Seven people were injured on Wednesday while working to dispose of ordnance at the Wehrtechnischen Dienststelle 91 near Meppen in Emsland.
Five members of the armed forces and two external explosives experts had to be brought to a hospital in Meppen for observation in the evening.
Nobody was seriously injured, said a spokesman for the fire department in Emsland.
Presumably the ammunition experts inhaled irritant gases.
According to the fire department spokesman, munitions that were no longer transportable were routinely blown up on the Bundeswehr premises.
Then it should be checked whether all weapons have been disposed of.
A first employee complained about respiratory problems, after which others reported complaints.
The rescue service of the Bundeswehr and the local fire brigade were then notified.
The hospital then notified the district fire brigade because the seven patients first had to be cleaned before they could be brought to the clinic.
A decontamination route had been built.
The Wehrtechnische Dienststelle 91 in Emsland is used for weapons and ammunition testing.
Three years ago there was a week-long moor fire on the site that broke out during a weapon test.