Sterilizing surgical scissors requires thorough cleaning first, followed by exposure to high heat or chemical agents that kill all microorganisms, including bacterial spores. The gold standard is steam sterilization (autoclaving) at 121°C for 30 minutes or 132°C for 4 minutes, but dry heat and chemical methods also work depending on your setting and equipment. Skipping or rushing any step, especially cleaning, compromises the entire process.
Clean Before You Sterilize
Sterilization cannot work on dirty instruments. Blood, tissue, and other organic material shield microorganisms from heat and chemicals, so removing that debris is the actual first step. Presoak or rinse scissors immediately after use to prevent blood from drying on the surface. Dried blood is significantly harder to remove and creates a reservoir for bacteria.
For manual cleaning, the two essentials are friction and fluidics. Friction means scrubbing with a brush, paying close attention to the hinge (the box lock) where debris collects. Fluidics means rinsing under pressurized water to flush out anything loosened by brushing. Use a neutral or near-neutral pH detergent, which offers good soil removal without corroding the steel. Enzymatic detergents containing proteases break down proteins like dried blood, while lipases and amylases handle fats and starches. Follow the manufacturer’s instructions for dilution ratio and soak time.
A note on detergent choice and corrosion: alkaline cleaners dissolve protein and fat efficiently, but research on stainless steel surgical instruments shows that alkaline solutions cause deeper corrosion marks on certain steel grades (particularly 420-series stainless steel commonly used in scissors) compared to enzymatic solutions. Enzymatic detergents are generally the safer bet for preserving your instruments long-term.
Steam Sterilization (Autoclaving)
Steam autoclaving is the most reliable and widely used method for stainless steel scissors. It works by exposing instruments to pressurized steam at temperatures that destroy all forms of microbial life, spores included. The two standard temperature settings are:
- 121°C (250°F) in a gravity displacement sterilizer: 30 minutes minimum for wrapped instruments.
- 132°C (270°F) in a prevacuum sterilizer: 4 minutes minimum for wrapped instruments.
Unwrapped instruments can have shorter exposure times, but wrapping protects scissors from recontamination after the cycle ends. If you sterilize unwrapped, the scissors must be used immediately. Wrapped instruments stay sterile until the packaging is opened or compromised.
Before loading the autoclave, open the scissors so the hinge is spread apart. This allows steam to contact all surfaces, including the inner faces of the blades. Overlapping or tightly packed instruments create air pockets that steam cannot penetrate, leaving those areas unsterilized.
Dry Heat Sterilization
Dry heat is a good alternative when you want to avoid moisture entirely. It is noncorrosive for metals and particularly gentle on sharp edges, which makes it well suited for scissors. The tradeoff is time: dry heat requires much longer cycles than steam because hot air transfers energy less efficiently than pressurized steam.
The standard time-temperature combinations are:
- 170°C (340°F) for 60 minutes
- 160°C (320°F) for 120 minutes
- 150°C (300°F) for 150 minutes
These times begin once the entire load reaches the target temperature, not when you turn the oven on. Dry heat sterilizers are relatively inexpensive to install and operate, making them practical for smaller clinics or field settings.
Chemical (Cold) Sterilization
Chemical sterilization uses liquid agents instead of heat. The most common is 2.4% glutaraldehyde. Immersing scissors for 20 minutes at 20°C achieves high-level disinfection, which kills most pathogens but not all bacterial spores. True sterilization with glutaraldehyde requires 10 hours of continuous contact, a duration that is rarely practical in busy settings.
Chemical sterilization is typically reserved for instruments that cannot tolerate heat, which does not apply to standard stainless steel scissors. If you do use it, rinse the scissors thoroughly with sterile water afterward, since residual glutaraldehyde is irritating to tissues. For routine use, steam or dry heat is faster, more reliable, and avoids chemical exposure risks.
Why Boiling Is Not Sterilization
Boiling scissors in water at 100°C for at least one minute kills most bacteria and viruses, but it does not eliminate bacterial spores, the most heat-resistant form of microbial life. This means boiling achieves disinfection, not sterilization. The distinction matters: a disinfected instrument may still carry spores that can cause serious infections in surgical wounds.
Boiling should be treated as a last resort, used only when no autoclave, dry heat oven, or chemical sterilant is available. It is better than nothing, but it does not meet the standard for any procedure involving broken skin.
Lubricate Before the Final Cycle
After cleaning and before sterilization, dipping scissors in a water-based instrument lubricant (often called “surgical milk”) protects the metal and keeps the hinge moving freely. These lubricants contain rust inhibitors and form a protective barrier on the steel surface. They are specifically formulated to be steam-permeable, meaning they do not interfere with autoclave sterilization. You do not need to rinse the lubricant off before loading into the autoclave.
Regular lubrication extends instrument life noticeably. Scissors retain their sharpness longer, the hinge resists stiffening, and the blades are less prone to corrosion from repeated sterilization cycles.
Inspect After Every Cycle
Sterilization can damage instruments over time, so inspect scissors after every cycle before they are used. Look at the blades for corrosion, pitting, discoloration, nicks, or burrs along the cutting edge. Check for cracks or chips in the metal. Open and close the scissors to confirm the hinge moves smoothly and the blades align properly without crossing or gapping.
Test sharpness by cutting through a single layer of surgical gauze or thin fabric. The scissors should slice cleanly without snagging, tearing, or requiring excessive force. Scissors that fail any of these checks should be sent for sharpening or repair, not returned to a sterile tray. A sterile instrument that cannot cut properly is still a liability.