# ACSS ET 08/2010: technical compressed air in hospitals (Portugal)

ACSS ET 08/2010 is the Portuguese NHS technical specification for technical, non-medical compressed air in hospital buildings, covering production, pipework, distribution and outlets; the version in force is V.2025, revised in November 2025, and medical air is excluded, being covered by ACSS ET 03/2006.

## Scope

ET 08/2010 sets design, installation, performance and test requirements for technical compressed air (ar comprimido técnico) in Portuguese hospital buildings. It applies only to networks serving support zones and functions: maintenance workshops and engineering, garages, technical floors, the boiler plant and emergency generators, the laundry, the sterilisation department, and pneumatic controls and actuators.

This air may not be used for therapeutic purposes, to drive surgical tools or to dry sterilisable medical devices. Medical air and instrument air are covered by ACSS ET 03/2006 (v.2024); dental compressed air and air for hyperbaric chambers are also outside ET 08/2010.

## Edition and status

- Approved and published in October 2010 and revised in April 2013; the current V.2025, last revised in November 2025, is its second revision.
- Earlier versions were titled as specifications for industrial compressed air in hospital buildings (ar comprimido industrial); V.2025 uses the term technical compressed air.
- No fixed date is set for the next revision: it follows technological or regulatory changes.

## Key technical requirements

- Air quality: at least ISO 8573-1:2010 class [2:4:2], which ET 08 spells out as particle class 2, a pressure dew point of +3 °C or lower (class 4) and an oil content of 0.1 mg/m³ or less (class 2).
- Distribution pressure: 800 kPa relative (+200/-100).
- Architecture: centralised, decentralised or hybrid production; the structure of the document is similar to ISO 7396-1.
- Risk category: defined by the health unit's risk manager, either category 4 (lowest risk) or category 3.
- Pipework: deoxidised and degreased copper joined only by capillary brazing under an inert gas purge, stainless steel AISI 304L or 316L, or treated aluminium; pipes marked blue (RAL 5012) according to NP-182.
- Oil-lubricated compressors: treating the condensate through a water-oil separator is mandatory.

## Ultra Controlo products

The [ACIH](https://library.ultracontrolo.com/products/acih/) is the Ultra Controlo industrial compressed air system for hospital buildings. Its datasheet presents it as kept separate from medical air, citing hospital standards that prohibit the use of medicinal air for industrial purposes, and states compliance with the Machinery Directive and the ACSS ET 08/2010 technical specifications.

### Is ET 08/2010 the Portuguese medical gas specification?

No. ET 08/2010 covers technical compressed air only; medical gases and vacuum are covered by ACSS ET 03/2006, last revised in June 2024.

### Can technical compressed air be used to dry instruments in the sterilisation department?

No. ET 08/2010 excludes drying sterilisable medical devices; it notes that medical devices may be dried with instrument air, covered by ET 03/2006.

## Sources

- [ACSS ET 08/2010 V.2025, Ar comprimido técnico em edifícios hospitalares](https://www.acss.min-saude.pt/wp-content/uploads/2016/10/ET-08_2010_V.2025_VF.pdf)
- [ACSS, Especificações técnicas (list)](https://www.acss.min-saude.pt/2016/10/04/especificacoes-tecnicas/)
- [ACSS ET 03/2006 v.2024, Gases medicinais e aspiração](https://www.acss.min-saude.pt/wp-content/uploads/2016/10/ET-03_2006_v2024-Gases-medicinais_VF.pdf)
- [ISO 8573-1:2010, iso.org](https://www.iso.org/standard/46418.html)
- [ACIH datasheet, p. 2](https://www.ultracontrolo.com/products/acih)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/standards/acss-et-08/