Before any test some steps are taken for the safety of ships and aircraft.
A notice is issued to all aircraft through ICAO channels called NOTAM which describes the effecitive danger zones and it advises all aircraft to stay out of these danger zones.
I am attaching a sample NOTAM that is issued for an upcomingGSLV launch
A0802/17 (Issued for VOMF PART 1 OF 2) - GSLV-F09 ROCKET LAUNCH FM SHAR RANGE,SRIHARIKOTA WILL TAKE PLACE AS PER FLW DETAILS. .
LAUNCH PAD COORD: 13 43.2N 080 13. 8E NO FLT IS PERMITTED OVER THE DNG ZONE. A. DANGER ZONE -1 IS A CIRCLE OF 10NM AROUND THE LAUNCHER B. DANGER ZONE -2 IS A RECTANGULAR AREA BOUNDED BY: 1150N 08515E 1235N 08525E 1215N 08625E 1130N 08615E
C. DANGER ZONE -3 IS A RECTANGULAR AREA BOUNDED BY: 1035N 08915E 1115N 08925E 1100N 09005E 1020N 08955E D. DANGER ZONE -4 IS A RECTANGULAR AREA BOUNDED BY: 0750N 09515E 0930N 09515E 0930N 09605E 0750N 09605EROUTES AFFECTED IN CHENNAI FIR ARE: N571, P761, N877, W20, A465, P762, L510, P628, L645, Q10, Q11, Q23, Q24, V3, V4, V9 & V11
CLOSURE/ALTERNATE ROUTINGS: 1)N571 NOT AVBL BTN DORAM AND BIKEN ALTN ROUTE: DORAM-DCT-MMV VOR-DCT AVGIR-DCT BIKEN-N571
(BIDIRECTIONAL) 2)P761 NOT AVBL MMV VOR AND PPB VOR ALTN ROUTE: MMV VOR - DCT-AVGIR- DCT- BIKEN- DCT -PT.B 0943N
08935E - DCT PPB VOR (BIDIRECTIONAL) 3)N877 NOT AVBL BTN LAGOG AND ORARA ALTN ROUTE: LAGOG-DCT-POINT Z 1200N 08951E-DCT-ORARA (BIDIRECTIONAL) 4)W20 NOT AVBL BTN MMV VOR AND BODEL ALTN ROUTE: MMV VOR-TR319/139DEG- 53NM -TTP VOR TR357/177DEG - 81NM- BODEL (BIDIRECTIONAL) 5)
A similar notice is issued to all sea vessels called NAVAREA warning advising all vessels to stay out of danger zones.
The launch teams make sure the missiles don't fly over civilian areas. There is a self destruct mechanism on missiles to destroy if they go out of the intended flight path.
Theses missiles are not radioactive, they use regular mostly safe propellants and carry conventional explosives.