USP 645 Water Conductivity

The USP <645> standard covers the electrical conductivity of water and is part of the United States Pharmacopeial (USP) Convention covering water for injection (WFI) and purified water (PW).

There’s a rationale for testing, because ions form when gases such as carbon dioxide dissolve in water in a process that affects the water’s conductivity. What’s more, ions coming from exterior sources, such as ammonium and chloride ions, can also impact whether you can use the water in your pharmaceutical operations, due to purity concerns.

About USP <645> Water Conductivity Testing

Pharmaceutical manufacturers know that you can accurately predict the electrical conductivity of water according to ions present in a sample, which speaks to the water’s purity. Since pure water is essential in your application, you need to conduct rigorous testing to verify its suitability.

USP <645> is a standard that guides manufacturers in measuring water conductivity in sterile water and bulk water. Industries use the standard when assessing water to make sure it meets their purity standards. Typically, two types of water are tested:

  • Sterile water: Sterile water for injection, sterile purified water and sterile water intended for inhalation or irrigation
  • Bulk water: Steam condensate and water for hemodialysis

To achieve accurate results, we use precisely calibrated instruments. Our team measures the conductivity cell constant to an accuracy of plus or minus 2%. We can check the cell constant:

  • Direct: The direct approach calls for verifying the constant by measuring a solution whose conductivity we already know.

Other factors come into play, including the water’s temperature, which affects conductivity readings.

Contact BA Sciences Today

It’s clear that adhering to USP <645> requirements regarding water conductivity is of the utmost importance in pharmaceutical production lines.

When your company is tasked with performing USP <645> water conductivity tests, it makes sense to partner with industry professionals. To harness our knowledge and expertise, please get in touch with us today.

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