What source of law determined the procedures Mary was supposed to follow in handling and disposal of blood and urine samples in her department Homework Help

Mary Small is a nurse for Providence Hospital.  Part of her job is to remove blood and urine samples from patient’s rooms.   Last week, Mary cut her hand (while wearing gloves) working with a patient who was badly injured.  She put the bloody towels in the property identified trash can as directed. She later developed an infection.   What source of law determined the procedures Mary was supposed to follow in handling and disposal of blood and urine samples in her department? Explain you answer fully.