The daily cleaning and disinfection process of the transfer window

As a key device for material/item transfer in clean areas, the daily cleaning and disinfection of transfer Windows directly affect the pollution prevention and control effect of the clean area. It is necessary to strictly follow the SOP (Standard Operating Procedure) and adjust the process details according to the different clean levels. The following is the general cleaning and disinfection process (taking the pharmaceutical production workshop as an example, other industries can refer to and adjust it) :
I. Preparations Before Cleaning and Disinfection
Personnel qualifications
The operation must be carried out by trained clean area operators, who should wear clean suits corresponding to the cleanliness level (for example, in the sterile area, sterile suits and sterile gloves should be worn).
Tool and material preparation
Cleaning tools: Clean cloths that do not shed fibers (such as microfiber cloths), special cleaning brushes (for crevices), purified water/water for injection (select according to the cleanliness level; water for injection is required for A/B grade areas).
Disinfectant reagents: 75% medical alcohol, peracetic acid, hydrogen peroxide solution (such as 5%), quaternary ammonium salt disinfectants, etc. (Select according to regional requirements to avoid chemical reactions with materials).
Auxiliary tools: Timer (for controlling the duration of disinfection), disinfection record form (for recording time, reagents, and executor).
Status confirmation
Check whether the interlocking function of the two doors of the transfer window is normal and ensure that both doors are closed during cleaning (to prevent the spread of contamination).
Empty all items in the transfer window. If there are any remaining materials, they should be disposed of according to the regulations (such as returning them to the temporary storage area or discarding them).
Ii. Daily Cleaning Procedure (At least once a day. Additional cleaning is required before switching production batches)
Pre-cleaning: Remove visible contaminants
Use a clean cloth dipped in purified water to wipe in the order of "from top to bottom and from inside to outside."
First, wipe the inner walls at the top and both sides of the transfer window, and then wipe the bottom countertop.
Focus on cleaning the corners, door gap sealing strips, and the gaps of interlocking devices (use a brush to remove accumulated dust).
Finally, wipe the outer surface (including the door handle and control panel).
If there are stubborn stains (such as material residues), you can use a cloth dipped in a small amount of neutral detergent (such as food-grade dishwashing liquid) to wipe, and then wipe off the remaining detergent with purified water.
Terminal cleaning: Remove fine dust
Change to A clean cloth, dip it in fresh purified water (or water for injection, A/B grade area), and repeat the above wiping sequence to ensure no detergent residue remains.
After cleaning is completed, open the inner side door of the transfer window (on the clean area side), and let the clean air flow (if it is a laminar flow transfer window) blow for 3 to 5 minutes to remove residual moisture and particles.
Iii. Disinfection Process (Adjust the frequency according to the cleanliness level: once A day for low-level areas, once per shift for A/B grade areas, or after each transfer of high-risk items)
Confirm before disinfection
Make sure there is no visible moisture in the transfer window after cleaning (to avoid diluting the disinfectant).
Select disinfectants that are suitable for the area (for example, chlorine-containing disinfectants are prohibited in the sterile area to avoid corroding equipment or leaving residual toxicity).
Disinfection operation
Use a special disinfectant cloth dipped in the detoxifying agent (which should be completely soaked but not dripping) to wipe the inner walls, countertops, door handles, and sealing strips of the transfer window in the same order as cleaning.
Focus on disinfecting the sealing rubber strips of the double doors (which are prone to dirt accumulation) and the interlocking buttons to ensure that the disinfectant fully contacts the surfaces.
If the transfer window is equipped with an ultraviolet lamp, after disinfection, the ultraviolet lamp can be turned on for 30 minutes of irradiation (as an auxiliary disinfection and cannot replace chemical disinfection).
Action time and ventilation
Disinfectants need to be used for a sufficient period (for example, 75% alcohol for 3 to 5 minutes and peracetic acid for 10 to 15 minutes, follow the reagent instructions).
After disinfection is completed, if low-volatile disinfectants (such as quaternary ammonium salts) are used, a clean cloth dipped in purified water should be used to wipe off the residue (to avoid contamination of the materials). Volatile disinfectants such as alcohol can be air-dried naturally.
4. Regular deep cleaning (once a week, or adjusted according to production intensity)
Disassembly and cleaning (if the structure permits)
For detachable parts (such as door handles and sealing strips), clean them separately: rinse with purified water, then soak in a disinfectant for 10-15 minutes, dry, and reinstall.
Use a high-pressure water gun (for low-level areas) or water for injection to rinse hard-to-wipe gaps (such as the connection between the door frame and the box).
High-efficiency filter (HEPA) cleaning (Laminar flow transfer window only)
Use compressed air (filtered) to blow back from the air outlet surface of the filter to remove surface dust.
Replace the HEPA filter every three months or when the pressure difference exceeds the standard (it should be replaced outside the clean area to avoid contamination).
Function verification
After cleaning, check whether the interlocking of the two doors is normal and whether the sealing strips are intact (without damage or deformation) to ensure there is no risk of leakage.
V. Recording and Traceability
The following information should be recorded each time for cleaning and disinfection:
Date, time, operator;
Cleaning reagents (such as purified water), types and concentrations of disinfectants;
Clean the area (inside/outside/whole);
Abnormal situations (such as equipment failure, stains that are difficult to remove) and their handling results.
Records should be archived for at least one year (in the pharmaceutical industry, they need to comply with GMP traceability requirements and are usually kept for more than three years).
Precautions
The cleaning tools for transferring Windows of different cleanliness levels should be dedicated (for example, tools for A-level areas cannot be used for C/C/D-level areas) to avoid cross-contamination.
Disinfectants should be used alternately (such as rotating alcohol and peracetic acid every week) to prevent microorganisms from developing drug resistance.
If contaminated items (such as substandard materials) have been passed on, emergency disinfection must be carried out immediately (increase the frequency and intensity of disinfection).
By strictly implementing the above process, the clean state of the transfer window can be effectively ensured, and the risk of contamination during the material transfer process can be reduced.