Cleaning for Health

Hard Surface Disinfecting Basics

Of major concern to health care, school, food service, and other workers in our industry, is cleaning and hard surface disinfecting. In this section, we present an overview of some of the key factors surrounding this issue.

After all­ "The dirt you see makes you mad. The dirt you don't see makes you sick".

What is the difference between a sanitizer, a disinfectant, and a sterilant?

  • Sanitizer- destroys 99.999% of all microbes present in 30 seconds.
  • Disinfectant- destroys 100% of all actively growing microbes, but not en- dospores.
  • Sterilant- destroys all forms of microbial life including spores.

We recommend you use detergent/ disinfectants that have excellent cleaning capability since sanitizers do not deliver a 100% kill, and sterilants are poor cleaners and are too expensive.

What is a "registered" disinfectant?

A product registered and approved by a government regulating body (in the U.S., the E.P.A.; in Canada, Health & Welfare Canada/ Agriculture Canada.) and exhibiting 100% destruction of Staphyloccus aureus, Salmonella choleraesuis, and Pseudomonas aeruginosa.

Not all registered, "hospital-type" disinfectants are equal in terms of the number of microbes they destroy or in their label claims. We feel that the above is a bare minimum rating and that an effective disinfectant should include claims to kill other bacteria, viruses, and fungi. Consider blood serum and hard water tolerance also.

How can I compare disinfectants?

Check to ensure the product is "registered" and compare label claims. Does the product carry a Drug Identification Number (D.I.N.)? More importantly, does it carry a Pest Control Product (P.C.P.) number issued by Agriculture Canada? In order to obtain the latter, a product must pass stringent tests designed by the Association of Official Analytical Chemists. Many consider E.P.A. registration, based on the stringent tests mandated by this organization a plus. In any case, a manufacturer should support claims with written reports and technical data indicating the following:

  • if and how it is registered;
  • what test methods it has used to achieve such registration;
  • exactly what the disinfectant can do under test and, if possible, real-world conditions.

Check labels for microorganism effectiveness. Compare the dilution ratios for cleaning and disinfecting. Check the soil load and hard water tolerances as well as odour counteracting capability.

Why is soil load tolerance and hard water effectiveness important?

Because you are disinfecting "dirty" surfaces with tap water dilution. Dirt (organic matter) and hard water salts tend to deactivate or "use up" the disinfectant molecules before they can kill microorganisms. Use disinfectants formulated for organic load and hard water deactivation so that they kill microorganisms under tough situations.

What is the OSHA recommendation for cleanup of blood spills and other body fluids?

There are a number of alternatives: sodium hypochlorite (bleach), products registered to be tuberculocidal (for example Airkem STAT III), and products effective against HIV-1. Review disinfectant labels and literature to ensure the products you use meet these guidelines.

Will all disinfectants clean and disinfect in one step?

No. To be rated as a "one-step" cleaner/ disinfectant, testing must show that the disinfectant retains efficacy in the presence of a 5% organic load. To find this data, check the product label, literature, and brochures.

Are all 1/2 ounce per gallon quaternary ammonium compounds the same?

No. Some 1/2 ounce per gallon disinfectants require a precleaning step while others don't. Also, there are a wide range of differences in other label claims...hard water tolerance, soil load, registered microorganisms. Always check the labels and use dilution.

What are the pros/ cons of phenolics, iodophors, quaternaries, and chlorine?



  • Effective against TB microbe


  • Irritating to skin­Toxic
  • Depigmentation of skin
  • Causes hyperbilirubinemia in infants
  • Poor water solubility causes ineffective disinfecting.



  • Low use concentrations
  • Low water temperatures
  • Not affected by hard water
  • Rapid kill on precleaned surfaces


  • Corrosive
  • Deactivates when exposed to UV light
  • Rapidly deactivates in presence of soil
  • Fresh solutions must be made daily (Labor cost)
  • Surfaces must be precleaned (Labor cost)
  • Hot/ warm water flashes off active ingredients
  • Will bleach out carpeting, clothing if spilled



  • Rapid kill time on precleaned surfaces
  • Not affected by hard water


  • Rapidly deactivated by organic soil load
  • Poor cleaner
  • Toxic
  • Must preclean surfaces (Labor cost)
  • Inactivated by anionic detergents
  • Staining of skin, clothes, hard surfaces
  • Interferes with chemistry test evaluations



  • Excellent cleaners allow one-step clean/disinfect
  • High soil load tolerance, remains active
  • Hard water tolerant, remains active
  • Less-toxic, less harmful to skin
  • Non-staining, non-corrosive
  • Full-spectrum bacteria/ virus kill of prime hospital pathogens
  • Use solutions have long life


  • Does not kill TB microbe

What about disinfecting. in schools? Is it really necessary?

Yes. Disinfecting is very important in schools to prevent transmission of disease between students. Areas to focus on include restrooms, shower stalls, locker rooms, gym mats, swimming areas, and dietary.

What areas are critical in dietary?

Here are the basics. Follow proper storage and handling procedures. Insist on frequent hand-washing. Sanitize all food contact surfaces with a no-rinse quat disinfectant/ sanitizer. Keep dumpsters free of insects and microbes. Airkem's F/H, or S.C. Johnson's J512 are good product choices for dietary.

Are there special disinfecting. issues in veterinary areas?

Disinfecting efficacy is the same as in hospitals. Disinfectants should tolerate high soil loads, hard water and be non-toxic. Once again, proper hand washing is critical. In animal research labs, disinfectants with odor counteractants should be used to prevent problems with chemical analysis. Airkem's A-456-N is a suitable product choice for veterinary areas.

Why is hand washing so important?

Most pathogenic bacteria are spread via hand contact, not from hard surfaces. In a health care facility, all people should carefully follow hand washing procedures after direct contact with any patient. This includes nursing staff, doctors, technicians, other employees, other patients, and even visitors. The primary success of a hand washing procedure is dependent on attitude and education, without which no hand washing program will be effective. Ensure both the products and procedures you use promote effective hand washing.

What about odor control? Won't a proper housekeeping program eliminate the need for odor control?

No. First, good housekeeping procedures do not address odors that emanate from patients (eg. cancer, burns, gangrene). Housekeeping cannot be everywhere at once. Problem odors (e.g.. incontinency) will spread faster than a containment crew can cover. Finally, many objectionable odors have no relation to housekeeping. These include cigarette smoke, lab chemicals, food service exhaust, etc.

How do I calculate REAL in-use cost?

EXAMPLE: Which has the lower in-use cost?
(A) A $21.00/ gallon, 1/2 oz (1:256) dilution with automatic preset control OR
(B) A $9.50/ gallon, 2 oz (1:64) dilution with no dilution control.

A. Divide $21.00/ gallon by 256 = 0.08203 use cost/ gallon. 0.08203 x zero waste factor = 0.08203 use cost / gallon.

B. Divide $9.50 by 64 = 0.1484 use cost/ gallon. 0.1484 x 1.25 waste factor (ISSA data) = .1855 use cost/ gallon. Although disinfectant A costs 121% more per gallon of concentrate, it will save 56% in actual in use cost. The "waste factor" can be eliminated by using a proportioning system.

The Bottom Line

Selecting the right disinfectant to suit the specific needs of your facility or area involves careful assessment of many factors, including:The degree of microorganism destruction required; the nature of the item to be "treated"; the cost and ease of usage of a particular product; odor control needs - all play a vital part in selecting the right product for the job. Ongoing, in - service training and education are important issues too. Does your supplier back his products up with these services?