Evidence Drying and Storage Cabinets: Utah Lab Guide
Quick answer
- Wet biological evidence should be dried before it is packaged and stored. If it stays wet, bacteria and mold can destroy the DNA.
- Small agencies can dry items in a secure, labeled locker or room. Agencies with a daily wet-evidence load usually move to a commercial drying cabinet with HEPA filtration.
- Pick ducted or ductless drying based on your building, your filters and your safety team’s review.
- Size drying capacity for your busiest intake days. Size long-term storage for your retention rules and growth.
- Keep intake, drying, packaging and storage in separate zones, and get a measured layout before you sign a PO.
A Utah evidence manager opens the drying cabinet and finds every space full. Wet clothing from a new case is waiting on a cart, and older items still need time before they can be bagged. The real problem is not one more cabinet. It is a workflow that has outgrown its drying, transfer and storage space.
This guide treats evidence drying and storage cabinets for Utah labs as one part of the evidence process, not a stand-alone purchase. It covers what the national guidance says about drying, which cabinet types fit which jobs, how to size and lay out the room, and what to check before you order.
Why Wet Evidence Has to Be Dried First
The NIST Biological Evidence Preservation Handbook is the main national reference for evidence handlers. It says that drying wet items, such as a blood-soaked shirt, should be the first task once the item has been collected. If wet biological material is not air-dried the right way, bacterial growth can destroy it and block a DNA result.
The handbook also covers what to do when drying space is not available yet:
- Short-term wet storage: Place the item in a sealed container that liquid and vapor cannot pass through, such as a metal can or glass jar. Keep it in a refrigerator at 2°C to 8°C (about 35°F to 46°F), out of direct sunlight, until it can be dried.
- Plastic bags: They can hold wet evidence for a short time only. They should not be used for long-term storage because of bacteria and mold. The exceptions are bags with desiccant and breathable Tyvek bags.
- Packaging after drying: Utah’s state crime lab requires paper bags for all biological and DNA evidence. See the Utah Bureau of Forensic Services evidence packaging guide for its sealing and labeling rules.
That is why the drying step drives the whole room. If drying backs up, wet items sit in temporary containers, packaging waits, and storage fills with items that are not ready.
The Four Stages an Evidence Room Has to Support
An evidence room may take in wet clothing, bedding, towels, shoes, swabs, firearms, phones and other case items. Each one carries a different handling risk. A bloody shirt needs controlled drying. A firearm needs secure, separate storage. A phone needs a clean, locked spot while it waits for exam.
Most operations move items through four connected stages:
- Intake and labeling. Staff receive the item, check the case details, note its condition and assign a tracked location.
- Drying. Wet or biological items go into a secure, ventilated space where they hang apart from items from other cases.
- Transfer and packaging. Dried items move to a clean bench to be packaged in paper, sealed and labeled.
- Long-term storage. Packaged items go into secure cabinets, lockers or shelving that match the retention plan.
Plan the bench, packaging supplies, scanner, cart parking, PPE, spill kit and the route to storage at the same time as the cabinets. The cabinet is only one piece of the system.
Keep items from different cases, and from victims and suspects, apart during drying. The Massachusetts evidence handling manual is another useful reference for separation and packaging controls.
Low-Tech Drying Areas vs. Commercial Drying Cabinets
The NIST handbook describes two ways to dry biological evidence. Which one fits depends on how much wet evidence you handle.
Low-tech: a designated locker or room
Agencies that do not handle much wet evidence often use an isolated, secure space, such as a metal locker labeled for biohazards, a shower stall or a small room. NIST recommends these conditions for that kind of space:
- Keep it out of direct sunlight.
- Hold the temperature between 60°F and 75°F (15.5°C to 24°C) as much as you can.
- Keep relative humidity at or below 60 percent.
- Use wall, ceiling and floor materials that can be decontaminated after every use.
- Hang garments with clean paper under and between them to catch trace evidence. Package that paper separately and submit it with the item.
High-tech: a commercial evidence drying cabinet
NIST calls a commercially made evidence drying cabinet one of the most accepted ways to dry biological evidence. The cabinet secures the item while air moves through a HEPA filter that captures airborne particles. NIST notes that the filter itself may become evidence. These cabinets are most common in larger agencies that need to dry evidence every day.
No matter which method you use, NIST says hangers should not be reused. It also recommends a written policy that names who cleans the drying area, how it is decontaminated, how the cleaning is recorded and how long those records are kept.
Cabinet Types That Fit the Application
No single cabinet fits every Utah evidence room. The right choice depends on biological risk, building services, security, floor space and case flow. Forensic cabinet guidance from Air Science lists controlled airflow, filtration and containment as the core needs for forensic drying.
