It happened at the Brand Packaging Group Inc., on Price Parkway around 2:40 p.m.
A worker heard a scream and ran into another room where he saw his co-worker, Beatriz Blaz, with her left arm stuck in a packaging machine.
The worker was able to free Blas and retrieve her arm.
The 37-year-old Wyandanch resident and her severed arm were airlifted to the Nassau University Medical Center.
Doctors are currently trying to reattach her arm and say she is in stable condition.