Appendix E – Chlorine disinfectant solution preparation
Best Practices for Environmental Cleaning in Global Healthcare Facilities with Limited Resources
The materials on this page were created for use in global healthcare facilities with limited resources, particularly in low- and middle-income countries. Environmental cleaning resources designed for U.S. healthcare facilities can be found at Healthcare Environment Infection Prevention.
Chlorine in liquid bleach comes in different concentrations. Any concentration can be used to make a dilute chlorine solution by applying the following formula:
(% chlorine in liquid bleach ∕ % chlorine desired) − 1 = Total parts of water for each part bleach [Footnote 1]
Example: To make a 0.5% chlorine solution from 3.5% [Footnote 2] bleach:
[3.5% ∕ 0.5%] − 1 = 7 − 1 = 6 parts water for each part bleach
Therefore, you must add 1 part 3.5% bleach to 6 parts water to make a 0.5% chlorine solution.
“Parts” can be used for any unit of measure (e.g. ounce, liter or gallon) or any container used for measuring, such as a pitcher.
In countries where French products are available, the amount of active chlorine is usually expressed in degrees chlorum. One-degree chlorum is equivalent to 0.3% active chlorine.
When bleach powder is used; the resulting chlorine solution is likely to look cloudy (milky)
If using bleach powder [Footnote 3], calculate the amount of bleach to be mixed with each litre of water by using the following formula:
[% chlorine desired ∕ % chlorine in bleach powder] × 1 000 = Grams of bleach powder for each litre of water
Example: To make a 0.5% chlorine solution from calcium hypochlorite (bleach) powder containing 35% active chlorine
[0.5% ∕ 35%] × 1 000 = 0.0143 × 1 000 = 14.3
Therefore, you must dissolve 14.3 grams of calcium hypochlorite (bleach) powder in each litre of water used to make a 0.5% chlorine solution.
Total Parts (TP) (H2O) = [% Concentrate ∕ % Dilute] − 1
Example: To make a 0.1% chlorine solution from 5% concentrated solution:
Calculate TP (H2O) = [5.0% ∕ 0.1%] − 1 = 50 − 1 = 49
Take one part concentrated solution and add to 49 parts boiled (filtered if necessary) water.
AVSC International (1999). Infection Prevention Curriculum. Teacher’s Manual. New York, p.267.