Storage Unit Safety: Things You Should Never Store

Storage facilities can be a lifesaver when you're moving, decluttering, or simply running out of space at home. It offers a flexible and secure way to temporarily or permanently store belongings—but that doesn’t mean you can put just anything inside. Certain items are not only unsuitable but can actually be hazardous, damaging, or illegal to store.

Ignoring these secure storage guidelines can lead to health risks, expensive clean-ups, or even breaches of your storage agreement. In this guide, we’ll walk you through four key categories of things you can’t store in a storage unit—and what to do with them instead.

Perishable Foods and Organic Materials

Why Food and Plants Don’t Belong in Storage

Storing perishable and organic items in a storage unit is one of the most common mistakes people make during a move or declutter—yet it’s one of the most damaging. These items are biologically active, which means they change over time, attract pests, emit odours, and break down. Even in climate-controlled units, they pose serious health, safety, and legal risks.

A typical storage facility is not equipped to handle rotting food or decomposing plant matter. Units are often sealed, dark, and not ventilated like your home pantry or garden shed—creating an environment where bacteria, mildew, and pests thrive.

What Counts as Perishable or Organic?

The category is broader than most people realise. If it grows, decomposes, or attracts pests, it doesn’t belong in a storage unit. Here's what to avoid:

• Fresh fruits and vegetables – including potatoes, onions, and garlic

• Frozen or refrigerated food – will spoil quickly once the temperature changes

• Leftovers or partially eaten items – even if sealed, they’re a rodent magnet

• Packaged snacks and cereals – can still be compromised by heat or humidity

• Canned or jarred foods – may explode or rust in fluctuating temperatures

• Pet food and birdseed – contains fats and oils that spoil over time

• Houseplants and garden plants – will die without light and air

• Compost, soil, and potting mix – often contain fungi, bacteria, and organic matter

• Dried flowers and wreaths – while decorative, they are still biologically degradable

The Real Risks of Storing Organic Material

Storing food or plants might seem harmless at first glance, but the consequences can be serious and expensive. Here are reasons why you shouldn't store food in a storage unit:

1. Pest Infestation

Food odours can attract rodents, cockroaches, ants, and flies. Once inside, pests can chew through boxes, fabrics, and insulation—not only ruining your property but also contaminating adjacent units.

2. Mould and Mildew

Organic materials hold moisture and break down over time, which can create the perfect breeding ground for mould. Once mould spores spread, they can damage wood, paper, textiles, and electronics—potentially affecting all items stored in your unit.

3. Foul Odours

Rotting food and decaying plants emit strong odours that are difficult to remove and may permeate porous materials like clothing, furniture, or bedding.

4. Contract Violation

Most storage facilities strictly prohibit storing perishable or organic items. If discovered, you may face penalties, eviction from the facility, or be held financially responsible for any damage caused to other units.

5. Health Hazards

Decomposing organic material can release harmful bacteria and spores into the air, posing respiratory and hygiene risks, especially in enclosed spaces.

Smarter Alternatives

Fortunately, avoiding these issues is easy with some forward planning. Here’s what you can do:

• Donate sealed, non-expired food to a local food bank or shelter. Many organisations will even pick up your donation.

• Compost fresh or expired items using a home composting bin or community composting service.

• Give plants to family or friends, or consider using a plant-sitting service during your move.

• Inspect all containers, boxes, and bins to ensure no accidental food remnants are packed—especially in kitchen boxes.

• Store pet food separately in a cool, dry area of your home where it can be monitored or consumed quickly.

Flammable or Hazardous Materials

What Makes These Items Dangerous?

When it comes to storage, safety is the top priority—and that’s why all facilities strictly prohibit the storage of flammable, combustible, or toxic substances. These materials pose a very real threat to life, property, and the entire facility. Even a small leak or spark can lead to catastrophic fires, chemical burns, or poisonous fumes, especially in confined, unventilated spaces.

Storage units are not designed to accommodate temperature fluctuations, chemical reactions, or pressurised containers. Most lack fire suppression systems suited for chemical fires, making the risk of explosion or toxic exposure dangerously high.

