CO2 plays a vital role in the UK food and drink industry and a fall in supplies risks severe disruption to supply chains that are already under huge pressure from rising inflation.

CO2 is used in product packaging, fresh food delivery, and adding fizz to soft drinks and beer. It's also used by farmers to humanely slaughter animals before they enter the market.

The UK industry is on high alert after US company CF Industries announced that soaring energy costs had forced it to pause operations at its fertiliser plant. CO2 is a by-product of fertiliser production and the UK gets over 40% of its CO2 from the firm.

Four key products affected by the shortage:

1. Fresh meat
   CO2 is used in all aspects of the meat supply chain, from stunning animals before slaughter to chilling and processing. It is also used in the shipment of meat as dry ice.
   
2. Cold cut meat
   Cold cuts are preserved similarly to fresh meat, with what's called modified atmospheric packaging. Essentially, CO2 and other gases are pumped in and oxygen is removed to give the product longer shelf life.
   
3. Pizza and other frozen products
   During the production of frozen foods, everything from pizza to chicken breasts move through "carbon-dioxide-filled tunnels to be frozen" quickly. The proper amount of CO2 is required to avoid hot spots that could translate to mold and bacteria growth.
   
4. Beer
   The most obvious one - CO2 is a vital ingredient in the beer production process, from putting frothy bubbles in brews to blocking oxidization that makes beer taste stale.