Two people have been hospitalised after a chemical spill at Dunedin Airport’s Wastewater Treatment Plant sent smoke into the air.

Fire and Emergency New Zealand said four crews responded to the spill shortly before midday today.

They said the spill contained a mix of hyperstat chloride and 99% sulphuric acid and had caused smoke to flow into the air.

Hato Hone St John said they sent one ambulance to the incident.

Two people were taken to Dunedin Hospital in a moderate condition.

A Dunedin Airport spokesperson said staff noticed an unfamiliar odour, which alerted them to the spill.

“Fenz and St John staff were in attendance in accordance with the airport’s HAZCHEM response process,” the spokesperson said.

“Two staff members who were onsite were taken to Dunedin Hospital for checks and observation as a precautionary measure.”

A Dunedin Airport spokesperson said staff noticed an unfamiliar odour, which alerted them to the spill. Photo / Supplied

The spokesperson said they had been in contact with both people, who had “not suffered any significant impact”.

“We have since heard from them both, and they are doing fine.”

They said Fire and Emergency was “neutralising and decontaminating the site, as is standard practice”.

“An investigation will be conducted in accordance with policy and procedure, but our focus for now is on our staff and the site.”

There was no impact on airport operations.

More to come ...