Soda makers may only have a few days worth of CO2 left in reserve.

Markets in the United Kingdom have been facing an uphill battle in recent months as stocks of certain foods and drinks begin to dwindle and fewer warehouse workers are on hand to make deliveries. These problems have been caused primarily by the COVID-19 pandemic making international trade and travel more difficult, as well as the Brexit process cutting the UK off from EU resources.

One sector that has been heavily hit by these problems is the soft drink sector. According to a statement from the British Soft Drinks Association to Bloomberg, UK-based soda manufacturers are running dangerously low on carbon dioxide, to the point that they only have enough in reserve to conduct business for about a day. Currently, many CO2 suppliers are overburdened by needs for the gas, as it serves a variety of food-related functions. As such, these suppliers have been keeping their orders to no more than 24 hours in advance, which means the soda manufacturers genuinely don’t know if they’ll have CO2 in a day’s time. The UK also can’t import CO2 from from European suppliers, as those suppliers are prioritizing member nations of the EU, which no longer includes the UK.

Environmental concerns have also made it more difficult to obtain CO2. CF Industries Holdings Inc., a fertilizer manufacturer, permanently closed all of their UK-based plants last week in response to rising natural gas prices. Without the gas that’s produced as a byproduct of fertilizer manufacturing, the UK is running out of domestic options.

As a direct result of these problems, the supplies of many popular soft drinks are in question. Scotland’s most popular drink, Irn-Bru, could be facing widespread shortages in the near future if the situation doesn’t improve soon.