and housing and emergency and other relief services

    NAICS 6242

    Vocational rehabilitation services

    NAICS 6243

    Child day care services

    NAICS 6244

  • Emergency service facilities including ambulance stations, paramedic units, and rescue operations

  • Coroners’ or medical examiners’ facilities, forensic pathology or autopsy laboratories, and crime laboratories

  • Drug addiction rehabilitation centers

  • Funeral homes and mortuaries

  • Tattoo and cosmetic ear piercing establishments

  • Health and quarantine stations in airports, ports, and immigration/customs facilities

  • First-aid positions

  • Health facilities, infirmaries, clinics, or health stations in colleges and universities, children’s schools and summer camps, military establishments, police stations, prisons, and commercial or industrial establishments

According to a 2012 United Nations study,1 hospitals in the United States alone comprise only about 1% of the number of health-related facilities but account for more than 70% of total medical waste generation. Doctors’ offices, nursing homes, clinics, and medical laboratories collectively make up about 36% of the health-related facilities and generated about 22% of total medical waste. The study also indicated that this is typical in most countries whereby larger health care facilities generate the large majority of medical waste, even though they account for a small percentage of health care establishments, whereas small health centers, clinics, primary health stations, doctors’ offices, etc, comprise the majority of health care facilities but generate a much smaller portion of the medical waste stream.


The definition or meaning of the term infectious waste has been debated for decades, and there is no universally accepted definition. More than a dozen different terms, such as medical waste, biohazardous waste, hospital waste, red bag waste, pathologic waste, and others are typically used interchangeably with or in place of the term infectious waste in scientific and medical literature, regulations and standards, guidance manuals, and in press reports and journals. There are distinct technical differences in the meanings of these terms, but they essentially refer to the same type of waste. However, as discussed in the following text, because only a small fraction of socalled infectious waste generated at hospitals and other health care facilities is actually or potentially infectious or capable of causing or transmitting an infectious disease, the term medical waste is used herein to refer to all health care waste that is collectively managed or typically considered as being potentially infectious, and the term infectious waste is intended to refer only to waste that is actually or potentially infectious.

Discussions or analysis involving waste management, treatment, or disposal, which is collectively termed herein
as waste management, should always begin with the establishment of clear definitions or at least a good understanding of the waste itself. In fact, failure to properly identify or correctly describe a particular waste stream and its characteristics in the course of making waste management decisions could result in any number of problems ranging from general misunderstandings and confusion to unexpected compliance difficulties or the procurement of an inadequate waste treatment system.

This may seem obvious and easily done, but it is not typically the case. Terms commonly used to identify waste types and categories are sometimes a bit vague and could have multiple meanings. For example, there are about 20 synonyms for the term waste, including trash, refuse, garbage, rubbish, debris, and so on, that are often used indiscriminately and interchangeably when referring to a waste, but the composition and characteristics applicable to these terms could be different under different scenarios. For example, the term garbage technically only means animal or vegetable waste from food service or kitchen activities, which is quite different from trash or rubbish typically originating from such activities as warehousing operations and office buildings. As another example, the term solid waste would normally be assumed to mean waste having a solid form or state, but the US Environmental Protection Agency (EPA) regulations define “solid waste” to include sludges from wastewater treatment plants, which, by most definitions and in most all cases, is far from being a solid.

TABLE 54.2 Typical infectious waste synonyms



Biohazardous waste

Used primarily because “infectious waste” was included in the EPA’s draft hazardous waste regulations

Biological waste

More applicable to activities in clinical, research, or pathology laboratories involving cells, tissues, organs, or other organisms

Biomedical waste

General term combining terms for biological- and medical-type waste; does not necessarily mean infectious or potentially infectious but commonly assumed to be so

Clinical waste

More applicable to activities in clinical, research, or pathology laboratories; is also a common term used for describing “infectious waste” in a number of countries

Contaminated waste

Disposed items that have contacted blood or body fluids regardless of whether such blood or body fluids are contaminated by a pathogen

