"The New Zealand Army takes its health and safety responsibilities seriously and an investigation into the incident will be launched," he added.
The spokesman refused to answer further questions until the investigation is complete.
Inquiries to Canterbury District Health Board were referred back to NZDF.
EOD operators are technical specialists trained at "neutralising all types of explosive hazards and threats", the Defence Careers website says.
"This means you will be extensively trained and equipped to detect, identify, render safe and dispose of munitions and explosives – such as Unexploded Ordnance (UXO), and Improvised Explosive Devices (IEDs), including those that involve Chemical, Biological, Radiological and Nuclear (CBRN) materials."
The incident comes just weeks after a New Zealand soldier was hospitalised after being shot in the shoulder at the Tekapo Military Training Facility.
He was treated by army medics at the scene before being transported to Fairlie by a Defence Force ambulance, where he was airlifted to Christchurch Hospital.
The private was a member of the Royal New Zealand Infantry Regiment's 2nd 1st Battalion based at Burnham Military Camp.
He was taking part in a night live-firing exercise when the incident took place.