Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

What standard must liquid bleach meet to be approved for disinfection in public water systems?

1. EPA standard 100

2. NSF standard 60

3. FDA standard 200

4. OSHA standard 150

The correct answer is: NSF standard 60

Liquid bleach, specifically sodium hypochlorite, is commonly used for disinfection in public water systems. For a disinfectant to be approved for such use, it must meet the NSF/ANSI Standard 60. This standard is specifically designed for drinking water treatment chemicals, ensuring that they are safe and effective for human consumption and do not introduce harmful contaminants into the water supply. NSF Standard 60 covers a range of criteria, including the quality and safety of the treatment chemicals, as well as their potential health effects. This regulatory framework assures water utilities that the disinfectants they are using will achieve sufficient microbial reduction while also being safe for public health. Other standards mentioned in the answer choices do not pertain to water disinfection in public systems. EPA standards are typically associated with environmental protection regulations, FDA standards pertain more to food and drug safety rather than water treatment chemicals, and OSHA standards are primarily concerned with workplace safety and health regulations. Therefore, NSF Standard 60 is the appropriate benchmark for the use of liquid bleach in disinfection processes within public water systems.