Germicidal detergents are an important part of environmental surface cleaning programs in many facilities. When used properly, they clean, disinfect and deodorize in a one-step operation. However, there is a good deal of misunderstanding about them - to the point where some cleaning operations may be using more disinfectant firepower than they need. To sort out the various issues, it helps to review the recent history of these products.

In 1986 the federal Centers for Disease Control and Prevention (CDC) published its still-current Guidelines for Handwashing and Hospital Environmental Control, which includes a section on housekeeping. The CDC adopted categories of desired microbial kill based on classes of infection risk first suggested by Dr. E.H. Spaulding. His original classification of medically related surfaces was expanded by the CDC's Walter Bond and Martin Favero to include housekeeping surfaces such as floors, walls, tabletops and window sills. Also included were frequently touched knobs or handles of medical equipment, such as hemodialysis machines or dental units, and, in non-healthcare settings, door handles, rails and other surfaces people touch.

Under these CDC guidelines, six types of "intermediate" and "low-level" products are adequate for non-critical surface cleaning/disinfection. These product types are:

 Ethyl or isopropyl alcohol (70 percent to 90 percent)

 Sodium hypochlorite (5.2 percent household bleach) diluted at 1:500 (100 ppm free chlorine)

 Sodium hypochlorite (5.2 percent household bleach) diluted at 1:50 (1,000 ppm free chlorine)

 Phenolic germicidal disinfectants

 Iodophors

 Quaternary ammonium compounds, or "quats."

Quats, phenols most common

Of these, the quats and phenolics are most commonly used in housekeeping. Although there is no "perfect" disinfectant detergent, the others have certain disadvantages: for instance, iodophors, with their iodine base, can stain; bleach is too harsh on surfaces and on the skin of housekeeping employees to be used as a day-to-day disinfectant.

Quats are appropriate for routine cleaning and housekeeping and for low-level cleaning and disinfection of certain non-critical medical instruments or devices. They are not designed for disinfecting invasive (critical) medical instruments or equipment. While it is true that hard water, soap, anionic residues and cotton mops can reduce their germ-killing effectiveness, quats still are generally considered to be good cleaning agents. In a recent study, about 78 percent of surveyed hospitals reported that quats were the disinfectant of choice for routine housekeeping activities. They are even more common in other types of facilities.

Phenolics (carbolic acid) fall into both the "low level" and "intermediate" germ-killing categories. Like the quats, they can be used to disinfect non-critical items, but they can also be used on some semicritical items because they make a tuberculocidal claim.

A more detailed discussion of the qualities of each of these types of disinfectants can be found in Guidelines for Selection and Use of Disinfectants, published in 1996 by the Association for Professionals in Infection Control and Epidemiology (APIC).

When to use disinfectants

Your cleaning operation needs to use a disinfectant in either of two situations: first, when there is a possibility that a disease-causing organism can be transmitted from an object or surface to people; second, when governmental or institutional rules tell you to do so.

These two conditions generally overlap, but not always. For instance, one could legitimately question whether anyone really needs to disinfect inanimate surfaces such as tables, chairs, floors or countertops.

Here's what the CDC has to say about this in Guidelines for Handwashing and Hospital and Environmental Control:

"Although microorganisms are a normal contaminant of walls, floors and other surfaces, these environmental surfaces rarely are associated with transmission of infections to patients or personnel. Therefore, extraordinary attempts to disinfect or sterilize these environmental surfaces are rarely indicated. However, routine cleaning and removal of soil are recommended."

The CDC continues: "Any hospital-grade disinfectant-detergent formulations registered by the EPA [U.S. Environmental Protection Agency] can be used for environmental surface cleaning, but the actual physical removal of microorganisms by scrubbing is probably as important, if not more so, than any antimicrobial effect of the cleaning agent used."

In other words, while housekeeping surfaces (that typically come into contact only with intact skin) seldom pose an infection risk, they should be continually maintained in the cleanest possible condition.

Germicidal detergents are an excellent tool for this process. But why are good cleaning procedures even more important?

One possible explanation is that the 10-minute exposure time manufacturers use to achieve their label claims is not typically employed by housekeeping operations when non-critical surfaces are cleaned. As a practical matter, this exposure time cannot be achieved without immersion. This is why it is just as important for your staff to use clean mops, clean or disposable wiping cloths, and solutions that are fresh and changed before they become dirty and overburdened with organic soil. In any cleaning situation, a dirty solution doesn't clean - it simply makes everything evenly dirty.

