She said she felt fine about the incident and would be put under the shower if needed.
Hawke's Bay Area Commander Ken Cooper said fire crews were called to the post shop on Napier Rd just after 9am as an unknown substance spilled out of a package.
His staff contained the scene until the substance could be identified.
"While it's an unknown substance we can't take any risks with public safety so we're erring on the side of caution until we can identify the product."
When it was, it was found to be a non hazardous cooking material.
Mr Cooper said such callouts were rare and it was good practice for fire crews working together with police and council staff.