'Harmful' in the Bible

The priest is to reexamine the contamination on the seventh day. If it has spread in the fabric, the warp, the woof, or the leather, regardless of how it is used, the contamination is harmful mildew; it is unclean.

He is to burn the fabric, the warp or woof in wool or linen, or any leather article, which is contaminated. Since it is harmful mildew it must be burned up.

the priest must come and examine it. If the contamination has spread in the house, it is harmful mildew; the house is unclean.