If, however, the spot is unchanged and has not spread in the skin but has faded, it is a swelling from the burn, and the priest shall pronounce him clean; it is only a scar from the burn.

火斑若在原处止住，没有在皮上发散，乃是发暗，是起的火毒，祭司窑定他为洁净，不过是火毒的痕迹。

youdao

With this, the scanning beam is not directed at any single spot, but moves around, so the plastic does not burn.

ECONOMIST: Recycling