To protect your whites, (jeans and dresses) spray them once over with Scotch Guard to create a barrier between the fabric and any possible stains. Unfortunately, white clothing requires great care, so avoid washing them with any other clothes in the washer. Your best bet? Wash them after every two or three uses and either take them to the dry cleaners or hand wash them with mild, colorless soap. Never apply bleach directly on your clothes, unless they are 100% cotton. If your whites have the slightest percentage of any other fabric, such as spandex or polyester, forego the bleach.
Feel free to breathe a little easier.