A 55-year-old man has been rushed to Christchurch Hospital with serious injuries believed to be chemical burns.
Emergency services were called to Westland Milk Products plant on Westland Pl in Rolleston at around 1:30pm on Thursday.
A St John spokesperson told Newshub the man's injuries are understood to be caused by a chemical. The exact chemical is unknown.
Westland Milk Products spokesman Steve Attwood told Newshub the man had been working on the ultra-high temperature processing filling line and was chemically burnt.
He said the plant has been closed and the incident will be investigated.
A WorkSafe spokesperson told Newshub they are also investigating the incident.