Negative Pressure Laminar Flow Workbench VS Vertical Flow Ultra-clean Workbench – Core Differences in Working Principles 1. The fundamental pressure difference is completely opposite (the most essential difference) 1. Ordinary Vertical Flow Workbench (Positive Pressure Type) Inside the cabinet: The air pressure is higher than that of the external room, creating positive pressure; The fan sucks in air from the interior and sends it down vertically through the top HEPA filter; The clean air fills the operation area, and the internal positive pressure keeps the outside dirty air outside; The excess air is directly discharged from the front operation opening and the bottom diffuser board back into the room, without an independent negative pressure suction channel. 2. Negative Pressure Laminar Flow Workbench (Negative Pressure Weighing Bench / Negative Pressure Workbench) Inside the cabinet: The air pressure is lower than that of the external room, maintaining negative pressure; Two independent air paths: laminar flow supply + negative pressure exhaust, dual fan system; Top supply: Air is filtered and sent down vertically to ensure the cleanliness of the work surface (the same as vertical flow laminar flow); Window air supply: The peripheral air of the operation opening continuously sucks in air to

Negative pressure weighing room operation inspection record form – Recheck verification frequency (GMP compliance stratified standard) I. First-level recheck: Operator self-inspection (every shift, immediate) Frequency: After filling out the inspection record form, the operator must immediately self-check. This is a mandatory pre-process that cannot be submitted for review without completing the self-check. Scenario: At the end of each shift, the operator fills out the form and conducts on-site self-check immediately, confirming that there are no blank items, the data is correct, and the signature is complete. II. Second-level recheck: Shift supervisor on-site recheck (every shift, before the end of the shift) Frequency: Once per shift. All inspection records must be rechecked on-site on the same day. Cross-shift and cross-day rechecks are not allowed. Requirements: Take the paper record to the weighing room for on-site comparison with the instrument and equipment status, and sign and return it after verification. III. Third-level recheck: QA / Equipment administrator random recheck (parallel two frequencies) 1. Daily surprise recheck (daily supervision) Frequency: Full coverage recheck every day. If there are multiple weighing rooms in the workshop, at least one recheck per day should be conducted; the monthly recheck should cover all shift records of all

Automatic Door Air Shower Room: Wind Speed and Air Shower Duration Adjustment Instructions 1. Air Shower Duration: All supported adjustable Adjustment Range Standard control system setting range: 0 – 99 seconds. Factory default: 10 seconds/15 seconds. Pharmaceutical factories and high-cleanliness workshops often set to 20–30 seconds. Adjustment Method Basic model: Panel buttons and digital display for setting; High-end automatic door air shower: 7-inch touch screen for direct digital input; Logical Limitation The air shower will be executed only when the front and rear doors are interlocked. The door will unlock automatically when the time is up; You can stop the air shower by pressing the emergency stop at any time. Industry Reference Electronic workshop: 10–15 seconds; Pharmaceutical GMP workshop: 20–30 seconds; Raw material workshop with heavy dust: 30–40 seconds. 2. Air Shower Wind Speed: There are two types of models, and the ability to adjust varies 1. Ordinary fixed-frequency fan model (market basic stainless steel air shower) Wind speed cannot be adjusted continuously Fan power is fixed, the standard wind speed at the nozzle outlet maintains 22–28 m/s (national standard requirement ≥ 25 m/s); Only two modes: full fan on air shower / shutdown, cannot adjust fast or slow. 2.

The complete maintenance and servicing plan for the automatic door and air shower room is divided into: daily inspection, weekly maintenance, monthly maintenance, quarterly/six-monthly maintenance, and annual overhaul. It also distinguishes three core modules: purified air path, automatic sliding door system, and electrical control system. It is applicable to stainless steel automatic air shower rooms, forklift air shower rooms, and AGV air shower rooms. 1. Daily daily maintenance (5 minutes before and after production shift) 1. Box body and internal cleaning Wipe the inner wall, nozzles, floor, and automatic door glass with dust-free cloth + 75% alcohol / workshop neutral disinfectant; Clean the floor tray debris and dust to avoid backflow blockage; Check the nozzles for no blockage, skewing, and remove any debris immediately. 2. Automatic door safety inspection Test the anti-clamping function: when closing the door, if it is blocked, the door will immediately rebound; Check the sensor probe for any accumulated dust and wipe it clean to prevent false sensing / non-sensing; Check if the sealing strip is loose or cracked, as leakage will reduce the dust removal effect. 3. Electrical control basic inspection Power on to check for no fault alarms on the display, normal pressure difference

