GIFSQ Tools · Module 10 — Packaging & Shelf-Life · Tool 190 of 500
Work out the volume of each gas in a modified-atmosphere pack from the target mix and the pack volume — oxygen, carbon dioxide and nitrogen must add to 100%.
Try sample values — fills the form with the worked example below.
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Oxygen (mL)
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Carbon dioxide (mL)
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Nitrogen (mL)
Equation: Gas volume (mL) = target (%) ÷ 100 × pack volume (mL), for oxygen, carbon dioxide and nitrogen. The three targets must add to exactly 100%.
Method: Modified atmosphere packaging (MAP) gas mix: the pack is flushed with a set blend, usually low oxygen with carbon dioxide to slow microbes and nitrogen as the inert filler.
Assumptions: the pack is fully flushed to the target mix; volumes are at the same temperature and pressure.
Limitations: real packs never reach the exact target — residual air and product uptake shift the mix, so verify with a headspace gas analyser; carbon dioxide dissolves into the product and the pack can collapse.
Rounding: gas volumes to 1 decimal place; percentages to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Modified atmosphere packaging (MAP) gas mix: the pack is flushed with a set blend, usually low oxygen with carbon dioxide to slow microbes and nitrogen as the inert filler.
Assumptions: the pack is fully flushed to the target mix; volumes are at the same temperature and pressure.
Limitations: real packs never reach the exact target — residual air and product uptake shift the mix, so verify with a headspace gas analyser; carbon dioxide dissolves into the product and the pack can collapse.
Rounding: gas volumes to 1 decimal place; percentages to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: A 500 mL pack at 5% oxygen, 30% carbon dioxide and 65% nitrogen: oxygen = 25.0 mL, carbon dioxide = 150.0 mL, nitrogen = 325.0 mL.
Enter values above to see results.
Common MAP mixes: fresh meat 70–80% O2 / 20–30% CO2; cooked meat 30% CO2 / 70% N2; bakery 100% CO2 or 50/50 CO2/N2. Tool 190 of 500 — GIFSQ
