Contamination Control in Hospitals and Healthcare Facilities
Recognizing the types of contamination possible in a hospital/laboratory and other healthcare facilities is the first step toward controlling and eliminating it.
By Zorach (Zory) R. Glaser, Ph.D.,M.P.H.
One definition of contamination, as referred to in the healthcare setting (after Taber`s Cyclopedic Medical Dictionary, 17th edition, published by F. A. Davis Co., Philadelphia 1993; and Dorland`s Illustrated Medical Dictionary, 24th edition, W. B. Saunders Co., Philadelphia, 1965), states that it is “…the act of contaminating, especially the introduction of disease-producing germs/organisms or infectious material on or into normally-sterile portions of the body.”
In many cases, healthcare facilities and associated laboratories consist of a constantly changing work environment and involvement with multiple physical, chemical, and/or biological agents. Also, due to the non-routine nature of the work conducted and the special characteristics of the work environment, there are potentially serious risks for exposure to contamination of various types, and significant challenges for personnel responsible for assuring the health and safety of the workers/ staff, patients, and visitors.
Some of the concerns and issues which necessitate that contamination be controlled within hospitals, healthcare facilities (including outpatient treatment clinics), related facilities (such as hospital pharmacies), and in many laboratories within the healthcare setting (such as pathology, hematology, etc.) are listed below.
The physical forms of the contamination present may involve matter in a number of states, including: gases and vapors, liquids, solids (including very finely divided particles, called particulate), and/or combinations of states, such as aerosols and mists (e.g., liquid in a gas), dusts (solid in gas), foams, etc. “States of Matter of Materials Comprising Contamination,” summarizes the states of matter of multiphase systems which comprise particulate, bubble, and aerosol contamination in the healthcare facility. Exposure to chemicals may involve the pure chemical, mixtures of chemicals, chemicals in solution, etc. It also might involve the chemical as an airborne contaminant, as a byproduct of a chemical reaction, as an impurity, and as an aqueous solution, etc.
Contamination may include: toxic, corrosive, infectious, radioactive, flammable, chemically reactive/explosive, extremely volatile (thereby producing rapid cooling of the skin, should contact occur), and/or quite possibly, odiferous/smelly, or otherwise hazardous materials.
These concerns involve not only the starting chemicals and materials in use within the healthcare facilities and associated laboratories, but also the generation of new chemicals and materials (i.e., reaction products) or byproducts; chemicals and materials in storage; and chemicals and materials released during the performance of acts such as: waste handling and disposal; compacting; composting; incineration; the performance of certain custodial, repair, updating, and/or maintenance procedures; some training procedures; and emergency operations, etc. It is important that warning labels and disposal instructions placed on the hazardous materials be in the language understood by those who will be handling or disposing of the material.
Also, contamination may include infectious organisms, including bacteria, their spores, fungi, viruses, yeasts, etc. (i.e., microbiological materials, called biological contamination or biocontamination). In addition, contamination exists in possible exposures to various parasites (including various worms, ticks, lice, fleas, etc.), and even to “critters” like leeches (yes, they are still used medically for certain procedures); and some botanicals (such as molds, plant spores, and pollens).
Biocontamination may consist of infectious solid particulate in air, infectious liquid droplets in air (sometimes called “droplet nuclei”), infectious material in water, or coated on surfaces (such as on countertops or on medical devices), etc.
Within the healthcare setting, special concern should be given to contact with “blood” (and its components: plasma, serum, and cells) “or other potentially infectious materials,” including “body fluids,” consisting of feces, urine, vomitus, sputum, saliva, nasal secretions, semen, vaginal secretions, breast milk, tears, drainage from surgical sites and wound secretions, etc. This has been highlighted by the Centers for Disease Control and Prevention (CDC), and the Occupational Safety and Health Administration (OSHA). (It should be noted that, while all of these “body fluids” may contain infectious virus particles, such as those associated with HIV/AIDS, the fluids do not all represent the same degree of risk).
The spread of such biological material and organisms can produce illness, infection, or death, especially in susceptible individuals (such as the healthcare facility in-patient population), some ambulatory patients, and/or in the care-provider/giver population.
