Crumpets have become the latest casualty of the carbon dioxide (CO2) shortage which is hitting production throughout the UK's food and drink industry - but why is CO2 so important?

Producer Warbutons admitted it is making "nowhere near" its usual amount of the British staple because of a shortage in the gas and pub chain Wetherspoons has reported similar issues with stocking drinks.

Meanwhile, the trade journal Gas World has described the shortage as the "worst supply situation to hit the European carbon dioxide (CO2) business in decades".

But we breathe in oxygen and breathe out carbon dioxide, so surely it can't be that difficult for producers to get hold of, can it?

  • Why is there a shortage in CO2?

The shortages are understood to have been caused by a longer than usual break in production of ammonia, one of the key sources of food grade CO2 in Europe - which is used to carbonate drinks and preserve some packed fresh foods.

Most of the CO2 used by the food and drink industry is a by-product created when producing ammonia, a compound used for fertiliser.

In the UK, three out of five fertiliser plants that produce CO2 have been closed for routine maintenance. This would usually not cause a problem, however many big mainland European fertiliser plants have also closed down.

Simply put, the crisis is down to bad timing - fertiliser plants don't usually all cease production at the same time.

  • Why do we need CO2?

Warburtons says it is making 'nowhere near' its usual amount of crumpets because of a lack of CO2. Credit: PA

In what might come as a surprise to some, CO2 is pretty much essential when it comes to the UK's food and drinks industry.

From putting the fizz in drinks such as beer to extending the shelf life of many packed fresh foods such as meat and poultry, CO2 is a vital ingredient for getting products on the shelf.

The gas is pumped into the packaging of perishable goods to make them last longer, making lettuce an unlikely casualty of the crisis - but that's just the tip of the iceberg.

Lettuce is perhaps one of the more unlikely casualties of the gas shortage. Credit: PA

Carbon dioxide is also seen as one of the most humane ways to stun animals before slaughter and animal rights campaigners have warned pigs and chickens are likely to suffer if abattoirs run out of the gas.

The gas is also needed to produce dry ice, something needed for transporting perishable goods.

Animal rights campaigners say pigs will suffer if slaughterhouses run out of CO2. Credit: PA
  • Will BBQ meat and beer still be available for the World Cup?

It may seems as though the reality of shops running out of products is a way off but producers have issued some serious warnings to customers and have even asked the government for help.

A spokeswoman for the British Retail Consortium (BRC) said CO2 supply issues remained and it was likely the "mix of products available may be affected".

The British Meat Processors Association (BMPA) said it was “very concerned” that "supply is running out and it’s pretty tight for some people".

Some pub chains reported they had temporarily run out or were short of John Smith's, Strongbow, Amstel and Birra Moretti as disruption to supplies of CO2 began to take effect at the bar.

There is concern that World Cup BBQ parties could seriously be at risk. Credit: AP

The British Beer and Pub Association (BBPA) said stocks of the gas remained low but brewers were "working their socks" off to ensure the beer continued to flow.

The Food And Drink Federation (FDF) has urged officials to work out possible solutions and in response, the government has started to collect information from across the sector.