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.