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Cleaning and Disinfecting the In
door Environment: Chlorine Bleach, Quats and Phenolics

By Roger McFadden
Technical Director
Coastwide Laboratories

Disinfectants and the Environmental Protection Agency (EPA)

In the United States, disinfectants and disinfectant cleaners must be reviewed and registered by the Environmental Protection Agency (EPA) before they can be offered for sale. EPA assigns a registration number for each product and that number must be clearly displayed on every container of the product. Companies submitting disinfectants for registration are required to include current efficacy data to prove that their product kills ALL of the microorganisms listed on the product label. For instance, if the product label claims to kill staphylococcus aureus, then test data must be submitted to EPA to prove that the product when diluted according to label directions kills the staphylococcus aureus bacteria.

Efficacy Tests Measure the Effectiveness of Disinfectants

The tests used to measure the effectiveness of disinfectants on various pathogenic (disease causing) organisms are called, efficacy tests. The EPA must pre-approve all “efficacy test methods” used to measure the effectiveness of disinfectants against specific microorganisms. The most common efficacy test prescribed by EPA is the Association of Official Analytical Chemist (AOAC) Use Dilution Confirmation Test.  Currently, for a disinfectant cleaner to be registered by EPA as hospital strength, it must be effective at its recommended dilution in killing targeted pathogens in the presence of 400 ppm hard water and 5% organic serum. It must kill 100% of the targeted test organisms.

Ask Your Supplier to Provide Current Efficacy Data

It is a good idea for you to require the manufacturer and/or distributor of a disinfectant or disinfectant-cleaner to provide efficacy data to your organization before you select it for use in your facilities. The data should include a listing of the microorganisms it effectively kills.  Before selecting a disinfectant product it is important to review the product label to confirm that it: 1) contains a valid EPA Registration Number, 2) effectively kills the pathogenic microorganisms you are concerned with eliminating and 3) clearly identifies both the proper application and safety procedures to be followed when using the product.

What are the Differences Between Disinfectants and Disinfectant Cleaners?

Disinfectants require the removal of soils from a surface before they are effective. Disinfectant cleaners combine the cleaner and disinfectant into a “one-step” process.  A disinfectant-cleaner is diluted and then used to remove soils and kill germs all in one application. One step disinfectant-cleaners save labor time and money. Simply stated, disinfectants “disinfect” and disinfectant-cleaners “disinfect and clean.” If you are uncertain if your product is a disinfectant or disinfectant-cleaner, read the product label carefully. If the label does not mention “cleans and disinfects,” then it is probably a disinfectant or sanitizer and not a one-step disinfectant-cleaner.

Chlorine Bleach Solutions Are Excellent Disinfectants, But Poor Cleaners

Household and institutional chlorine bleaches contain 5.25% active sodium hypochlorite when they are manufactured. The remaining 94.75% is primarily water. Chlorinated compounds such as sodium hypochlorite when diluted in water form hypochlorous acid. This acid is extremely effective against many types of microorganisms including bacteria, fungi and viruses. For instance, the product label for Purex household bleach claims it is effective against staphylococcus and streptococcus bacteria, Influenza A and B viruses and athletes foot fungus. However, chlorine bleach products require that the surfaces be cleaned prior to their use.  This means doubling the time that it takes to clean and disinfect a soiled surface.

Disadvantages of Using Chlorine Bleach

Many institutions do not commonly use chlorine bleach products because they:

1.                   Lack detergency

2.                   react with other chemicals to create toxic gases

3.                   emit unpleasant odors

4.                   attack hard surfaces

5.                   discolor fibers and colored surfaces

6.                   damage floor finishes

7.                   lose their strength rapidly

8.                   are expensive to use

Phenolics, Iodines and Pine Oils

Phenols or phenolic disinfectant-cleaners are not as corrosive as chlorine bleach. But they aggressive enough to attack and damage floor finishes and sensitive flooring. Phenolic disinfectants are still the preferred product in a few health care facilities. It is used in areas where gross contamination of blood and body fluids exist. Phenolics are effective against pathogenic bacteria like tubercle bacillus that cause tuberculosis. Sporeforming bacteria like tubercle bacillus are extremely difficult to disrupt because to the protective shell which forms around the bacteria. Phenolic disinfectants are able to penetrate this shell and kill the TB organism inside.

Iodines and iodophor compounds can be very effective disinfectants with a broad range of killing power. But iodophors and iodines can stain surfaces and corrode metals.

Distilled pine oil can be formulated as a disinfectant.  Pine oils are not water-soluble. High levels (80%) of pine oil are required to kill many pathogens. Pine oils are seldom used alone to disinfect. They are combined with alcohols and quats to improve their disinfecting and cleaning properties. Pine Sol is an example of a pine oil based product that also contains isopropyl alcohol and quaternary ammonium compounds.

Quats Are The Best Choice: They Provide  Safe and Effective One-Step Cleaning and Disinfecting

Quaternary Ammonium Chlorides or “quats” as they are commonly known are based upon the active ingredient benzalkonium chloride. These quaternary salt compounds can be formulated with a variety of ingredients to provide a safe and effective neutral pH, disinfectant-cleaner without damaging floor finishes or sensitive floor surfaces.  In addition, quats are economical and extremely effective odor control agents when used according to label directions.    

Quats are effective in destroying a broad spectrum of harmful microorganisms. They are effective in killing the following microorganisms while cleaning the surfaces upon which they reside – all in one simple step.

1.                   Gram negative and gram positive bacteria like salmonella typhi, staphylococcus aureus, streptococcus epidermidis and pseudomonas aeruginosa,

2.                   viruses like HIV-1, Herpes simplex 1 and 2

3.                   Antibiotic resistant strains of bacteria including methicillin resistant staphylococcus aureus (MRSA).

4.                   and fungi like trichophyton interdigitale (athlete’s foot).

Ten Questions to Answer Before Selecting a Disinfectant-Cleaner 

1.                   Does the product have an EPA Registration Number?

2.                   What is the active ingredients? (Quats, Phenolics, Chlorine Bleach, Iodine or Pine Oil?)

3.                   Is it safe for daily use by housekeepers and custodians?

4.                   Will it damage the surfaces cleaned with it?

5.                   What germs does it kill?

6.                   What is the dilution ratio of the product?

7.                   Is it a “one-step” disinfectant-cleaner or a disinfectant?

8.                   Is it effective in hard water?

9.                   Is it effective in the presence of organic soil?

10.              What is the end-use cost of the product?