Questioning the Selection of Disinfectants is a White Paper prepared for Avmor and is bylined by Mike Watt, a thought leader for the professional cleaning industry.
In recent years, some of our clients in a variety of different industries have reported that some Canadian health inspectors have been questioning their selection of disinfectants. For instance, health inspectors may suggest to the client that the disinfectant they have selected is not really a disinfectant and will not protect public health.
In such cases, what we advise our clients to do is show the inspector the DIN (Drug Identification Number) on the label. This number, as we shall discuss in greater detail later, verifies that the product has been independently tested and proven to be an effective disinfectant.
But before venturing further, we should define what we mean when we use the term “protect public health.” A definition accepted by Health Canada is the following:
Public health is defined as the organized efforts of society to keep people healthy and prevent injury, illness and premature death. It is a combination of programs, services and policies that protect and promote the health of all Canadians. 1
Further, one of the goals of public health, is to help improve the quality of human life through the preventing one of the goals of a public health inspector, charged with protecting p on of disease. This typically refers to the actual inspection of public facilities, such as restaurants, schools, medical locations, and other places used by many people.
Here is Where Cleaning and the Selection of Disinfectants Comes Into the Picture.
Health inspectors, according to the Canadian Institute of Public Health Inspectors (CIPHI), are charged with helping to educate facility managers and cleaning professionals in these public facilities and confirm that they are using the right cleaning chemicals–solutions, sanitizers, and disinfectants—and using them correctly to help protect human health.
This is a critical job. With the health of hundreds, if not thousands of people at stake every day, administrators and cleaning workers cannot turn everything over to public health inspectors. They must take proactive steps to protect public health, and this all begins by having a solid understanding of some of the cleaning, sanitizing, and disinfecting terms and procedures that apply to keeping surfaces clean and healthy.
For instance, what is the difference between cleaning and disinfecting? Cleaning is the complete removal of unwanted matter using appropriate detergent chemicals under recommended conditions. 2
This is typically accomplished with water, cleaning solutions, and mechanical action. When used to clean a surface, these components work together to break apart soils so that they can be removed.
However, removing soil does not mean that pathogens that can cause disease have also been removed or “killed” to protect human health from harm. For that to happen, we need to use a disinfectant. A disinfectant, according to Health Canada, is the following:
A substance, or mixture of substances, capable of destroying or irreversibly inactivating all microbial pathogens. 3
While Health Canada identifies different types of disinfectants based on their efficacy (effectiveness), they typically fall under three key categories. These are:
Limited Disinfectant – A limited disinfectant is effective against only a specific group of microorganisms. More specifically, efficacy data is required against pathogens, Salmonella enterica (Gram-negative) or Staphylococcus aureus (ATCC 6538) (Gram-positive).
General Disinfectant– This is a disinfectant that is effective against a variety of different types of bacteria, germs, and pathogens.
Hospital Disinfectant – These are also general or broad-spectrum disinfectants but far more powerful. Through tests, these disinfectants have proven effective at eliminating many types of nosocomial (healthcare-acquired) bacterial pathogens. As the name implies, these disinfectants are generally for use in hospitals, clinics, dental offices, or other healthcare-related facilities. Health Canada adds that efficacy data is required against Pseudomonas aeruginosa and Staphylococcus aureus for a disinfectant to be labeled a hospital disinfectant. 4
We should also clarify what a sanitizer is because, in many cleaning situations, a sanitizer is all we need. According to Canada’s National Collaborating Centre for Environmental Health (NCCEH), a disinfectant is an antimicrobial agent capable of destroying specific pathogens as listed on the products label.
On the other hand, the Canadian Bureau of Chemical Safety (BCS) says that a sanitizer is designed to reduce the numbers of microorganisms on a surface to levels considered safe for public health.
In other words, while a disinfectant is designed to kill all pathogens on a surface if the right disinfectant is selected and used correctly, a sanitizer is designed to reduce the number of pathogens on a surface as long as the surface has been cleaned first and the sanitizer is used correctly. Remember this when it comes to the selection of disinfectants.
The Environmental Protection Agency (EPA) in the U.S. and Health Canada are closely linked and are often the global reference for anything related to healthcare, emerging or present challenges. Both categorize disinfectants based on their efficacy, but a question many have is why can’t one disinfectant (or sanitizer) kill all types of bacteria and pathogens? The answer is rather simple: not all pathogens are created equal.
Some pathogens such as HIV, HBV, Influenza, RSV, Ebola, even SARS are referred to as “lipid” pathogens because they are enveloped (enclosed) in a very soft shell. Others are non-lipid, having no envelope at all. In both cases, these types of pathogens are relatively easy targets for disinfectant eradication.
Cleaners, DINs, and the Selection of Disinfectants
We have mentioned several times the importance of cleaning a surface first before disinfecting. This method is referred to as the “two-step” process of cleaning and disinfecting, which Avmor wholeheartedly supports. However, new cleaning solution technologies are helping eliminate this two-step process. They can clean and disinfect a surface effectively all in one step. As you can imagine, this can reduce cleaning time significantly.
