Medico Knowledge

Handling and storage of chemicals in a laboratory  Proper handling and storage of chemicals and reagents is necessary to prevent hazards. Chemicals are stored according to their physical and chemical properties. Types of chemicals 1. Flammable Chemicals - eg :- Acetone, Ether, Xylene, Alcohol 2. Corrosive chemicals - eg :- Concentrated Acids, Alkalies, phenol etc 3. Oxidising Chemicals - eg :- Potassium dichromate, Chromic acid, Chlorites etc.  4. Explosive Chemicals - eg :- Picric Acid. 5. Radioactive chemicals- eg :- I 125 , I 131 , H3 6. Carcinogenic chemicals-eg :- Benzidine, O- toluidine, Selenite, etc  7. Toxic Chemicals -eg :- Potassium Cyanide Handling and Storage of chemicals   1. Label the chemicals with hazard symbol, simple instruction for use, strength and Expiry date (it is mandatory for manufacturers). 2. Flammable chemicals are stored in fire proof metal containers at ground level in a cool dry place and always handle them away from direct flame. 3. C...

 CHEMICAL METHODS OF DISINFECTION  Disinfectants are those chemicals that destroy pathogenic bacteria from inanimate surfaces. Different disinfectants have different target ranges. Some chemical have very narrow spectrum of activity and some have very wide. Those chemicals that can be safely applied over skin and mucus membranes are called antiseptics. Bacteriostatic chemicals are those inhibit multiplication of bacteria without killing them. Bactericidal is that chemical that can kill or inactivate bacteria. Mode of action of various Chemical Disinfectants include. Protein coagulation, disruption of cell membrane, enzyme damage etc.  Different chemicals used as disinfectants   ALCOHOLS : E.g.: Ethyl alcohol, isopropyl alcohol and methyl alcohol.70% ethyl alcohol (spirit) is used as antiseptic on skin.  ALDEHYDES E.g.: Formaldehyde, and Glutaraldehyde 40% Formaldehyde (formalin) is used for surface disinfection and fumigation operation theatres, biological...