Using Human Papillomavirus (HPV) detection tests for cervical cancer screening and managing HPV-positive women – a practical guide / Activity 9

Infection prevention – Preparation of 0.5% chlorine solution



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Preparation of 0.5% chlorine solution from dry powder (household bleach)

To prepare chlorine solution of a particular strength, the following formula may be used to calculate the required amount of dry powder (household bleach):
g/L = [% of dilute solution/% of concentrate of active ingredient (calcium hypochlorite) of dry powder] × 1000
For example, to make 0.5% chlorine solution from a dry powder of 35% calcium hypochlorite: [0.5%/35%] × 1000 = 14.2 g. Hence, 14.2 g of dry powder will be required to prepare 1 L of solution.







Materials required for preparation of 1 L of 0.5% chlorine solution:

  • Plastic bucket (medium-sized) and mug
  • Wooden stirrer
  • Teaspoon
  • Bleaching powder kept in an airtight container
  • Water: 1 L
  • Utility gloves
  • Laboratory apron

Preparation:

  • Put on a laboratory apron, and wear utility gloves.
  • Take 1 L of clean water in the plastic bucket.
  • Measure 14.2 g (~3 teaspoons) of bleaching powder and put it into the bucket.
  • Stir with the wooden stirrer until a milky white solution is obtained.
  • Keep the solution covered. The 0.5% chlorine solution is ready for use.

Label: 0.5% chlorine solution prepared on dd/mm/yyyy













Caution:

  • Chlorine solution must be prepared daily, because it loses strength over time.
  • Clean water free of organic matter should be used.
  • Chlorine solution should be prepared in a well-ventilated area.
  • Wearing of gloves and a laboratory apron is necessary to avoid direct contact of chlorine solution with skin.
  • Plastic containers should be used for the preparation and storage of chlorine solution.





Preparation of 0.5% chlorine solution from liquid bleach:





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