Health care waste

Used to describe or identify all waste generated from a health care facility whereby potentially infectious waste is typically only a small fraction

Hospital waste

Used to describe or identify all waste generated from a hospital whereby potentially infectious waste is typically only a small fraction of total hospital waste

Infectious medical waste (IMW)

Common regulatory term to define waste that must be managed and disposed as being potentially infectious; does not technically apply to any other health care waste

Medical waste

Defined by the EPA as waste generated at health care facilities such as hospitals, doctors’ offices, etc, that has the potential to be contaminate by blood or body fluids

Pathologic waste

Comprises recognizable body parts, tissues, organs, animal carcasses; also termed anatomical waste; may or may not be infectious or potentially infectious

Red bag waste

Color-coded bags typically used in the United States to collect and contain regulated or potentially infectious waste. For most health care facilities, most of the waste in such bags is not contaminated or potentially infectious. It should be noted that yellow-colored bags are used to collect potentially infectious waste in many other countries.

Regulated medical waste (RMW)

Waste specifically designated or defined as being potentially infectious according to regulatory definitions

Abbreviation: EPA, US Environmental Protection Agency.

The term infectious waste is a prime example of a waste type or category where clarification and specificity are often needed to avoid potential problems. This is particularly important to prevent misunderstandings about potential risks for a particular waste stream that impact decisions on its management and disposal. As an example, usage of terms like infectious or biohazardous waste by local newspaper reports when referring to waste generated at any particular hospital or health care facility could readily lead to unwarranted fears within the local community as well as unjustifiable opposition by environmental activist groups of a proposed medical waste treatment, transport, or disposal of project. Examples of various synonyms typically used for infectious or medical waste are summarized in Table 54.2.

Regardless of origin or composition, any waste that is identified or designated as being infectious is almost always understood and assumed to have been contaminated by an infectious agent and therefore readily capable of causing or transmitting an infectious disease. However, the fact is that a very high percentage of waste generated from hospitals and other health care facilities is not infectious and poses virtually no threat of transmitting an infectious disease. Instead, only a small fraction of health care waste is even considered potentially infectious and only under very specific conditions.

Technically and scientifically, infectious waste comprises disposed items or materials that have been contaminated by a pathogenic microorganism, or etiologic agent, or pathogen, such as bacteria, viruses, parasites, or fungi, having sufficient virulence and in sufficient quantity that it is capable of causing infectious disease in healthy humans. The primary means or source for such contamination is direct contact in some manner with contaminated blood or body fluids during medical procedures or diagnostic activities. Accordingly, medical waste is either infectious if pathogenically contaminated or it is not infectious if not so contaminated. However, this distinction is often not clear because it is typically problematic if not impossible to know with certainty whether blood or body fluids released or exposed in connection with most health care-related activities is in fact infectious or contaminated with a pathogen. Likewise, it is not possible to know whether any particular waste or disposed item has been in contact with blood or body fluids that are not readily discernible or that are possibly too small to be visibly detected. Therefore, prudent practice is that any and all waste or disposed items having been in contact with or exposed to blood and/or body fluids be managed as “potentially infectious waste,” and this is the basis of most medical waste regulations and standards. In addition, practice at most health care facilities and most medical waste regulations standards also identify specific health care procedures, areas, and activities where there is a high likelihood that waste and disposed items generated therein have contacted blood and/or body fluids and, accordingly, need to be managed as being potentially infectious.

CDC Medical Waste Definitions

Decisions by most health care facilities to manage any and all waste that may have contacted blood or body fluids as being potentially infectious originated from interpretations of CDC’s 1983 guidance commonly known as Universal Precautions.2 These guidelines were published shortly after CDC’s initial reports about AIDS and subsequent concerns that just about all health care waste was likely to be contaminated by the HIV and that such waste posed unacceptable risks to patients and public health.

