1. The effect of the pH on the germicidal action of soaps has been studied. The lower members of the series were found to be most active in acid solution; the higher members, in alkaline. The point of transition varied with the test organism used. 2. This is probably due to the effect of the pH on the dissociation residue and on the solubility of the soap. The dissociation residue may affect th...

RATIONALE Transmission is driving the global tuberculosis epidemic, especially in congregate settings. Worldwide, natural ventilation is the most common means of air disinfection, but it is inherently unreliable and of limited use in cold climates. Upper room germicidal ultraviolet (UV) air disinfection with air mixing has been shown to be highly effective, but improved evidence-based dosing gu...

Ultraviolet germicidal irradiation (UVGI) is a disinfection method that uses ultraviolet (UV) light at sufficiently short wavelength to kill microorganisms. It is used in a variety of applications, such as food, air and water purification. UV has been a known mutagen at the cellular level for more than one-hundred years. The 1903 Nobel Prize for Medicine was awarded to Niels Finsen for his use ...

BACKGROUND Heat-sensitive medical devices require chemical disinfection between patients, and certain formulations for this purpose can be reused for several days. Because dilution, evaporation, and breakdown or neutralization of active ingredients can occur during reuse, it is vital to ensure that the solution retains its broad-spectrum germicidal activity even at the end of the recommended re...

BACKGROUND UVC light generated by conventional germicidal lamps is a well-established anti-microbial modality, effective against both bacteria and viruses. However, it is a human health hazard, being both carcinogenic and cataractogenic. Earlier studies showed that single-wavelength far-UVC light (207 nm) generated by excimer lamps kills bacteria without apparent harm to human skin tissue in vi...

STUDY OBJECTIVE We evaluate the frequency of emergency department (ED) ultrasonographic probe contamination and the bacterial species involved and evaluate probe cleaning and disinfection methods. METHODS This was a 3-part observational cross-sectional study. Surveillance cultures were taken of linear and curvilinear probes on 3 ultrasonographic machines between patient encounters. Cultures o...

We have previously shown that 207-nm ultraviolet (UV) light has similar antimicrobial properties as typical germicidal UV light (254 nm), but without inducing mammalian skin damage. The biophysical rationale is based on the limited penetration distance of 207-nm light in biological samples (e.g. stratum corneum) compared with that of 254-nm light. Here we extended our previous studies to 222-nm...

Healthcare-associated infections (HAIs) can be caused by microorganisms present in common practice instruments generating major health problems the hospital environment. The aim of this work was to utilize disinfection capacity a portable ultraviolet C equipment (UV Sanitizer Box and UV-C Sterilization Torch) developed disinfect different objects. Pollution macro micro environment has concerns f...