How to get in there?
OK, so it’s great to have that isolated workstation where you and the stuff you’re working on are both safe from each other… but how do you get in there to work?
What exactly do you need and what must you know to safely reach into that pressurized space and deal with the isolated stuff?
Well, assuming that it has gloves installed, and that they are big enough for your hands to fit, there are still a few things to do:
- Make sure it’s ready before you start (gotta be safe!),
- Prepare to sit or stand in a healthy user position,
- Avoid touch contamination of hands in the gloves,
- Prepare for smooth insertion and extraction,
- Insert hands correctly to avoid process issues inside,
- Do your inside work and
- Extract hands correctly to avoid process issues inside
Now lets expand on these points with a bit of advice on how to do it:
1. Get ready to do it
Either read the operating guidelines, or consult with a trained glove box operator to ensure that it is loaded with tools and materials you need and fully operational. If not, make sure that happens before you attempt to use it. If you’re not sure about the safety of yourself, the room or the process inside, then you are not ready to proceed. Keep working on understanding and preparing the isolation system until you’re sure.
2. Prepare to sit or stand correctly
Check the position of the glove box window and glove ports, and compare it with your eyes and arms when standing or seated. If it seems uncomfortable, unhealthy or unworkable, make adjustments to the chair height, standing platform height or glove box height for good ergonomics. This may require an adjustable chair or work platform for proper, healthy operation.
3. Clean gloves & hands
Your hands will be in intimate contact with the interior of the gloves, so both gloves and hands should be clean before you start. If others have used this unit, they may have left something in the gloves, and it could be something sticky or hazardous. If there is any doubt, clean the gloves. Ensure that hands and gloves are clean and dry.
4. Prepare for a clean slide or roll
The gloves are likely to stick to your hands making it harder to insert and remove them. If you cool your hands, this will be easier, but using talcum powder or thin cotton gloves on them may help avoid skin sticking to the rubber. This is really important if gloves are snug, or if the glove box is positively pressurized, as that presses the rubber against your skin. It also is helpful to control the temperature and ventilation in the room, as perspiration is not your friend when you want to get into or out of these gloves.
5. Slide or roll hands in smoothly
Now that you’re ready, the hands should slide in slowly, one at a time. The way you do this is different for negative pressure and positive pressure glove boxes.
In negative pressure units, the gloves will inflate toward the back of the chamber, making a clear opening for your hands. In that case, just slide them in slowly, taking care not to bump into the wrong things inside, or to change the pressure too quickly by your hand movements.
In a positive pressure glove box the gloves should be inflated inside-out when you start. If gloves are stuck inside, work them free to inflate outward before proceeding. By inserting your fingers in at the glove finger tips you can roll fingers and hands into the gloves instead of sliding them. As you push your hands into the glove box the pressure inside will rise. Insert hands slowly, to allow the pressure control system to adjust.
6. Do the work inside
When both hands are fully inserted and the chamber is at the required pressure, you can proceed to work in the unit. Execute your applications according to your operations protocol, including any final steps for cleanup, anti-microbial or clean-air treatments and materials containment inside.
7. Getting them out
When the work is done, or you need a break, withdraw your hands slowly. The idea is to get them out without much disturbance to the chamber pressure. Pressure changes may not be important if your process isolation is no longer required, or if the chamber pressure control system is exceptionally fast and very dynamic. If not, pay attention to the pressure as you extract the first hand. This is easier for the first one, as the other hand can help. Extracting the last hand may require very slow motion or help with the other hand partially in the chamber.
In a negative pressure system, a clinging glove will tend to make the chamber more negatively pressurized as you pull the hand out, but when you release the glove the pressure may ease quickly toward ambient. In a positive pressure system the pressure will drop as each hand comes out, so you may need to move even more slowly to allow gas injection flow to catch up keeping pressure high enough.
Final checks – preparing for next time
After your hands are out, take note of what worked well, and what did not. If the gloves were too tight, larger gloves might be needed. If pressure changes were a problem, pressure system flow rates or pressure settings might be adjusted. In any case, record what worked well, and what did not, so you or others will be better prepared next time.
Now that you know how to get your hands in, it will be useful to know how to get your tools and materials in and out. That is the topic for a later post, Ins and Outs of Barrier Isolation: Stuff in the Box.
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Photo credit: UNMEER via Visual Hunt / CC BY-ND