Control of contamination significantly assists in reducing the transmission of pathogenic (disease-causing) organisms–such as those responsible for hepatitis-B, HIV/AIDS, and the organism which causes TB–to patients, among the patients, and between the patients and the caregiver/practitioner/staff.
Blood and other body fluids (i.e., bloodborne pathogens) can enter the body of other patients, caregivers, and others by way of percutaneous injuries [such as cuts, punctures, injections (including unintended “needlesticks”), and implantations], as well as by other routes (such as receiving a transfusion of tainted blood, practicing some forms of unprotected sex, etc.) Concern also exists about the possibility of contact of bloodborne pathogens with other mucous membranes, e.g., mucocutaneous eye splashes, and contact of such materials with non-intact skin. The so-called “Universal Precautions” protection strategy for those working with such materials requires adoption of the attitude that the handling of all blood and body fluids from all patients be conducted as though the fluids were infectious.
As noted earlier, contamination may include particulate matter, which can produce complications in the repair and/or healing process following certain surgical procedures, or with burn victims, or immunocompromised patients.
Patients with certain respiratory (or related) ailments can experience their condition being severely aggravated, as a result of contaminated air.
Reuse of many medical devices, instruments, and equipment (intended to be used multiple times, and/or with multiple patients) is another possible contamination issue. Such devices, instruments, and equipment require (prior to being reused) being reprocessed, being disinfected, and (as necessary, being sterilized, so as to remove all microbiological contamination). These procedures are performed by following rigorous protocols which have been developed, tested, and validated, so as to assure that the devices, instruments, and equipment are as safe and effective for the next use, as they were expected to be upon receipt from the manufacturer, when new. The essential reprocessing of such devices and related equipment demands proper attention within the healthcare facility. Such reprocessing is generally performed by a trained, dedicated staff within the facility. To a lesser degree, some healthcare facilities share the reprocessing operations with other, nearby facilities, or have the reprocessing performed by an off-site contractor. Certification of competency of those who perform, supervise, and manage such reprocessing has been gaining favor within the past six or so years.
These, and other issues necessitate the imposition of rigorous biosafety techniques, procedures, and controls within the healthcare workplace.
The Hazards of Physical Agents
Healthcare facilities and associated laboratories often utilize physical agents (which may pose a health and/or safety hazard, and a contamination consideration), including:
Ionizing radiation (particulate–including alpha, beta, neutron, etc.), and/or waves [including gamma, X-ray, and short wavelength ultraviolet (UV) energy];
Lasers (including their chemical and/or biological plumes from target materials);
Infrared (IR) energy, and visible “light” energy;
Ultraviolet (UV) energy at a longer wavelength;
Radiofrequency (RF) energy including electric and/or magnetic field components; lower frequency fields, such as those associated with such equipment as video display terminals; and extremely low frequency (ELF) fields, such as those associated with power transmission.
Other physical stressors include: flow of electrical current, heat, cold, vibration, noise, ultrasound, and pressure gradients.
It should be realized that performing/conducting certain procedures/operations within healthcare (and related) settings can generate especially large amounts of contamination. Examples include: cutting, grinding, certain cleaning operations, etc. (See “Actions Generating Contamination,” p. 27.)
Exposure to multiple chemicals, single or multiple physical agents, and single or multiple biological agents can occur in the healthcare setting. Various combinations and permutations of chemicals, physical agents, and biological contamination are possible. While occupational (and in many cases, environmental) exposure standards exist for humans for many chemicals, for most physical agents, and for some biological agents, the assumption that is generally made is that the individual contamination exists alone, and is not in combination with other agents. In other words, standards generally do not exist for exposure to multiple agents.
There are many additional special factors impacting on the need to control contamination within the healthcare setting. (Space does not permit a listing at this time. Nor does it permit a listing of examples of significant problems caused by contamination in the healthcare environment.)
Some of the techniques/methods/ strategies used for control/elimination of contamination in healthcare facilities, laboratories, etc., are listed below.
