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You should not put anything illegal, dangerous, perishable, living, wet, or highly valuable in a storage unit. For bedding storage options, compare Best Comforter Storage Bags and Best Under-Bed Storage for Bedding by dimensions, material, closure, and moisture protection. Most facilities also ban fuel, explosives, chemicals, weapons, and pressurized containers.
Rules can vary by facility and location. Always read the rental agreement before moving items into the unit.
Items That Usually Are Not Allowed in Storage Units
Flammable or Explosive Items
Do not store anything that can easily catch fire or explode. The related guide, What Should You Not Put in a Vacuum Bag?, explains moisture, compression, and material limits before storage. These items can put the whole facility at risk.
Common examples include:
- Gasoline
- Diesel fuel
- Propane tanks
- Kerosene
- Fireworks
- Lighter fluid
- Paint thinner
- Fuel-powered tools with fuel still inside
- Camping fuel
- Some aerosol products
- Explosive materials
Drain fuel from lawn equipment, generators, and similar tools before storage. Follow the manufacturer’s directions for preparing the equipment.
Hazardous Chemicals
Storage units are not meant for toxic, corrosive, or dangerous chemicals.
Do not store:
- Pesticides
- Pool chemicals
- Strong cleaning chemicals
- Fertilizers that contain hazardous ingredients
- Acids
- Laboratory chemicals
- Medical waste
- Radioactive materials
- Containers with unknown liquids
Even a sealed container can leak, rust, or build pressure over time.
Pressurized Containers
Pressurized tanks can become dangerous when temperatures rise.
These may include:
- Propane cylinders
- Oxygen tanks
- Scuba tanks
- Compressed gas cylinders
- Large fire extinguishers
- Certain aerosol containers
Some facilities may allow empty tanks that have been properly prepared. Check the facility’s current policy before storing one.
Illegal or Stolen Property
You cannot use a storage unit to hide stolen property, illegal drugs, counterfeit goods, or other unlawful items.
The unit must also be used only for legal purposes. A rental agreement does not protect stored items from a lawful search or investigation.
Firearms, Ammunition, and Weapons
Many storage facilities do not allow firearms, ammunition, explosives, or certain weapons. Local laws may also limit how these items can be stored.
Do not assume that a locked storage unit is a legal or secure place for them. The related guide, What Should I Not Store in a Storage Unit?, explains moisture, compression, and material limits before storage. Check local laws, the facility policy, and any required storage rules.
Food and Other Perishable Goods
Fresh and opened food can spoil, smell, leak, and attract insects or rodents.
Avoid storing:
- Fresh produce
- Meat
- Dairy products
- Frozen food
- Open snack bags
- Pet food
- Birdseed
- Flour
- Rice
- Cereal
- Food in thin cardboard boxes
Some facilities allow unopened shelf-stable food in sealed containers. However, even dry food can attract pests. Check the rental rules before storing any food.
Plants, Animals, or People
A storage unit is not a safe place for living things.
Never store:
- Houseplants
- Pets
- Farm animals
- Insects kept as pets
- Aquariums with live animals
- A person’s living or sleeping space
Storage units do not provide safe ventilation, plumbing, temperature control, or emergency access. Living or working inside one may also violate the rental agreement or local rules.
Items You Should Avoid Storing Even When They Are Allowed
Some items may not be banned, but they are still poor choices for long-term storage.
Cash and High-Value Items
Avoid storing cash, jewelry, rare coins, expensive watches, and small valuable collectibles.
Storage units can be damaged by fire, water, pests, or break-ins. Insurance may also have limits or exclusions for high-value property.
A secure bank or specialized storage service may be a better choice.
Important Papers and Irreplaceable Records
Do not place your only copy of an important document in a storage unit.
Examples include:
- Birth certificates
- Passports
- Property deeds
- Wills
- Tax records
- Family records
- Insurance documents
- School records
- Medical records
- Business records
Keep original documents in a secure, accessible place. Digital copies can also help, but they may not replace an official original.
Family Photos and Sentimental Items
Printed photos, letters, scrapbooks, and keepsakes can be damaged by moisture, heat, pests, or fading.
A climate-controlled unit may lower some risks, but it cannot remove them all. Keep truly irreplaceable items somewhere you can monitor more closely.
Medications and Medical Supplies
Heat, cold, and moisture can affect medications and some medical supplies. Storage units also may not stay within the temperature range listed on the product label.
Follow the storage instructions on the package or ask a pharmacist where an item should be kept.
Wet, Damp, or Dirty Items
Never pack an item while it is wet or even slightly damp.
Moisture can lead to:
- Mold
- Musty smells
- Fabric stains
- Rust
- Wood swelling
- Cardboard damage
- Pest problems
Dry tents, outdoor cushions, towels, blankets, rugs, and clothing fully before packing them.
Clean kitchen items, furniture, and appliances so food crumbs and grease do not attract pests.
Scented Candles and Wax Items
Candles, wax decorations, crayons, and similar items may soften or melt in a hot unit. Melted wax can stain boxes, furniture, and fabric.
A climate-controlled unit may be safer, but you should still place wax items inside sealed, leak-resistant containers.
Learn what never to store in plastic containers, including hot food, chemicals, damp fabric, fuel, batteries, leather, and valuable papers long term.
Electronics
Computers, televisions, speakers, game systems, and other electronics may be damaged by heat, humidity, dust, or condensation.
