When it started, no one else smelled it. Now it is so bad by eyes burn and nose runs.I had plumbers check for blockage; a neighbor checked the roof vents and my furnace man went around with a poison gas detector. It comes and goes; the last 2 days it comes often. One other mystery; every once in a while there is a perfume smell for a few minutes not from my washing; I do not use scented detergent and do not use a fabric softener.