Potential for overuse

Regulatory standards governing use of disinfectants can potentially prompt overuse of these products. This could be the case if you are trying to combat organisms that are not - at least for environmental surfaces like floors and countertops - a gross health threat, and if good cleaning procedures would accomplish much of the job.

Still, while use of a powerful (e.g., tuberculocidal) disinfectant might seem excessive and the logic of the regulations questionable, as in the case of the OSHA bloodborne pathogens rule, designed to limit transmission of Hepatitis B (HBV), facilities are mandated to follow rules to the letter or risk OSHA citations or fines. In the meantime, patients, housekeepers and others in the building environment may have been exposed to a strong disinfectant, and the facility may have spent more money on expensive chemicals than was necessary.

To review this issue, EPA convened a Scientific Advisory Panel in September 1997. In this and other forums, disinfection and sterilization experts have criticized the OSHA "tuberculocidal" requirement. They argue that:

 Traditional non-tuberculocidal disinfectants like the quats inactivate HBV.

 Noncritical surfaces are rarely involved in disease transmission.

 The exposure time manufacturers use to achieve their label claims (10 minutes) cannot be used in healthcare or most other settings to disinfect noncritical surfaces, without immersion.

This issue is still under investigation, and EPA is expected to issue some new criteria that would permit many other products to be used for decontamination to prevent HBV transmission, perhaps by this summer.

Tough microbes

The controversy over how much and what type of disinfectant to use on environmental surfaces also is related to a growing concern about antibiotic-resistant pathogens in hospital, extended-care, home-care and similar facilities. Some have raised the possibility that antibiotic-resistant bacteria might exhibit cross-resistance to antiseptics and disinfectants. Of special concern is the increased incidence of infections caused by:

 Methicillin-resistant S. aureus (MRSA). This is a strain of the bacterial species Staphylococcus aureus that is resistant in the human body to the antibiotic methicillin (and the related antibiotics oxacillin and nafcillin). It is believed that human hands are the major instrument for transmission of this and other bacteria in medical facilities.

 Vancomycin-resistant enterococci (VRE). Enterococci are a part of the normal flora of the intestines but may cause disease when they move into the bloodstream, urinary tract or meninges (the three thin layers of tissue that cover the brain and spinal cord). They are occasionally associated with food poisoning. Some strains of enterococci have become virtually untreatable, having developed resistance to vancomycin and all other commonly used antibiotics.

 Clostridium enterocolities (C. difficile). This infectious disease has symptoms ranging from self-limiting diarrhea to severe hemorrhagic colitis. Some investigators have recommended the use of dilute solutions of sodium hypochlorite for routine environmental disinfection of rooms of patients with C. difficile-associated diarrhea or colitis. But this practice would appear to be unnecessary because studies have shown that patients without symptoms can also have the organism and that person-to-person transmission is the principal means of infection. Handwashing, barrier precautions and meticulous environmental cleaning may, therefore, be effective in preventing the spread of C. difficile.

Cleaning still most effective

Studies have shown that bacteria resistant to antibiotics are not simultaneously resistant to commonly used chemical germicides. There could be some instances in which VRE on environmental surfaces - such as frequently touched bed rails, charts, carts, doorknobs, faucet handles and bedside commodes, that is, any surface that might be touched by the patient or by a healthcare worker before touching a patient - might be part of a pathway of transmission.

Note: The most effective control strategy in all of these instances is good cleaning procedures. For these and other reasons, the CDC does not recommend any special strategies or germicides with higher potencies for cleaning noncritical surfaces in rooms of patients who are infected with multi-antibiotic-resistant organisms. Any EPA-registered germicidal detergent is appropriate for this purpose.

There is little question that infection transmission is a frightening possibility. But overdependence on environmental surface disinfectants is not the solution to the problem.

A housekeeping department should accurately use the appropriate EPA-registered disinfectant detergents where applicable. But department managers should concentrate on ensuring that their personnel are using good, thorough cleaning procedures. Workers should have generous access to clean wiping cloths, clean mop heads, the best possible equipment and, perhaps most important, sufficient time to do their work effectively.

Hal Temkin is president of HIT Marketing Services, Highland Park, IL, and was formerly marketing director of PortionPac Chemical Corp. He is a member of the Association for Professionals in Infection Control and Epidemiology, and has served on the board of directors of the Environmental Management Association.