# Appendix E – Chlorine disinfectant solution preparation

Best Practices for Environmental Cleaning in Healthcare Facilities: in RLS

Footnote 1
“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.

Footnote 2
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.

Footnote 3
When bleach powder is used; the resulting chlorine solution is likely to look cloudy (milky)

### Example 1 — Using Liquid Bleach

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.

### Example 2 — Using Bleach Powder

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.

### Example 3 — Formula for Making a Dilute Solution from a Concentrated 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.

Source:

AVSC International (1999). Infection Prevention Curriculum. Teacher’s Manual. New York, p.267.

Page last reviewed: March 27, 2020