A Hato Hone St John spokesperson said the Tuakau incident was reported at 9.45am.
“One ambulance has responded, the crew assessed and treated one patient in a minor condition at the scene.”
A WorkSafe New Zealand spokesperson said the watchdog had been notified of the incident and was making initial inquiries.
GrainHub has been contacted for comment.
Maryana Garcia is a Hamilton-based reporter covering breaking news in Waikato. She previously wrote for the Rotorua Daily Post and Bay of Plenty Times.