Effective Cleaning and Health

(Editor’s Note: This article was written under the auspices of the Cleaning Industry Research Institute – CIRI.)


As health issues and microbiology-based concerns related to cleaning emerge, ­ like HIV, Anthrax, mold, West Nile Virus, and more recently Avian or Bird Flu, it is vitally important that we understand, in fundamental scientific terms, what it is we are confronting. Without this basic knowledge we are limited in solving problems, protecting our clients, our cleaning professionals, not to mention ourselves.


We need to recognize three facts:

  1. That we have, and probably will always have, incomplete knowledge of the microbiological world around us – it is a very unpredictable environment;
  2. That cleaning by itself will not always quell epidemics; and,
  3. That effective cleaning historically has successfully removed biological hazards and created conditions that reduce the risk of disease and enhance human longevity and the quality of life.

Therefore, to help the public approach these issues in a systematic, science-based manner, we have put together this overview of effective cleaning and health.


The Science Behind Cleaning


“Clean” is a condition free of unwanted matter. “Cleaning” is the systematic management process used to achieve the “clean condition.” Cleaning is a fundamental environmental management process in that it is the process of putting unwanted matter in its proper place so as to not get in the way of human endeavors or cause harm to humans or valuable materials. The process of cleaning reduces exposures and risks; it lessens the probability of an adverse effect.


We cannot manage what we do not understand. Therefore, science is essential to effective cleaning. Science answers the question “how.” “How does the environment of which we are a part function?” “How is cleaning effective?”


Every effective cleaning process, especially as it applies to human health and environmental protection, requires:

  1. Knowledge of the environment and the matter to be removed,
  2. Separation, isolation, and containment of unwanted substances;
  3. Transport and removal of the substance from the object or environment; and,
  4. The proper relocation, reposition, or disposal of the unwanted substance.

Science tells us that an environment is a system of interconnected compartments and subcompartments through which matter and energy flow. Matter and energy are never destroyed, they continuously move around. Without effective cleaning, unwanted matter collects and concentrates, particularly in the built environments where we spend the vast majority of our life. Various forms of out-of-place matter can cause a multitude of adverse effects and conditions that make us miserable, drive us away, or ultimately kill us.


Pathogens as Disease Producers


“Pathos” is Greek for suffering, and ‘Gen’ is a suffix meaning producer. Therefore a “pathogen” is a disease producer and “Pathology” is the study of disease in general. Unwanted matter – often referred to as a pollutant or pathogen – can be a solid, liquid, or gas; it can be organic or inorganic; it can be living or dead, or derived from a living or dead organism. Biopathogens are pathogenic microorganisms or substances derived from living organisms that cause disease.


“Germ” is a term to describe a microscopic organism that takes in food and excretes waste, grows, reproduces, and dies. Germs are bacteria, viruses, fungi, and protozoa.


Bacteria are single-celled organisms that receive nutrients from their environments in order to live. In some cases, that environment is a human body. Bacteria can reproduce outside of our bodies or within our bodies as they cause infections. But not all bacteria are bad. Some bacteria are essential for our bodies – they help keep human physiology in balance.


Bacteria fall into a category of life called the Prokaryotes. Prokaryotes’ genetic material (DNA) is not enclosed in a cellular compartment called the nucleus. Bacteria and Archaea are the only prokaryotes. Other life forms including plants, animals, and fungi, are Eukaryotes, creatures whose cells have nuclei. Viruses are not considered cells, and are a separate category of living organism.


Bacteria live on or in virtually every material and environment on Earth. A square centimeter of skin averages about 100,000 bacteria. A cubic centimeter of topsoil contains somewhere in the order of billion (1,000,000,000) bacteria. Bacteria can live in temperatures above the boiling point of water and in temperatures that freeze blood. They “eat” everything from sugar and starch derived through photosynthesis to sulfur and iron in rocks.


Protozoa are one-celled organisms like bacteria. Protozoa require water and thrive in water and often spread diseases through contaminated water. Some protozoa cause intestinal infections that lead to diarrhea, nausea, and stomach pain.


