We present a new test of modified Newtonian dynamics ( MOND ) on galactic scales , based on the escape speed in the Solar Neighbourhood .
This test is independent from other empirical successes of MOND at reproducing the phenomenology of galactic rotation curves .
The galactic escape speed in MOND is entirely determined by the baryonic content of the Galaxy and the external field in which it is embedded .
We estimate that the external field in which the Milky Way must be embedded to produce the observed local escape speed of \sim 550 { km } { s } ^ { -1 } is of the order of a _ { 0 } / 100 , where a _ { 0 } is the dividing acceleration scale below which gravity is boosted in MOND .
This is compatible with the external gravitational field actually acting on the Milky Way .