All are true regarding disinfectants except ?
Gluteraldehyde is sporicidal
Hypochlorites are virucidal
Ethylene oxide is intermediate disinfectant
All
Ans. is 'c'i.e., Ethylene oxide is intermediate disinfectant Phenols do not require organic matter to act, rather they are slowly and paly deactivated by organic matter. Organic matter tends to absorb phenol and lowers the concentrationu available to kill microorganism. Do not get confused with the answer of previous question; phenols are not readily inactivated by organic matter, they are inactivated slowly and paly. . Ethylene oxide gas is a high level disinfectant ( not intermediate). . Gluteraldehyde has sporicidal activity and hypochlorite (chlorine) has virucidal activity. . Option 'c' requires detailed explanation. Categories of effective potency . Sterilants :- are capable of completely eliminating or destroying in all forms of microbial life, including spores. . Disinfectants :- Destroy some, but not necessarily all organisms. The category is fuher divided into subcategories:- i) High level disinfectants :- In their usual concentration and contact period, they destroy all microorganisms, with exception of high number of bacterial spores ( small number of spores can be destroyed). It is woh noting that at higher concentrations and prolonged contact period, high level disinfectant can act as steriliant, i.e. can kill high numbers of spores as well. Examples are :-2% gluteraldehyde, 8% formaldehyde, 6-10% hydrogen peroxide and ethylene oxide gas. ii) Intermediate level disinfectants :- Inactivate even resistant organisms such as mycobacterium tuberculosis as well as vegetative bacteria, most viruses and most fungi, but do not necessarily kill bacterial spores. Examples are :-0.5% iodine, 70-90% ethanol and isopropanol, chlorine compounds (hypochlorite), some phenolic compounds and iodophor based disinfectants. iii) Low level disinfectants :- kill most bacteria, some viruses and some fungi, but cannot be relied on to kill resistant microorganisms such as tubercular bacilli or bacterial spores. Examples are :- quaerly ammonium compounds, mercurials,some phenolic compounds and iodophores. Note:- the disinfectant levels of iodophors (iodines) and phenolic compounds may be classified as intermediate or low depending on the concentration employed. Levels of disinfectant Activity Level of activity Bacteria Spores Fungi Viruses Vegetative Tubercular Lipid medium size Nonlipid & Small High Intermediate Low + + + + + - + - _ + + + + + + + -