The topic we’re going to discuss today is the storage of perishable goods in warehouses. This isn’t a problem that every warehouse faces, but it’s an issue that can’t be ignored, as many industries around the world still need to store goods that can spoil easily.
So, in the following sections, I’ll tell you everything you need to know about storing perishables!
What is a Perishable Item?
From a professional standpoint, a simple way to define a perishable item is any product that can deteriorate or lose its effectiveness due to changes in time, temperature, humidity, or other factors.
They have strict requirements for storage and transport. If these conditions aren’t met, they’ll “go bad” very quickly. For this reason, managing perishable goods is one of the most challenging tasks in warehouse logistics.
Main Categories and Specific Examples
Perishable items are a broad category, covering almost every aspect of our daily lives. Here are some of the main types and specific examples:
- Food and Beverages: This is the most common type of perishable.
- Fresh Produce: Fresh meat, seafood, milk, eggs, fruits, and vegetables. These need to be refrigerated or frozen to stay fresh.
- Processed Foods: Baked goods (like bread and cakes), dairy products (like yogurt and cheese), and some juices without preservatives.
- Specialty Foods: Items like chocolate and candy have a relatively longer shelf life, but they can melt or spoil if stored at high temperatures.
- Pharmaceuticals and Medical Supplies: Many medicines have strict storage requirements, as improper conditions can reduce their effectiveness or even make them toxic.
- Vaccines: Most vaccines must be kept at low temperatures to maintain their potency and efficacy.
- Biologics: Insulin and blood products, for example, require precise temperature control.
- Certain Chemical Reagents: Reagents used in labs or for medical testing often have specific requirements for light, temperature, and humidity.
- Flowers and Plants:
- Cut Flowers and Potted Plants: Once cut, flowers have a very short shelf life and need to be kept moist at a suitable temperature to prevent wilting.
- Seeds: The seeds of certain crops can lose their ability to germinate if not stored properly.
- Other Categories:
- Some Cosmetics: Certain skincare products that contain natural active ingredients or don’t have many added preservatives.
- Film and Photo Paper: These require low-temperature storage to prevent a loss in image quality.
Why Do They Spoil?
The “spoilage” of perishable goods is primarily caused by a few key factors:
- Temperature: This is the most significant factor causing spoilage.
- High Temperatures: Accelerate the growth of bacteria and other microorganisms, causing food to spoil. They can also deactivate drugs or cause products like chocolate to melt and deform.
- Low Temperatures: For some products, like certain vegetables, freezing can destroy their cellular structure, leading to a mushy texture after thawing.
- Humidity:
- High Humidity: Easily leads to mold growth, causing food and medicine to become damp and moldy.
- Low Humidity: Can cause products like fresh fruits and vegetables to dehydrate and wilt.
- Time: This is an intrinsic property of perishables.
- Natural Degradation: Even in ideal storage conditions, many perishables will naturally degrade over time, with changes in flavor, color, and texture.
- Enzymatic Action: After fruits and vegetables are harvested, internal enzymes continue to work, causing them to ripen and eventually rot.
The Unique Challenges of Perishable Goods Warehousing
Strict Temperature Control
Perishables have extremely high temperature requirements, because temperature directly determines their “shelf life.”
- The Temperature Danger Zone: This is a crucial concept to remember. For most perishable foods, the “danger zone” is typically between 4°C and 60°C (40°F and 140°F). In this temperature range, bacteria multiply at an exponential rate, causing food to spoil quickly and even produce toxins. Therefore, we must ensure that perishables, especially fresh foods, are kept either below 4°C in a refrigerated or frozen state, or above 60°C in a heated state, to avoid this “danger zone.”
- The Importance of the Cold Chain: The cold chain refers to a continuous series of operations—from production, processing, storage, and transport to sales—that keep an item within a specific low-temperature range. It’s like giving perishables an “anti-spoilage suit,” ensuring they stay at a safe temperature all the way from the farm to the table, or from the pharmaceutical plant to the hospital. If the cold chain is broken, even for a few minutes, the goods can be ruined.
Complex Inventory Management
Perishable items don’t just fear heat, they also “fear” getting old. Their inventory management is more complex than that of regular goods.
- FIFO (First-In, First-Out) vs. FEFO (First-Expired, First-Out):
- FIFO (First-In, First-Out): The oldest items in the warehouse are the first ones to be shipped out. This works for most general merchandise, like clothes or furniture.
- FEFO (First-Expired, First-Out): The items with the earliest expiration date are the first ones to be shipped out. This principle is specifically for perishables. For example, if you have two cases of milk that came in last month but one expires three days before the other, the one with the earlier expiration date must be shipped out first. For perishables, FEFO is more important than FIFO because it directly impacts the product’s effectiveness and safety.
