Cleanroom Material Storage Racks — Perforated & Wire Grating Shelving for Uninterrupted Laminar Airflow
Solid shelving is the single most common cause of stagnant air pockets in cleanroom storage areas. Metrolabs Material Storage Racks use fully perforated or wire-grating shelf construction — allowing vertical laminar airflow to pass through every tier without obstruction, preventing the dead-air zones where particles settle and accumulate on stored materials.
Why Perforated Shelving Is Non-Negotiable in a Cleanroom
The difference between a solid-shelf rack and a perforated-shelf rack is not cosmetic — it is the difference between a compliant storage zone and a recurring particle monitoring excursion source.
Dead-Air Pockets — The Solid Shelf Problem
In a cleanroom with vertical laminar airflow from ceiling HEPA filters to floor-level return risers, a solid shelf acts as a horizontal barrier that stops the downward air column. The volume of air directly beneath each solid shelf becomes stagnant — it is no longer swept by the laminar piston, so any particles generated in that zone (from handling, from packaging, from personnel movement) settle onto the shelf surface and onto the stored materials rather than being carried down to the return air path. Over a shift, this accumulation is measurable at particle monitoring points near the rack.
Perforated Shelving — Continuous Downward Airflow Through Every Tier
Metrolabs perforated shelves use 25mm circular perforations on a 45mm pitch, providing approximately 30% open area — sufficient to allow the vertical laminar column to pass through the shelf plane and continue to the next tier and ultimately to the floor return. The result is that every tier of the rack, and the materials stored on it, remain within the swept laminar zone. There is no stagnant volume anywhere within the rack envelope. Wire grating construction offers an even higher open area (typically 60–70%) for the most critical Grade A/B applications.
Fully TIG-Welded Frame — No Bolted or Slot-and-Clip Assembly
Conventional industrial slotted-angle racking is assembled with bolts, or with slot-and-clip connectors. Both create crevices at every junction that cannot be cleaned, and both shed metallic particles as vibration from trolley movement and cleaning activity loosens the connections over time. Metrolabs rack frames are fully TIG welded — every junction is a continuous, ground-flush, polished weld with no thread, no gap, and no fastener to loosen. This is the only frame construction compatible with cleanroom particle requirements.
Tool-Free Shelf Adjustment — 25mm Pitch Reconfiguration
Shelf heights adjust on a 25mm pitch without tools — a critical operational feature because tool use inside a cleanroom introduces contamination risk and requires re-cleaning of the tool and the work area afterward. The shelf support brackets locate into pre-formed slots in the vertical uprights and lock by gravity and load, with no threaded fasteners. Shelves can be repositioned by a single gowned operator without removing the rack from service or bringing tools into the classified zone.
Four Storage Rack Configurations for Every Cleanroom Zone
Metrolabs manufactures four standard rack configurations — each engineered for a specific storage function and cleanroom grade:
Perforated Shelf Storage Racks
The standard cleanroom storage rack — SS 304 or SS 316L uprights with fully perforated shelf panels (∅25mm holes on 45mm pitch, ~30% open area). Shelf heights adjust tool-free on a 25mm pitch. Load rated to 250 kg uniformly distributed per shelf. Available in 3, 4, 5, and 6-tier configurations with standard bay widths of 900mm, 1200mm, and 1500mm, or fully custom dimensions to suit your floor plan.
Wire Grating Shelf Racks
Maximum airflow configuration — welded SS wire grating shelves providing 60–70% open area, the highest available for a load-bearing shelf. Recommended for Grade A and B zones where the rack is positioned directly within a laminar flow field and any airflow obstruction is a validation concern. The grating is fully TIG welded at every wire intersection and electropolished as a complete assembly.
Mobile Storage Racks
The same perforated or wire-grating shelf construction mounted on medical-grade non-marking polyurethane castors (four swivel, two with brakes) — allowing the entire loaded rack to be repositioned within the cleanroom or moved between zones for cleaning access. Castors are rated at 150 kg each, giving a total loaded capacity of 600 kg. Push handles are TIG welded to the frame with no bolted attachment.
Modular Multi-Bay Runs
Continuous racking runs formed by connecting multiple bays that share common uprights — eliminating the double-upright gap that creates an uncleanable crevice between adjacent free-standing racks. A shared-upright run of any length can be built, and the run can be extended later by adding further bays without disturbing the existing installation. Ideal for bulk storage rooms and material staging areas.
