Airborne cool chain
Have you ever wondered how many tonnes of perishable foods take to the air each year? Recent data show that of the 19-25 million tonnes of air freight transported annually, perishables, including fruit, vegetables, fish, meat, cut flowers and medicines, account for 2.5-3 million tonnes. Airports have developed sophisticated facilities for temperature-sensitive goods and airlines are adopting strategies to ensure that aircraft are used to full capacity at all times. Few planes are equipped with cold storage facilities, so temperature-controlled refrigerated containers cooled using dry ice and ventilation are now used; batteries provide energy for these containers and the temperature range can be adjusted from -20 to +20°C. The Coolchain Association (http://www.coolchain.org), founded in 2003, focuses on standards, certification and monitoring of refrigerated goods.