Collocations for harmless - adj.

appear, be, look, seem, sound | make sth, render sth
chemical wastes which have to be rendered harmless

consider sth

absolutely, completely, perfectly, quite, totally | almost, virtually | enough
He looks harmless enough.

comparatively, fairly, pretty, reasonably, relatively | apparently, seemingly
a small and seemingly harmless creature

environmentally

to
The substance is harmless to people.