# Class 0

The most stringent oil class for compressed air in ISO 8573-1. Ultra Controlo describes its oil-less ULTRACECO compressors as Class 0.

## Sources

- [Ultra Controlo, Medical gas answers: glossary](https://www.ultracontrolo.com/medical-gas-answers#term-class-0)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/glossary/class-0/