As noted in Table 2, the FDA TFM of 1994 classified povidone iodine, 5 to 10%, as a Category I agent, i.e., generally safe and effective for use in antiseptic hand wash or HCW handwash products.27 Povidone iodine is an iodophor composed of elemental iodine, iodide or triiodide, and a polymer carrier or complexing agent. The amount of free iodine determines the level of antimicrobial activity of iodophors.33 Iodine molecules rapidly penetrate the microbial cell wall and inactivate cells by forming complexes with amino acids and unsaturated fatty acids, resulting in impaired protein synthesis and alteration of cell membranes. The extent to which iodophors exhibit persistent antimicrobial activity is unclear.1
Antiseptic handwash (follow handwashing recommendations in Figure 1) with povidone iodine removes or destroys transient microorganisms and reduces the resident hand flora.1 It is an acceptable method of hand antisepsis when the hands are visibly soiled and it is an acceptable alternative to handwashing. However, when the hands are not visibly soiled, the CDC and the WHO recommend the use of an alcohol-based handrub (see Figure 2) for routine hand hygiene.1,25,27 The concomitant use of an alcohol-based handrub and an iodophor-based antimicrobial soap is contraindicated and the use of antimicrobial-impregnated wipes (i.e., towelettes) are not acceptable for antiseptic handwash.
The antimicrobial activity of iodophors can be affected by both organic (e.g., blood and sputum) and inorganic compounds (e.g., alcohols and detergents).34 Iodophors cause less skin irritation (irritant contact dermatitis) and fewer allergic contact dermatitis than iodine, but more irritant contact dermatitis than other antiseptic agents.35,36 Occasionally, povidone iodine antiseptic agents have become contaminated with gram-negative bacilli and have caused outbreaks of nosocomial infection.33