Great question. If you wash the pants at 40 degrees that won't remove all the microorganisms, sadly – however (here's the good news) a wash time of 90 minutes at 40 degrees has shown a reduction of many pathogens between 99,99% and 99,99999% depending on type of organism. (The stuff you don't want is basically all gone, is what we're trying to say. See ya, organisms!)