Selection and wearing of protective clothing, garments, gloves, shoe covers, and other appropriate barrier-protective apparel for employees. Double gloving, and/or the wearing of protective outer gloves (of various types) are techniques used to help to protect the caregiver from needlestick injury. (Attention should be given to individuals who are hypersensitive to certain chemicals/proteins in some latex gloves because it may represent a significant problem. Hypoallergenic, disposable latex gloves are available).
Treatment of all body fluids from all patients as though the fluids were infectious (the so-called “Universal Precautions” protection strategy for working with such materials).
Use of protective drapes, gowns, and other patient-protective items, while care is being provided.
Air filtration (through HEPA filters) to remove airborne particles and many types of biocontamination.
Cleaning and replacing of air purifying filters at regular intervals.
Use of cleanrooms and related enclosures.
Use of localized exhaust ventilation for sources of contamination such as “laser plume.”
Use of air curtains and air showers.
Use of ultraviolet (UV) germicidal lamps as an important engineering control technique for assisting in the prevention or reduction of the transmission of infectious droplet nuclei containing Mycobacterium tuberculosis (the airborne bacteria responsible for causing TB). [The use of low-pressure, mercury vapor ultraviolet (UV) germicidal lamps (operating at a wavelength of about 254 nm), alone, or as a supplemental engineering control, to assist in reducing (and/or eliminating) the concentration of infectious droplet nuclei containing M.tuberculosis, is again being used within some healthcare facilities. For TB control years ago, many hospitals used UV germicidal lamps alone or in combination with some other early control techniques.]
Product substitution (e.g., use of a less volatile solvent, or a less toxic chemical).
Keeping volatile products covered/stoppered/capped, thereby significantly reducing escaping vapors.
Use of respiratory protection by affected staff/employees.
Use of special packaging and wrapping, thereby reducing dust and particulates.
Opening shipping cartons in special areas designed to contain biological, chemical, or particulate contamination.
Appropriate housekeeping, including regular, and thorough cleaning of the facility`s spaces.
Use of glove boxes, laminar flow benches and workstations, capture hoods, and special enclosures (such as in some laboratory settings and pharmacy operations).
Use of leak detectors to help pinpoint sources of chemical contamination.
Positive pressure used in certain rooms and areas, to minimize the possibility of the entrance of airborne bacteria (such as that responsible for the TB infection) becoming part of the “breathing zone” air.
Negative pressure used in certain rooms and areas, to assist in venting exhaled radioisotopes and/or exhaled anesthetic agents to the outside, and to minimize the possibility of certain airborne bacteria escaping from the room.
Shielding installed in certain areas to minimize interference from internal/external electromagnetic fields, and/or to minimize problems from ionizing radiation sources.
Sealed floors and drains to prevent leakage of radioisotopes.
Special care with laundry handling (including “contaminated,” and clean/sterile laundry).
Sterile reprocessing and distribution of instruments, devices, and equipment, by trained and certified personnel.
Aeration steps taken to minimize the outgassing/offgassing of vapors/gases/byproducts of the chemicals used to sterilize/reprocess instruments/devices/equipment.
Choice of special materials to help prevent/minimize the development of rust and corrosion (which can contribute to particulate, and other contamination).
Use of vibration damping (to minimize the generation of airborne particulate matter, vibration, and noise).
The use/wearing of hearing protection equipment/devices in high noise environments (where noise contamination exists).
Special control procedures and engineering techniques to eliminate or minimize the risk of contact with blood-borne pathogens (as prescribed by OSHA).
Use of safety protocols, techniques, and equipment designed to minimize needlestick and “sharps” injuries, such as: blunt tip suture needles, automatic cap shields for needles, staples (rather than sutures), needleless systems for IV administration, etc.
Increased ventilation and increased air flow rates, to reduce the buildup of toxic chemicals, heat, etc.
Use of special containers (“sharps containers”) to safely hold used needles, blades, etc., for disposal.
Use of specially marked “biohazard waste” containers.
Treatment of certain bio-hazardous waste, to render it non-hazardous, prior to its being removed from the healthcare facility.
Routine monitoring for toxic, hazardous, infectious, radioactive, etc., materials in the patient/worker environments, and proper maintenance of exposure records.
Testing of patients and workers for presence of various infectious agents, and use of various medications, vaccinations, record keeping, etc.
