Four people have been taken to hospital after a chemical released in Kirkby.
Emergency services were called to Suez Recycling and Recovery in the Knowsley Industrial Estate at around 10.25am on Thursday (November 12).
Merseyside Fire and Rescue confirmed that an unknown chemical linked to animal feed had entered the process of the Woodward Road recycling centre.
All staff were evacuated as an immediate safety protocol with 19 workers reported to have suffered mild irritation after a dust plume filled the site.
Four were also taken to hospital for further assessment as a precautionary measure while the Fire Service left the scene at 1.17pm.
Victoria Crabtree, Suez’s UK regional manager, said: “Earlier this morning, incorrectly disposed of hazardous waste subsequently identified as an irritant was discovered.
“The facility bulks up household and commercial waste from across Merseyside and transfers it to an energy-from-waste facility via train where it is burnt and generates electricity.
“The site was evacuated as a precautionary measure and emergency services were contacted, with all staff on site being assessed by medical teams.
“We are thankful for the swift response of the emergency services and will assess resuming operations once it is safe to do so.”