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INFECTIOUS WASTE MANAGEMENT

Debra L. Hunt, Dr.P.H. Environmental Safety

Duke University Medical Center, Durham, NC

In developing an infectious waste management program for a hospital

or other institution, one must realize that there is no one optimum

plan.

facility in order to design a safe and effective plan for the handling

and disposal of infectious waste at each location and type of facility.

The purpose of this presentation is to review the elements within the

Environmental Protection Agency "Guidelines for Infectious Waste

Management" as well as the North Carolina regulations, and to discuss

the various options and interpretations.

Regulations and/or recommendations must be interpreted by each

Several variables should be considered before developing the

specific elements of an infectious waste management program:

1. Zocat ion. The proximity of the facility to other hospitals,

institutions, or commercial treatment facilities will influence the

decision to treat waste off-site or to share treatment processes (i.e.,

a common incinerator). If location of the facility is within an urban

area, public reaction to the management policy will also need to be

considered.

2 . The funds available for managing infectious waste

will, of course, be a prevailing factor in determining cost-effective

alternatives. Variables considered will include personnel, maintenance

costs, service fees, hauling fees, and annual operation of waste

disposal eqiuipment.

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3. Available eauiDment. The decision to treat waste on-site vs

off-site will largely depend on what treatment equipment is available.

One advantage to use of on-site equipment is that the single generator

of infectious waste maintains control of the waste until it is rendered

non-infectious. Since this reduces the risk for workers outside the

facility, on-site treatment offers a liability advantage. In addition,

many hospitals already have autoclaves available in laboratories or

incinerators in pathology.

The use of readily available off-site equipment (commercial

treatment facilities or shared equipment with other institutions) can be

the most cost-effective alternative if personnel costs or initial

purchases of large treatment equipment are considered. However, if off-

site treatment is used, proper processing of the waste by the outside

facility must be insured,.

4. Ouantitv and nature of infectious waste eenerated. - The type

and size of the institution must be considered. For example, does the

institution deal primarily with animal research?

quantities of needles used?

the primary treatment method.

microbiological research, an autoclave will be adequate.

Are there large

If so, an incinerator may be justified as

If the institution deals primarily in

5. Reeulatorv constraints, Several agencies affect and even

regulate the types of treatment and/or disposal methods for infectious

waste (see Table 1). Local sewage authorities, state regulations, and

federal guidelines will all impact on management decision. Locally, the

county or municipal authorities may present the most restrictive

requirements. For example, in New York City on August 2, 1985, Mayor

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Koch signed into law the requirement that all laboratory, isolation,

sharps, and surgical wastes be incinerated before acceptance into a New

York City landfill (1).

On July 1, 1985, the North Carolina legislature passed a law

dictating that infectious waste must be treated by an approved method

prior to disposal in a state landfill (2).

interpretations will be discussed in more detail throughout this

presentation.

The contents and

In May 1986, the EPA published revised guidelines for infectious

waste management (3). While the EPA Guidelines are meant to be used as

a reference manual and not as a set of regulations, it is possible that

they may be regarded as "community standards" from a liability

standpoint.

recommendations to date, and will also be discussed in more detail.

These Guidelines probably represent the most detailed

The Centers for Disease Control (CDC) recommendations identify

specific infective material from patients on infectious disease

isolation (4). and are referenced in the EPA Guidelines. The Joint

Commission on Accreditation of Hospitals (JCAH) also offers

recommendations for handling infectious waste in hospitals ( 5 ) , but

these are the least restrictive of all the agencies' recommendations.

These five variables listed above are the prevailing restrictions

that must be confronted when designing an infectious waste management

plan.

terms of the interpretations of the agencies' guidelines and

regulations.

