Fire crews were deployed to the scene. Hospital parking at the front of the department was also closed. The hospital said that the incident occurred after a “patient presented after exposure to an unknown chemical substance”.
Nottinghamshire Fire and Rescue Service was called to the hospital at 5.10am.
Crews were sent from across the county and from neighbouring Leicestershire.
According to a social media post from Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust, the rest of the hospital was unaffected.
The fire and rescue response was scaled down after first being deployed and the hospital has now reopened.
When the incident first occurred, the hospital said: “Please note, colleagues are currently dealing with an incident within the Emergency Department at Bassetlaw Hospital, which means the service is temporarily closed.
“The area directly in front of the main entrance is also not available for parking – alternative arrangements have been made within the triangle car park.
“We are currently working closely with partners and will update shortly when this matter has been resolved.”
The hospital said that the “appropriate decontamination procedures” have now been followed, reassuring the public that “no additional harm occurred”.
In an update posted to Facebook at 9.15am, the hospital said “We anticipate Bassetlaw Hospital’s Emergency Department to reopen at 9.30am.
“The service was temporarily closed earlier this morning as a patient presented after exposure to an unknown chemical substance.
“The appropriate decontamination procedures were followed and colleagues worked with the relevant agencies.
“Following final checks, the Emergency Department will safely reopen – no additional harm occurred during this incident and we thank colleagues for their response and our communities for their patience in this matter.”
The hospital reopened at 10am.
Announcing the end of the incident on social media, it said: “Bassetlaw Hospital’s Emergency Department has now reopened!
“Phew, so how was your morning?”