Fungi are multi-celled plant-like organisms. Fungi do not produce their own food from soil, water, and air. They are decomposers. Their main role on Earth is to recycle carbon, which along with water is essential to all life. Fungi have an absolute requirement for water. They thrive in damp, warm environments. They get their nutrition from plants, animals, and just about any matter derived through photosynthesis.

Viruses require a host to survive, grow, and reproduce. Viruses cannot live outside of other living cells. Once inside the body, viruses can spread and make people sick. Viruses cause chicken pox, measles, flu, and many other diseases.


The vast majority of microorganisms cause humans no harm. Most microorganisms are not pathogenic or bio-pathogenic. In fact, many microorganisms are essential for our well-being. However, there are exceptions.


Hygiene for Disease Prevention


The “germ theory of disease” (“pathogenic theory of medicine”) is a 180-year-old theory that proposes that microorganisms are the cause of many diseases. Germ theory is the foundation of most areas of the health professions that include hygienic and sanitation practices. Hygiene is commonly understood as preventing disease and infection through cleaning. Good hygiene includes the absence of visible soil or malodors and harmful levels of bacteria and other microorganisms and harmful matter. Good hygiene as indicated by a state of cleanliness creates a sense of well being and among other benefits enhances health, aesthetics, comfort, social interactions, and human productivity. In many instances the process of high performance cleaning directly aids in disease prevention and isolation. Good hygiene – as manifested by cleanliness – maintains a healthy condition and avoids sickness and disease. In the midst of an epidemic, good personal hygiene and effective cleaning processes reduce contagiousness.


Washing with water is the most common means of personal hygienic behavior. Washing is often done with soap or detergent that helps to separate oils and to break up dirt particles so they may be carried away by the flow of water. Frequent hand-washing is among the most common hygienic advice. Hand-washing and effective cleaning has an enormous impact on reducing the spread of disease. This is because they kill or remove disease-causing organisms in the immediate surroundings. These cleaning processes reduce the risk of disease by reducing exposure to the pathogen. For example, washing one’s hands after using the toilet and before handling food reduces the chance of spreading E.Coli bacteria and Hepatitis, both of which are spread from fecal contamination of food. Hand-washing has been shown to reduce the spread of the common cold virus and various forms of influenza, especially in sensitive environments like hospitals, nursing homes, day-care facilities, schools and universities.


The primary method of preventing the spread of disease is to isolate the infectious organism from the human population. By eliminating the source of infection, there is no transfer, exposure and risk. Often – but not always – effective cleaning provides this isolation and risk reduction.


Below, you will find a table of common infectious diseases and their transmission routes.

Common Infectious Diseases Found in Sensitive Environments
Health Care-Day Care-Schools &Universities


Transmission Routes


Direct Contact

  • Chickenpox
  • Cold Sores
  • Conjunctivitis
  • Head Lice
  • Impetigo
  • Ringworm
  • Scabies


  • Chickenpox
  • Common Cold
  • Diphtheria
  • Bacterial meningitis
  • Hand-Foot-Mouth Disease
  • Impetigo
  • Influenza
  • Measles
  • Mumps
  • Pertussis
  • Pneumonia
  • Rubella


  • Campylobacter
  • E. Coli O157
  • Enterovirus
  • Giardia
  • Hand-Foot-Mouth Disease
  • Hepatitis A
  • Infectious Diarrhea
  • Pinworms
  • Polio
  • Salmonella
  • Shigella


  • Cytomegalovirus
  • Hepatitis B
  • Hepatitis C
  • HIV Infection

Direct contact related diseases are best managed by isolation. Skin infections are spread by touching fluid from another person’s infected sores. Effective cleaning takes place in form of personal hygiene on the part of the infected human so as to contain, destroy, remove, or inhibit the life of the bio-pathogenic organism or its toxic by-products.


Respiratory-tract infections, frequently manifested by coughs, sneezes, and runny noses, are spread through exposure to fluids present in or expelled from another person’s mouth and throat (saliva or mucus). These often occur when an uninfected person touches these discharges with their hands and then touches their mouth, eyes, or nose. These organisms tend to be viruses which do not live long without a living host. Personal hygiene, especially frequent hand washing, reduces exposure. Also rapid response in the form of effective cleaning of surfaces contaminated by virus-active-fluids will break the transmission chain, and reduce the transfer opportunities and risks.


