How close can my plants be to my Led light?

Can they touch the bulb?

LEDS CAN burn the plants too , as well as other lights. The glass panel also gets very hot. Do the simple hand method , place your hand between light and canopy top. If you can't keep your hand there comfortably , then your plants can't either.

When I run LED 18" - 24" is the " normal height range , but I have moved to 8" with out issues. ( I have my vegging autos around 10" ) and they dig it. As they get larger I keep the 18" height.

I let my plants touch the LED when they run out of vertical space. Sometimes they burn sometimes they do not.
If the LED panel you are using has a lens then there is a "sweet spot" - if you are not able to keep the plant in that "sweet spot" it is not a big deal - keep on keepin' on.

I have the kind led k300 and a seedling around 4 days old. I have my light around 12 inches.