- Economic Losses from Spoilage: Because of their short shelf life, perishables have a high risk of spoilage. If not managed properly, a large number of goods can expire and be thrown away, leading to huge financial losses. This includes not just the cost of the goods themselves, but also the costs of storage, labor, and transport. Therefore, accurate inventory forecasting, a high turnover rate, and strict adherence to the FEFO principle are key to reducing spoilage and increasing profitability.
Hygiene and Safety
Imagine a warehouse storing fresh meat, live fish, fruits, and vegetables, and maybe even some medicines that are sensitive to odors. If not managed well, problems can easily arise.
- Preventing Cross-Contamination:
- Zoning: This is a fundamental principle. Different types of perishables must be stored in separate areas, or at least on physically separated racks. For instance, raw meat and ready-to-eat foods (like cooked items or fruit) must never be stored together. Bacteria from raw meat can spread through liquids or the air, contaminating food that is ready to be consumed, which poses a serious food safety risk.
- Separate Equipment: Tools and equipment used for handling different types of goods must be kept separate. For example, the knives, trays, and gloves used for raw meat should not be used for fresh vegetables.
- Odor Control: Some perishables, such as fish or certain spices, have strong odors. If stored with items that easily absorb smells (like cheese or butter), it can affect the quality of the goods. Therefore, products with different odors should be stored separately, using independent ventilation systems if necessary.
- Difficulty of Cleaning and Maintenance:
- Frequent Cleaning: Perishable goods warehouses need to be cleaned and sanitized more often than regular warehouses. The presence of biological materials, liquids, and residue makes them breeding grounds for bacteria, mold, and pests. Floors, racks, walls, and even ceilings require regular deep cleaning.
- Professional Cleaning Agents: You must use food-grade or medical-grade cleaning and sanitizing agents to ensure they effectively kill germs without causing chemical contamination to the goods.
- Equipment Maintenance: Equipment like cold rooms, refrigerated cabinets, and ventilation systems need regular professional maintenance and calibration to ensure they are always in optimal working condition. Any equipment failure can cause temperature fluctuations, leading to widespread product spoilage.
How Racks Are Key to Perishable Goods Warehouses
Rack Types Designed for Cold Storage
In low-temperature environments, traditional racks can warp or rust. Therefore, specialized rack systems designed for cold storage are used to maximize space and improve efficiency:
- Pallet Shuttle Racking:
- How it works: It uses an electric shuttle car to automatically store and retrieve goods deep inside the rack. The forklift simply places the pallet at the entrance of the rack, and the shuttle car automatically transports it to the designated location.
- Advantages: This system significantly reduces the time forklifts spend inside the cold room, lowering energy consumption and reducing the operator’s exposure to the cold environment. It’s perfect for storing a large volume of a limited number of product types and naturally supports the FEFO (First-Expired, First-Out) or FIFO (First-In, First-Out) principle, as you can set the shuttle’s operation mode as needed.
- Mobile Racking:
- How it works: Traditional racks are installed on movable bases, so there are no fixed aisles between them. An operator can use a control panel to open the required aisle, while the other racks remain tightly packed together.
- Advantages: The biggest benefit of mobile racking is its incredibly high space utilization, which can save up to 50% of warehouse floor space. In a cold room where every inch counts, this can significantly reduce operating costs.
How Racks Support FIFO/FEFO
The racking system is the physical foundation for implementing the FEFO principle.
- Gravity Flow Racking:
- How it works: Goods are loaded from one side of the rack and, with the help of gravity, slide automatically to the other side’s exit.
- How it supports FEFO: This is a perfect FIFO solution. The first item loaded (which is usually the one with the earliest expiration date) will be the first to reach the exit, ensuring that items are shipped out in the correct order.
- Double-Deep and Drive-In Racking:
- Although these systems typically support LIFO (Last-In, First-Out), we can still achieve FEFO with a precise inventory management system. For example, the system can strictly record the expiration date of each batch of goods and instruct the operator to prioritize picking the batch with the earliest expiration.
Choosing the Right Rack Material
The humid environment of a cold room demands higher-quality rack materials.
- Galvanized Steel: By coating steel with a layer of zinc, you can effectively prevent rust and corrosion. It’s a cost-effective and durable option.
- Stainless Steel: This is the top choice for cold room racks. Stainless steel not only has excellent corrosion resistance, but its smooth surface is also easy to clean, effectively preventing bacterial growth. It’s the ideal choice for industries with the highest hygiene standards, such as medicine and food.
Conclusion
While storing perishable goods can be highly complex, as long as you set up your warehouse strictly according to the type of goods you’re handling, I don’t think you’ll face too many problems with your warehouse operations.
If you don’t want to invest too much effort into this area, you can also find a professional supplier to help you with the solution—like us! So, if you have any racking needs for your warehouse, feel free to contact us!
