Disinfectants – Frequently Asked Questions….


My label says to pre-clean heavily soiled surfaces before applying a disinfectant. Is there a reason for this?

Yes. Since a disinfectant doesn't know the difference between greasy soil and bacteria, it is best to pre-clean heavy soil first. This way there is more active disinfectant (Quat)* to attack germs instead of attacking dirt.

*Quat – Short for quaternary ammonium compounds used in the manufacturing of disinfectants.  The active ingredients which destroy or disrupt the cell wall or microorganisms.

How do quaternary disinfectants actually work?

Quat-based disinfectants carry a positive charge. Bacteria, viruses and fungi carry a negative charge. When a bacteria-laden surface is sprayed or mopped with a disinfectant, the charge distribution of the bacteria cell changes from negative to positive. This results in the disruption of the bacteria cell wall and eventual death to the microbe.

My floor is protected with an acrylic floor finish. Can I clean it with a quat-based disinfectant?

Yes. We only recommend using neutral pH disinfectants to clean finished floors.

Your disinfectant labels state to "apply solution with a mop, cloth or hand-pump trigger sprayer as to wet all surfaces thoroughly. Allow to remain wet for 10 minutes..." Why is the 10-minute contact time necessary?

In short, quats need time to work. The process explained above (under bullet point two) takes time to occur. The cell walls do not break down immediately - thus necessitating the 10-minute contact time.

Some manufacturers and distributors claim that trigger spray bottles containing ready-to-use disinfectant solution should be changed daily. Is there any truth to this claim?

No. A raw material manufacturer of quaternary ammonium compound disinfectants performed testing on the ready-to-use version of a 10% disinfectant to determine the time frame wherein the product would remain effective. The original testing was performed in August of 1994 and passed all efficacy testing requirements. The testing was then repeated in May of 1996. The product again proved to be efficacious a year and nine months later. Therefore, it is concluded that the shelf-life of quaternary ammonium compound disinfectants in their ready-to-use form is at least one year. Note, however, that there are many variables to consider concerning shelf-life. These include hardness of water, contamination of the concentrate or ready-to-use product and the integrity (composition and seal) of the container.

What is the difference between disinfecting and sanitizing?

Disinfection is the removal or destruction of pathogens from inanimate objects. Non-pathogenic environmental organisms (coliforms) may not be completely eliminated through disinfection.  Sanitization is the cleansing of inanimate objects to reduce the microbial count to a safe level.

I want to make sure my disinfectant performs as it should. What factors affect how well a disinfectant works?  

There are six main factors listed below with a short description of each:

Concentration - this is dilution rate. Proper dilution is very important. Read label for complete dilution directions.

Contact Time - for quats, this is very important and is discussed more thoroughly above. For other disinfectants, such as bleach, contact time is not very critical.

pH - certain disinfectants work best under acidic conditions (bleach) and others work best under alkaline conditions (quats).

Temperature - certain disinfectants work best in cold water (bleach). Most, like quats, work best in warm water.

Soil Load - quats and other disinfectants do not know the difference between soil and bacteria. That is why heavy soil should be removed before disinfecting. See explanation above for more details.

Organism Type - not all disinfectants work on all types of organisms. When in doubt, read the product label for a complete list.

How can I calculate active parts per million (PPM) of the disinfectant I'm using?

To calculate active PPM, you'll need three things - the active ingredient list from the disinfectant label, dilution rate of the product and a calculator. Below is an example of how this would be done using Neutral Germicidal Cleaner:

  • Step 1: 
    Add together active ingredient percentages from the label: 
    5.07% + 3.38% = 8.45% total active ingredients.
  • Step 2:
    Multiply by 10,000: 
    8.45 X 10,000 = 84,500
  • Step 3:
    Divide the result of Step 2 by the dilution rate (128 in the case of 1 oz. per gallon): 
    84,500 ÷ 128 = 660 PPM.