What is Oxygen Transmission Rate (OTR)?

Oxygen is essential for life, but it also drives food spoilage. Oxidative reactions can alter the color, flavor, and microbial stability of foods like coffee, tea, nuts, chocolate, cheese, meats, snacks, and nonfoods like pet food and treats.

To reduce oxygen-related degradation, two main packaging methods are used: vacuum packaging, which removes air, and modified atmosphere packaging (MAP), which replaces air with nitrogen or carbon dioxide. The effectiveness of either method depends on the packaging film’s ability to block oxygen, resisting the pressure difference between the low oxygen inside (0–2%) and the air outside (21%).

Oxygen transmission rate (OTR) is the steady rate at which oxygen passes through a film. It's measured as the volume of oxygen (in cc) that penetrates a given area over 24 hours—typically reported as cc/m²/24hr or cc/100in²/24hr—under standard conditions: 73°F (23°C) and 0% relative humidity.

Barrier Classifications

Typical OTR ranges by barrier category are shown below.

Barrier Classification	OTR (cc/m²/24hr)	OTR (cc/100in²/24hr)
High barrier	~1 - 10	~ 0.06 - 0.65
Standard barrier	~1,000	~64.50
Low / Breathable barrier	~10,000	~645.20

Tailoring OTR for Performance and Cost

OTR can be tailored to meet the specific needs of products and brands. Options like foil and metalized films like VMPET combine strong oxygen barriers with UV protection, while materials such as EVOH, AlOx and SiOX offer low OTR while allowing for a clear window. Increasing film thickness can improve OTR, but thicker materials can also raise costs.

Flair's Technical Services & Development team leverages vertical integration to tailor barrier performance while managing costs, using strategies like adjusting copolymer ratios, plasticizer content, and polymerization processes to meet product and budget requirements.