A cold chain is a

supply chain A supply chain is a complex logistics system that consists of facilities that convert raw materials into finished products and distribute them to end consumers or end customers, while supply chain management deals with the flow of goods in distri ...

that uses

refrigeration Refrigeration is any of various types of cooling of a space, substance, or system to lower and/or maintain its temperature below the ambient one (while the removed heat is ejected to a place of higher temperature).IIR International Dictionary of ...

to maintain perishable goods, such as pharmaceuticals, produce or other goods that are temperature-sensitive. Common goods, sometimes called cool cargo, distributed in cold chains include fresh agricultural

produce In American English, produce generally refers to wikt:fresh, fresh List of culinary fruits, fruits and Vegetable, vegetables intended to be Eating, eaten by humans, although other food products such as Dairy product, dairy products or Nut (foo ...

, seafood,

frozen food Freezing food Food preservation, preserves it from the time it is prepared to the time it is eaten. Since early times, farmers, fishermen, and trappers have preserved grains and produce in unheated buildings during the winter season. Freezing foo ...

photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the ...

, chemicals, and

pharmaceutical product A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via inhalation, injection, smoking, ingestion, ...

s. The objective of a cold chain is to preserve the integrity and quality of goods such as pharmaceutical products or perishable good from production to consumption. A well functioning, or unbroken, cold chain requires uninterrupted sequence of refrigerated production, storage and distribution activities, along with associated equipment and logistics, which maintain a desired low-temperature interval to keep the safety and quality of perishable or sensitive products. Unlike other goods or merchandise, cold chain goods are

perishable Decomposition is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is esse ...

and always en-route towards end use or destination. Adequate cold storage, in particular, can be crucial to prevent

food loss and waste The causes of food going uneaten are numerous and occur throughout the food system, during production, processing, distribution, retail and food service sales, and consumption. Overall, about one-third of the world's food is thrown away. A s ...

History

Mobile

with

ice Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 ° C, 32 ° F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally oc ...

from the

ice trade The ice trade, also known as the frozen water trade, was a 19th-century and early 20th-century industry, centering on the east coast of the United States and Norway, involving the large-scale harvesting, transport and sale of natural ice, and ...

began with

reefer ship A reefer ship is a refrigerated cargo ship typically used to transport perishable cargo, which require air conditioning, temperature-controlled handling, such as fruits, meat, vegetables, dairy products, and similar items. Description ''Types ...

s and

refrigerator car A refrigerator car (or "reefer") is a Refrigeration, refrigerated boxcar (U.S.), a piece of railroad rolling stock designed to carry perishable freight at specific temperatures. Refrigerator cars differ from simple Thermal insulation, insulated b ...

s (

icebox An icebox (also called a cold closet) is a compact non-mechanical refrigerator which was a common early-twentieth-century kitchen appliance before the development of safely powered refrigeration devices. Before the development of electric refrig ...

es on wheels) in the mid-19th century. The term ''cold chain'' was first used in 1908. The first effective cold store in the UK opened in 1882 at

St Katharine Docks St Katharine Docks is a former dock in the St Katherine and Wapping ward of the London Borough of Tower Hamlets. It lies in the East End of London, East End on the north bank of the River Thames, immediately downstream of the Tower of London an ...

. It could hold 59,000 carcasses, and by 1911 cold storage capacity in London had reached 2.84 million carcasses. By 1930 about a thousand refrigerated meat containers were in use which could be switched from road to railway. Mobile mechanical refrigeration was invented by

Frederick McKinley Jones Frederick McKinley Jones (May 17, 1893 – February 21, 1961) was an American inventor, entrepreneur, engineer, winner of the National Medal of Technology, and an inductee of the National Inventors Hall of Fame. He innovated mobile refrig ...

, who co-founded

Thermo King Thermo King is an American manufacturer of transport temperature control systems for refrigerator trucks and trailers, refrigerated containers and refrigerated railway cars along with heating, ventilation and air conditioning systems for bus and ...

with entrepreneur Joseph A. "Joe" Numero. In 1938 Numero sold his Cinema Supplies Inc. movie sound equipment business to

RCA RCA Corporation was a major American electronics company, which was founded in 1919 as the Radio Corporation of America. It was initially a patent pool, patent trust owned by General Electric (GE), Westinghouse Electric Corporation, Westinghou ...

to form the new entity, U.S. Thermo Control Company (later the

Thermo King Corporation Thermo King is an American manufacturer of transport temperature control systems for refrigerator trucks and trailers, refrigerated containers and refrigerated railway cars along with heating, ventilation and air conditioning systems for bus and ...

