DISINFECTIONS

3. DISINFECTIONS • Disinfection is the killing of infectious agents out the body by direct exposure to physical or chemical agents.

4. DISINFECTANT A disinfectant or germicide is a substance which destroys harmful microbes (not usually spores) with the objective of prevention oftransmission of disease. Disinfectants are suitable for application only to inanimate objects.

5. ANTISEPTIC An antiseptic is a substance whichdestroys or inhibit the growth of micro organism.

6. DEODORANTS Itis a substance which suppresses orneutralizes bad odour.

7. DETERGENTS A detergent is a surface cleaning agent. It acts by lowering the surface tension eg: soap which remove bacteria along with dirt.

8. STERILIZATION Sterilization is a process of destroying all life including spores.

9. TYPES OF DISINFECTION Three types: • Concurrent disinfection. • Terminal disinfection. • Precurrent disinfection or prophylactic disinfection.

10. 1.CONCURRENTDISINFECTION Itis the application of disinfective measures as soon as possible after the discharge of infectious material from the body of an infected person or after the soiling of articles with such infectious discharges.

11. 2.TERMINAL DISINFECTION It isthe application of disinfectivemeasures after the patient has been removed by death or to a hospital or has ceased to be a source of infection or after other hospital isolation practices have been discontinued.

12. 3.PRECURRET DISINFECTION Disinfection of water by chlorine pasteurization of milk and handwashing may be cited as examples of precurrent disinfection. TYPE OF DISINFECTANT 1. Natural Agents 2. Physical Agents 3. Chemical Agents

13. Different Types of Chemical Disinfectents • Bleaching Powder • Savlon • Alum • Detergent • Formalin • Alcohol • Iodine • Dettol

15. BLEACHING POWDER Bleaching Powder or chlorinated lime is a white amorphous powder with a pungent smell of chlorine. Agood sample of bleaching Powder contains about 33% of available chlorine. it kills most of the organisms when used in the strength of 1-3%.The chief draw back of bleaching Powder is that it's an unstable compound and loses its chlorine content on storage.

16. It's action is rapid but brief or short duration. A 5% solution (3-4 rounded table spoons to one litre of water) is suitable for disinfection of faeces and urine allowing a period of one hour for disinfection.

18. ALCOHOL Ethyl and isopropyl alcohols are commonly used as antiseptic and disinfectants. Ethyl alcohol in the form of industrial methylated spirit is the alcohol most commonly used for skin disinfection and hand washing. Pure alcohol has no powers of disinfection but when diluted to 70% strength it,s a good antiseptic, it,s activity decreases rapidly below 50% concentration.

20. FORMALIN Formaldehyde more commonly known in solution as formalin, Formaldehyde is a highly toxic and irritant gas which precipitates and destroys protein. It's effective against vegetative bacteria, fungi and many viruses but only slowly effective against bacterial spores (eg: tetanus spores) and acid - fast bacteria.

21. It does not injure fabrics and metals. It may be used as a 2 - 3% solution (20 - 30 ml of 40% formalin in one litre of water ) for spraying rooms, walls and furniture.

23. SAVLON Savlon is a combination of cetavlon and hibitane. Plastic appliances like lippe's loop may be disinfectedby keeping them in normal strength Savlon for 20 minutes. . Savlon 1 in 6 in spirit is more effective than a Savlon 1 in 20 aqueous solution. Clinical thermometers may be best disinfected in Savlon 1 in 6 in spirit in just under 3 minutes.

24. ALUM

25. ALUM It isone of the chemical disinfectant used for purification of water. It acts as a chemical coagulant itis an odourless, colourless, crystalline substance with local astringent property & sweetish taste.It is prepared from boxate and hydrogen sulphate with addition of potassium or ammonia. Itis also used as an adjuvant in adsorbed vaccine and toxoides.

27. PHENOL Crude phenol that is commonly used for disinfection. which is a mixture of phenol and cresol. Itis a dark oily liquid. Itis effective against gram +ve and gram -ve bacteria, but only slowly effective against spores and acid - fast bacteria. Itis also effective against certain viruses.

29. DETTOL Dettol is relatively non toxic antiseptic and can be used safely in high concentrations. Itis more easily inactivated by organic matter than many other phenolic disinfectants. Itis active against streptococci but worthless against some gram negative bacteria. Dettol (5%) is suitable for disinfection of instruments and plastic equipment.

31. IODINE Iodine inalcoholic solution of 1-2% is one of the most effective skin antiseptic available. But it stains the skin & may produce sensitivity reaction in some persons. Plastic equipments like lippe's loop may be sterilized by keeping in 1/25 aqueous solution of Iodine. Iodine is cheap, readily available and quick in action.

33. POTASSIUM PERMANGANATE Itis not a satisfactory agent for the disinfection of water. it may kill cholera vibrios but it hasvery little use against other disease agents, it may alter the colour, smell and taste of water.

34. AND

35. INSECTICIDE

36. DEFINATION: Insecticides are substances which are used to kill insects. They are classified into 3 groups : • Stomach poison • Contact poison • Fumigants

37. STOMACH POISON : Stomach poisons are those which when ingested cause the death of the insects. CONTACT POISON : Contact poisons are those which kill insects primarily by contact.Eg - Pyrethrum, DDT , HCH (Hexachloro cyclo - hexane).

38. FUMIGANTS: These are the substances that give off vapours which have a lethal effect on the insects. eg- sulphur dioxide.

40. MALATHION Malathion has the least toxicity of all organophosphorus compounds. This product is a yellow or clear - brown liquid with an unpleasant smell. Malathion is used in doses of 100-200 mg. Sq. ft., every 3 months. Because of its low toxicity, malathion has been recommended as an alternative Insecticide to DDT.

42. METHYL PARATHION Itis one of the Insecticides that will kill or repel insects and related species. This is available in the market in the following means: • Agrotex • Metacide • Paracrop • Parahit

43. FURUDAN Itis an Insecticide and is crystalline substance and violet in colour. Itis highly toxic and is effective in control of DDT resistant Insects.

45. HCH Itis a white or chocolate coloured powder with a musty smell. It will cause irritation to the, nose and skin on exposure. It kills insects by direct contact but itis residual action is of a shorter duration that is 4-6 months. A dose of 25-50 mg of gamma HCH/Sq ft is recommended for residual treatment. Itis about twice as toxic as DDT.

47. DDT Itis a white amorphous powder but not having unpleasant smell. Itis insoluble in water but dissolves in most organic solvents. Itis primarily a contact poison. Itis a nerve poisons and increased nervous excitability and causes tremor and convulsions. Lethal dose of human is 150 mg/ kg of body weight.

48. SANITATION

50. SANITARY WELL A sanitary well is one which is properly located well constructed and protected against contamination with a view to yield a supply of safe water. The Following points should be taken into consideration while constructing sanitary well.