Rust-coloured film Cause:
In new hospital foreign matter may be left in steam pipes during installation. Should subside 2-3 months. Water softeners and water can contain high content iron.
Solutions:
Consult engineering.
Purplish-Black Stain
Cause:
- Exposure to ammonia
- Amine chemicals in steam lines
- An amine is a compound in which one or more of the hydrogen atoms in ammonia have been replaced by an organic functional group.
Solution:
- Rinse instruments avoid ammonia.
- Use distilled or demineralized water to cycle through autoclave.
Bluish gray Stain
Cause:
- cold sterilizing solutions
Solution:
- Follow manufactures recommendations
- Prolonged use will cause corrosion
- Change solutions often
- Distilled water and rust inhibitor
Brownish Stain
Cause:
- A chromic oxide film forms on stainless steel when it is heated to give the instrument a dull blue or brown cast. Traced to sterilizer.
- Polyphosphates in detergent- which have a copper solubilizing action on parts of the sterilizer and this layer of copper are deposited on the instruments by electrolytic action.
Solution:
- Experiment with another compound.
- Measure the quantity accurately and be sure that the sterilizer fills with cold water.
