Living Bomb limit

Does the limit on Living Bomb apply to the target (i.e. max 1 active seed per target) or to the total amount of active seeds (across all targets)? When slotted into CoC/CoA it seems to be spawning infusions all the time, but not sure if that's because I'm killing stuff fast enough for individual bombs to be placed and triggered one after another or because multiple are active at the same time (across various targets).