That depends on a lot more than the weight of the explosive.
The type of explosive
How it's packed
The material being fragmented
The shape of the fragments
To give you an illustration, a Mark II grenade (the "pineapple" one) has an effective injury radius of about 10 meters, but someone could still be injured by one 100 meters away.
Half a Mile
Tiny fragments can travel all the way around the earth from a 1-pound explosion.
how far can fragments travel from a 1 pound explosion
they travel how far they want to
Depending on the material, it will be 1/2 mile CBRNE - 1/2 mile
half a mile
If the projectiles are small enough, they can travel around the world from a 1-pound explosion.
half a mile
half a mile
It depends upon the size of the fragments. Very small fragments can be blown into the air and carried by air currents around the world.
5 miles depending on what explosive it is and what debris is in it
half a mile