Board of Public Works
HTM Office
City of Los Angeles
Hazardous & Toxic Materials Office Board of Public Works
City Hall
200 N. Spring Street, Room 353
Los Angeles, California 90012
(213) 237-1209
Rev. 1/95
Medical waste has been a growing concern because of recent incidents of public exposure to discarded blood vials, needles, empty prescription bottles and syringes, particularly along the nation's beaches. Medical wastes include all types of wastes generated by health care organizations such as hospitals, clinics, physicians' offices, dental offices, veterinary facilities and other medical laboratories and research facilities. This waste is very heterogeneous in nature and often contains some infectious elements, thus it is essential that the handling and disposal of the waste is conducted safely. Medical waste, often called hospital waste, can typically include the following:
Chemical wastes in the hospital present a different but significant disposal hazard. These cover a wide range and represent a large volume of the hazardous wastes generated in the hospitals. Sources include chemotherapy, X-ray developing, laboratory solvents and chemicals, broken mercury-containing equipment, anesthesia, and sterilization. Hazardous chemical wastes are regulated separately from medical waste under Title 22 California Code of Regulations. Radioactive wastes which are regulated by the Nuclear Regulatory Commission are generated by nuclear medicine and clinical testing laboratory departments.
The California Medical Waste Management Act of 1990 (California Health and Safety Code sections 25015-25099.3) regulates, manages, and controls the treatment of disposal of medical waste in a safe and proper manner. It requires
California's regulations apply to anyone who produces more than 100 kilograms of infectious waste per month. However, there are a couple of exceptions. The regulations also apply, without regard to quantity produced per month, to any licensed health-care facility that is a primary care clinic, chronic dialysis clinic, general acute-care hospital, acute psychiatric hospital, skilled nursing facility, or intermediate-care facility for the developmentally disabled. And finally, all producers of infectious waste, regardless of how much they produce, are required to comply with regulations for sharps disposal, cultures of viable etiologic agents, and human anatomical remains. Manifests are not required for the production, hauling, or disposing of infectious waste in California.
Generators who incinerate medical waste on site must also submit a report to the California Environmental Protection Agency (Cal-EPA).
Laws and regulatory programs addressing medical waste management also have been enacted by several states in response to the public's concerns over the AIDS epidemic. Although not all of them require tracking, they typically require certain packaging and labeling techniques and treatment before land disposal.
Medical waste management practices that should be employed include strictly segregating, packaging, labeling, and tracking the waste according to state requirements or through private agreement with transporters or disposal facilities. The establishment of these waste management plans stems from the recommendation of the Environmental Protection Agency (EPA) in its publication, "Guide for Infectious Waste Management" (Cheremisinoff 1990).
Infectious waste must be segregated from other waste at the point of origin in the producing facility. It may not be contained at a producing facility for more than four days at temperatures above 32 degrees. Infectious waste may not be stored for more than 90 days at the generator's facility, or more than 96 hours off site of the facility without the written approval of Cal-EPA Department of Toxic Substances Control (DTSC).
A successful waste segregation plan by hospital and health care organizations is important in implementing cost-effective disposal of waste. Combining regulated and unregulated waste requires that all the waste be treated as regulated waste. Treating the waste otherwise can result in fines and criminal charges. Furthermore, disposal cost is directly proportional to the stringency of the disposal regulations. Thus, there is definitely an economic advantage to segregating waste streams because it minimizes the quantity of regulated waste and reduces the disposal costs. Generators that incinerate all their trash and infectious waste do not need to keep these waste streams separate, however any waste that does not go to the incinerator must be segregated as indicated below. For healthcare facilities, the following waste streams are to be segregated
According to United States Environmental Protection Agency (US-EPA) recommendations, the segregation of infectious waste should occur at the point of origin. Containers of medical wastes must be properly labeled and marked, and infectious waste containers must have the universal biological hazard symbol on them.
Polyethylene bags are frequently used for containing bulk wastes, although they may have to be double-bagged with polypropylene bags that are resistant to autoclaving. Color-coded bags are frequently used to aid in the segregation and identification of infectious wastes. Most often red or red-orange bags are used, hence the term "red bag" waste.
Needles (sharps) are of concern because of their infectious potential and because of the direct injury they can cause. The EPA recommends the use of puncture-proof containers for sharps. The previous practices of recapping or chopping needles are no longer being used because of the potential for worker injury and for aerosolization of micro-organisms during the chopping procedure.
Infectious wastes should be stored in areas that are disinfected regularly and that are maintained at appropriate temperatures, particularly if wastes are being stored prior to treatment. Such storage areas should be clearly identified with the biohazard symbol, and access should be limited. The packaging should be sufficient to ensure exclusion of rodents and vermin. It is important to note the duration and temperature of strong infectious wastes due to their association and increases in rates of microbial growth and putrefaction.
