The TOC (Total Organic Carbon) limit for cleaning validation is generally less than 15 ppm.
While a specific, universally mandated TOC limit for cleaning validation doesn't exist, guidance and industry practices point to certain levels based on the solubility of residues. Since water solubility is often a key factor, the target residue usually needs to be soluble in water at 10-30 ppm, which translates to approximately 5-15 ppm when measured as TOC.
Here's a breakdown:
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Solubility Consideration: Cleaning validation often considers how well residues dissolve in water.
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Target Solubility: Ideally, residues should be water-soluble at levels around 10-30 ppm.
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TOC Correlation: This solubility level typically corresponds to a TOC measurement of approximately 5-15 ppm.
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Practical Limit: Therefore, a commonly accepted TOC limit in cleaning validation is often less than 15 ppm.
In essence, the TOC limit during cleaning validation serves as an indicator of the effectiveness of the cleaning process in removing organic residues. The less than 15 ppm figure acts as a practical benchmark in many cases.