Six Engineering Features of the Metrolabs Storage Rack
Every Metrolabs Material Storage Rack is built to these engineering standards:
Perforated / Wire Grating Shelves — Laminar Flow Preserved
Every shelf is perforated (∅25mm on 45mm pitch, ~30% open) or wire grating (60–70% open) — allowing the vertical laminar air column to pass through every tier without creating a stagnant pocket beneath. This is the defining cleanroom requirement that distinguishes a compliant storage rack from industrial shelving adapted for cleanroom use.
SS 304 / SS 316L — Fully TIG-Welded Construction
Uprights, cross-braces, and shelf frames fabricated from SS 304 (standard) or SS 316L (optional) tube, fully TIG welded at every junction with welds ground flush and polished. No bolts, no slot-and-clip connectors, and no threaded fasteners that create crevices or shed metallic particles from vibration-induced loosening over the service life.
250 kg Per Shelf — Verified Load Rating
Each shelf is rated to 250 kg uniformly distributed load, verified by structural calculation and confirmed by physical load testing during production. The rating accounts for the perforated shelf panel, the shelf frame, the support brackets, and the upright section — the complete load path from stored material to floor is engineered, not estimated.
Tool-Free Adjustment — 25mm Pitch Reconfiguration
Shelf heights adjust on a 25mm pitch without any tools — brackets locate into pre-formed slots in the uprights and lock under load. A single gowned operator can reconfigure the rack in place without bringing tools into the classified zone, and without taking the rack out of service or requiring a re-clean of the area afterward.
Electropolished Finish — Ra <0.5μm Biofilm Resistant
Optional electropolishing to Ra <0.5μm removes the microscopic surface asperities that provide anchorage for biofilm formation. At this surface roughness, bacterial adhesion is dramatically reduced, cleaning agents remove biofilm precursors in a single wipe, and disinfection validation is simplified — directly reducing microbiological risk in pharmaceutical and food cleanrooms.
Fixed or Mobile — Levelling Feet or PU Castors
Supplied with SS adjustable levelling feet incorporating neoprene contact pads (preventing metal-on-floor vibration transmission and floor marking), or with medical-grade non-marking polyurethane castors for mobile configurations. Castor units include swivel-lock brakes on two wheels to hold the rack stationary during loading.
Material Storage Rack — Standard Specification
Metrolabs storage rack standard specification — customisable at any parameter:
| Specification | Details |
|---|---|
| Frame Material | SS 304 (SS 316L optional) |
| Shelf Type✓ Std | Perforated — ∅25mm on 45mm pitch |
| Shelf Alternative | Wire Grating — 60–70% open area |
| Open Area (Perforated) | Approx. 30% |
| Load Rating | 250 kg UDL per shelf |
| Tier Options | 3 / 4 / 5 / 6 tier |
| Standard Bay Widths | 900 / 1200 / 1500 mm |
| Shelf Adjustment | Tool-free — 25mm pitch |
| Welding | Fully TIG welded — ground flush |
| Surface Finish | Brushed (EP Ra <0.5μm optional) |
| Base | SS levelling feet / PU castors |
| Passivation | Citric acid — ASTM A967 |
Storage Racks Across Every ISO Class and Regulated Sector
Perforated and wire-grating storage for every cleanroom where stored materials must remain within the swept laminar zone:
Pharmaceutical GMP
Raw material, packaging component, and consumable storage in Grade C/D areas. Perforated shelving maintains airflow. Full MTC and passivation documentation.
Aseptic & Sterile
Wire grating racks in Grade A/B zones — maximum open area for sterile component and single-use system storage within the laminar field.
Biotech & ATMP
Media, reagent, and consumable storage in cell therapy GMP suites. SS 316L electropolished option for VHP decontamination environments.
Semiconductor
Wafer cassette and process component storage in ISO Class 4–7 fabs. Wire grating for maximum airflow. ESD specification available on request.
Hospital & CSSD
Sterile instrument tray and consumable storage in CSSD sterile stores and hospital pharmacy cleanrooms. NABH compliant construction.
Microbiology Labs
Media plate, sample, and consumable storage in BSL-2 laboratories. Perforated shelving prevents settling of airborne particulates on stored plates.
