Hypo on tarmac is fine if it’s older and wetherd but on very new tarmac it can bleach it , I think it was so one on here did a plastic clean using hypo and it dripped on the drive and left pale marks , we did a drive clean and the run off went onto the pavement and we rinsed it down and to this day you can still see the lighter colour , I’ll try and remember ti take some pictures of it next time we are there .