The worker fell into a boiling solution of water and 1% caustic soda, according to a spokesman for Greater Manchester Fire and Rescue Service.
The man, aged 37, suffered heat and chemical burns to his arms and back. He was taken to the Rochdale Infirmary. He was later transferred to Royal Oldham Hospital to be treated for his burns.
Two fire engines from Greater Manchester Fire and Rescue Service attended the incident at the factory on Whitelees Road, which took place at 7am in the morning.
Boiling water
The caustic soda and boiling water were being used to clean food preparation areas at the plant.
No one else was involved in the incident.
A spokeswoman for McCormick said: “We can confirm an accident took place yesterday (November 27) at our factory in Littleborough which resulted in one employee being hospitalised. An incident team was set up immediately and investigations are in progress. We are in close contact with his family and are co-operating fully with the relevant authorities.”