UPDATED 11.07AM Warkworth Countdown is now operating as usual after a chemical fire forced evacuations just after 5:30am.

The fire happened when tubs containing a chloride product burst in the bin and caused the blaze.

One staff member was treated on site after complaining of sore eyes and a burning sensation on their face following the fire.

A spokesperson for Countdown said they will investigate this further to ensure it doesn't happen again.

A member of Countdown's safety team and a senior operations manager is investigating on site.

Auckland Council's pollution line was called because there was concern run-off could go into drains.