17. • The growth of bacteria from the cockroach
after 24 hours
18. • Washing hands with solid and liquid soaps
• Soaps are not designed to kill microbes.
• The help to wash them of skin, better than
water alone.
• The solid soap had more bacteria living on it
than the liquid soap, which had none
19. • Cutting boards
• Cutting boards are another source of bacteria
and should be washed thoroughly after each
use.
20. • Missed washing hands areas
• Fluorescent dye is applied to the hands before washing.
Following washing, the hands are examined under UV
light for any traces of dye. Compare your handwashing
with the diagram that shows commonly missed area