Rust vs. Stain
Stains can be removed, whereas rust will leave permanent damage. To determine if a brown or orange
discoloration is a stain or rust, use the eraser test. Rub a pencil eraser over the discoloration. If the discoloration
is removed with the eraser and the metal underneath is smooth and clean, this is a stain.
If a pit mark appears under the discoloration, this is corrosion or rust.

Trouble-Shooting Stain Guide for Surgical Instruments
Stain Color: Brown / Orange
Cause: A result of high-pH detergents, Chlorhexidine usage, or improper soaking of instruments.
This color stain can also be caused by soaking in tap water.

Stain Color: Dark Brown
Cause: Low-pH instrument solutions. The brownish-colored film may also be caused by a malfunctioning
sterilizer. Similar localized stain spots can also be a result of baked-on blood.

Stain Color: Bluish Black
Cause: Reverse plating, when instruments of different metal (e.g., chrome and stainless steel) are
ultrasonically processed together. Additionally, exposure to saline, blood, or potassium chloride will cause this
bluish black color.

Stain Color: Multicolor
Cause: Excessive heat by a localized hot spot in the sterilizer. The rainbow-colored stain can be removed.

Stain Color: Light and Dark Colored Spots
Cause: Water droplets drying on the instruments. With slow evaporation, the minerals sodium, calcium, and
magnesium left behind can cause this spotting.

Stain Color: Bluish Gray
Cause: Liquid (cold) sterilization solutions being used beyond manufacturer's recommendations.

Stain Color: Black Stains
Cause: Contact with ammonia or a solution containing ammonia.

Stain Color: Gray
Cause: A liquid rust remover being used in excess of manufacturer's recommendations.

Stain Color: Rust
Cause: Dried blood that has become baked on the serrated or hinged areas of surgical instruments. This
organic material, once baked on, may appear dark in color. Also can be caused by soaking in tap water.

Scissors Testing
Until recently, it's been difficult to gauge if scissors were performing optimally. To test them, surgeons often tried
cutting a piece of material, but this yielded inconsistent results due to the variety of materials used. Today, there
is a rubber-like material known as Theraband to test scissors' sharpness.

Medium-grade red Theraband is used for scissors measuring 4.5 inches to 12 inches in length.

Yellow Theraband is used for scissors measuring 3 inches to 4 inches in length.