Each institution must review its own unique set of variables in

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Table 1. Agencies Which May Regulate or Affect

Infectious Waste Management

Local (county, municipal)

State - 10 NCAC 10G, Solid Waste Management, July 1, 1985 Solid and Hazardous Waste Management Branch Division of Health Services Department of Human Resources P.O. Box 2091 Raleigh, N.C. 27602 (919) 733-2178

Environmental Protection Agency Guidelines - May, 1986 National Technical Information Services Springfield, Va. Order #PB86-199130 EPA Document #EPA/530-SW-86-014

(704) 487-4650

Centers for Disease Control - Guideline for Handwashing and Hospital Environmental Control, 1985, Section 4: Infective Waste

Joint Commission on Accreditation of Hospitals

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Elements of an Infectious Waste Management Plan

The following are the important elements that must be defined in

order to develop an effective, safe, infectious waste management policy.

They are outlined in the EPA Guidelines, but are discussed here in light

of existing NC state regulations.

1. Definition of Infectious Waste. In both the EPA Guidelines and

the state regulations, infectious waste is defined as "...waste capable

of producing an infectious disease" (2, 3). The statement is a rather

broad one, but lays the foundation for decisions that must be made in

defining infectious waste within certain llgray" areas within the

institution. Note that neither definition states that waste

"contaminated" with organisms is considered infectious. Rather, the

waste must be capable of initiating an infectious disease.

2. TvDes of Inf ectious Waste. The EPA and the state of North

Carolina have designated categories of waste that each considers

infectious.

their designations (Table 2). There are'some major differences,

however, that will influence the amount of waste considered infectious

as well as the methods used for treatment. Ultimately, these have a

large impact on the cost of implementation of the waste management plan.

A comparison of the two indicates that they are similar in

The most distinguishable difference between the two is the absence

of isolation waste (i.e., waste from patients placed on infectious

disease isolation) from the NC state regulations and its inclusion in

the EPA categories. Isolation waste is handled in a more contained

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Table 2. Categories of Infectious Waste

Environmental Protection Aeencv

Isolation Wastes

Cultures & Stocks

Human Blood/Products

Pathological Waste

Contaminated Animal Carcasses, Body Parts, and Bedding

Contaminated Sharps

Miscellaneous

North Carolina

Microbiological Waste

Blood/Products (Bulk)

Pathological Waste (human and contaminated animal)

Sharps

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manner within hospitals if CDC isolation precautions are followed.

However, in the state of North Carolina, this category of waste need no t

be treated prior to disposal in a landfill.

While both agencies categorize blood and blood products as

infectious waste, the NC regulations specify "bulk" blood. This

definition allows an area of interpretation for each hospital.

example, Duke Medical Center sets a quantity of 20 milliliters or above

to denote "bulk" blood, primarily to exclude the small quantities of

blood that might be contained in vacutainer tubes.

For

The third difference noted in the categorization of infectious waste

is that the EPA has included a miscellaneous category in its Guidelines

that includes the following types of waste:

o surgery and autopsy wastes (soiled dressings, sponges, etc.)

o miscellaneous laboratory wastes (used specimen containers,

parafilm, slides, etc.)

o dialysis unit wastes (tubing, filters, etc.)

o contaminated equipment (disposable equipment used in patient

care)

The NC regulations include "human tissues, organs, body parts,

secretions and excretions, blood and body fluids that are removed during

surgery and autopsies" under the classification of pathological waste,

. and, therefore, require them to be handled as infectious waste. The

regulations, however, do not include materials "contaminated" by the

above wastes (soiled dressings, sponges, etc.)

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The EPA leaves the final determination of infectious waste to the

individual institution. A designated, responsible person must make the

decision regarding the infectious nature of the above wastes based on a

rational and logistical approach. For example, surgery waste

originating from septic cases might be handled as infectious, whereas

that from aseptic cases might be handled as routine trash.

The designation of the types of infectious waste will be one of the

more important decisions for an infectious waste manager. It will

determine the extent of the problem, the treatment method chosen, the

cost of the program, and the liabilities involved.

3. Handline of Infectious Waste, Once the difficult decisions

regarding infectious waste designation have been made, the "nuts and

bolts" of the operation can be established. First, it may be useful to

determine a rough estimate of the quantity of infectious waste that the

hospital generates. The amount that needs special processing will, of

course, effect the type of treatment, transport, and storage of the

waste, and, ultimately, the cost of the program.

