Certified Pool Operator Practice Test

What is the accepted minimum of free chlorine in pool water to destroy harmful organisms?

1. 1 ppm

2. 2 ppm

3. 3 ppm

4. 4 ppm

The correct answer is: 1 ppm

Chlorine is a common disinfectant used in pool water to destroy harmful organisms. The minimum accepted level of free chlorine is typically 1 part per million (ppm), which is the equivalent of one drop of chlorine solution in one million drops of pool water. This amount is sufficient to kill most harmful bacteria and viruses, while also being safe for humans to swim in. Option B, C, and D are incorrect because they are higher amounts of chlorine that are not necessary and can potentially be harmful to swimmers. In fact, levels of free chlorine above 4 ppm can cause skin and eye irritation. Additionally, option D may be incorrect because 4 ppm may not be considered effective in killing all harmful organisms in pool water. Therefore, option A, 1 ppm, is the correct and accepted minimum of free chlorine in pool water to ensure safety and effectiveness.