Food & Beverage
High-care zone packaging and ingredient storage. SS 304 with electropolish option. FSSAI and HACCP compliant surface specification.
Warehouse & Staging
Modular multi-bay runs for cleanroom material staging areas and bulk stores. Shared uprights eliminate inter-rack crevices across long runs.
Purpose-Built for Cleanrooms — Not Adapted Industrial Racking
Metrolabs does not adapt commercial slotted-angle racking for cleanroom use. Every storage rack is designed and fabricated from the ground up to cleanroom particle, cleaning, and airflow requirements:
Airflow-First Design — Every Shelf Open, Every Tier Swept
The perforation pattern and open area are specified before the structural design, not after — the shelf is engineered to achieve 30% open area while carrying 250 kg, rather than a solid shelf having holes added. Wire grating shelves reach 60–70% open for the most critical Grade A/B applications.
Zero Fasteners — No Crevices, No Particle Shedding
Fully TIG-welded frames with no bolts, threads, or slot-and-clip connectors anywhere in the load path. Every junction is a continuous ground-flush weld. This eliminates both the uncleanable crevice and the metallic particle shedding that loosening fasteners cause over the service life.
Custom Dimensions — Built to Your Floor Plan
Standard bay widths of 900, 1200, and 1500mm are available, but every rack can be fabricated to exact dimensions matching your room, column positions, aisle widths, and ceiling height — with no minimum order quantity for custom sizes.
Audit-Ready Documentation from Day One
Every rack is supplied with material test certificates confirming the SS grade and heat number, an ASTM A967 passivation certificate, and an optional load test certificate — the documentation package required for GMP facility validation and regulatory audit evidence.
Cleanroom Rack vs Industrial Racking vs Solid Shelving
The bottom line: industrial slotted-angle racking is significantly cheaper, but its bolted joints, painted finish, and solid or partly-open shelves make it a recurring particle source in a classified environment. A cleanroom-specific rack costs more upfront and eliminates that risk for the life of the facility. See all cleanroom furniture →
From Specification to Installed & Documented Storage Racks
Metrolabs manages the complete storage rack supply process:
Survey & Specification
Floor area, ceiling height, aisle widths, column positions, and door swings measured. ISO class confirmed. Shelf type, tier count, bay widths, and load requirements agreed. Layout drawing produced and signed off.
Fabrication
Uprights and frames cut and TIG welded. Welds ground flush and polished. Shelf panels perforated or grating welded. Passivated to ASTM A967. Electropolished if specified. MTCs issued for all SS components.
Load Test & QC
Shelf load test to 250 kg UDL with deflection measurement. Weld inspection. Surface finish verification (Ra measurement if EP specified). Dimensional inspection against approved drawing. Test report produced.
Install & Handover
On-site assembly, levelling, and anchoring where specified. Minimum 150mm floor clearance verified. Shelf adjustment demonstrated. MTCs, passivation cert, and load test certificate handed over for IQ.
Built to Meet Global Cleanroom & GMP Requirements
Every Metrolabs storage rack is designed and documented for regulatory compliance:
ISO 14644-4
Cleanroom design and construction requirements — including the specification for furniture and fittings that must not obstruct airflow or generate particles within the classified zone.
Cleanroom DesignEU GMP Annex 1
Manufacture of sterile medicinal products — equipment in cleanrooms must be designed for effective cleaning and must not compromise the unidirectional airflow in critical zones.
Sterile GMPASTM A967
Chemical passivation of stainless steel — every rack is citric acid passivated post-fabrication to restore the passive chromium oxide layer removed by welding and mechanical finishing.
SS Passivation21 CFR Part 211
Current Good Manufacturing Practice — equipment used in drug manufacturing must be of appropriate design and adequate size, and suitably located to facilitate cleaning and maintenance.
US FDA cGMPFactory & Office
4, SIDCO-MICRO, Thirumudivakkam,
Chennai – 600 132, Tamil Nadu
Ready to Equip Your Cleanroom with Airflow-Compliant Storage?
Contact Metrolabs for a free consultation. Our specialists will confirm your ISO class, shelf type, tier count, bay dimensions, and load requirements — then fabricate, load-test, and install your storage racks with full material and passivation documentation at handover.
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