Standards for Contamination Control
The following are some examples of regulatory and related standards and guidelines pertaining to contamination control that impact the healthcare facility and associated laboratories.
OSHA Bloodborne Pathogens Standard, and other related workplace standards;
OSHA Hazard Communication (Haz-Com) Program, and the “Worker`s Right-to-Know” Requirements;
Environmental Protection Agency (EPA) Air and Water Quality Standards;
EPA Regulation of Toxic Chemicals, Hazardous Waste Disposal Standards, and the regulation of chlorofluorocarbon (CFC) chemicals;
FDA regulation of the manufacture, sale, distribution, directions for use, certain advertising, importation/exportation, etc., of medical devices, diagnostic test kits, electronic and radiological medical equipment, and pharmaceuticals, etc. Also, disposal of certain radiological and X-ray equipment;
EPA and FDA joint regulation of pesticidal chemicals and related compounds used in various germicides and disinfectant formulations, especially those used in the healthcare environment, and those used with medical devices;
FDA Good Manufacturing Practice (GMP) Requirements;
FDA Good Laboratory Practice (GLP) Requirements, and the Requirements for conducting clinical investigations (i.e., using human subjects);
FDA Drug and Medical Device Problem Reporting Requirements;
National Institutes of Health (NIH) requirements for the care, handling, housing, etc. of laboratory animals used in medical/ healthcare research;
Various CDC recommendations and guidelines (such as the TB and AIDS Control Guidelines), and recommendations on the safe handling, use, and disposal of various other infectious agents;
Nuclear Regulatory Commission (NRC) and Department of Energy (DOE) requirements for use, storage, and disposal of radioactive sources and equipment;
Department of Transportation (DOT) requirements relating to the transportation of hazardous materials, and waste;
Various National Institute for Occupational Safety and Health (NIOSH) recommendations and guidelines, including those relating to the selection and use of personal protective equipment (PPE), (especially respiratory protection, and eye protection equipment);
The Clinical Laboratory Improvement Act (CLIA), pertaining to quality assurance in the conduct, performance, record keeping, and interpretation of diagnostic, and other tests;
The Patient Protection Act (the “Bergalis Bill,” enacted in response to the exposure of patients to infectious agents);
Various federal, state, and local requirements, regulations, recommendations and guidelines relating to waste handling and disposal, and to the packaging, shipping, tracking, and transporting of various materials (such as pressurized gases, cryogenic materials, etc.) used within the healthcare facility and associated laboratories.
As noted, a number of occupational exposure standards have been established (for many chemicals, physical agents, and biological agents, i.e., the “contamination”) by OSHA. Some additional exposure recommendations and voluntary guidelines (relating to the workplace) for exposure to a number of physical and chemical agents exist, as developed by the American Industrial Hygiene Association (AIHA), and the Threshold Limit Values (TLVs) of the American Conference of Governmental Industrial Hygienists (ACGIH).
Recommendations, guidelines, standards, standards-of-practice, test methods/procedures, and/or reference standards, many pertaining to exposure to the general public, and/or to the patient population, in these, and related areas (including contamination), also have come from the CDC, the Federal Communications Commission (FCC), the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), the U.S. Pharmacopeia (USP), the American Medical, Dental, Nursing and Hospital Associations, the National Committee for Clinical Laboratory Standards (NCCLS), the Association for the Advancement of Medical Instrumentation (AAMI), the American National Standards Institute (ANSI), the American Society for Testing and Materials (ASTM), various other professional and technical societies, such as the American Chemical Society (ACS), the Association for Professionals in Infection Control and Epidemiology (APIC), and the American Biological Safety Association (ABSA).
In addition, other organizations include the American Dental Hygienists` Association (ADHA), the Association of Occupational Health Professionals in Healthcare (AOHP), the Society for Occupational and Environmental Health (SOEH), the Society for Healthcare Epidemiology of America (SHEA), trade associations [such as the Health Industry Manufacturers Association (HIMA)], and labor organizations [such as the American Federation of State, County, and Municipal Employees (AFSCME), and the Service Employees International Union (SEIU), etc.] Many of these recommendations, guidelines and standards, are directly applicable to the issue of exposure to contamination of various types, and to its reduction and control.