Universal Precautions guidelines were originally interpreted by most health care facilities as meaning anything whatsoever that came into contact with any patient or staff person should be considered and managed as potentially infectious. This interpretation had far-reaching consequences because countless health care facilities suddenly began considering just about all waste as being potentially infectious thereby greatly increasing medical waste generation rates nationwide. At that time in the United States, not only was there insufficient on-site or off-site capacity for treating such waste but also many municipal waste disposal firms abruptly refused to pick up or dispose of any waste from hospitals, including trash, cardboard, and recyclables, because of fears that it was possibly contaminated with HIV.

In light of continued uncertainties and confusion about HIV and its transmission as well as increasing problems associated with health care waste management and disposal, CDC undertook efforts to clarify the meaning and intent of the universal precautions in the 1985 publication Guideline for Handwashing and Hospital Environmental Control.3 This identified four specific health care waste categories as having “sufficient potential risk of causing infection during handling and disposal and for which some precautions are prudent since precise definition of infective waste that is based on the quantity and type of etiologic agents present is virtually impossible.” The listed categories are

  • Microbiology laboratory waste such as microbiological cultures and stocks of microorganisms including specimen containers; slides and cover slips; and disposable gloves, aprons, and laboratory coats

  • Pathology and anatomical waste such as from surgery and autopsy including body parts, soiled dressings, sponges, drainage sets, underpads, and surgical gloves

  • Blood and blood products including blood specimens and body fluid specimens

  • Contaminated sharps including used needles, scalpel blades, and broken glass

EPA Medical Waste Definitions

The US Congress enacted the Solid Waste Disposal Act of 1965 (SWDA) to promote improved waste management technologies and standards for reducing pollutants in municipal waste disposal programs, but it did not address medical waste in any manner. The Resource Conservation and Recovery Act of 1976 (RCRA) amended the SWDA and gave the EPA authority to regulate hazardous waste. Initial drafts of EPA’s hazardous waste regulations included the term infectious characteristic as a descriptor for waste to be regulated as hazardous, but EPA’s final Hazardous Waste Regulations in 1980 neither listed infectious waste as a hazardous waste nor included “infectiousness” as one of the characteristics for identifying a waste as being hazardous. However, in anticipation that infectious waste would eventually be identified as hazardous waste,
the EPA published the Draft Manual for Infectious Waste Management4 in 1982 and the EPA Guide for Infectious Waste Management5 in 1986.

During the summers of 1987 and 1988, there were numerous reported incidents of needles and other medical waste washing up on beaches and shorelines of the United States along the eastern seaboard and Great Lakes that caused a national sensation and great public concern. These incidents led to congressional enactment of the Medical Waste Tracking Act (MWTA) of 1988.6 The MWTA was only a 2-year program that ran from June 1989 through June 1991, and it only applied to four states (New York, New Jersey, Connecticut, and Rhode Island as well as Puerto Rico). Its primary objectives were to gather information about medical waste management, to evaluate various medical waste treatment technologies, and to provide a model for states and other federal agencies to use in developing their own medical waste programs.

The MWTA adopted the definitions and descriptions that were included in the EPA’s 1986 Guide for Infectious Waste Management.5 It defined medical waste as “any solid waste that is generated in the diagnosis, treatment, immunization or autopsy of human beings or animals, in research pertaining thereto, in the preparation of human or animal remains for interment or cremation, or in the production or testing of biologicals” and it included the following categories:

  • Cultures and stocks of infectious agents and associated biologicals including cultures from medical and pathologic laboratories; cultures and stocks of infectious agents from research and industrial laboratories; wastes from the production of biologicals; discarded live and attenuated vaccines except for residue in emptied containers; and culture dishes, assemblies, and devices used to conduct diagnostic tests or to transfer, inoculate, and mix cultures

  • Pathologic wastes including tissues, organs, body parts, and body fluids that are removed during surgery or autopsy

  • Waste human blood and blood products including serum, plasma, and other blood components

  • Contaminated sharps that have been used in patient care or in medical research or industrial laboratories including hypodermic needles, syringes, pipettes, broken glass, and scalpel blades

