hand hygiene, is the act of cleaning one's hands with soap and water to remove microorganisms., or other harmful and unwanted substances stuck to the hands. Drying of the washed hands is part of the process as wet and moist hands are more easily recontaminated. If soap and water are unavailable, hand sanitizer that is at least 60% alcohol in water can be used if hands are not visibly excessively dirty or greasy. Hand hygiene is central to preventing the spread of infectious diseases in home and everyday life settings.

The importance of hand washing for human health – particularly for people in vulnerable circumstances like mothers who had just given birth or wounded soldiers in hospitals – was first recognized in the mid 19th century by two pioneers of hand hygiene: the Hungarian physician Ignaz Semmelweis who worked in Vienna, Austria and Florence Nightingale, the English "founder of modern nursing". At that time most people still believed that infections were caused by foul odours called miasmas.

BBASS discusses the sterile theatre and describes how to scrub up, dry hands and put on a gown. There are simple principles that must be adhered to but often forgotten.  The action and ritual of washing the hands can be used as an opportunity for clearing the mind and setting focus on the task in hand.