Skip to main content
Controlled Atmosphere

Controlled Atmosphere Offerings in the Container Shipping Industry

Did you know that Purfresh offers both controlled atmosphere and ozone atmosphere services for fresh perishable fruit and produce transported in refrigerated ocean containers?


There are many different and sometimes similar definitions for the term controlled atmosphere, (AKA… “CA” in English or “AC” in Spanish, atmósfera controlada). The same can be said for the term modified atmosphere or “MA”. Both of these quality shelf life extension processes are well known in the fresh fruit and produce industry. Some institutions will define controlled atmosphere as managing unique levels of CO2 and O2 when fruit or produce is kept in bulk storage, and define modified atmosphere as the unique composition of the internal atmosphere for fruit or produce being stored in bags or packages, but there are many definition variations that can be found.


In the world of overseas refrigerated container shipping there are many shippers, importers, ocean carriers, and 3PL’s that can sometimes interpret controlled atmosphere (CA), and modified atmosphere (MA) very differently. The consistent and common thread for most controlled atmosphere technologies is that they all manage some form of increased CO2 (carbon dioxide) and decreased O2 (oxygen), from the normal levels of breathable air, that we see at sea level, 21% oxygen and 0.04% carbon dioxide. The process of increasing CO2 and decreasing O2 as a controlled atmosphere process, when fruits and produce are transported in ocean containers, can result in shelf life extension benefits for several different perishable cargo types.


Controlled atmosphere systems for refrigerated ocean containers dates back more than 20 years, and over that period there have been several different systems available that attempt to manage increased CO2 and decreased O2, inside the ocean container, during overseas voyages. Over these 20+ years there have been more than twelve different brand names of controlled atmosphere systems that have provided CA environments for refrigerated ocean containers. Some of these brand name CA systems have different processes to increase the CO2 and decrease the O2 inside the ocean containers, and some are actually identical systems, with identical manufactures, but simply branded differently.


One of the latest and most modern controlled atmosphere systems in the ocean container industry is Purfresh. What makes Purfresh different is that in addition to increased CO2 and decreased O2, Purfresh is the only system in the industry that adds ozone, or O3, into the container controlled atmosphere environment, and also transmits in real-time, internal container environmental readings to the cloud. Purfresh utilizes dual satellite and GSM modems to provide continuous, independent container level monitoring, of the controlled atmosphere environment, while the containers are at sea or on land.


Purfresh offers two different model systems, one for controlled atmosphere with ozone, and the other model for ozone (O3) only atmosphere, inside of the refrigerated ocean container. Both models offer real-time monitoring during the ocean voyage, of the fruit or produce air environment, as it travels to is overseas destination.


Some of the primary cargos that benefit from controlled atmosphere in refrigerated containers are asparagus, avocados, bananas, blueberries, melons, cut flowers, kiwi, mangos, papayas, stone fruit, and snow peas. Other cargos that have little to no benefit from controlled atmosphere, but do have significant quality shelf life extension benefits from ozone O3 atmosphere are bell peppers, citrus, garlic, ginger, table grapes, onions, pineapples, and potatoes or sweet potatoes.


Historically Purfresh has been most well-known for its significant commercial expertise as an “ozone” atmosphere supplier, but now more recently, Purfresh is becoming well known for its modern and sophisticated controlled atmosphere technology.


More information about Purfresh, controlled atmosphere, ozone atmosphere, and real-time monitoring can be found at:

Or email your questions to: