Foodstuffs is urging supermarket shoppers to take a chill pill as shelves are stripped bare thanks to panic buying.
North Island chief executive Chris Quin says the amount of products being sold is equivalent to a population of twice the size of New Zealand.
Foodstuffs owns and supplies Pakn'Save, New World, and Four Square supermarkets.
Quin told The AM Show on Friday that employees are working around the clock to meet demand.
"I just spoke to a crew that started at midnight and are finishing now," he said.
"We've got people who have worked six days, 11 hour days in a row.
"We worry a lot about their safety and wellbeing."
Quin said New Zealanders were shopping like a nation with a population of between five and 10 million people.
"We just need to keep stressing - the issue that we're facing into is a demand issue, not a suppy issue," he said. "We have the products in the country - we make the products in New Zealand. We can keep people looked after, we just need to calm down a little how we're going about it.
"The challenge is just getting the stock out through the supply-chain to our stores as fast as it's being bought."
Quin said the pace at which people are shopping is unnecessary.
"What we need people to do is just shop normally and if they do that we'll have an easier experience together," he told The AM Show.
"We're in a different position to many other countries in the world that we're seeing the panic from.
"The spread of that stuff on social media probably isn't helping people feel settled about that."
Since the coronavirus COVID-19 pandemic took hold, panic-buying in turn has become a pandemic. Photos posted to social media show large queues for supermarkets, bare shelves, and even fistfights over food across the Tasman.
The situation has become so serious in Australia that New South Wales police has increased its security presence in supermarkets.
On Wednesday, Prime Minister Scott Morrison had a blunt message for those hoarding products.
"It is not sensible, it is not helpful and, I've got to say, it has been one of the most disappointing things I have seen in Australian behaviour in response to this crisis.
"There is no reason for people to be hoarding supplies from fear of a lockdown or anything like this."
New Zealand Prime Minister Jacinda Ardern has also called for calm at home.