A ducted drying cabinet sends exhaust to the building system. It fits facilities that already have exhaust capacity and a steady biological workload. It also brings mechanical design, roof or wall penetrations, air balancing and inspection into the project.
A ductless filtered drying cabinet cleans the air and returns it to the room. It can make sense in an older building where new exhaust runs would mean major construction. The filters must match the actual hazard. Our ducted vs. ductless guide explains the general tradeoffs.
As one example, the evidence drying cabinet in the TopAir Systems forensic catalog is ductless and built from polypropylene with safety glass. The catalog lists a pre-filter on the incoming air, HEPA and carbon filtration on the exhaust, a UV light with a safety interlock for disinfection between sessions, and a bottom drain basin with a tap. Standard widths run from 30 to 96 inches at 75 inches tall, and the maker offers custom sizes. Confirm the exact model, filters and listing for your project before approval.
A combination drying and storage unit saves floor space but can blur the line between wet evidence and finished storage. Use one only when the internal separation, airflow, cleaning steps and access control are clear.
Secure evidence lockers work well for intake, temporary holding and case separation. They do not replace a drying cabinet when evidence is wet.
High-density mobile shelving adds long-term capacity for packaged items. It is not drying equipment, and it adds floor load, rail and aisle questions.
| Cabinet type | Airflow and filtration | Security | Space and services | Best fit |
|---|---|---|---|---|
| Ducted drying cabinet | Building exhaust plus specified filters | Lockable enclosure | Needs an exhaust connection | Steady biological drying where exhaust is available |
| Ductless filtered drying cabinet | Pre-filter, HEPA and carbon as specified, air returned to room | Lockable enclosure | Flexible placement, needs power and filter service | Retrofits and rooms without a practical exhaust route |
| Designated drying locker or room | Room air, no cabinet filtration | Locked, labeled space | Low cost, needs cleanable surfaces | Low wet-evidence volume (NIST low-tech method) |
| Combination drying and storage unit | Drying zone plus enclosed storage | Moderate to high | Compact, needs clear separation | Small operations with strong procedures |
| Secure evidence locker | Not a drying system | High, per compartment | Wall or floor modules | Intake, temporary holding, case separation |
| Mobile or static storage shelving | Storage only | Lockable options | Dense, needs floor and rail review | Packaged evidence and long retention |
To compare broader cabinet families, see our laboratory safety cabinets and storage systems or the Utah safety cabinet hub. Controlled substances need their own plan, covered on our narcotic and controlled substance cabinet page.
Practical rule: Size drying cabinets for your busiest wet-evidence period. Size long-term storage for your retention policy, current inventory and planned growth. Do not use one number for both.
Sizing, Layout and Access
Sizing starts with evidence flow, not room size. A large room can still fail if carts cannot turn, intake is far from drying, or staff must cross a secure boundary to pick up a package.
Start with your own case records. Pull a recent report and split it into wet items, dry packaged items, firearms, digital media, oversized items and restricted items. Record how long each type holds a cabinet or shelf spot. That tells you far more than asking how many cabinets “a lab like yours” buys.
Plan the room in working zones
Put the intake bench near the receiving path. Keep drying cabinets close enough for short, controlled transfers, but out of the path to long-term storage. Place a clean packaging bench between drying and storage so dried items never go back past wet ones.
Check these conditions before you draw the layout:
- Cart movement: Measure doorways, turning areas and the route from intake to drying.
- Service access: Leave room for filter changes, fan access, electrical work and cleaning.
- Exhaust route: For ducted units, confirm ceiling space, connection points and access.
- Doors: Review door swings, pass-through options, lock zones and sight lines.
- Separation: Give wet, packaged and restricted evidence their own locations.
- Growth: Reserve space and utility stubs for added cabinets instead of filling every wall now.
Stainless steel is a good fit for benches and cabinets that are cleaned and decontaminated often. Compare stainless steel laboratory cabinets and stainless steel casework for the packaging and intake zones. To sketch the zones and send them to us for review, use the free lab layout designer.
Use throughput records, not guessed capacity
One cabinet space does not equal one item. Bedding, coats and shoes take far more room than swabs. A shared cabinet also becomes a bottleneck when one case is still wet and another arrives.
Build the drying schedule from:
- Peak wet-item arrivals
- Drying times your own staff have recorded
- How many cases must stay separated at once
- Staff loading and unloading patterns
- Packaging and transfer time
- Long-term retention volume
- Planned expansion or phased installs
Planning a Utah evidence room or crime lab update?
Send us your floor plan and a recent intake report. We will lay out drying, packaging and storage zones and quote the cabinets and casework. Start with the lab layout designer, request a quote, or call (801) 855-8560.