Intestinal tract infections, such as diarrhea, are spread through exposure to bacteria in the feces. Bacteria are spread through “fecal-oral” transmission. Pathogenic organisms are excreted from the infected person and enter the body of another person through the mouth. This happens when objects which have become contaminated with undetectable amounts of feces are placed in the mouth. Fecal-oral transmission can occur if food or water is contaminated with undetectable amounts of human or animal feces, and then ingested. Improperly prepared foods made from animals (meat, milk, and eggs) are often the source of infection with Campylobacter, E.coli O157, and Salmonella. Well designed, focused, effective cleaning systems and programs can be very effective in reducing and often eliminating these types of disease.

Infections like Salmonella and Campylobacter are spread through direct exposure to infected animals. Isolation of infected animals, hand-washing and the frequent cleaning of animal holding areas reduce risk.


Blood-Borne Pathogens


Blood infections are spread when blood (and sometimes other body fluids) from a person with an infection gets into the bloodstream of an uninfected person. This happens when infected blood or body fluid enters the body of an uninfected person through cuts or openings in the skin; the mucous membrane that lines body cavities, such as the nose and eye; or directly into the bloodstream, as with a needle.


The cleaning industry must stay current with public health guidance provided by the Surgeon General related to management of blood borne pathogens and medical wastes. The AIDS epidemic continues to grow. This means that there is more infected blood, especially in our ever expanding, mobile, global society. Consequently, every time we come upon an accident or situation where blood must be cleaned up, it is more likely that HIV and other infectious viruses are present. Therefore, we have to be more cautious when working around blood today than in the past because the risk of exposure is greater.


Uninfected blood is not a health threat. We simply wash it away. We cannot know the status of any blood we encounter. Because of this, whenever we clean up blood, especially fresh blood, we must treat it as if it were infected with the HIV virus.


HIV virus is thought to be short lived once it is outside its human host. But its exact behavior, as with most viruses, is not fully understood. To prevent viral infection, it is prudent to avoid contact with even dried blood.


We can form barriers to pathogenic viruses. When cleaning, the most effective way to guard against infection is to form a protective barrier between the skin and the virus. Workers should always wear rubber gloves and ensure splash protection. Workers with open sores or fresh cuts should not work on clean-up projects.


We can disinfect blood with a registered disinfectant. Despite the growing tendency to avoid chlorinated products, in the absence of a registered biocide that has been demonstrated to deactivate viruses, bleach is a proven option. Preventing a fatal infection far outweighs any known side effect that might be associated with chlorinated compounds. Household bleach contains 5% sodium hypochlorite. When mixed in the ratio 1 part bleach to 10 parts water, it becomes a 0.5 percent water-based solution of sodium hypochlorite. This solution will disinfect blood and kill the HIV virus when blood is saturated with it for at least 30 minutes.


Assume all blood is infected with HIV virus or some other infecting virus. Protect your skin with protective gloves. Be extremely careful not to puncture the skin or gloves while cleaning. Surround any blood spots with a ring of registered disinfectant or the water-based solution of sodium hypochlorite. Let the blood become saturated with the solution. If glass or other debris is mixed with blood, make sure it is also bathed in the solution. Disinfectants take time to work. Blood spots or blood-infected items should remain saturated for at least 30 full minutes.


Keep the blood from splattering when you apply the disinfecting solution. You may need to cover the blood with a paper towel, and pour or spray the solution onto the blood through the paper towel.


Waste Disposal


Treat all blood-soaked debris, glass, carpet, and used protective gloves as medical waste. Put them in a medical waste container, and dispose of it at a medical waste treatment facility.


Medical or infectious wastes are special kinds of “hazardous wastes” which can cause illness or death. They threaten human health or the environment when improperly treated, stored, transported, or disposed. Keep medical and infectious wastes separate from ordinary wastes at the point of origin. Place them in distinctive, clearly marked containers designed for them. The containers should be labeled with the “universal biological waste hazards” symbol.


