Mildew, a type of mold, is often the cause of musty smells on towels and clothing. Breathing mold spores on musty clothing can be hazardous to your health. Mold and mildew love damp, dark areas to grow. That makes moist clothing left in any dark area, like a clothes hamper or poorly ventilated closet, an ideal breeding ground for the microscopic invaders. Musty odors can also form on laundry left in the washing machine. Here's how to remove musty and mildew odors on fabric with OdoBan.