Code, Safety and Site Checks in Utah
Treat compliance as a checklist you verify, not a promise you accept. Ask the maker and your project safety team to name which rule applies to each cabinet and each material.
Know which standard applies to which cabinet. UL 1275 is the standard for flammable liquid storage cabinets. It does not cover evidence drying cabinets. The University of Utah EHS chemical storage guidance tells labs to buy flammable cabinets that are OSHA and NFPA approved (which meets UL 1275) with self-closing doors to meet fire code. It also says flammable cabinets usually should not be vented, because poor venting can defeat their fire protection. For a drying cabinet, ask instead for the electrical listing, the filter specifications and the maker’s installation instructions for that exact model.
Do not use a drying cabinet for chemicals. If the room also stores flammable or corrosive liquids, they need their own listed cabinets. The NIH chemical storage cabinet fact sheet notes that flammable and corrosive cabinets are built for one hazard class and should not be used for general storage. Our guide to flammable vs. corrosive safety cabinets covers the differences.
Biological drying is a ventilation question. A filtered drying cabinet should pull air in and filter it before it leaves, so contaminated air does not spill into the room. Depending on the model, features can include pre-filters, HEPA and carbon filters, negative pressure, drains, locks and UV disinfection. Your EHS team decides which features the work requires. For the room itself, see our forensic evidence lab ventilation guide.
For teams that want outside help running the review, outsourced health and safety advisers can organize the process. Your facility’s authorities and EHS professionals still make the site decisions.
Verify the site before the PO
Confirm these items with the architect, contractor, EHS lead, fire marshal and installer:
- Listings and fire requirements for each cabinet type
- Exhaust, filtration and room airflow
- Electrical service and disconnect location
- Door, ceiling, sprinkler and service clearances
- Floor condition, anchoring and seismic restraint
- Cleaning, decontamination, spill response and PPE
- Local permits and inspections
- Access control and chain-of-custody procedures
The Wasatch Front is a seismic area, so tall cabinets and shelving should be reviewed for restraint. See seismic lab shelving and storage restraint in Utah and review it with your project engineer.
Utah public agencies may be able to buy through the state contract. Review the Utah state contract for lab shelving and storage when it fits your purchasing path. Some agency teams also find Utah evidence locker and cabinet guidance helpful as background on locker styles.
Long-Term Storage After Drying
Once an item is dry and packaged in paper, it moves to storage. NIST defines “temperature controlled” storage as 60°F to 75°F with less than 60 percent humidity. For dry biological stained items, its short-term storage table rates temperature-controlled storage as best and room temperature as acceptable. Items that must stay frozen or refrigerated need their own equipment.
NIST also recommends that agencies standardize packaging and set up shelving for faster retrieval, and that they keep different kinds of biohazardous evidence apart. Plan storage around these points:
- Retention volume: Count current packages and estimate growth from your retention rules.
- Package sizes: Match shelf depth and spacing to your real boxes and bags.
- Security tiers: Put firearms, drugs, money and high-profile cases in locked zones with access logs.
- Density: Mobile shelving saves floor space but needs a floor load and rail review.
Price storage layouts with the high-density shelving designer or the security shelving designer.
How to Plan an Evidence Drying and Storage Room in 7 Steps
- Pull your intake data. Use 6 to 12 months of records to count wet items, packaged items and restricted items, and find your peak weeks.
- Choose the drying method. Low volume can work with a designated locker or room. Daily wet evidence points to a commercial drying cabinet.
- Pick ducted or ductless. Check exhaust access, filter needs and your EHS team’s review.
- Draw the four zones. Lay out intake, drying, packaging and storage in a one-way sequence.
- Size each zone. Size drying for peak days and storage for retention and growth.
- Check the site. Confirm power, exhaust, clearances, floor, anchoring and permits.
- Get a drawing and a written quote. Ask for a layout with clearances, model numbers, filters, install scope, warranty and service terms.
Installation, Lead Time and Service
Lead time depends on the cabinet model, filters, finish, controls, exhaust needs and any custom sizes. Ask for a written lead time on your exact configuration rather than relying on a general estimate. If the room also needs casework, our quick-ship lab casework program can help align the schedules.
Ducted systems usually take more site coordination than ductless units. Before ordering, confirm power, exhaust stubs, ceiling access, floor condition, the delivery path and where evidence will be staged during the install.
Put these items in writing
- Submittals: Product drawings, electrical data, filter details and installation instructions.
- Startup checks: What the maker tests before shipping and what the installer checks on site.
- Delivery: How to report shipping damage or missing parts.
- Commissioning: Who checks airflow, alarms, locks, lights and controls.
- Filter handling: How filters are changed, who changes them, and whether a used filter must be held as evidence.
- Parts: Availability of replacement filters and parts over the cabinet’s life.
