There is no PW or WFI water generation and distribution system that is sterile over the whole lifecycle. Microorganisms always find a way into the plant. Either through the raw water, or during maintenance activities et cetera. Sterility is technicallynot achievable and would generate a high effort and cost.
Frequent sanitization procedures reduces the lifetime of some components or even worse may result in malfunction like membrane damage in a reverse osmosis which would reduce the barrier effect for microorganisms and thus result in a higher bioburden of the water after this purification step. The goal is not to achieve a sterile system but to keep the bioburden below specific limits. The limits are defined for the final product e.g. for WFI the limit is 10 CFU / 100ml, but there are no limits defined after each purification step. As part of a contamination control strategy, it’s more and more important to not only prove the quality of the final product, but also to show that each step of the water purification process is working within its specified parameters.
The procedures used are defined during the PQ phase of the commissioning of the plant.
By at-line monitoring of the bioburden, procedures can be adjusted to the real needs. Unnecessary or too aggressive sanitizations can be avoided to protect the facility.
BWT offers solutions for hot water and chemical sanitization like hot water sanitizable softeners or Ozone generators.
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