Filter replacement criteria for supply air ceiling filters (4 determination methods, priority: pressure difference > leak detection > appearance > usage duration) 1. Core determination: Pressure difference value (the most standard, GMP / hospital mandatory basis) Each filter is equipped with an independent pressure difference meter. If the pressure difference exceeds the limit, it should be replaced immediately, regardless of the usage time. Primary efficiency filter (G3/G4) Initial pressure difference: 40-60 Pa Final resistance threshold: ≥ 100 Pa Treatment: Can be disassembled for water washing. If the pressure difference remains high after washing, it should be replaced. Intermediate efficiency filter (F7/F8/F9) Initial pressure difference: 70-110 Pa Final resistance threshold: ≥ 200 Pa Treatment: Cannot be washed. If the pressure difference meets the standard, it should be replaced immediately. HEPA/ULPA high-efficiency filter (H13/H14) Judgment rule: Actual pressure difference ≥ initial pressure difference × 2 Example: Newly installed high-efficiency filter with an initial pressure of 120 Pa, rising to 240 Pa, must be replaced. Supplement: The fan automatically increases frequency, the air volume significantly decreases, and the room fails to reach the set cleanliness level, which are basically caused by filter blockage and increased pressure difference. 2. Leak detection determination (specific to

Explosion-proof FFU Filter Complete Selection Scheme (divided into 6 major dimensions, applicable to lithium battery / pharmaceutical / chemical industries) Selection logic sequence: First determine the explosion-proof working condition → Cleanliness level → Filter material → Structural form → Matching pre-filter → Dimension sealing, while taking into account explosion-proof safety and service life. I. Step 1: Select filter materials based on the flammable and explosive media in the workshop (core of explosion-proof, priority judgment) 1. Lithium battery workshop (electrolyte, NMP, lithium powder, organic solvents) Media characteristics: prone to crystallization, oily, combustible dust, high humidity Recommendation: PTFE-coated H13/H14 high-efficiency filter Advantage: Surface filtration, dust does not penetrate the filter paper; resistant to electrolyte and organic solvents; hydrophobic and moisture-proof; dust accumulation can be blown away, life is more than 50% longer than glass fiber Not recommended: Ordinary glass fiber, easily soaked by electrolyte and clogged, resistance rapidly rises. 2. Pharmaceutical / medical device explosion-proof area (alcohol, small amount of solvents, low dust) Media characteristics: Small amount of alcohol solvents, dry and clean, low dust Recommendation: Ultra-fine glass fiber without partition H14 Advantage: Stable filtration accuracy, initial wind pressure low, low cost, meets GMP cleanliness requirements; clean working condition, sufficient service life.

Complete application scope of vaporized hydrogen peroxide VHP transfer cabinets I. Pharmaceutical industry (core applicable scenarios, GMP mandatory recommendation) Aseptic preparation workshop Injectables, freeze-dried products, powder injections, eye drops, materials transferred from D/C class to A/B class aseptic areas, packaging materials, equipment, sampling consumables sterilization transfer. Biological drugs / vaccines / cell culture workshop Virus vaccines, cell therapy, monoclonal antibody workshops, culture media, cryovials, experimental consumables, sample cross-zone transfer, killing spores and viruses, eliminating cross-contamination. Aseptic medical device production Implantable devices (stents, artificial bones, sutures), sterile dressings workshop, semi-finished products, tooling molds sterilization transfer. Chinese medicine aseptic workshop Aseptic herbal slices, Chinese medicine injection products, supporting clean zones for materials transfer. II. Medical, disease control, biological safety laboratories PCR nucleic acid laboratories, microbiological testing rooms Positive samples, bacterial strains, reagents sealed transfer to prevent aerosol leakage and contamination of the environment. BSL-2/BSL-3 biological safety laboratories, animal laboratories Pathogens, experimental animal feed bedding, experimental equipment entry and exit, internal and external two-way sterilization isolation. Hospital clean areas Operating rooms, central supply rooms, negative pressure isolation wards, transplant wards, instruments, specimens, aseptic consumables clean area and contaminated area intercommunication. III. High-end cosmetics and aseptic food Medical aesthetic aseptic skincare workshop Essence, aseptic

The comprehensive impact of the glass material of the ultra-clean bench on its usage The observation window glass of the ultra-clean bench is divided into three types: qualified 5mm tempered glass, ordinary white glass, and acrylic organic glass. The material differences directly affect operational safety, experimental results, equipment lifespan, and GMP compliance. The following will explain the actual usage differences in detail by dimension. 1. Safety aspect (the most critical, concerning personal risks) 1. Qualified tempered glass Resistance to impact: Experimental equipment, pipettes, centrifuge tubes accidentally colliding will not break easily; Explosion-proof and cut-resistant: Once broken, it will break into fine, smooth-edged particles, without sharp large pieces of glass that can cause hand injuries; Temperature stability: UV sterilization heating, indoor cold and hot alternation, will not self-burst. 2. Ordinary non-tempered thin glass (4mm and below) Minor bumps, sudden temperature changes are likely to cause the entire piece to explode, with sharp edges, easily causing cuts; During lifting and pushing, the edges are sharp, easy to scratch during daily cleaning and reaching for operations. 3. Acrylic / organic glass (strictly prohibited as a substitute) Hardness is extremely low, slight impact will cause cracking and chipping, without explosion-proof capability, completely failing to