Rutala and Sarubbi ( 6 ) , in a survey of hospitals in North Carolina,

estimated that an average of 13.05 lb of solid waste per patient per day

was generated (11.85 to 15.15 lb depending on hospital size). They also

determined that "infectious waste" in this study comprised 10.9% of the

total solid waste generated.

following estimate can be made:

Using Duke Hospital as an example, the

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Amount of Solid Waste:

15 lb./patient/day x 1,000 patients = 15,000 lb/day

Solid Waste

Amount of Infectious Waste:

15,000 lb/day x 10.9% = 1,635 lb/day

Infectious Waste

Wallace et al. (7) have shown that different areas in an institution

generate different quantities of solid waste. For example, the heavy

.care units (ICUs, operating room) produce twice as much waste as support

areas such as administration or pharmacy. They developed a table of

formulas that allows calculation of waste quantity generated by these

various units (Table 3 ) . Calculation of the quantity of infectious

waste might be further modified, depending on designations of infectious

waste from each of the areas.

The calculations are further complicated by estimation of the

quantities of the tTes of infectious waste (e.g., sharps,

microbiological, blood). Preliminary audits, surveys, and actual daily

logs will provide this additional data, and will be more accurate than

using a general formula.

A . Segregation. The first procedure in an infectious waste

management program will be the actual physical separation of the

infectious waste from general trash at the point of generation. .

4 2

Table 3 . Quantity of Solid Wastes

Areas

Light Care Units - (Psychiatric, ENT, Gen Med)

Heavy Care Units - (Surgery, Cardiovcascular, Burn, ICUs, OR)

Support Units - (Admin., Laundry)

Special Units: x-ray, ER

. Laboratories

Kitchen

Ouantitv (lb/dav)

2.77 X number paid staff

4.47 X number paid staff

2 . 2 1 X number paid staff

0.48 X number pts treated/day

0.19 X number tests run or patients treated/day

1.5 X number meals served/day

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Segregation is useful not only to insure that the infectious waste is

identified for proper treatment or handling, but to reduce the cost of

special handling that might be applied to non-infectious waste.

The infectious waste should be contained in clearly marked bags or

receptacles such as a red bag or a container marked with a biohazard

symbol. Infectious waste that also contains other recognized hazards

(i.e., antineoplastics, radioactive materials) should be further

separated and handled according to the federal or state regulations

regarding these hazards.

B. Packaging. More than any other element in an infectious waste

management program, packaging of the waste becomes the most effective

means of protecting the personnel who must deal with the waste from the

point of generation to final disposal. Although infectious waste has

not been shown to be a hazard for the general environment, documented

occupational infections have occurred when an infectious waste has been

improperly packaged for disposal.

instruments that have been improperly handled or disposed have been a

major mode of transmission of hepatitis B in health care personnel for

decades. Therefore, integrity of the packaging of infectious waste

should persist through all steps of the program - transport, storage, and treatment.

Needlesticks and cuts from sharp

Several factors that effect packaging should be considered:

o Waste type. Liquids should be contained in capped bottles,

solids in appropriate bags, and needles in puncture-

resistant, rigid containers.

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4 4

o Handling and transport. If transporting waste for long

distances, plastic bags should be placed in boxes to insure

their integrity. Infectious waste should not be compacted

before treatment since this might effect the integrity of

the containers and actualy disperse the waste. If

transporting microbiological waste before treatment,

specific packaging requirements by the CDC and Department of

Transportation (DOT) must be considered.

o Special considerations. Again, containers of infectious

waste need to be marked in some manner for identification.

Besides color coding and biohazard designations, some bags

are available that have special tape or markings that change

color or disappear/appear after treatment. Not only are

these bags useful for identification of infectious waste,

but they also assist in quality assurance of the program.

