Cold Chains: Moving Food and Vaccines

How temperature-controlled supply chains keep food and medicines safe, why gaps in them cause waste, and what it takes to build them.

Many products must be kept cool, or frozen, from the moment they are made or harvested until they are used. Fresh fruit, vegetables, milk, meat, fish and many vaccines and medicines all spoil if they get too warm. The network of refrigerated storage and transport that keeps them safe is called a cold chain.

Links in the chain

A cold chain includes:

Pre-cooling produce right after harvest.
Cold storage warehouses.
Refrigerated transport: trucks, rail wagons and shipping containers with cooling units.
Retail refrigeration in shops.
Temperature monitoring to make sure products stay in the safe range throughout.

A break at any point, such as a truck waiting in the sun or a power cut at a warehouse, can ruin the product.

Cold chains and food loss

Where cold chains are weak, a large share of perishable food is lost before it reaches consumers. The Food and Agriculture Organization estimates that around 13 percent of food produced globally is lost between harvest and retail. For fruits and vegetables, losses are especially high in countries with limited cold storage. In India, studies have found significant losses of fruits and vegetables after harvest, with poor cold storage and transport among the causes.

A mango's journey

A farmer harvests mangoes. Without cooling, they ripen quickly and may spoil within days, forcing the farmer to sell immediately at whatever price local traders offer. With access to a pack house and cold storage, the farmer can hold the mangoes for longer, ship them to distant cities or export markets, and sell when prices are better. The cold chain raises both the farmer's income and the amount of food that reaches consumers.

Vaccines

Vaccines typically must be kept between 2 and 8 degrees Celsius, and some need much colder storage. Some COVID-19 vaccines required ultra-cold freezers at around minus 70 degrees Celsius, which made them very hard to distribute in places without specialised equipment. India’s electronic vaccine intelligence network, eVIN, tracks vaccine stocks and storage temperatures across the country’s immunisation system.

Building cold chains

Cold chains are expensive, especially where electricity is unreliable. Solutions include solar-powered cold rooms for farmers, shared cold storage run by cooperatives, and government support for refrigerated transport. Economists see cold chain investment as a way to raise farm incomes, reduce waste and improve public health at the same time.

Thinking food waste only happens in kitchens

In rich countries, much food is wasted by shops and households. But in many developing countries, most losses happen earlier, between the farm and the market, often because of missing cold storage and transport. Solving that requires investment in the supply chain.

Key takeaways

A cold chain keeps perishable food and medicines cool from production to use.
A single break in the chain can ruin products.
Weak cold chains cause large food losses, especially of fruits and vegetables.
Cold chains are vital for vaccines, and investment in them can raise farm incomes and cut waste.