Audit Record Form for Negative Pressure Weighing Chamber – Accuracy and Completeness Control Plan I. Avoiding Omission and Missing Items through Form Design (Source Control) Require quantification in mandatory columns, prohibiting only marking a check without filling in data. Separate columns for negative pressure and wind speed settings for independent digit entry. Do not allow only checking “normal”; any value without a number directly determines that the record is incomplete. Fixed items for each area, no blank spaces Basic information: Equipment number, date, shift, start and stop time, operator, reviewer all set as fixed filling columns; Exception columns and shift handover remarks column marked as “No exceptions, please fill in ‘None’, no blank spaces allowed”. Exception linkage filling design Only check “exception”, then the fault description + handling measures must be filled in, binding the two columns, any missing item makes it unqualified. Post the on-site filling standard card Post the parameter standards (negative pressure – 15~-30Pa, wind speed 0.35~0.45m/s), filling norms, modification requirements beside the weighing chamber to facilitate real-time comparison by employees. Uniform numbering of forms, monthly binding Each record form has consecutive page numbers, invalidated documents cannot be torn off, all attached to the ledger to prevent

Among all the daily physical disinfection methods for transfer windows, the UV-C ultraviolet radiation operation is the simplest. Comparison illustration UV radiation (the simplest operation) Operation steps: Place the materials → Close the double doors → Press the UV switch, the timer will automatically stop and close, no additional tools are needed, no wiping is required, no air source connection is necessary. Just one button start, the entire process does not require personnel on duty, it is the standard equipment for most workshops and is used by all shifts. Other methods are more cumbersome Dry dust-free wiping: requires dust-free cloths, wipe the box and sealing strips one by one, time-consuming; Clean compressed air blowing: need to connect the air source, hold the air gun and blow the materials one by one; FFU laminar flow self-cleaning: although it can also be started with one button, it is only applicable to laminar flow transfer windows, and the application range is narrow; Ozone and dry heat disinfection: the process is complex, and ventilation / cooling are required, and they cannot be used frequently in daily operations. Summary The most commonly used, least demanding in operation and with the strongest universality for physical disinfection:

Installation and operation process of clean room FFU + full acceptance inspection steps The overall process is divided into four major stages: installation appearance acceptance → electrical system acceptance → single machine performance test acceptance → comprehensive performance acceptance of the clean room. All must be qualified before it can be handed over for use, in accordance with standards GB51110-2015, GB/T36068, and GB/T13554. The first stage: preliminary installation appearance and structure acceptance (after the installation of the ceiling truss / keel / FFU is completed) Data verification acceptance Verify the drawings, FFU factory certificate of conformity, high-efficiency filter test report, motor parameters, spare parts list; Verify the model, size, air volume, EC/AC motor, and the design of the group control system are consistent. Ceiling keel structure acceptance The hangers, main / secondary keels have no deformation, are firmly welded, and the hanger spacing is ≤ 1.2m; The levelness of the keels is detected with a level ≤ 2mm/m, the overall flatness ≤ 5mm; Confirm that the ceiling load meets the FFU load, and there is no loosening or sagging. FFU arrangement and installation appearance acceptance The outflow surface of the FFU is uniformly downward, the arrangement is aligned, the positioning

High-efficiency filters correctly installed + Complete maintenance plan (core points for extending service life) I. Standard Installation (Installation errors will directly shorten half of the service life and cause dust leakage) 1. Pre-installation Preparation Clean the cleanroom ducts, static pressure boxes, and DOP supply air boxes thoroughly, removing any welding slag, dust, or debris; Installation of high-efficiency filters is not allowed without cleaning. Pre-install the first-stage G4 + second-stage F8/F9 pre-filters in advance. Pre-filters are the first line of defense for high-efficiency filters; their absence will quickly block the high-efficiency filters. Open the box to inspect the filter: the filter material is undamaged, the aluminum frame is not deformed, and the liquid tank sealant is not cracked; if damp or damaged, it must be scrapped and cannot be used. When transporting, do not grasp the filter material, only hold the frame edge to avoid scratching the glass fiber filter paper. 2. Installation Key Points for DOP Liquid Tank High-Efficiency Supply Air Outlet Pour the sealing gel into the liquid tank, ensure the liquid level is within the standard range. Place the filter vertically and steadily, with the entire ring of the frame completely submerged in the gel, without any suspended