The discovery forced the cancellation of more than 110 surgeries at Chinook Regional Hospital this week.
Dr. Karin Goodison, medical health officer for the south zone, said the residue is related to an approved stainless steel polishing product routinely used in cleaning and sterilization.
She's confident the residue does not and never did pose a risk to patients.
"This is a part of normal processing ... and it has been determined that it doesn't create any additional risk to patient safety," Goodison said Friday.
The hospital will modify the use of the polishing product.
Surgeries should be back to normal on Monday, Goodison said. Patients affected by the cancellations were being contacted for rebooking.
"We would do the exact same thing again. If we have an unknown substance, we need to know what it is before we can do a proper risk assessment." she said.