  • Contaminated animal carcasses, body parts, and animal bedding that were exposed to infectious agents during research, production of biologicals, or testing of pharmaceuticals

  • Waste from surgery or autopsy that was in contact with infectious agents including soiled dressings, sponges, drapes, underpads, and surgical gloves

  • Laboratory waste from medical, pathologic, or pharmaceutical laboratories that were in contact with infectious agents

  • Dialysis waste that was in contact with blood of patients undergoing hemodialysis including contaminated disposal equipment and supplies

  • Discarded medical equipment and parts that were in contact with infectious agents

  • Isolation waste including biological waste and discarded materials contaminated with blood, excretion, exudates, or secretion from humans or animal who are isolate to protect others from communicable diseases

US State Medical Waste Definitions

Incidents leading up to enactment of the MWTA as well as the fact that the EPA appeared to have no intentions of enacting more permanent medical waste regulations after the 2-year program ended prompted most US states to enact their own medical regulations. To date, all states in the United States have enacted medical waste regulations, and the regulations and requirements among each state vary widely with particular differences in the terminology and definitions of the waste being regulated. Many states adopted definitions and categories identical to those in the MWTA, whereas others established relatively unique definitions and identifiers of medical waste types, categories, and sources. As an example, some states define medical waste strictly in accordance with its degree of contamination, that is, whether it has only been in contact with blood or body fluids or whether it is saturated or grossly contaminated with blood or body fluids.

Most state environmental protection agencies are primarily responsible for developing and enforcing medical waste management regulations, but the department of health is the agency primarily responsible for medical waste management in some states. In several states, both agencies have responsibility for medical waste management, with the department of health typically responsible for on-site management and the environmental protection agency responsible for off-site transportation and disposal. In addition to definitions and designations, most states also specify requirements for medical waste containerization, labeling, storage, transportation, treatment, and disposal. They also specify procedures for permitting, operating, and testing medical waste treatment systems and equipment inclusive of requirements for training and certifying medical waste treatment system operators and for recording and reporting operating parameters of medical waste treatment systems.


Agencies that have enacted regulations and standards applicable to medical waste management in the United States are the EPA, the CDC, the Occupational Safety and
Health Administration (OSHA), and the US Department of Transportation (DOT). Each of these has its own congressional mandate that serves to direct or focus the approach that each adopts with respect to implementing its regulations and standards, but their collective goal is to protect the environment, public health, and workers including practices and procedures involving the management and disposal of infectious or medical waste. These are discussed in the following text.

EPA Regulations

The EPA has not had congressional authority to regulate medical waste management since expiration of the MWTA in 1991. However, the EPA strives to serve as a resource for medical waste management information and to work with or help support state health departments and environmental agencies in matters involving environmental protection as related to off-site medical waste disposal.

The EPA has authority to regulate two specific medical waste treatment technologies, namely, medical waste incinerators and treatment technologies using chemicals for disinfection or sterilization. The EPA regulates medical waste incinerators pursuant to the Clean Air Act (CAA) amendments of 1990 under regulations entitled Hospital, Medical, and Infectious Waste Incinerators (HMIWI). The HMIWI regulations, which were promulgated in 1997 (40 CFR §60 Subparts Ce and Ec) and amended in 2009 (40 CFR §62, Subpart HHH), establish highly stringent emissions standards for nine different air pollutants along with requirements for incinerator system operations, compliance testing, monitoring and reporting, and the training and certification of incinerator system operators and supervisors.7,8

The EPA regulates medical waste treatment technologies that use antimicrobial chemicals proclaimed to reduce the infectiousness of waste under the authority of the US Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Companies making such claims are required to register their product or technology under FIFRA through the EPA’s Office of Prevention, Pesticides, and Toxic Substances (OPPTS) Antimicrobial Division.

