GIFSQ Tools · Module 10 — Packaging & Shelf-Life · Tool 183 of 500
Calculate oxygen transmission rate (OTR) from the oxygen volume passed, test area and time — with the value normalised to a 25 µm film (ASTM D3985).
Try sample values — fills the form with the worked example below.
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OTR (cc/m²/day)
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OTR at 25 µm (cc/m²/day)
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Oxygen per day (mL)
Equation: OTR (cc/m²/day) = oxygen volume (cc) ÷ [area (m²) × time (days)]. OTR at 25 µm = OTR × thickness (µm) ÷ 25. 1 cc = 1 mL.
Method: Coulometric oxygen transmission measurement per ASTM D3985 (oxygen gas transmission rate through plastic film and sheeting using a coulometric sensor). Report the test temperature and humidity with the result.
Assumptions: steady-state transmission; the film is uniform and undamaged; the stated thickness applies across the test area.
Limitations: OTR depends strongly on temperature and humidity, so values at different conditions are not comparable; the 25 µm normalisation assumes transmission scales inversely with thickness, which is approximate for coated films.
Rounding: OTR to 2 decimal places; oxygen per day to 4 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Coulometric oxygen transmission measurement per ASTM D3985 (oxygen gas transmission rate through plastic film and sheeting using a coulometric sensor). Report the test temperature and humidity with the result.
Assumptions: steady-state transmission; the film is uniform and undamaged; the stated thickness applies across the test area.
Limitations: OTR depends strongly on temperature and humidity, so values at different conditions are not comparable; the 25 µm normalisation assumes transmission scales inversely with thickness, which is approximate for coated films.
Rounding: OTR to 2 decimal places; oxygen per day to 4 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: 2.5 mL of oxygen through 50 cm² in 24 h: OTR = 2.5 ÷ (0.005 × 1) = 500.00 cc/m²/day; at 25 µm the normalised value is also 500.00 cc/m²/day.
Enter values above to see results.
Typical OTR: high-barrier film under 1 cc/m²/day; plain polyethylene 500–2000 cc/m²/day at 23 °C. Tool 183 of 500 — GIFSQ
