Compressed nitrogen? That's very odd - do you have any pictures? I'm a fire protection engineer and haven't heard of them, but that certainly doesn't mean they don't exist (obviously). Now nitrogen is commonly used to charge ABC and BC type dry chemical extinguishers because it's "dry" and doesn't mess up the powder. If these are "charged with nitrogen", then I'd be very careful, because they very well may be dry chemical = BAD for electronics.

You can tell by the nozzle also-a bell horn nozzle is one for rapidly expanding gasses (CO2, etc.), straight nozzles the same size as the hose would be for liquids and powders (Halon, water, dry chemical etc.).

If they are really nitrogen, then there might be an issue with temperature; you might have to get colder (upon release) than CO2 to compress it properly, don't really know. Otherwise they'd be fine.