Use packaging materials appropriate for the waste being managed. Use puncture-resistant containers for sharp objects. Use packaging material that will maintain its integrity during storage. Keep all containers closed once wastes are placed in them. Keep containers for infectious liquids tightly capped; they must not leak. Never compact packaged wastes before having them treated.


Store medical or infectious wastes for the shortest possible time. Do not allow there to be any chance for rodents and vermin to get into them and become carriers of disease. Ensure limited access to areas where medical and infectious wastes are stored. Have storage areas marked with the universal biological hazards symbol.


When medical or infectious wastes are transported, load them by hand. Mechanical loading devices can rupture the packaging. Disinfect carts that deliver the wastes to loading areas frequently. Ensure that infectious wastes are transported only in leak-proof trucks or dumpsters.


The treatment of medical or hazardous wastes is any method, technique, or process that changes its biological composition. Treatments include steam sterilization, incineration, thermal inactivation, chemical disinfection, discharge to a sanitary sewer, burial, and cremation. To treat wastes properly, always follow the documented standing operating procedure for each category of waste. Monitor the treatment process continuously. Use biological measurements to evaluate whether the waste is properly controlled at the site and effectively treated.


Finally, always comply with state and local public health laws for the proper disposal of medical or infectious wastes. http://www.cdc.gov/niosh/topics/bbp/.

Avian Flu


The possibility of an Avian Flu Pandemic is an emerging and every growing topic of concern throughout the world. Given the virulence and potential mortality harvest of the H5N1 virus, there are indeed good grounds for emergency preparation but not public hysteria. Health intelligence related to Avian Flu is changing daily. CDC and the World Health Organization are intently studying the virus and as appropriate, updating information. At this time, there is no special science-based guidance for effective or professional cleaning beyond that which health care and cleaning professionals follow in flu epidemics. This includes inoculations, isolation of infected persons, protective gloves and frequent hand washing, splash protection, an elevated level of personal hygiene, quick response to body-fluid spills, use of registered disinfectants, the intense management of infectious waste, and effective ventilation. Given that this is literally a life and death issue, it would be fully irresponsible to give additional specialized guidance without complete factual information. Keep an eye on the CDC website http://www.pandemicflu.gov/. The Surgeon General of the United States, the CDC and the World Health Organization are the experts. Should those in cleaning or related industries have technical questions we can help answer, they can contact us through email at [email protected] and review our postings on the CIRI Web site. We will update information on Avian Flu as it becomes available.


Dr. Michael A. Berry

Science Advisory Council

Cleaning Industry Research Institute

September 29, 2006

Michael A. Berry, PhD serves on the Science Advisory Council of the Cleaning Industry Research Institute (CIRI).


Dr. Michael A. Berry retired from the US Environmental Protection Agency in 1998 after a 28 year career with that agency. In EPA he was a senior manager and scientist. He was the Deputy Director of National Center for Environmental Assessment at Research Triangle Park, NC for 22 years. During his EPA career, he had extensive interactions with private industry, trade associations, environmental organizations, governments, the federal courts, US Congress, universities world-wide, and institutions such as the National Academy of Sciences, the World Health Organization, and the North Atlantic Treaty Organization. Dr Berry is recognized internationally as an expert in the subject of indoor environmental quality. Between 1985 and 1994, he directed EPA's indoor air research program.

Since his retirement from EPA he has been a Research Professor at the University of North Carolina at Chapel Hill where he taught several course and wrote numerous articles related to business and environment, built environments, and environmental science and management. He serves as a consultant to businesses and public institutions in the evaluation of environmental management strategies and policy. He directs research on the performance of products and services related to indoor environmental quality. Currently his research focus is the area of cleaning science and indoor environmental management programs for schools and universities.

Dr. Berry served as an Army Officer in Viet Nam 1967-68. He earned a Doctor of Philosophy in Public Health from the University of North Carolina at Chapel Hill, and a Master of Science in Management from Duke University's Fuqua School of Business. He holds both Bachelor and Master of Science degrees in Mathematics from Gonzaga University.