Radioactive wastes cannot be treated, destroyed or immobilized by any methods in this fact sheet. However, radioisotopes decay by emitting radiation until they eventually become stable (non-radioactive) material that can be disposed of as a non-hazardous waste. The length of time depends on the isotope. Containers of radioactive wastes are isolated in temporary collection areas with minimum exposure to individuals until the waste has decayed to the point that it can be disposed of in a designated labeled container. Items used in handling radioactive materials, such as pipettes, disposable syringes, tissues, should also be segregated in labeled containers. Sharps contaminated with radioactive materials should also be kept in a separate waste container. The waste containers are eventually collected by the hospital Radiation Safety Office, so that the quantities disposed of can be monitored.
Collected wastes must be transferred from the point of generation to collection points for processing and appropriate disposal. The wastes should be placed in rigid or semi-rigid and leak-proof containers. The infectious waste management plan should include procedures to be used if liquid infectious wastes are spilled, plastic bags ruptured or other containers leak, or equipment fails.
Hospital wastes are collected in one of three ways:
Carts are primarily for horizontal transport of bagged or containerized wastes. The main risk is that bags may be broken or torn during transport, potentially exposing the worker to the wastes. Using automated carts can reduce the potential for exposure.
Pneumatic tubes offer the best performance for waste transport in a large facility. Advantages include high-speed movement, movement in any direction, minimal intermediate storage of untreated wastes. Some objects cannot be conveyed pneumatically. Overall, the advantages outweigh the disadvantages, and the pneumatic system is now widely used in both new and old facilities.
Waste containers must be secured to deny access to unauthorized individuals, and must be marked with prominent warning signs in both English and Spanish.
Except for sharps, infectious waste must be contained in double disposable plastic bags that are impervious to moisture. The bags must be strong enough to prevent ripping, tearing or bursting during normal use and handling. All disposal bags must be red and conspicuously labeled "Infectious Waste" or "Biohazard" with the international symbol.
Sharps must be contained in secure, leak-proof, rigid puncture-resistant containers. Hypodermic needles and syringes must be contained to prevent reuse.
California law allows infectious waste to be disposed of four ways:
Off-site disposal of regulated medical wastes remains a viable option for smaller hospitals (less than 150 beds). However, some preliminary on-site processing such as compaction or hydropulping may be necessary prior to sending the waste off-site. Compaction reduces the total volume of solid wastes, often reducing transportation and disposal costs, but does not change the hazardous characteristics of the waste. However, it may not be economical if transportation and disposal costs are based upon weight rather than volume. Containers could also burst during compaction, releasing pathogens into the environment.
Hydropulping is a method whereby the waste is ground in the presence of an oxidizing fluid, such as hypochlorite solution. The waste is fed into the top of a hammer mill, where it is pulped while being sprayed with the hypochlorite solution. The liquid is separated from the pulp and discharged directly into the sewer, unless local limits require additional pretreatment prior to discharge. The pulp can often be disposed of at a sanitary landfill. The advantage of hydropulping is that the waste can be rendered innocuous and reduced in size within the same system. Disadvantages are the added operating burden, difficulty of controlling fugitive emissions and the difficulty of conducting microbiological tests to determine whether all organic matters and infectious organisms from the waste have been destroyed.
On-site disposal is a feasible alternative for hospitals generating 2 tons per day or more of total solid waste. Common treatment techniques include steam sterilization and incineration. Although other options are available, incineration is currently the preferred method for on-site treatment of hospital waste.
Steam sterilization is limited in the types of medical waste it can treat but is appropriate for laboratory cultures and/or substances contaminated with infectious organisms. The waste is subjected to steam in a sealed, pressurized chamber. The liquid that may form is drained off to the sewer or sent for processing. The unit is then reopened after a vapor release to the atmosphere, and the solid waste is taken out for further processing or disposal. One advantage of steam sterilization is that it has been used for many years in hospitals to sterilize instruments and containers and to treat small quantities of waste. A disadvantage is ensuring that the proper time/temperature relationship has been met. Since sterilization does not change the appearance of the waste, there could be a problem in gaining acceptance of the waste for landfilling.
A properly designed, maintained and operated incinerator achieves a relatively high level of organism destruction. Incineration reduces the weight and volume of the waste as much as 95%, and is especially appropriate for pathological wastes and sharps. The most common incineration system for medical waste is the controlled-air type. The principal advantage of this type incinerator is low particulate emissions. Rotary kiln and grate type units have been used, but grate type have been discontinued due to high air emissions. The rotary kiln also puts out high emissions and the costs have been prohibitive for smaller units.
Most hospitals now use a two-chamber, hearth-burning, pyrolytic controlled-air incinerator unit. Waste is fed into the primary chamber, where it begins to burn with less than a stoichiometric quantity of air. More air is added in the secondary chamber to completely oxidize the waste. Ash is removed from the back end of the primary combustion unit. A complete system often includes a waste heat boiler for energy recovery, followed by an air pollution control system to remove acid gas and meet the particulate standards proposed by many states (0.015 to 0.030 grams/standard cubic foot at 7% O2).
