Cleaning Validation — Recovery Study

Swab Recovery Calculator

Calculate percent recovery from a swab recovery study and use it to adjust your cleaning validation acceptance limit for real-world sampling efficiency.

Why Recovery Studies Matter

Swabbing rarely recovers 100% of the residue actually present on a surface — some is left behind due to surface texture, swab material, or technique. A recovery study spikes a known amount of analyte onto coupons of the actual (or representative) surface material, swabs them using the routine method, and measures how much is recovered.

% Recovery = (Amount Recovered / Amount Spiked) × 100 Recovery-Adjusted Limit = Original Swab Limit / (% Recovery / 100)

Typical Acceptance

Recovery Range	Interpretation
≥ 70%	Generally good recovery; adjustment optional depending on site procedure
50% – 70%	Acceptable in many programs, but requires recovery correction factor applied to the limit
< 50%	Often considered inadequate — review swab material, technique, or surface/analyte combination

Regardless of the exact site-specific threshold, most cleaning validation programs apply a recovery-adjusted (tighter) acceptance limit whenever recovery is below 100%, to ensure the true residue level cannot exceed the actual MACO-derived limit.

Interactive Calculator

Surface / Coupon	Amount Spiked (µg)	Amount Recovered (µg)	% Recovery

Mean % Recovery

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Min % Recovery

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Max % Recovery

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Original Swab Limit (µg/swab)

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This tool illustrates the recovery calculation and limit adjustment concept for educational purposes. Formal recovery studies should follow a validated protocol across multiple spike levels, surface materials, and analysts, per your site's cleaning validation program.