Before storing electronics:
- Back up important files.
- Remove batteries when the manufacturer allows it.
- Use the original box when possible.
- Keep items off the floor.
- Avoid wrapping electronics tightly in plastic if moisture could become trapped.
- Consider climate-controlled storage.
Check the product manual for storage temperature guidance.
Battery-Powered Items
Loose batteries can leak, swell, or corrode. Lithium-ion batteries may also be restricted by the facility.
Remove replaceable batteries from toys, clocks, remotes, flashlights, and small appliances. Do not store damaged, swollen, or recalled batteries.
Check the storage facility’s rules for e-bike batteries, power-tool batteries, battery backups, and other large rechargeable batteries.
Refrigerators and Other Appliances
Appliances can be stored, but they must be clean and completely dry.
Before storage:
- Remove all food.
- Defrost the appliance.
- Drain water lines and trays.
- Clean the inside.
- Let it dry fully.
- Leave the door slightly open during storage.
A closed refrigerator can trap moisture and develop strong odors or mold.
Can You Store Mattresses and Bedding?
Mattresses, pillows, blankets, comforters, and sheets can usually go into a storage unit. They need careful preparation to prevent moisture, odors, stains, and pest damage.
Mattresses
Clean and dry the mattress before storage. Use a mattress storage bag that fits the mattress size.
Do not place heavy boxes on top. Long-term pressure can damage the comfort layers and change the mattress shape.
Store the mattress flat when possible. Some mattress makers may allow short-term upright storage, but long-term upright storage can cause certain mattresses to bend or sag. Check the manufacturer’s guidance.
Comforters and Blankets
Wash bedding only when the care label allows it. Dry every layer completely before packing.
A thick comforter can feel dry outside while still holding moisture in the center. Give bulky bedding enough drying time.
Use a clean storage container or breathable bedding bag. Avoid crushing down comforters for a long period, especially if they contain down or a lofty synthetic fill. Loft means the soft, raised thickness of the filling.
Pillows
Clean pillows according to their care labels. Make sure they are fully dry before storage.
Do not place heavy items on them. Compression can flatten the filling or change the shape.
Foam pillows may be sensitive to heat. Check the manufacturer’s storage instructions before placing one in a unit without climate control.
Sheets and Duvet Covers
Clean sheets and duvet covers are easier to store than bulky bedding. Fold them loosely and place them in a sealed plastic bin or a clean fabric storage bag.
Do not use cardboard boxes if the unit is damp or likely to have pests.
Items That May Need Climate-Controlled Storage
Climate-controlled storage helps reduce large swings in temperature and humidity. It does not create perfect indoor conditions, but it can be a better choice for sensitive items.
Consider it for:
- Wood furniture
- Leather furniture
- Mattresses
- Foam pillows and toppers
- Electronics
- Musical instruments
- Books
- Artwork
- Photographs
- Vinyl records
- Important collections
- Seasonal bedding
- Delicate clothing
Climate control may be especially useful in places with high humidity, extreme heat, freezing weather, or frequent temperature changes.
How to Decide Whether an Item Is Safe to Store
Ask these questions before placing anything in the unit:
- Is it banned by the rental agreement?
- Can it burn, explode, leak, or release fumes?
- Can it spoil or attract pests?
- Is it alive?
- Is it wet, damp, or dirty?
- Can heat or cold damage it?
- Would losing it be impossible to fix?
- Does it need regular maintenance?
- Does the manufacturer list special storage conditions?
- Will your insurance cover it?
When the answer raises a concern, choose another storage location or ask the facility manager before move-in.
Simple Storage Unit Safety Tips
Use sturdy containers and label each one clearly. Keep boxes off the concrete floor with shelving or pallets allowed by the facility.
Do not block the entrance with heavy furniture. Leave a narrow walkway so you can reach items without unloading the whole unit.
Place bedding, clothing, and fabric items only in clean, dry containers. Avoid using thin grocery bags, which can tear and trap moisture.
Check the unit from time to time when possible. Look for leaks, pests, odors, damaged boxes, and signs of moisture.
Frequently Asked Questions
Can you put food in a storage unit?
Most storage facilities do not allow fresh, open, or perishable food. Even dry food can attract insects and rodents. Check the rental agreement before storing any unopened shelf-stable food.
Can you store a propane tank in a storage unit?
Usually not. Propane tanks are pressurized and flammable, so many facilities ban them even when they seem empty. Ask the facility where an empty tank can be handled or stored safely.
Can you sleep in a storage unit?
No. Storage units are not designed or approved as living spaces. They do not provide safe ventilation, plumbing, emergency exits, or suitable temperature control.
Can you store a mattress in a storage unit?
Yes, in most cases. The mattress should be clean, completely dry, covered with a fitted storage bag, and kept away from moisture. Store it flat when possible and check the manufacturer’s guidance.
Can you store clothes and blankets in plastic bins?
Yes. Clean and fully dry them first. Use sturdy bins with secure lids, but avoid packing damp fabric because sealed containers can trap moisture and odors.
Can you store electronics without climate control?
You can, but heat, cold, humidity, dust, and condensation may cause damage. Back up important files, remove batteries when appropriate, and check the manufacturer’s storage guidance.
What happens if you store a prohibited item?
The facility may end the rental agreement, remove access to the unit, contact authorities, or take other action allowed by the contract and local law. Prohibited items may also affect insurance coverage.
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