Why instrument milk is used instead of oil

CRCST practice question · Preparation & Packaging

Why is a water-soluble lubricant (instrument milk) used on hinged instruments instead of mineral oil or silicone spray?

  • A. Mineral oil corrodes stainless steel within a few cycles
  • B. Water-soluble lubricants also act as a disinfectant
  • C. Oils are approved only for low-temperature sterilization
  • D. Water-soluble lubricants let the sterilant contact the surface, while oils form a barrier that blocks it

Answer

D. Water-soluble lubricants let the sterilant contact the surface, while oils form a barrier that blocks it

Oil- and silicone-based products leave a film that steam can't get through, so surfaces under it may not be sterilized. Water-soluble lubricants keep joints moving without getting in the sterilant's way. They are not disinfectants.

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