Woolworths Bomaderry and Coles Nowra were seen with gaps in their shelves on Friday, as many Shoalhaven residents received communication that supply chain issues are the main cause.

Woolworths CEO Brad Banducci said delays to store deliveries are due to the "magnitude" of supply chain workers in isolation amid the spread of Omicron.

"When you're shopping with us at the moment, you might unfortunately have noticed gaps on shelf, or substitutions in your online order," he said in an email to shoppers on Friday.

"This is because of the number of people in our supply chain in isolation - from suppliers to truck drivers and distribution centre team members - which in turn is causing material delays to store deliveries."

The email said Woolworths is experiencing COVID-driven absences of more than 20 per cent in distribution centres and 10 per cent in stores.

Mr Banducci reassured there is "more than enough stock in the system and plenty more coming".

"We also have good supply within each 'category' of product...so it really helps if you can be flexible with the choices you make," he said.

This comes as Coles introduced buying limits on stock on Thursday. The items with limitations are:

The latest national cabinet meeting resulted in changes to testing requirements for truck drivers, removing the need for a PCR test every seven days.

Prime Minister Scott Morrison said the decision would ensure food distribution networks could continue to operate.

"We need truckies keeping on trucking...to keep moving things around," he said on Thursday.