Manual of basic techniques for a health laboratory - libdoc.who.int

84 Manual of basic techniques for a health laboratoryTable 3.1 Commonly used disinfectantsIntended object of Disinfectant Recommended Minimum Stock preparation ofdisinfection dilution for duration of disinfectantdisinfection (v/v) treatmentBlood Cresol, 5% solution 2 : 1 6 h crystals or liquidCalcium hypochlorite solution (1% 2 : 1 6 h powderavailable chlorine)Stool Cresol, 5% solution 2 : 1 6 h crystals or liquidCalcium or sodium hypochlorite solution 3 : 1 6 h powder(1% available chlorine)Calcium hydroxide, 20% solution 2 : 1 6 h powderChloramine (4% available chlorine) undiluted 6 h powderUrine Cresol, 5% solution 1 : 1 4 h crystals or liquidSputum Cresol, 5% solution 1 : 1 4 h crystals or liquidSkin Cresol, 50% solution undiluted 2 min 50% cresol in soap solutionEthanol, 80% solution undiluted 2 min 95% solutionIodine, 1% solution undiluted 2 min 5% solutionPolyvidone iodine, 1% solution undiluted 2 min pureIsopropanol, 70% solution undiluted 2 min puren-Propanol, 60% solution undiluted 2 min pureChloramine (1% available chlorine) undiluted 2 min powderQuaternary ammonium compounds undiluted 2 min solutionDrinking- Chloramine, 0.25% solution undiluted 16 min powderwaterWork benches Cresol, 50% solution undiluted 4 h 50% cresol in soap solutionCresol, 5% solution undiluted 4 h crystals or liquidChloramine (5% available chlorine) undiluted 4 h powderSodium hypochlorite (1% available undiluted 4 h powderchlorine)Laboratory Sodium hypochlorite (0.1% available undiluted 4 h 5%, 10%, 15% solutioninstruments a chlorine)Glassware Sodium hypochlorite (1% available undiluted 12 h 5%, 10%, 15% solutionchlorine)aChemical disinfection for skin-cutting and invasive instruments should be employed only as the last resort, if neither sterilization nor highleveldisinfection by boiling is possible, and then only if the appropriate concentration of the chemical is available and if the instrumentshave been thoroughly cleaned to remove gross contamination before soaking in the chemical disinfectant.exposure of material to phenol solution must be longer than for cresol. Phenol andcresol solutions cause irritation of the skin and eyes.Sodium and calcium hypochloriteSodium and calcium hypochlorite solutions (household bleaches) are very strongdisinfectants. They are used in a number of laboratory, household and industrialapplications. Hypochlorites are rapidly inactivated by particles of dust and organicmaterials and must be freshly prepared from stock solutions every day. Hypochloritescause irritation of the skin, eyes and lungs.Strong, undiluted solutions should contain 10% available chlorine.For preparing working dilutions, the following dilutions are recommended:● For jars and containers in which used pipettes, slides or other glassware arediscarded and for swabbing bench surfaces: 10ml of concentrated hypochloritesolution in 990ml of water (0.1% available chlorine). Place the used glasswareinto the jars of hypochlorite solution and leave for at least 12 hours. Do notoverfill the containers. Change the containers daily.