Common Examples of Prohibited Hazardous Materials

Even everyday household products can fall into the category of flammable materials storage restrictions. Below are items you should never store in a storage unit:

• Gasoline, kerosene, and diesel fuel – highly flammable and vapor-emitting

• Paints, thinners, and varnishes – can ignite at low temperatures or with minimal spark

• Propane tanks and butane bottles – pressurised and extremely volatile

• Fireworks and explosives – unpredictable and illegal to store in non-certified facilities

• Household cleaning agents and bleach – may release toxic fumes if spilled or mixed

• Fertilisers and pesticides – often contain combustible or environmentally toxic elements

• Bulk lithium-ion batteries – fire risk due to thermal runaway or puncture damage

• Aerosols, spray paints, or gas canisters – combustible under heat or pressure

Legal, Financial, and Insurance Implications

Storing hazardous materials doesn’t just risk safety—it can lead to severe legal and financial consequences. Here’s what happens if you store banned items:

Violation of Your Storage Agreement

Every legitimate storage facility has a contract clause that prohibits flammable and hazardous materials. Breaching this agreement may result in:

• Immediate eviction from the facility

• Financial liability for any damage caused

• Denial of access to your storage unit

Loss of Insurance Coverage

Even if you’ve purchased insurance for your unit, your claim may be denied if prohibited items are discovered—especially after damage or fire. In fact, many insurance providers will void your coverage altogether if dangerous goods are stored.

Criminal and Civil Liability

Depending on the material and local laws, you could face criminal charges for improper chemical storage. If your stored items cause harm to others—whether from fire, exposure, or contamination—you may be legally responsible for:

• Medical bills

• Property damage

• Facility shutdown and cleanup costs

Safer Alternatives

You don’t have to risk it. If you have hazardous materials on hand while moving or decluttering, consider these better options:

1. Use Your Local Council’s Hazardous Waste Drop-Off Programs

Most cities and councils offer designated hazardous waste disposal services for:

• Paints, solvents, and varnishes

• Garden and pool chemicals

• Fuel, oil, and gas canisters

• Batteries and e-waste

• Cleaning supplies and bleaches

2. Transport with Care (If Absolutely Necessary)

If you absolutely must move hazardous goods:

• Transport only small quantities

• Use original containers with safety labels intact

• Never store these items in a hot car or confined vehicle

• Follow transport guidelines outlined by your local state or territory

3. Ask Your Storage Provider for a Prohibited Items List

Most storage facilities, like that of Chess Moving, provide a detailed list of things you can’t store in a storage unit. If you’re unsure about a product—especially less obvious items like aerosols or pesticides—ask the staff directly. Being proactive helps avoid contract breaches and keeps your belongings and others' safe.

High-Value or Irreplaceable Items

Why These Belong in Your Personal Care—Not a Storage Unit

While most storage facilities offer security features such as gated access, CCTV, and individual locks, no facility is completely immune to theft, fire, flood, or accidental damage. That’s why you should never place valuables in storage units. If something is one-of-a-kind or deeply personal, it simply isn’t worth the risk—even if you’re storing for a short period.

Storage units are ideal for furniture, clothing, or excess household goods—but not for sentimental keepsakes, financial assets, or legal documents that are impossible to replace.

What Should Never Go in a Storage Unit

Here are the most commonly stored items that shouldn’t be, and the reasons why they’re better off elsewhere:

Jewellery & Precious Metals

• Gold, silver, platinum, diamonds, and fine jewellery are attractive targets for thieves.

• These items often exceed the per-item claim limit on storage insurance policies.

• High humidity or poor packaging may cause tarnish or damage.
  
  

Cash, Banknotes & Rare Coins

• Storage insurance does not cover cash—even in sealed containers.

• Rare coins are valuable and sometimes irreplaceable if damaged or lost.

• Even locked units can be accessed by bolt-cutters or staff under certain circumstances.
  
  

Legal & Personal Documents

• Many documents are required to open bank accounts, get medical care, or prove identity.

• Losing them may delay legal processes or even cause visa issues if relocating abroad.

• They are easily damaged by moisture, mold, or pests.

Heirlooms, Antiques, & Collectibles

• Sentimental value can’t be insured.

• Paper, fabric, wood, and artwork degrade quickly in storage without climate control.

• Fire or flood can wipe out generations of family history in minutes.

Electronics & Digital Storage Devices

• USBs, hard drives, SD cards, or backup servers can become corrupted due to heat, dust, or humidity.

• Devices often contain sensitive data like financial info, family photos, or intellectual property.

Safer Alternatives for Storing Irreplaceables

If you're relocating, downsizing, or in-between homes, here are more secure ways to keep your valuables protected:

Invest in a Fireproof & Waterproof Safe at Home

• Choose a safe rated for fire resistance (UL 350) and water submersion.

