Elimination of the source of contamination is fundamental to the prevention and control of biological hazards. Engineering controls such as improvement of ventilation, partial isolation of the contamination source, installation of negative pressure and separate ventilation and airconditioning system (e.g. in medical wards for infectious diseases) and the use of ultraviolet lamps can help contain the spread of contaminants. If the contact with biological hazards cannot be prevented, the employees must use personal protective equipment and adhere strictly to the practice of personal hygiene. The personal protective equipment includes masks, gloves, protective clothing, eye shields, face shields and shoe covers