Oxygen Transmission Rate Calculator

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Oxygen Transmission Rate (OTR) Calculator

Calculate the steady-state rate at which oxygen gas permeates through a barrier material.

Volume of oxygen passing through the film.
The test area of the barrier material.
Time taken for the oxygen to permeate.
Optional: Used to calculate Permeability.

Calculation Results

Oxygen Transmission Rate: cc/(m²·24h)
Permeability Coefficient: cc·µm/(m²·24h·atm)

Understanding Oxygen Transmission Rate (OTR)

Oxygen Transmission Rate (OTR) is a critical measurement in the packaging industry, particularly for food, pharmaceuticals, and electronics. It quantifies the amount of oxygen gas that passes through a plastic film or barrier over a specific period. Maintaining a low OTR is essential for preserving shelf life and preventing oxidation.

The OTR Formula

The standard formula used in this calculator to determine the OTR normalized to a 24-hour period is:

OTR = (Volume / Area) × (24 / Time)
  • Volume: Amount of oxygen in cubic centimeters (cc).
  • Area: Surface area of the barrier in square meters (m²).
  • Time: The duration of the measurement in hours.

Permeability vs. Transmission Rate

While OTR measures the performance of a specific film thickness, Permeability is a material property that factors in the thickness. By multiplying the OTR by the thickness, engineers can compare the inherent barrier properties of different polymers (like PET vs. PE) regardless of their gauge.

Practical Example

If a 0.01 m² sample of polypropylene film allows 2.5 cc of oxygen through in a 48-hour test, the calculation would be:

OTR = (2.5 / 0.01) × (24 / 48) = 250 × 0.5 = 125 cc/(m²·24h).

This data helps packaging engineers decide if a foil laminate or an EVOH barrier is required to keep the product fresh.

function calculateOTR() { var volume = parseFloat(document.getElementById('oxygenVolume').value); var area = parseFloat(document.getElementById('surfaceArea').value); var time = parseFloat(document.getElementById('testTime').value); var thickness = parseFloat(document.getElementById('thickness').value); var resultDiv = document.getElementById('otrResults'); var otrSpan = document.getElementById('otrVal'); var permSpan = document.getElementById('permVal'); var permRow = document.getElementById('permeabilityRow'); if (isNaN(volume) || isNaN(area) || isNaN(time) || area <= 0 || time 0) { // Permeability Coefficient = OTR * thickness // Note: Standard assumes 1 atm pressure difference unless specified var permeability = otr * thickness; permSpan.innerHTML = permeability.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 4}); permRow.style.display = "block"; } else { permRow.style.display = "none"; } resultDiv.style.display = "block"; resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }

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