OSHA Regulations

Congress established OSHA as an agency of the United States Department of Labor under the Occupational Safety and Health Act of 1970 with a mandate to “assure safe and healthful working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education, and assistance.” The OSHA regulations cover most private-sector employers and their workers as well as some public-sector employers and their workers in all states and certain territories either through federal OSHA or through an OSHA-approved state plan. Currently,22 US states or territories have OSHA-approved state programs.

The OSHA regulations generally cover hazards associated with specific workplace activities, conditions, or practices, and they include certain aspects of medical waste management designed to protect health care workers and other employees against possible injury and risks of infection under the Bloodborne Pathogen Standard of 1991.9 This standard includes specific requirements covering the management of contaminated sharps, the containerization and labeling of medical waste, employee training, hazard communications, and hepatitis B virus (HBV) vaccinations. Although medical waste management operations are not identified as a specific OSHA workplace activity with its own activity-specific regulations, workers involved with such operations are protected against workplace injury under the OSHA General Duty Clause (Section 5[a][1]). The General Duty Clause states that employers are required to provide their employees a workplace that is “free from recognized hazards that are causing or are likely to cause death or serious physical harm.”

DOT Regulations

The DOT regulates the transportation of medical waste as an “infectious substance” (49 CFR Parts 171-180), particularly under Subchapter C, “Hazardous Materials Regulations” (HMR), which includes information on various hazardous materials and pertinent requirements for their packaging and their shipment by rail, air, vessel, and public highway. The HMR applies to any material the DOT determines is “capable of posing an unreasonable risk to health, safety, and property when transported in commerce.” The DOT regulations adopted the definitions for medical waste that were included in the MWTA.10

The DOT regulations primarily apply to medical waste transporters rather than medical waste generators. However, the DOT regulations include specific requirements for the packaging, labeling, and manifesting of medical waste that is transported off-site via public highways for treatment or disposal. Such requirements include mandatory Hazardous Materials Training for all managers and employees who prepare, assist, or who are responsible for the packaging and loading of hazardous materials, including medical waste, for off-site transport. Such training is also required for anyone who signs hazardous or medical waste transport manifest papers.

International Regulations and Standards

There are no international regulations or standards exclusively covering medical waste management, treatment, or disposal. However, two international agreements or treaties have been established and signed by a number of participating countries that are designed to reduce the transboundary movement of hazardous waste, including
those designated as “biohazardous,” between countries. The particular focus of these agreements is to prevent the transfer of hazardous waste from developed to less developed countries. One treaty, the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal (typically known as the Basel Convention), became effective in 1992. The other treaty, the Bamako Convention on the Ban on the Import into Africa and the Control of Transboundary Movement and Management of Hazardous Wastes within Africa (typically known as the Bamako Convention), was negotiated by 12 African nations in 1991 and became effective in 1998 because of reported failures of the Basel Convention to prohibit trade or imports of hazardous waste to less developed African countries.

It is believed that most developed countries have medical waste regulations in place that are comparable in many respects to those enacted in the United States. Such regulations vary widely in terms of content and specific requirements, and most are a component of or included within a country’s hazardous waste regulations whereby medical waste is defined as a type of hazardous waste. On the other hand, most developing countries have no such regulations in place and have no legal policies or standards in place for managing and disposing of medical waste in a safe, sanitary manner that will not endanger the environment or public health. Additionally, a high percentage of developing countries lack proper sanitary landfills such that medical waste is typically disposed at dump sites that not only are regularly scavenged by people for goods but also are sources of ground and drinking water contamination. As a means to help deal with such disposal problems, health care facilities in some developing countries use incinerators for on-site medical waste disposal, but such incinerators are typically of an inferior quality that operate poorly, at best, and tend to have exceedingly high air pollutant emissions during operations. International organizations, such as the United States Agency for International Development (USAID), typically attempt to work with or assist developing countries to help correct such problems whenever possible, but doing so tends to be exceptionally difficult if not insurmountable.

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May 9, 2021 | Posted by in MICROBIOLOGY | Comments Off on Infectious Waste Management, Treatment, and Disposal

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