# Surgical air (air for driving surgical tools)

Surgical air, which ISO 7396-3 calls air for driving surgical tools, is compressed air piped at a higher pressure than medical air to power pneumatic surgical tools; HTM 02-01 designs it for at least 700 kPa at the terminal unit.

ISO 7396-1 covers surgical drive gases with the other pipeline gases. Pressures differ by document: HTM 02-01 (2026) treats medical air at 400 kPa and asks for surgical air of at least 700 kPa at the terminal unit at a flow of 350 L/min, or 100 L/min for ophthalmic equipment, while the Portuguese ACSS ET 03/2006 follows ISO 7396-1 with 8 bar +2/−1 for surgical instruments.

HTM 02-01 notes that surgical air use is declining as battery and electrically powered tools spread. Where it is installed, the supply can be a cylinder manifold, a dedicated 700 kPa compressor plant or one compressor plant serving both the 700 kPa and 400 kPa systems. Nitrogen, where available on site, may be used instead, with attention to the risk of oxygen depletion. ISO 7396-3:2025 also covers proportioning units that blend oxygen and nitrogen into air for driving surgical tools.

Surgical air is not the same as hospital industrial air: the ACIH system from Ultra Controlo supplies industrial compressed air and is not surgical or medical air.

## Sources

- [ISO 7396-1:2016, Medical gas pipeline systems, Part 1 (ISO summary)](https://www.iso.org/standard/60061.html)
- [HTM 02-01 (2026) Part A, paragraphs 4.48, 4.89, 8.2 to 8.4 (NHS England)](https://www.england.nhs.uk/wp-content/uploads/2016/05/health-technical-memorandum-02-01-medical-gas-pipeline-systems-part-a-design-installation-validation-verification-aug-2026.pdf)
- [ACSS ET 03/2006 v.2024, Gases medicinais (Portugal)](https://www.acss.min-saude.pt/wp-content/uploads/2016/10/ET-03_2006_v2024-Gases-medicinais_VF.pdf)
- [ISO 7396-3:2025, Proportioning units (ISO summary)](https://www.iso.org/standard/86136.html)
- [ACIH datasheet, p. 2](https://www.ultracontrolo.com/products/acih)

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