Steam Sterilisation

Question 1

Why can steam be used for sterilisation?

Answer 1

• steam carries high quantities of energy
• non-toxic
• recondensed and reused
• readily available
• no waste products
• small volume water produces lots of steam

Question 2

What types of water can be used for sterilisation?

Answer 2

• purified water
  
  • reverse osmosis
  • de-ionised
  • distilled
  • sterile

Question 3

What are the 3 types of sterilisers

Answer 3

• type N
• type B
• type S

Question 4

What are type N sterilisers?

Answer 4

• gravity displacement steriliser
• autoclave

Question 5

What are type B sterilisers?

Answer 5

• vacuum capable
• porous load steriliser

Question 6

What are type S sterilisers

Answer 6

• specialised steriliser
  
  • e.g. handpieces

Question 7

How does a type N steriliser work?

Answer 7

• water heated in chamber
• water turns to steam
• air passively forced out of chamber

Question 8

Why are type N sterilisers not as useful as type B sterilisers?

Answer 8

• not entirely effective
  
  • pockets of air left in chamber
  • air at a lower temperature than steam
    
    • 131 vs 135 degrees
  • if not in contact with steam, not sterile
• cannot process some instruments
  
  • cannot be wrapped
  • channelled or lumped instruments

Question 9

What can type N sterilisers be used for?

Answer 9

rigid steel or solid instruments with no pockets, channels or lumens

Question 10

What temperature, pressure and hold time is required for a type N steriliser?

Answer 10

• temperature
  
  • 134-137 degrees
• pressure
  
  • 2.05-2.35 bar
• minimal hold time
  
  • 3 minutes

Question 11

How do type B sterilisers work?

Answer 11

• all air removed from chamber
  
  • vacuum pump
• chamber filled with steam
  
  • steam generator
• steam rushes in due to vacuum
  
  • effectively contacts all surfaces
  • penetrates wrappings

Question 12

What can type B sterilisers be used for?

Answer 12

• wrapped instruments
• channelled and lumped instruments
• porous items (e.g. cotton swabs)

Question 13

What temperature, pressure and hold time are required for type B sterilisers?

Answer 13

• temperature
  
  • 134-137
• pressure
  
  • 2.05-2.35 bar
• hold time
  
  • 3 minutes

Question 14

What does a type S steriliser do which type N and type B cannot?

Answer 14

washes and lubricates handpieces

Question 15

Describe how instruments must be stored after being sterilised by a Type B steriliser

Answer 15

• can be stored for a long period of time
• clean area
• free from aerosol contamination
• dry
• temperature controlled
• away from direct sunlight
• stock rotation system in place

Question 16

What daily tests must be carried out for sterilisers?

Answer 16

• check door seals
• check chamber is free from damage/debris
• check condition of load carrier
• fill an drain the feed water reservoir
• drain the used water reservoir

Question 17

What daily and weekly tests must be carried out for type B sterilisers?

Answer 17

• daily
  
  • steam penetration test
    
    • Bowie Dick
    • Helix
• weekly
  
  • air leakage test
  • air detector function test
    
    • ADFT

Question 19

What guidance covers sterilisation?

Answer 19

SHTM 01-01 Part D