Flexible-packaging glossary

OTR

Oxygen transmission rate: a measured rate at which oxygen passes through a material under stated test conditions.

Why buyers encounter it

An OTR number is incomplete without units, temperature, humidity, method, and a clear description of the tested material or package.
Oxygen and water-vapor transmission through film
Buyer diagramReference diagram for otr.

Use the term carefully

This definition helps interpret a packaging conversation. It does not establish a complete film structure, machine setting, regulatory conclusion, shelf-life result, or approval for a particular application.

Research source: PC-029. Application-specific details remain subject to manufacturer and technical review.