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1. DISINFECTANT EFFICACY TEST
PRESENT BY MAHA ALADHAM

2. INTRODUCTION.
 Testing of disinfectant is a
complex process used to test the efficacy of
disinfectants..
 Disinfectants are used mainly in hospital labs
so effectiveness of disinfectant is checked
periodically

3. DISINFECTANT.
substance applied on non-living objecte to
destroy all pathogens or organisms capable of
producing infection but not necessaraly spore ,
its less efective than sterlization
all organism may not be killed , the
number of organism reduce to the level
no longer harmfull to health

4. CHEMICAL DISINFECTANT
• Halogens , iodine
• Phenols
• Alcohols
• Aldehydes
• Hydroxy acids
• Dyes
• Metals and salts

5. LEVEL OF DISINFECTANT
High level
disinfectant hydrogen peroxide
–peracetic acid ) with critical
items like implant device ,
endoscope)
1
Intermediate level ) phenolic
,ETHyl ) with semi critical
items , otoscope)
2
Low level disinfectant )
Quaternary ammonium
compounds ) with ECG leads ,
ultrasound
3

6. CARACTERISTICS OF AN IDEAL
DISINFECTANT

8. JOSEPH
LESTER 1
FATHER ANTISIPTIC
SURGUEY

10. NEED FOR DISINFECTANT TESTING?
A disinfectant must be tested
 To know the emit
nekat for eht
tesno
fo
noitca
 Periodical montoring of its activity

11. METHOD OF DISINFECTANT TEST;
1
- suspension test
2
- in use test

12. SUSPENSION TEST;
Principle:
A sample of the bacterial culture is suspended into the
disinfectant solution
after exposure its verified by subculture if there is inoculum is
killed or not .

13. TYPE OF SUSPENSION TEST;
 A- Qualitative suspension test:
 Loopfull of bacterial suspension brought into contact with disinfectant
 Result expressed as ( GROWTH or No growth )
 B- Quantitative suspension test:
 The number of surviving organisms (B) is counted and compared to the original
inoculum (A)
 ME = 1
➡️ Killing of 90% of the initial number
 ME = 2
➡️
99% killed
 General accpted ME is less than 5
➡️
99.999% of the germs are killed

14. IN USE TEST:
Princple:
Test can used in laboratory and hospitals to detect
contamination of disinfectant
 1ML sample of disinfectant is add to 9 ML Diluted
which also contains inactivators
ten drops . Each of 0.02 ml volum of the diluted
sample placed on each of two nutrient agar plate

15.  One is incubated at 37 C for three days and the other at room
temperature for 7 days.
Five or more colonies on either plate indicate
contamination.