- Warranty: Coverage, exclusions, response times and labor.
- Recurring checks: Who owns any performance checks your facility requires.
Common Utah Buyer Scenarios
Two rooms with the same size can need very different cabinet plans.
County sheriff’s property room. Mixed evidence, irregular deposits and thin staffing. Use secure intake lockers, a filtered drying cabinet for wet items and separate storage for packaged evidence. Next step: pull a recent intake report and schedule a site walk.
Midsize city police evidence bay. Frequent access and a need to keep wet biological items away from general storage. Set intake, drying, packaging and storage in a logical line, and avoid open shelving for restricted items. Next step: mark the intake-to-storage route on your floor plan.
University forensic teaching lab. Shared use and changing users. Choose lockable, cleanable drying and storage units with clear controls. Next step: ask university EHS to review the cabinet and room use.
State crime lab expansion. Repeatable workflows, strong records and room to grow. Ducted or high-performance filtered drying may suit a steady biological load. Next step: request coordinated mechanical and architectural drawings. Our forensic crime lab furniture guide covers the rest of the lab room by room.
Small private toxicology intake room. Compact secure storage and a receiving bench, with drying only if items arrive wet. Do not buy a large system to fix a paperwork problem. Next step: sort material types and list which ones need drying.
| Scenario | Main pressure | Suggested setup | Layout driver | First step |
|---|---|---|---|---|
| County property room | Mixed items, irregular deposits | Intake lockers plus filtered drying | Secure handoff path | Review intake records |
| City evidence bay | Frequent access, case separation | Drying cabinet plus secure storage | Short intake-to-storage route | Mark the current flow |
| University teaching lab | Shared users, supervision | Lockable, cleanable units | Controlled access | Schedule EHS review |
| State lab expansion | Steady biological load | Ducted or high-performance filtered drying | Mechanical coordination | Request coordinated drawings |
| Private toxicology intake | Small space, selective drying | Secure cabinet, drying only if needed | Limited footprint | Classify materials first |
For more on public-sector projects, see government and federal lab furniture and our guide to public health and forensic lab casework in Utah.
FAQ: Evidence Drying and Storage Cabinets
Why must wet evidence be dried before storage?
Wet biological material can grow bacteria and mold, which can destroy DNA. The NIST handbook says drying wet items should be the first task after collection, and that plastic bags should only hold wet items for a short time.
Do we need a commercial drying cabinet, or will a locker work?
It depends on volume. NIST describes a secure, labeled locker or room as a workable low-tech method for agencies with little wet evidence. Agencies that dry evidence daily usually use a commercial cabinet with HEPA filtration.
Are ductless filtered drying cabinets accepted in Utah?
They can be, but approval depends on the model’s listing, its filters, the materials handled, your EHS review and local authority rules. Get model-specific documents before approval and confirm the setup fits your workflow.
Does UL 1275 apply to evidence drying cabinets?
No. UL 1275 covers flammable liquid storage cabinets. Store flammable liquids in a listed flammable cabinet, and ask the drying cabinet maker for that model’s electrical listing and filter specifications instead.
How often should HEPA or carbon filters be changed?
There is no single interval. It depends on use, contaminants, airflow readings, alarms and the maker’s instructions. Write the inspection method, the change trigger and the person responsible into your service plan, and decide in advance whether a used filter must be kept as evidence.
What temperature and humidity should a drying area have?
For low-tech drying areas, NIST recommends 60°F to 75°F, relative humidity at or below 60 percent, and no direct sunlight. A commercial cabinet controls its own airflow, but the room should still be kept stable.
Do cabinets need to be anchored on the Wasatch Front?
Anchoring may be required by the project design, cabinet type, building or engineer. Have a qualified engineer or installer review the floor, cabinet height, seismic restraint and clearances before you order.
What should a quote include?
Ask for the model, dimensions, filters, electrical needs, locks, accessories, delivery, installation, commissioning, warranty, maintenance instructions and any site work. Ask for a layout drawing that shows clearances and access, not just a price list.
Get Help Planning Your Evidence Room
The right setup gives you clean separation, controlled airflow, secure access and documented transfers. Cabinet count alone does not set capacity. Evidence mix, drying time, staff movement and room limits do.
Labs USA supplies laboratory furniture, safety storage, casework and planning support for Utah crime labs, property rooms and teaching labs. Use our free design tools to rough out the room, then send it to us for pricing:
- Lab layout designer for intake, drying, packaging and storage zones
- Base cabinet designer for packaging and intake benches
- Lab bench designer for exam and packaging workstations
- High-density shelving designer for long-term evidence storage
- All free laboratory design tools
Prefer to talk it through? Request a quote or call Labs USA at (801) 855-8560 for a free layout review.