chemical agents of sterilization

CHEMICAL AGENTS OF STERILIZATION

**IDEAL QUALITIES OF A GOOD DISINFECTANT:1. ATTACKS ALL TYPES OF MICROORGANISMS2. RAPID IN ITS ACTION3. DO NOT DESTROY BODY TISSUES OR ACT AS

POISON IF TAKEN INTERNALLY4. NOT RETARDED IN ITS ACTION IN THE PRESENCE

OF ORGANIC MATTER5. CAN PENETRATE THE MATERIALS BEIN

DISINFECTED

6. DISSOLVE EASILY IN OR MIX IN WATER TO FORM A STABLE SOLUTION OR EMULSION

7. DO NOT DECOMPOSE WHEN EXPOSED TO HEAT, LIGHT RAYS, OR UNFAVORABLE WEATHER CONDITIONS

8. DO NOT DAMAGE MATERIALS BEING DISINFECTED SUCH AS INSTRUMENTS AND FABRICS

9. DO NOT HAVE AN UNPLEASANT ODOR OR DISCOLOR THE MATERIAL BEING DISINFECTED

10. BE EASILY OBTAINED AT A COMPARATIVELY LOW COST & READILY TRANSPORTED

**MOST IMPT FEATURE OF A DISINFECTANT IS ITS ABILITY TO FORM LETHAL COMBINTIONS WITH MICROBIAL CELLS.

I. SURFACE-ACTIVE COMPOUNDS***SOAPS---MECHANICAL REMOVAL OF DIRT THROUGH SCRUBBING; FLOAT AWAY DIRT AS THE LATHER IS WASHED OFF***DETERGENTS---CLEANING AGENTS WHICH IONIZES IN WATER & ITS ELECTRONICALLY CHARGED IONS ATTACH THEMSELVES TO THE DIRT

COMPARISON BETWEEN SOAPS & DETERGENTS

SOAPS:1. MADE FROM FATS & RYE2. DEPEND ON THEIR ALKALI CONTENT FOR ITS CLEANING ACTION3. COMBINES WITH CALCIUM & MAGNESIUM SALTS IN HARD WATER TO FORM AN INSOLUBLOE SCUM6. GERMICIDAL FOR PNEUMOCOCCI, STREPTOCOCCI,GONOCOCCI, MENINGGOCOCCI.

SPIROCHETE OF SYPHILIS AND INFLUENZA VIRUS

DETERGENTS:1. MADE FROM FATS & OILS2. IONOZES IN WATER; ATTRACTS DIRT INTO ITS

CHARGED PARTICLES3. DISSOLVE QUICKLY IN COLD WATER & IN HARD

WATER

II. SURFACE ACTIVE COMPOUNDS/QUARTERNARY AMMONIUM DISINFECTANTS

1. BENZALKONIUM CHLORIDE/ZEPHIRAN CHLORIDE---USED TO DISINFECT THE HANDS AND PREPARE THE FIELD OF OPERATION

2. A 1:1000 AQUEOUS SOLUTION IS USED FOR ENDOSCOPES & SHARP-EDGED CUTTING INSTRUMENTS

3. INEFFECTIVE AGAINST SPORES BUT EFFECTIVE AGAINST VEGETATIVE BACTERIA

except Mycobacterium tuberculosis

2. DIAPARENE CHLORIDE---BACTERIOSTATIC AGAINST BREVIBACTERIUM AMMONIAGENES(PRODUCES AMMONIA IN DECOMPOSED URINE)

3. CEEPRYN CHLORIDE---1:1000 SOLUTION SERVES AS MOUTHWASH

III. HEAVY METAL COMPOUNDS

---EXERTS INHIBITORY EFFECT ON THE VITAL CELLULAR ENZYME’S FUNCTION

A. ORGANIC MERCURY COMPOUNDS---EFFECTIVE AGAINST NON-SPORING PATHOGENIC BACTERIA EXCEPT M. TUBERCULOSIS

EX. MERCUROCHROME/METAPHEN/MERTHIOLATE/MERCRESIN

B. SILVER NITRATE---USED AS A CAUSTIC SUBSTANCE(AN AGENT THAT DESTROYS LIVING TISSUE) AND AS AN ASTRINGENT ( WITH BINDING/ CONSTRICTING EFFECT

