1. Why are there no microbial requirements included in the monographs for Purified Water and Water for Injection?
  2. What is the purpose of microbial Alert and Action Levels for Purified Water and Water for Injection?
  3. For off-line testing of water samples for Water Conductivity <645> and Total Organic Carbon <643>, how long can I store samples before testing?
  4. For off-line testing of water samples for General Chapters Water Conductivity <645> and Total Organic Carbon <643>, how should I store the samples?
  5. Can I do Water Conductivity <645> and Total Organic Carbon <643> testing on-line?
  6. What is the total organic carbon (TOC) limit for Purified Water and Water for Injection?
  7. How often do I perform the system suitability test in Total Organic Carbon General Chapter <643>?
  8. How long can I store and reuse reference standard solutions prepared for the Total Organic Carbon <643> system suitability test?
  9. What is the main reason for KCl addition in the Water Conductivity <645> test for pH measurement?
  10. Can I start at Stage 2 for Water Conductivity <645>, or do I need to start at Stage 1?
  11. Is the requirement for conductivity cell constant of ±2% of the nominal value?
  12. What is a “suitable container” for off-line determination of conductivity?
  13. There are no tests for pH, nitrates, or heavy metals? Is this correct?
  14. May I release water for use by performing microbial testing on water from a sample port?
  15. Is the outlet on the water distribution system, sometimes called a point of use outlet, considered to be the point of use?
  16. If I do not have a water microbial specification but only an Alert and Action Level, is there a microbial level considered to be unfit for use?
  17. What are the most common issues encountered in the WFI production systems produced under GMP. What should we look for?
  18. Do you get nuclease generation from biofilm and is more released during sanitization?
  19. In the new USP 1231 the recommended temperature in hot sanitizing has changed. The previous recommendation of at least 80°C has been lowered to 65-80°C. Now temperatures far in excess of 80°C are explicitly deemed inadvisable. Is this correct?
  20. When sampling water ports should we hook up process hoses?  Is this a requirement or a recommendation?
  21. What is your risk in increasing endotoxin levels due to the different sanitization methods?

 

SOURCE :https://www.usp.org