The public has been particularly concerned over the siting and permitting of incinerators because of problems with air emissions, air toxics and the ultimate disposal of the ash at sanitary landfills. The concern has been for the potential organic and HCL emissions and metals, such as cadmium, mercury and lead, in the stack gas and ash. Organic emissions are prevented by properly designing the secondary chamber. HCL and particulate emissions are controlled by installing appropriate air pollution control systems. Ash must be managed as a hazardous waste unless it passes the Toxicity Characteristics Leaching Procedure (TCLP) tests. In the Los Angeles area, medical waste incinerators are regulated by SCAQMD Rule 1406.
Table 1 compares the unit costs for incineration, hydropulping and steam sterilization. Assuming that the facility treats 500 lbs/hr of waste, 12 hours per day, for a year, the investment and annual operating costs for the three methods would be:
| Investment | Operating Total $ | $/yr | $/yr |
|---|---|---|---|
| Hydropulping | 100,000 | 131,400 | 141,400 |
| Sterilization | 150,000 | 153,300 | 168,300 |
| Incinerating | 250,000 | 87,000 | 112,600 |
Total cost assumes a 10-year equipment life with straight line depreciation.
Table 1
Cost Comparison of Medical Waste Treatment Technologies
| Operation and Maintenance | Equipment Cost ($/lb/hr) | ($/lb/hr) |
|---|---|---|
| Incineration | 0.04 | 500(1) |
| Hydropulping | 0.06 | 200 |
| Sterilization | 0.07 | 300 |
Example: 500 lb/hr Incinerator 12-hr operating day
Capital Cost 500 lb/hr x $500 lb/hr=$250,000
Operating Cost 500 lb/hr x $0.04 lb/hr x 12 hr/day x 365 days/yr = $87,000
(1) Controlled Air Incinerator
Generators who produce more than 100 kilograms per month of infectious waste may only transfer the waste to a hauler registered with the Department of Toxic Substances Control (DTSC) (any one who generates less than 100 kilograms per month is exempt from this requirement).
Shipments of more than 100 kilograms must be transported separately from other waste unless it is segregated by barriers or stored in separate, rigid, reusable containers.
Waste must not be loaded and reloaded, transferred to another vehicle, or stored for more than 96 hours at any off-site location or facility, except at a hazardous waste transfer station or a facility that has a valid and appropriate permit. The waste must also be delivered to a properly permitted TSD facility.
Vehicles transporting more than 100 kilograms of waste must be placarded on each side with the name or trademark of the hauler, and with conspicuously displayed rectangular signs or decals, 25 by 35 centimeters. The words "Infectious Waste" or "Biohazard" must appear on the sign in red lettering with a white background, and be legible in daylight from a distance of 50 feet.
Waste minimization includes any source reduction or recycling activity by a generator that results in reducing either the quantity or the toxicity of the hazardous waste, consistent with the goal of minimizing present and future threats to health and the environment.
Source reduction can be achieved by materials or process modification and by the implementation of policies and procedures that would reduce waste. The key operating practices that can be utilized to affect waste minimization are as follows:
Mercury usually becomes a waste because of instrument breakage and cannot be treated by techniques described here. Mercury should be collected in a special container and shipped to a recycler. Using electronic devices for measuring temperature and blood pressure is the most effective way to eliminate mercury from the waste streams.
Spent solvents are generated by the laboratory, pathology, histology and maintenance departments. Sometimes aqueous-based cleaners can be substituted for hazardous solvents used in maintenance. Many solvents can be recovered by on-site distillation and recycled.
Dialysis units generate spent solutions that contain 3 to 4% formaldehyde in water. Some users reportedly use reverse osmosis (RO) units to recover formaldehyde, although this practice is not widespread.
Radiography departments generate significant amounts of hazardous waste from developing X-ray films. In particular, spent fixer solution contains high concentrations of silver, which is economically valuable and can be recovered easily. However, the DTSC regards the desilvering process as treatment, requiring a permit, since the silver cannot be recycled to the generating process. Many healthcare businesses have contracted with commercial recyclers who collect spent photoprocessing solutions and reclaim the silver. One commercial X-ray lab found that after it began controlling its processor temperature very closely to improve image quality, it also greatly extended the useful life of the processing chemicals, reducing the quantity sent to disposal.
Cheremisinoff, Paul, and M.K. Shah, 1990. "Hospital Waste Management." Pollution Engineering, April 199. pp. 60-66
For further information and assistance or to request additional publications please contact the HTM Office at:
City of Los Angeles, Board of Public Works
Hazardous and Toxic Materials Office
200 N. Spring Street, Room 353
Los Angeles, CA. 90012
Phone (213) 237-1209
or
California Department of Health Services
Medical Waste Management Unit
P.O. Box 94732
601 North 7th St.
Sacramento, CA. 94234-7320
Phone (916) 322-2042
It is the hazardous waste generator's responsibility to understand and comply with all applicable environmental regulations. This fact sheet is provided as an informational resource from the City of Los Angeles HTM Office and should not be used as a substitute for legal advice on environmental regulatory compliance.
Technical assistance for this fact sheet provided by the Jacobs Engineering Group.
Last Updated: November 16, 1995