), in partnership with Jones, his engineer. Jones designed a portable air-cooling unit for trucks carrying perishable food, for which they obtained a patent on 12 July 1940, subsequent to a challenge to invent a refrigerated truck over a 1937 golf game by associates of Numero's, Werner Transportation Co. president Harry Werner, and United States Air Conditioning Co. president Al Fineberg, This technology has been frequently in use since the 1950s, when it was most often used for preserving animal-based cells or tissue. As medical breakthroughs, such as in cancer treatment, have taken place, the demand for cold chain systems has grown. The

COVID-19 pandemic The COVID-19 pandemic (also known as the coronavirus pandemic and COVID pandemic), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), began with an disease outbreak, outbreak of COVID-19 in Wuhan, China, in December ...

and its associated

vaccinations Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating ...

, have caused vastly increased need.

Uses

Cold chains are common in the food and

pharmaceutical Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the ...

industries and also in some chemical shipments. One common temperature range for a cold chain in pharmaceutical industries is , but the specific temperature (and time at temperature) tolerances depend on the actual product being shipped.

Produce

Unique to fresh produce cargoes, the cold chain requires to additionally maintain product specific environment parameters which include air quality levels (carbon dioxide, oxygen, humidity and others).

Vaccines

The cold chain is used in the supply of

vaccines A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an ag ...

to distant clinics in hot climates served by poorly developed transport networks. Vaccines can lose their efficacy if cold chain management fails. Disruption of a cold chain due to war may produce consequences similar to the

smallpox Smallpox was an infectious disease caused by Variola virus (often called Smallpox virus), which belongs to the genus '' Orthopoxvirus''. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (W ...

outbreaks in the Philippines during the

Spanish–American War The Spanish–American War (April 21 – August 13, 1898) was fought between Restoration (Spain), Spain and the United States in 1898. It began with the sinking of the USS Maine (1889), USS ''Maine'' in Havana Harbor in Cuba, and resulted in the ...

, during which the distributed vaccines were inert due to lack of temperature control in transport. For vaccines, there are different types of cold chains. There is an ultralow, or deep freeze, cold chain for vaccines that require -70 degrees C, such as the Ebola and Pfizer–BioNTech COVID-19 vaccines, and some animal vaccines, such as those for chickens. Next the frozen chain requires -20 degrees C. Varicella and zoster vaccinations require this level. Then the refrigerated chain, which requires temperatures between two and eight degrees C. Most flu vaccinations only require refrigeration. In 2020, during the

, vaccines being developed may need ultracold storage and transportation temperatures as cold as , requiring what has been referred to as a "colder chain" infrastructure. This creates some issues of distribution for the

Pfizer vaccine Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered at The Spiral in Manhattan, New York City. Founded in 1849 in New York by German entrepreneurs Charles Pfizer (1824–1906) and Charles ...

. It is estimated that only 25 to 30 countries in the world have the infrastructure for the required ultracold cold chain.

Validation

Sunwell fish packing pumpable slurry ice

The cold chain distribution process is an extension of the

good manufacturing practice Current good manufacturing practices (cGMP) are those conforming to the guidelines recommended by relevant agencies. Those agencies control the authorization and licensing of the manufacture and sale of food and beverages, cosmetics, pharmaceutic ...

(GMP) environment that all drugs and biological products are required to follow, and are enforced by the various health regulatory bodies. As such, the distribution process must be validated to ensure that there is no negative impact to the safety, efficacy or quality of the drug substance. The GMP environment requires that all processes that might impact the safety, efficacy or quality of the drug substance must be validated, including storage and distribution of the drug substance. A cold chain can be managed by a

quality management system A quality management system (QMS) is a collection of business processes focused on consistently meeting customer requirements and enhancing their satisfaction. It is aligned with an organization's purpose and strategic direction ( ISO 9001:2015). ...

Temperature data logger A temperature data logger, also called temperature monitor, is a portable measurement instrument that is capable of autonomously recording temperature over a defined period of time. The digital data can be retrieved, viewed and evaluated after it h ...

s and

RFID Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When tri ...

tags help monitor the temperature history of the truck,

reefer container A refrigerated container or reefer is an intermodal container (shipping container) used in intermodal freight transport that is capable of refrigeration for the transportation of temperature-sensitive, perishable cargo such as fruits, vegetab ...

, warehouse, etc. and the temperature history of the product being shipped. They also can help determine the remaining

shelf life Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or no longer on a s ...

. Also, temperature sensors may need to be

National Institute of Standards and Technology The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of p ...

(NIST) traceable depending on the body monitoring the cold chain.

History

Uses

Produce

Vaccines

Validation

See also

Sources

References

Further reading