At least one cleaner/disinfectant uses hydrogen peroxide as its primary ingredient. Canadian approved Hydrogen Peroxide have been tested and found to be effective in the presence of light to have the ability to disinfect surfaces without a pre-cleaning step even in situations where there is a moderate amount of soiling.
As useful as these hydrogen peroxide cleaner/disinfectants can be, some Canadian health inspectors, as well as facility managers and cleaning professionals, have questioned whether these one-step cleaners are indeed disinfectants. All that is necessary to address this question is to see if the product has a “DIN” number on the label.
A Drug Identification Number (DIN) is “a computer-generated eight digit number assigned by Health Canada to a drug product prior to being marketed in Canada. It uniquely identifies all drug products sold in a dosage form in Canada and is located on the label of prescription and over-the-counter drug products that have been evaluated and authorized for sale in Canada.” 4
It is placed on all products sold in Canada that have been tested and proven to meet the stringent disinfecting standards and criteria developed by Health Canada. It is similar to an EPA registration number placed on proven effective disinfectants in the U.S. This can make the selection of disinfectants easier.
Health Canada, just like the EPA, works independently. When a DIN is placed on a disinfectant, it tells health inspectors as well as facility administrators and cleaning professionals that they can trust this product to disinfect a surface effectively when used per manufacturer’s instructions.
Using Disinfectants Properly
Along with a DIN number, manufacturers will list instructions on how to use their disinfectants properly. While these instructions are often similar that does not mean they are all the same. When first using a new disinfectant, administrators and cleaning professionals are advised to read all user instructions before proceeding.
No matter what type of disinfectant is used and whether it is a two-step or one-step cleaning solution, Avmor offers the following recommendations for cleaning professionals:
- Evaluate the disinfectant as to cost-effectiveness before selecting; while two products may have similar price tags, depending on the dilution ratios, one may be far more cost-effective over the long-term than the other. (See Sidebar 1)
- Make sure the product is non-corrosive to the types of surfaces where it will be used; this helps ensure the product is safer for both surfaces and users.
- Never mix different types of disinfectants.
- Only use disinfectants where and when needed; this helps prevent microbes from building immunities to the ingredients in certain disinfectants.
- If resistance is discovered by specific testing, use a disinfectant with a different active ingredient. Using higher concentrations of the same disinfectant is discouraged, as this could promote the emergence of resistant microbes. (See Sidebar 2: Resistance to Sanitizers)
- Mechanical force, also known as agitation, is always needed when cleaning and disinfecting. The agitation helps ensure soils and pathogens are loosened from surfaces, so they can be removed.
- In some cases, the surface will need to be rinsed with pure water after disinfecting. This prevents re-soiling of the surface. However, this is not always the case. For instance, rinsing is typically not necessary when using sanitizers. Rinsing requirements should be listed on the product’s label.
- The manufacturer will list the dilution or concentration levels of the disinfectant. Follow these closely. Higher concentrations are not necessarily more effective, and once again, they can cause microbes to become resistant to the disinfectant.
- Always use disinfectant and sanitizer according to manufacturer’s instructions and only for their intended purpose
As you can see, there is a lot to know about the proper use of disinfectants. Because of this, we cannot always depend on Canadian health inspectors to be our guides when it comes to protecting human health. We mentioned earlier, we must take a proactive approach; ultimately the challenge of protecting public health in our hands. The more we know about cleaning, sanitizing, and disinfecting, the easier it will be for us to address this challenge.
Mike Watt is Director of Training and New Product Development at Avmor, a leading North American manufacturer of professional cleaning solutions. He can be reached at email@example.com.
Sidebar 1: What is a dilution ratio?
If a disinfectant says it is to be used with a dilution ratio of 1:10, this means one-part chemical should be used to ten parts water for a total of 11 parts
In some cases, the product will list a dilution factor. In this case, a 1:10 dilution factor would indicate one-part chemical and nine parts water for a total of 10 parts.
Sidebar 2: Resistance to Sanitizers
According to Canada’s National Collaborating Centre for Environmental Health, resistance can also develop when using sanitizers.
“The three types of resistance that may occur are innate, apparent, or acquired. As most sanitizers are non-specific, the development of resistance is mostly caused by innate factors, which are chromosomally controlled properties naturally associated with the organism.” For more information on resistance to sanitizers, visit: http://www.ncceh.ca/sites/default/files/Food_Contact_Surface_Sanitizers_Aug_2011.pdf
- A Dictionary of epidemiology. 4th Edition. Oxford University Press (2001)
- Joint Institute for Food Safety and Applied Nutrition; written by Alan Parker and published by the University of Maryland, 2007
- Government of Canada; Classification and Licensing of High-Level Disinfectants and Sterilants as Medical Devices; https://www.canada.ca/en/health-canada/services/drugs-health-products/medical-devices/activities/announcements/notice-classification-licensing-high-level-disinfectants-sterilants.html
- Government of Canada; Guidance Document – Disinfectant Drugs; https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/applications-submissions/guidance-documents/disinfectants/disinfectant-drugs.html
- Government of Canada; Drug Identification Number: https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/fact-sheets/drug-identification-number.html