Hello and thank you for choosing Jade rug pads. Our Rubber Anchor pads are definitely safe and one our best pads to use on a hardwood floor. It will not stain or harm your floor. However, with that being said, because that area of the floor will be covered and protected from natural sunlight, the rest of the surrounding floor may get discolored from the part that is covered and protected by the rug and the pad.

I'll explain a little further:

Most tend to think that it's the actual padding itself that will discolor a floor, but it's due to actual sunlight. The rug and the pad covers the area, but the surrounding floors will be exposed to the natural sunlight that shines through windows and doors.

I hope this helps!