, C . Storage. If same day treatment for infectious waste cannot be

obtained, storage of the waste should be addressed in the management

program. The following factors will effect adequate storage:

o Integrity of packaging. A recurring factor, integrity of

the containers should also insure that no rodents or vermin

are able to penetrate during storage.

o Temperature and time. Some states place restrictions on

storage time and temperature.

permits storage for a maximum of four days at temperatures

For example, California

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greater than 32F. North Carolina regulations, however, do

not address this issue. The EPA broadly recommends that

storage times "be kept as short as possible" ( 3 ) .

o Location and design. The storage area should be

specifically designated as such with limited access,

addition, the area should be well marked, as with a

biohazard symbol.

In

D. Transport. Safe transport of infectious waste should be

.insured not only within the institution, but also if shipping off-site

for treatment. Several factors to address include:

o Proper packaging. As previously mentioned, rigid or semi-

rigid leak-proof containers need to be used for off-site

transport for treatment. Also, CDC and DOT packaging

requirements need to be maintained.

o Safe in-house transfer. To avoid dispersal of infectious

material throughout the institution, trash chutes should not

be used for transport. Rather, carts are recommended for

transport in-house.

transport should be frequently disinfected.

Carts or vehicles used for in-house

E. Treatment, The EPA notes that potential hazards resulting from

- infectious waste are those that may occur when package integrity is

compromised and infectious material is dispersed. The EPA, therefore,

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recommends that infectious waste be treated before disposal in order to

insure protection from these potential hazards.

require that those wastes designated as infectious be treated and

rendered non-infectious before disposal at a landfill.

The NC regulations

Treatment is defined by EPA as "any method, technique, or process

designed to change the biological character or composition of waste . . . Treatment must reduce or eliminate pathogens (present in the waste) so that

it no longer poses a hazard to persons who may be exposed to it." ( 3 )

Several optional means of treatment are recommended by the EPA as

well as the NC regulations.

waste management program will probably constitute the majority of the

costs and liabilities of the program. For these reasons, several

important factors need to be considered:

The treatment(s) selected for an infectious

o Use of recommended treatment techniques. Using recommended

treatment techniques for infectious waste is desired because

of proven efficacy and for liability purposes.

following techniques are recommended by the EPA:

The

(1) Steam Sterilization.

Use:

except pathological and animal bedding.

Recommended for treatment by the EPA of all waste

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Advantages

I

Disadvantages

- availability; most facilities

have autoclaves

- no initial expense - inexpensive to run and monitor

- easy to operate

- time consuming

- small quantities only

- no reduction of waste volume

(2) Incineration.

Use:

and NC

Recommended for treatment of all waste types by EPA

Advantage s Disadvantages

- up to 9 5 % reduction in waste volume - burning of non-regulated

- pathological incinerators chemicals or plastics

available in most hospitals require capability of

- usable energy may be generated heat > 1,088F

(heat recovery) - must meet federal, state, and local air

pollution standards

- expensive initial

investment and high

maintenance costs

- requires trained personnel to operate

( 3 ) Thermal Inactivation.

Use:

generally large volume liquids of known pathogens

(industrial).

Recommended by EPA for microbiological cultures,

(4)

oxide).

Use: Formaldehyde may be used for certain items such as

HEPA filters from biological safety cabinets.

GaS/VaDOr Sterilization (formaldehyde and ethylene

Advantages Disadvantages

- effective - both are potential human

- ET0 commonly used as a sterilant carcinogens

- requires highly trained

personnel

( 5 ) Chemical Disinfection. (Discussed in another chapter.)

Use:

equipment, liquid waste, and bloodfiody fluids.

Recommended by EPA for disinfection of contaminated

Advantages Disadvantages

- effective if properly used - inexpensive - available

- increases volume for disposal

- residue must comply with local sewer restrictions

4 9

(6) Ionizing Irradiation.