** 1 % SOLUTION PREVENTS OPTHALMIA NEONATUM, A FORM OF CONJUNCTIVITIS IN YOUNG CHILDREN

c. ZINC SALTS----CONTROL INFECTIONS CAUSED BY ANAEROBIC BACTERIA & MICROAEROPHILES IN GUNSHOT WOUNDS, BITES & DEEP PUNCTURED WOUNDS

D. COPPER SULFATE---MORE EFFECTIVE AGAINSTMOLD & ALGAE**USED IN SWIMMING POOLS AND WATER

RESERVOIRS IN CONC. OF 1:4000,000 WATER DESTROYS TYPHOID BACILLI IN 24 HOURS

IV. ALCOHOLS & ALDEHYDES

1. ETHYL ALCOHOL* ONE OF THE MOST WIDELY USED AND ONE OF THE BEST* DESTROYS MICROORGANISMS BY COAGULATING ITS PROTEIN THROUGH THE ADDITION OF WATER* CRITICAL SOLUTION AT 70%* NOT SPOROCIDAL* EFFECTIVE AGAINST M. TUBERCULOSIS & OTHER VEGETATIVE FORMS

2. ISOPROPYL ALCOHOL* SLIGHTLY SUPERIOR TO ETHYL ALCOHOL* CHEAPER* ACTS ON VEGETATIVE BACTERIA

3. FORMALDEHYDE (GAS)* FAOMALIN IN 37 % SOLUTION* USED AS DISINFECTANT AND PRESERVATIVE OF TISSUES

* USED TO CONVERT TOXINS TO TOXOIDS* DISINFECTS CYTOSCOPES AND CERTAIN INSTRUMENTS DAMAGED BY HEAT

4. GLUTARALDEHYDE* MARKETED AS ACTIVATED GLUTARALDEHYDE SOLUTION (CIDEX)

* BACTERICIDAL, VIRICIDAL, SPOROCIDAL* DISINFECTS ANESTHETIC EQUIPMENT, BREATHING APPARATUS AND INSTRUMENTS WITH OPTICAL LENSES

V. PHENOLS & DERIVATIVES1. PHENOL ( CARBOLIC ACID)

* CORROSIVE POISON

* INHIBITS BACTERIAL GROWTH IN 0.2 % SOLUTION* KILLS VEGETATIVE BACTERIA AND LESS RESISTANT SPORES IN 5 % SOLUTION* ACTION IS INHIBITED BY ALCOHOL, ETHER & SOAP* ACTION IS ENHANCED WITH 5-10 % HCl* EXCELLENT DISINFECTANT FOR FECES.

BLOOD, PUS, SPUTUM & PROTEINACEOUS MATERIAL* INJUROUS TO THE SKIN & MUCOUS MEMBRANES2. CRESOL* MORE EFFECTIVE THAN PHENOL*LESS POISONOUS

* LYSOL---SAPONATED CRESOL SOLUTION; CRESOL AND SOAP IN 2.5 % SOLUTION* USED TO DISINFECT FECES, SPUTUM,INSTRUMENTS, FURNITURE, TABLES, WALLS, RUBBER GOODS, RECTAL THERMOMETERS* TUBERCULOSIDE

3. HEXACHLOROPHENE ( G-11):* USED IN PRE AND POST OPERATIVE HAND SCRUBS OF SURGICAL TEAMS* EFFECTIVE AGAINST GRAM+ BACTERIA ESPECIALLY STAPHYLOCOCCI* UNVERSAL ANTIBACTERIAL AGENT & INCORPORATED INTO SOAPS, SHAMPOOS,TOOTHPASTES, DEODORANTS, LOTIONS, POWDERS, OINTMENTS,

COSMETICS, MEDICINAL CLEANERS

VI. HALOGEN COMPOUNDS:* STRONG OXIDIZING AGENTS THAT FORM HALOGENATED DERIVATIVES OF MANY OF THE NITROGENOUS COMPOUNDS IN THE PROTOPLASM

1. IODINE:* AMEBICIDE, BACTERICIDE, TUBERCULOSIDE, FUNGICIDE* CAUSES IODINATION OF AMINO ACIDS RESULTING IN THE INACTIVATION OF ITS PROTEIN* TINCTURE---2 % IODINE IN ALCOHOL* USED IN MINOR CUTS, ABRASIONS, WOUNDS

