This cartridge is used for salutes and simulated fire in 76mm guns.
The cartridge contains a charge of sodium nitrate black powder, loosely assembled in a primed brass or steel cartridge case. Slightly recessed in the mouth of the cartridge case is a plastic closing cup which retains the loose charge. Earlier models of this cartridge contain a bagged charge of potassium nitrate black powder.
No information about hazardous components.
Nothing else to see.