One other contamination issue relates to contaminated laundry, which OSHA refers to as laundry which has been soiled with blood or other potentially infectious materials, or may contain “sharps.”
Many of the contamination control considerations in use within healthcare settings are very similar to those in use in other industries, such as microelectronics manufacture. n
Zory R. Glaser serves as President of Glaser and Associates (Laurel, MD), consultants in occupational and environmental health engineering, toxicology, and related regulatory and litigation aspects involving medical devices, and polymeric biomaterials. His career includes service in the U.S. Navy, and the U.S. Public Health Service (PHS), including with the National Institute for Occupational Safety and Health, and 10 years with the FDA. Upon his retirement from the PHS, he became Senior Scientific Consultant for the Division of Standards Development, at the U.S. Pharmacopeia (Rockville, MD), with responsibility for medical devices, diagnostic products, and biomaterials. He also teaches and is on the faculty at Johns Hopkins University, George Washington University, and Georgetown University.
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Contamination in the Healthcare Environment Examples include:
Chemicals: Solvents, Cleaning Agents, Smoke, Oils, etc.
Biological Materials: Bacteria, Fungi, Blood, Saliva, Fleas, etc.
Physical Agents: Radiation of various types, Noise, Heat, etc.
States of Matter of Materials Comprising Contamination* in the Healthcare Environment
Chemicals and Materials in Multiphase Systems
Solids in gas (particulates in air, dusts, smoke and fumes)
Solids in liquid (particulates, slurries, and suspensions)
Liquids in gas (sprays, mists, aerosols, fogs)
Liquids in gas containing a solid carrier, such as talc or colloidal silica, and liquids in gas in an immiscible liquid (three-phase aerosols, foams, semi-solid fluids)
Immiscible liquids in liquid (lattices, emulsions, silicone oil and silicone lubricant droplets or particulates in injectable products)
Undissolved gases in liquids (micro-bubbles and bubbles)
* Contamination includes particulate, bubbles, and aerosols.
Source for “States of Matter…” and “Some Actions…” charts: Glaser, Z.R. (1994), Invited Article in Pharmacopeial Forum, 20 (1); pps. 6949-6955, (Jan/Feb.), published by the U.S. Pharmacopeial Convention, Inc. (USP), “Some Health and Safety Aspects Involving Particulates, Bubbles, and Aerosols Related to the Use or Reuse of Medical and Dental Devices.” Used by Permission of the USP.
Separating or removing material: cutting, drilling (esp. at high speed), grinding, filing, scraping, sanding, sharpening, deburring, cleaning, brushing, irrigating, rinsing, use of air or water jets, ultrasonic cleaning;
Smoothing operations: polishing, smoothing, buffing, finishing;
Coating operations in which brush bristles are involved: painting, coating, sealing;
Operations such as spraying and dusting;
Mixing and dissolving operations: compounding, stirring, mixing, ultrasonic mixing, vortexing, spinning, centrifuging, heating, boiling, melting, supercooling, dissolution, freezing, condensing;
Specific actions: polymerizing; curing; drawing medication up into the syringe and then expressing the liquid to remove bubbles often generates aerosols; injecting; puncturing the cover, septum, or elastomeric closure of a cartridge or an injectable container with a needle or “spike” in preparation for use (a process sometimes referred to as “coring”); cutting needles during disposal; performing certain laser procedures, which may generate the so-called “laser plume,” consisting of smoke and aerosolized biological material that may be infective;
Certain heating or joining procedures: melt ing, welding, brazing, soldering fusing.
* Actions performed in the dental and biomedical environment which generate particulates, bubbles, and aerosol contamination.
Source: Glaser, Z.R. (1994), Invited Article in Pharmacopeial Forum, 20 (1); pps. 6949-6955, (Jan/Feb.), published by the U.S. Pharmacopeial Convention, Inc. (USP), “Some Health and Safety Aspects Involving Particulates, Bubbles, and Aerosols Related to the Use or Reuse of Medical and Dental Devices.” Used by Permission of the USP.