ISO 9170-2: terminal units for anaesthetic gas scavenging

What the standard covers

ISO 9170-2 is Part 2 of the ISO 9170 series on terminal units for medical gas pipeline systems. Part 1 deals with the outlets for compressed medical gases and vacuum; Part 2 deals with the outlets of anaesthetic gas scavenging disposal systems designed in accordance with ISO 7396-2, and with the probe that mates with them.

The standard sorts AGSS terminal units into two types according to whether the power device of the disposal system is upstream or downstream of the terminal unit.

Edition in force and status

The edition in force is ISO 9170-2:2008, the second edition, published in July 2008. On 22 October 2026 ISO lists it as confirmed (stage 90.93) at its last systematic review.

What it means for a hospital or designer

• An AGSS is a chain of three parts, each with its own standard: the disposal system (ISO 7396-2), its terminal units (ISO 9170-2) and the receiving system, which ISO 7396-2 refers to ISO 8835-3; ISO has withdrawn ISO 8835-3, revised by ISO 80601-2-13, whose edition in force is ISO 80601-2-13:2022 + Amd 1:2026. ISO 7396-2 itself refers to terminal units that comply with ISO 9170-2.
• AGSS outlets are kept apart from vacuum outlets: ISO 7396-2 requires the avoidance of cross connections between AGS disposal systems and medical gas and vacuum pipelines.
• When specifying terminal units, state the type, which follows from where the power device sits in the disposal system design.
• Terminal units for compressed medical gases and vacuum follow ISO 9170-1:2017, which aims to prevent interchange between different gases and services.

Related standards

• ISO 7396-2: anaesthetic gas scavenging disposal systems.
• ISO 80601-2-13:2022: anaesthetic workstations, including the anaesthetic gas scavenging system. ISO 80601-2-13 revised ISO 8835-3 (AGSS transfer and receiving systems), which ISO has withdrawn.
• ISO 9170-1: terminal units for compressed medical gases and vacuum.

The ULTRASEG active AGSS from Ultra Controlo complies with EN ISO 7396-2, according to its datasheet, and its terminal units have an adjustable orifice to set the flow.