Use: Effective means of treatment for all infectious

material except body parts (does not render unrecognizable)

Advantages Disadvantages

- effective - high initial cost - requires highly trained p e r s onne 1

- requires large space - problem of ultimate

disposal of radiation

source

As implied above, different treatment methods may have specific

applications for certain types of infectious waste.

and NC regulations each specify recommended treatment techniques for the

various categories of infectious waste (Tables 4 and 5).

recommend incineration as a means of treatment for all types of

infectious waste. The EPA recommends steam sterilization for

practically all waste types except for animal bedding.

reasons, both EPA and NC recommend that pathological waste such as body

parts be rendered unrecognizable before disposal in a landfill.

Therefore, steam sterilization is an adequate method of treatment for

the infectious nature of pathological waste, but this waste must be

ground up and discharged to the sewer.

The EPA Guidelines

Both agencies

For aesthetic

-

Table 4 . Recommended Techniques for Treatment of Infectious Waste

I

Type of Steam Incineration Thermal Chem Other Infectious Steril. Inactiv. Disinf. Waste

Isolation Waste X X

Cultures & Stocks (Microbiological) X X

Human Blood/

(sewer) Pathological

Blood Products X X

Wastes X X

Sharps X X

X X

X

X

X

X (mortician)

Contaminated Animal carcasses Parts, Bedding X X

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Table 5. Recommended Techniques for Treatment of Infectious Waste

Type of Steam Incineration Other Infectious Waste Sterilization

Microbiological Wastes

Human Blood/

(Bulk) Blood Products

Pathological Wastes X

Sharps

Contaminated Animal Carcasses and Parts X

X

X

X

X

X

X (sewer)

X (hardwalled container)

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Unlike the EPA Guidelines, the NC regulations do not specifically

recommend steam sterilization as a treatment technique for bulk blood or

sharps. Instead, bulk blood must be either incinerated or discharged to

the sewer (contingent on local sewer restrictions). Sharps must be

either incinerated or mutilated, presumably to render needles inoperable

and to interrupt their mode of transmission of infectious diseases.

Note: Effective November 1, 1987, a new NC statute (G.S. 90-113.4A)

prohibits mutilation of needles and syringes as a means of treatment.

Rather, sharps should now be placed unbroken in either an incinerator or in a hardwalled container and disposed of in a sanitary landfill. This

.statute is consistent with the CDC's "Recommendations for Prevention of

HIV Transmission in Health-Care Settings" (August 21, 1987; MMWR, vol.

36, No. 2s) .

It must be noted that although EPA and NC recommend specific

treatment methods, both agencies recognize that other technologies might

be available for effective treatment of infectious waste. If an

institution chooses an alternative method of treatment, the EPA

recommends that it must demonstrate that the method is effective before

use, and biological testing schedules should be developed for monitoring

the treatment process. NC regulations, likewise, will approve

alternative methods "upon determination that the method effectively

renders infectious waste non-infectious." ( 2 ) .

o Establish standard operating prodecures. For whatever

treatment process is selected, the institution must be

familiar with its limitations, such as maximum temperature,

waste feed rate, and time required for optimum treatment.

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o Monitoring. The EPA further recommends that each process be

monitored, perhaps as part of a quality control protocol. For

example, the US Pharmacopeia recommends the use of biological

indicators for monitoring treatment processes such as steam

sterilization, incineration, and thermal inactivation ( 8 ) .

Biological indicators are standardized products inoculated

with spores of resistant strains of bacteria that are placed

within a load of waste as it is processed. For more

information, please refer to Perkins (9).

o Treatment Combinations. In many instances, the most cost-

effective means of treating the infectious waste spectrum of

an institution might be a combination of treatment methods,

both on- and off-site. For example, laboratory wastes can

be steam sterilized since most laboratories already have

autoclaves, and sharps, animal bedding, and pathological

waste can be incinerated.

o Disposal. Generally, infectious waste that has been treated

by an approved method can be disposed of as common solid

waste in a sanitary landfill. Again, it is prudent for each

hospital or institution to contact its local and state

governments to insure compliance with any restrictions.