• Ideal for: passports, backup drives, marriage certificates, cash, jewellery.

• Portable models available for apartment dwellers or frequent movers.

Rent a Bank Safe Deposit Box

• Safe deposit boxes are climate-controlled and housed inside bank vaults.

• Best for: jewellery, rare documents, gold bars, small collectibles.

• Typically cost $50–$300/year, depending on size and bank.

Leave with Trusted Family or Friends

• If you're moving overseas or can’t take everything with you:

  • Leave heirlooms or legal documents with someone you trust.

  • Use tamper-proof containers and detailed inventories.

  • Set clear expectations and timelines for return.

Digitise & Encrypt Sensitive Information

• Scan paper documents and store in secure cloud platforms with two-factor authentication.

• Back up on encrypted USBs and keep in your personal care.

• Useful if you’re travelling or moving to a new country and need access on the go.

Wet or Damp Items

Why Moisture Is One of the Most Destructive Elements in Storage

When preparing for storage—whether short- or long-term—most people focus on security and space, but one critical issue is often overlooked: moisture. Damp or wet items can introduce a chain reaction of problems, leading to permanent damage to your belongings and potentially impacting other units in a shared facility.

Moisture doesn’t need to be visible to cause trouble. A slightly damp towel, leftover condensation in a washing machine, or humid camping gear can create the perfect breeding ground for mould, mildew, and corrosion. In a closed environment with little airflow, like a storage unit, that risk increases exponentially.

Items Commonly Stored While Still Wet (and Why You Shouldn't)

Even responsible movers accidentally store items that retain moisture. Here's a list of common culprits—and the hidden dangers they bring:

• Washing machines & dishwashers - Water remains in hoses, drums, and filters.

• Wet laundry & towels - Often packed fresh from the dryer, but still hold humidity.

• Camping gear, sleeping bags, & tents - Exposed to morning dew, rain, or condensation.

• Gardening tools & hoses - Store water internally and carry mud or organic debris.

• Rain gear (coats, boots, umbrellas) - Frequently packed away without airing out.

• Coolers or esky boxes - Trap condensation even after emptying.

These items might appear dry to the touch but can retain internal moisture that leads to:

• Fungal growth (mould, mildew, and spores)

• Rust and corrosion of metal components

• Warping or rotting of wooden furniture and paper-based items

• Lingering, musty odours that affect entire storage units

• Structural box failure—particularly cardboard—when it softens from humidity

How to Prevent Moisture Damage in Storage

Taking a few proactive steps before and during packing can save thousands in damage and protect irreplaceable items:

Deep Clean and Drain Appliances

• Run an empty cycle with a cleaning agent before unplugging.

• Detach hoses and filters, wipe down all surfaces.

• Leave doors open for 24–48 hours to air dry completely before sealing.

Fully Air-Dry Textiles and Equipment

• Dry camping gear, towels, and clothes outdoors when possible.

• Avoid packing “fresh from the dryer” as even minimal humidity can cause trouble.

• Lay out items on a clothesline or drying rack overnight.

Use the Right Containers

• Switch from cardboard to airtight plastic storage bins.

• These repel moisture and help contain humidity.

• Use breathable cotton bags for items that shouldn’t be sealed in plastic (e.g., leather, wool).

Add Moisture Absorbers

• Place silica gel packs, baking soda, or calcium chloride absorbers in boxes and bins.

• For larger units, hang desiccant pouches or use portable dehumidifiers if allowed.

Do a Final Moisture Check

• Before sealing a box or bin, feel every item with your hand.

• Shine a flashlight into appliances to detect hidden water pools.

• Avoid vacuum-sealing any item that hasn’t been completely aired out.

Conclusion: Check Before You Store

Not everything is storage-friendly—and assuming otherwise can lead to expensive mistakes. From perishable food that attracts pests, to hazardous chemicals that risk fire, to high-value items that are best kept in your personal care, it’s important to know what shouldn’t go into your unit. Damp or wet belongings, in particular, can quietly destroy not only your items but those stored nearby.

Before loading up your storage space, take the time to do a final check. Make sure everything is clean, dry, safe, and permitted under your storage facility’s guidelines. And when in doubt? Ask Chess Moving. We can supply a clear list of things you can’t store in a storage unit, offer packing tips, and even help you choose a better storage solution when needed.

For enquiries, visit https://www.chessmoving.com.au/ or call us on 13 14 69.