A 62-year-old worker is in a critical condition after falling into a vat of diluted potassium cyanide.
An investigation into the accident is under way
Two colleagues at metal plating specialists Karas Industries Ltd, in Leigh, Greater Manchester, pulled the man from the vat.
Firefighters in chemical protection gear removed the man's clothes and hosed him down to decontaminate him before he was taken to hospital.
Cyanide can cause fatal cardiac arrests if ingested.
An investigation has been opened and the Health and Safety Executive (HSE) informed.
The man, who comes from the Leigh area, fell into the chemical vat shortly before 0400 GMT.
The two colleagues who pulled him out were treated at the scene for shock.