When opening a sterile container, you should first confirm the package is intact, then open the flap farthest from your body first, followed by the side flaps, and finally the flap nearest to you. This sequence keeps your arms from crossing over the sterile contents and prevents contamination. The entire process starts with clean hands and ends with a sterile field you haven’t touched, breathed on, or reached over.
Check the Package Before You Open It
Before you break any seal, inspect the container or package. Look for tears, punctures, moisture, or any sign that the wrapper has been compromised. A damp package is not sterile, even if the seal looks fine. Moisture creates a pathway for bacteria to travel through the material, a process called strike-through. If anything looks off, discard the package and grab a new one.
Also check any chemical indicator strips on the packaging. These change color during sterilization to confirm the contents were properly processed. An indicator that hasn’t changed means the contents may not be sterile.
Wash Your Hands First
Perform hand hygiene before touching sterile supplies. Use an alcohol-based hand sanitizer or wash with soap and water. This happens before you put on any personal protective equipment and before you handle the outer wrapper. Even though you’ll only be touching the outside edges of the packaging, contaminated hands can transfer bacteria to areas that will later contact the sterile field.
The Correct Flap Sequence
Sterile kits and trays typically have an outer protective wrapper and four inner flaps. The order you open them matters because it controls where your arms travel relative to the sterile contents inside.
- First flap: Open the one farthest from your body (the distal flap). Lift it up and let it fall away from you.
- Second and third flaps: Open the side flaps one at a time, using one hand for each. Pull each flap to the side.
- Last flap: Open the flap closest to you by pulling it toward your body.
Touch only the very outer edges of each flap. The logic behind this sequence is simple: by opening the far side first and the near side last, you never have to reach over exposed sterile contents. If you opened the near flap first, you’d need to extend your arm across the entire field to reach the far flap, and your clothing, skin, or breath could drop contaminants onto the sterile surface below.
Opening Sterile Glove Packages
Sterile glove packages follow the same principles but with a slightly different layout. Place the outer package on a dry, flat, clean surface at waist level. Peel apart the sides of the outer package and remove the inner packet. Lay the inner packet flat, then open the top flap away from your body and the bottom flap toward you. Open the side flaps without letting them fold back and touch the gloves inside. At no point should you touch the inner surfaces of the wrapper or the outside of the gloves with your bare hands.
The One-Inch Border Rule
Once a sterile wrapper is open and lying flat, it becomes your sterile field. But the outer edge of that field is not considered sterile. An imaginary one-inch border runs along the entire perimeter of the wrapper, and this zone is treated as contaminated. When placing items onto a sterile field or sliding instruments around, keep everything away from this border. If something touches or lands within that inch, it’s no longer sterile.
Anything that falls below the level of the table surface is also considered contaminated. If a corner of the drape hangs over the table edge, that portion is no longer part of your sterile field, and anything it touches afterward is compromised.
Keep Your Body and Arms Clear
Never let any part of your body hover directly above a sterile field. This includes your hands, arms, and torso. Bacteria shed from skin and clothing constantly, and even breathing or talking over a sterile field introduces microorganisms. Position yourself so you can work at the edges of the field without leaning over it.
The sterile zone also has vertical limits. Anything below your waist or above your shoulders is considered non-sterile. This means if you raise a sterile item above shoulder height or let it drop below waist level, it’s contaminated. Work within the zone between your waist and shoulders at all times.
Pouring Sterile Solutions
If you need to pour a sterile liquid into a container on your sterile field, hold the bottle with the label facing your palm so that any drips run down the back of the bottle rather than obscuring the label. Position the lip of the bottle one to two inches above the rim of the receiving container. Pour slowly and steadily. Splashing is the main risk here: if fluid lands on the sterile drape surrounding the container, it creates a wet pathway for bacteria to migrate through the material and contaminate the entire field.
Never let the bottle touch the sterile container or the field itself. Once the lip of an unsterile bottle contacts a sterile surface, that surface is compromised.
Timing Matters
Open sterile supplies as close to the time of use as possible. The longer a sterile field sits exposed, the more airborne particles settle on it. The Association of periOperative Registered Nurses (AORN) does not set a specific time limit for how long a sterile field remains usable, because the evidence is limited. However, one study found that covering sterile instrument tables significantly reduced bacterial contamination at four and eight hours compared to uncovered tables, but by 24 hours there was no difference between covered and uncovered setups.
The practical takeaway: don’t open sterile containers early as a matter of convenience. Set up when you’re ready to proceed, and if there’s a significant delay, a fresh setup is safer than hoping the old one stayed clean.
Common Mistakes That Break Sterility
Most contamination events come from a handful of preventable errors. Reaching across a sterile field to grab something on the other side is one of the most frequent. Turning your back on a sterile field is another, because you can no longer see if something has fallen onto it or if someone has walked too close.
Letting the inner surface of a wrapper spring back and touch sterile contents happens when you don’t secure the flaps properly after opening them. Coughing, sneezing, or talking directly over the field introduces respiratory droplets. And touching the inside of a wrapper with bare, ungloved hands contaminates the contact point immediately.
If you suspect any break in sterility, treat the entire field as contaminated. It is always safer to start over with fresh supplies than to guess whether contamination occurred.