lec 6 Flashcards
………….It is the treatment of objects or materials with a
chemical in the gaseous or vapor state to destroy all
contaminating microorganisms.
Gaseous Sterilization
what are the Advantages of gases as sterilizing agents?
- Sterilization is done at low temperatures thus avoiding damage to heat-sensitive materials.
- Gaseous sterilant penetrates into areas not reached by liquids.
- Applied to disinfect all or a part of a building.
what are the Disadvantages of gaseous sterilization?
- They sterilize only exposed surfaces
- It leaves toxic residues on sterilized material.
- It requires prior cleaning of articles to be sterilized and removal of organic materials.
- Long time for sterilization
- The flammability of some gases requires special operating procedures.
- Toxicity hazards exist with most sterilizing gases.
- High cost
what is the mechanism of action of alkylating agents in sterilizing gaseous?
They react with amino (-NH2), sulphydryl (-SH) and hydroxyl groups (-OH) in proteins and nucleic acids in
microbial cells, thus blocking replication and enzymatic activity.
what is the Mechanism of action of oxidizing agents?
They act by oxidizing vital molecules in microbial cells.
……………..is the most widely used gaseous sterilant in the medical device and pharmaceutical industry.
Ethylene oxide (EtO)
……………… has high penetration power in narrow spaces
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
The boiling point of………… is 10.8°C
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
…………………… It’s very inflammable and highly explosive in mixtures of more than 3.6% v/v in air.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
Ethylene oxide has High penetration power in narrow spaces why?
Due to
The small size of the molecule.
It’s very weak polarity.
the Ethylene oxide is very inflammable and highly explosive in mixtures of more than 3.6% v/v in air. how can we avoid this problem?
EtO is mixed with a noninflammable gas such as CO2. Alternatively, EtO can be used in air evacuated chambers.
the Ethylene oxide affected with………………
- temperature.
- humidity.
- gas concentration.
the activity of ethylene oxide decreases with temperature, humidity and gas concentration.
T or F?
F, increases.
the. …………… is relatively inexpensive.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
……………… has effective microbicide and kills microbial endospores.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
………… is mutagenic and carcinogenic.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
d. both a and b
e. both c and b
d. both a and b
…………. is very toxic and irritant (Eye, skin and bronchi).
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
d. both a and b
e. both c and b
d. both a and b
the Ethylene oxide is able to inactivate pyrogens.
T or F?
F, Unable
GIVE A REASON Humidity of the sterilizing atmosphere affect E.O. Sterilization?
Because organisms are more resistant to ethylene oxide treatment in a dried state.
GIVE A REASON Air must be removed from the chamber by evacuation before sterilization via E.O.?
Because EO is highly explosive in mixtures of more than 3.6% v/v in air.
…………….. Used for sterilization of:
Single-use devices (Disposable catheters and syringes)
a.Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
…………. Used for sterilization of Disposable Petri dishes.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
…………..Used for sterilization of Surface sterilization of powders.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
…………..Used for sterilization of Plastic or rubber gloves.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
…………..Used for sterilization of blankets and mattresses
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
…………..Used for sterilization of Dressings, Dried fruits, nuts and spices.
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
a.Ethylene oxide
…………….It is produced by heating formalin (37% w/v aqueous solution of formaldehyde) to a
the temperature of 70–75°C with steam, in a process known as “Low-temperature steam and
formaldehyde” (LTSF).
a.Ethylene oxide
b. Formaldehyde
c. Propiolactone
b. Formaldehyde
identify the “Low-temperature steam and
formaldehyde” (LTSF).
heating formalin (37% w/v aqueous solution of formaldehyde) to a temperature of 70–75°C with steam
Formaldehyde has high penetrating power
T or F?
F, Ethylene oxide has high penetrating power
OR
Formaldehyde has LOW penetrating power
WHAT ARE THE Applications of Formaldehyde?
(Not widely used due to toxicity)
Nowadays, its main application is the fumigation of empty rooms after infectious diseases.
…………is corrosive
a. Ethylene oxide
b. Formaldehyde
c. Propiolactone
d. Chlorine dioxide
e. ozone
f. hydrogen peroxide
g. d,e, and f
h. a, c, and e
g. d,e, and f
Chlorine dioxide, ozone and hydrogen peroxide
the ………… can be used to remove endotoxin
a. Alkylating agents
b. Oxidizing agents
b.Oxidizing agents
………… is a chemotherapeutic antimicrobial agent that is isolated from microorganisms
Antibiotics.
give an example of Non-antibiotic antimicrobial agents.
- Disinfectants.
- Antiseptics,
- Preservatives
Antimicrobial agents are classified into:
- …………………
- ………………..
- ………………..
I. Antibiotics.
II. Antimicrobial chemotherapeutic agents.
III. Non-antibiotic antimicrobial agents.
iodine is an example of………….
- Disinfectants.
- Antiseptics.
- Preservatives.
- Antiseptics.
chlorine is an example of………….
- Disinfectants.
- Antiseptics.
- Preservatives.
- Disinfectants.
sodium benzoate is an example of………….
- Disinfectants.
- Antiseptics.
- Preservatives.
- Preservatives.
The ideal preservative should be Effective in high concentration.
T or F?
F, low
ethanol and isopropanol (60%–90% solutions in water) (v/v). have -Bactericidal, fungicidal, virucidal and Sporicidal activity.
T or F?
F, HAVE NO Sporicidal activity.
give a reason, the absolute ethyl alcohol, is less bactericidal than mixtures of alcohol and water?
the Mode of action of alcohol by denaturation of proteins and the proteins are denatured more quickly in the presence of water.
ethanol is not active against the nonlipid
enteroviruses but is fully active against the lipid viruses.
T or F?
F, Isopropyl alcohol.
Phenols are USED AS
A.disinfectants and antiseptics
B.disinfectants and preservatives
B.disinfectants and preservatives
………….. IS Injuring lipid-containing plasma membranes
a. phenols
b. alcohol
c. halogen * iodine
d. Biguanides *Chlorhexidine
a. Phenols
the phenols have Bactericidal and sporicidal.
T or F?
F, not sporicidal.
phenols are more active at basic pH
T OR F?
F, acidic PH.
……………. Effective against all kinds of bacteria, many endospores, various fungi and some viruses.
a. phenols
b. alcohol
c. halogen * iodine
d. Biguanides
c.halogen * iodine
what is the Mechanism of action of Halogens?
Combines with certain amino acids of enzymes and other cellular proteins.
write a short note on Iodophor.
a combination of iodine and an organic molecule.
▫ Iodophores have some spectrum as iodine but with no staining and less irritation.
