As several European borders limit travel to stop the spread of COVID-19, two of the world's biggest pulp makers say transportation logjams are delaying shipments of the raw material — the only ingredient in the toilet paper that people are hoarding to weather quarantines.

In March, countries including Norway, Germany and Spain shut their borders to nonessential travel. Freight can still pass through, but enforcing the new rules holds up deliveries to cargo trains and vessels bound for warehouses and factories in North America and China.

As a result, Finland's Metsa Fibre and Sweden's Sodra Cell International said truckloads of pulp going through Europe are getting caught in traffic jams for hours, or even a couple of days.