Tango shoes' outsoles are made of different materials like suede, chroma, real leather, etc...
Suede outsoles are not good against concrete or asphalt outside, or on any other rough surface, obviously.
If your shoes have suede outsoles don't wear them outside, not even to get off the car and enter somewhere.
There may be water on the street that could wet the outsoles making them unfit for dancing, for instance....
Or there may be small pebbles, dirt or dust that can get impregnated/encased into the sole, rendering it improper for dancing in a short while.
However, there are other types of outsoles like chroma, or Italian 'Vero Cuoio' (real leather), which Tango shoes could be fitted with. These, in certain circumstances, can be used outside as well, but it would still take a toll on the shoes' smoothness while dancing, so try to avoid wearing them outside if/whenever possible.
For special occasions like open-air, outside milongas, various parties/events, try using one of your older pairs that you are not wearing while dancing in milongas anymore.
Alternatively ask a cobbler to fit your older shoes with a new outside-able outsole and voila, you can use them outside safely.
We have many clients, wearing end-of-range sizes like #34 or #41/42 (ladies), or #39 or #46/47 (men), who confessed they buy our shoes for day-to-day usage as well, given they are so very comfortable and otherwise they can hardly find such beautiful models available from other brands (types of shoes, other than Tango made-for) anyway.
Especially for tiny feet ladies (#34) who usually buy shoes from children's shops, where they do not find high-heels shoes, who use Tango shoes on the street or at the office, mostly.