* IODINE SOLUTION---2% IODINE IN WATER; EFFECTIVE LIKE TINCTURES; USED TO DISINFECT WATER IN SWIMMING POOLS* IODOPHORS----COMPOUNDS IN WHICH IODINE IS CARRIED BY A SURFACE-ACTIVE SOLVENT; GERM-KILLING ACTION RESULTS FROM THE RELEASE OF FREE IODINE WHEN THE COMPOUND IS DILUTED WITH WATER.

* ENHANCES BACTERICIDAL ACTION OF IODINE AND REDUCES ODORE.X. BETADINE-POVIDONE-IODINE COMPLEX

2. CHLORINE:* MOST EFFECTIVE & WIDELY USED DISINFECTANT

* HYPOCHLOROUS ACID---STRONG OXIDIZING AGENT; USED TO DISINFECT DRINKING WATER, PURIFICATION OF SWIMMING POOLS, TREATMENT OF SEWAGE* 0.5-1 PPM--- EFFECTIVE CONCENTRATION FOR DISINFECTION* SODIUM HYPOCHLORITE (NaOCl) –POWERFUL OXIDIZING AGENT USED AS A BLEACH & BACTERICIDAL TREATMENT OF FOOD-HANDLING EQUIPMENT

• DAKIN’S SOLUTION----WEAK NEUTRAL SOLUTION OF SODIUM HYPOCHLORITE• 5 % NaOCl---VALUABLE AGENT IN DENTAL

SURGERY* CHLORAMINES---ORGANIC CHLORINE

COMPOUNDS THAT DECOMPOSE SLOWLY AND LIBERATE CHLORINE; USED TO

SANITIZE GLASSWARE & EATING UTENSILS AND TO TREAT DAIRY & FOOD MANUFACTURING EQUIPMENTS

VII. ACIDS:1. BORIC ACID----USED AS EYEWASH2. FUMING NITRIC ACID---USED FOR

CAUTERIZING WOUNDS INFECTED BY RABID ANIMALS* BENZOIC ACID & SALICYLIC ACID---FUNGISTATIC AGENTS* WHITFIELD’S OINTMENT---USED TO TREAT FUNGAL INFECTIONS OF THE FEET* BENZOIC ACID---USED AS FOOD PRESERVATIVE

VIII. OXIDIZING AGENTS:* HYDROGEN PEROXIDE---USED TO CLEAN WOUNDS DUE TO ITS EFFERVESCENCE QUALITIES* POTASSIUM PERMANGANATE---ANTISEPTIC & ANTIFUNGAL AGENTS DUE TO THEIR STRONG OXIDIZING QUALITIES

IX. DYES:* CRYSTAL VIOELT/GENTIAN VIOLET---

INHIBIT THE GROWTH OF GRAM-POSITIVE BACTERIA & FUNGI* ACRIFLAVINE & PROFLAVINE---INHIBIT THE GROWTH OF GRAM-NEGATIVE BACTERIA BUT HAVE NO EFFECT ON GRAM-POSITIVE ONES

X. MISCELLANEOUS AGENTS:* ETHYLENE OXIDE---GAS WITH BROAD RANGE OF ANTIMICROBIAL ACTIVITY; ODORLESS, POISONOUS, EXPLOSIVE GAS THAT IS EASILY KEPT AS A LIQUID

• LIME---MOST COMMON & EFFECTIVE GERMICIDAL AGENT

* LIMESTOME---CALCIUM CARBONATE; HEATED

TO QUICKLIME (CALCIUM OXIDE) WITH THE CORRESPONDING RELEASE OF CARBON DIOXIDE* SLAKED LIME (MILK OF LIME)---USED AS DISINFECTANT FOR FECES & AS A WHITEWASH FOR PAINTING WALLS & GUTTERS* CHLORINATED LIME---USED AS A BLEACH & FOR DISINFECTING FECES

* FERROUS SULFATE---USED AS IMPURE COMMERCIAL SALT & INCORPORATED INTO DEODORANTS AS WELL AS BEING USED AS A DISINFECTANT.