4. Contineen CY Plannim Any effective waste management program

should include a contingency plan to provide for emergency situations.

An office or responsible person should be designated as a resource to

call when the following situations arise:

.

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Spills. The plan should include written procedures for clean-

up, personnel protection, and disposal of the spill residue. The

procedures should be available at sites of infectious waste generation,

storage, and disposal.

Rupture of plastic bags. When solid infectious waste is

inadvertently dispersed, the contingency plan should indicate the person

responsible for repackaging the waste.

Equipment failure. If a treatment method is disrupted because

of equipment failure, plans need to be made for storage and/or

alternative treatment methods. For example, is off-site treatment

readily available, or is there a back-up treatment method on-site?

5. Staff Training. Once developed, the infectious waste

management plan should be explained not only to those employees who

transport the waste, but also to those employees who generate the waste.

They should know what kind of work practices are necessary, what

protective garments need to be used for handling infectious materials,

etc.

Employee Health Office.

when exposed to a contaminated needle?

reported? Staff training should begin during employee orientation, and

should recur in continuing education classes and when management

practices are changed.

The staff should be aware of exposure policies offered by the

For example, what can be done for an employee

How and when should it be

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6. Policv Implementation. The EPA recommends that a designated

person or division be responsible for making policy decisions and f o r

implementing the program. This information should be written into the

program with strong support from administration.

Conclusions

There is no one optimum infectious waste management plan that is

effective for all hospitals or institutions. Each facility will need to

consider budgetary constraints, availability of cost-effective treatment

.methods, and local, state, and federal regulatory constraints in order

to design its own unique plan.

Carolina offer reasonable guidelines, but contain trgrayt' areas that are

subject to interpretation.

division within the facility make rational decisions that comply with

regulations, and that the infectious waste management plan be made

available to all employees.

The EPA as well as the state of North

It is important that a responsible person or

The infectious waste manager is in a unique position as a liaison

with the public regarding a realistic approach to infectious waste

management. Diseases such as AIDS will continue to feed emotional

rather than rational decisions regarding infectious waste within local

and state governments. National legislation is not forthcoming because

"considerable evidence that these wastes cause harm to human health and

the environment is needed to support Federal rulemaking" ( 3 ) .

. Therefore, it is necessary that an infectious waste management plan

first address the occopational risk within the facility, and then insure

proper treatment and safe packaging for transport and disposal to

protect the off-site handlers from the small, if not negligible, risk

posed by infectious waste.

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References

1. Local laws of New York City, no. 57, Aug. 2, 1985. In Hemorrhage from the hospitals: Mismanagement of Infectious Waste in New York State. Legislative Commission on Solid Waste Management, Albany, N.Y.. March 25, 1986.

2. 10 NCAC 10G; Statutory Authority G.S. 130A-294; Eff. April 1, 1982; amended Eff. July 1, 1985.

3. U.S. Environmental Protection Agency, Office of Solid Waste. EPA Guide for Infectious Waste Management, May, 1986. Washington, D.C.

4 . Garner, J.S. and B.P. Simmons. 1983. CDC Guidelines for Isolation Precautions in Hospitals. Infection Control 4:245-325.

5. Joint Commission on Accreditation of Hospitals. In Accreditation . Manual for Hospitals, 1985 edition. Chicago, 11171985. pp. 133-

134.

6. Rutula, W.A. and F.A. Sarubbi, 1981. Management of Infectious Waste from Hospitals. Association for Practitioners in Infection Control Annual Meeting, Atlanta, Ga.

7. Wallace, L.P., R. Zaltzman, and J.C. Burchinal. 1972. Where solid waste comes from; where it should go. Mod Hosp 118(2): 92-95.

8. U.S. Pharmacopeia1 Conventin, Inc., Sterilization. In the United States Pharmacopeia. 20th revision. Rockville, MD. 1980.

9. Perkins, J.J. Principles and Methods of Sterilization in Health Sciences. 2nd edition. Charles C. Thomas, Springfield.