Does volatile capture technology replace an AGSS?

Neither guidance document says so directly: SHTM 02-01 (2026) makes local exhaust ventilation the next control if capture and destruction units cannot assure safe exposure levels, while HTM 02-01 (2026) says removing nitrous oxide does not remove the need for an AGSS, because it also removes anaesthetic agents.

What capture rates have been reported for VCTs?

The SHTG review (May 2024) found two bench studies reporting about 95% capture for one system and two patient studies reporting 25% and 51%.

Active scavenging vs volatile anaesthetic capture devices

Q: Active scavenging vs volatile anaesthetic capture devices

Under NHS England's HTM 02-01 (2026), an active anaesthetic gas scavenging system (AGSS) uses an electric pump or fan to remove waste gas from the breathing circuit through fixed pipework, while volatile capture technology (VCT) captures the agent to cut emissions; NHS Scotland's SHTG (May 2024) found insufficient evidence to buy VCTs.

The two are described with different aims. HTM 02-01 Part B (2026) says anaesthetic gas discharges are usually controlled by scavenging or ventilation to comply with COSHH, in order to protect staff from overexposure (10.38). The Scottish Health Technologies Group (SHTG) gives the intended purpose of VCTs as reducing volatile anaesthetic gas emissions, which are greenhouse gases, entering the atmosphere.

Side by side

	Active AGSS	Volatile capture technology (VCT)
Stated aim	Protect staff from overexposure to anaesthetic gases (HTM 02-01 Part B, 10.38)	Reduce volatile anaesthetic gas emissions to the atmosphere (SHTG, 2024)
Gases handled	Waste anaesthetic gases, including anaesthetic agents as well as nitrous oxide (HTM Part B, 10.41)	Volatile agents such as desflurane, sevoflurane and isoflurane (SHTG)
How it works	Low-pressure system powered by an electric pump or fan, removing waste gas through fixed pipework; HTM asks for a duplex set (Part A, 12.5 and 12.26)	Captures the volatile agent; SHTG reports no established process in the UK for recycling it, nor regulatory approval for reuse
Standard or guidance	ISO 7396-2 (disposal systems); HTM 02-01 chapter 12; SHTM 02-01	SHTG Recommendation (May 2024)
Position in NHS Scotland	Local exhaust ventilation (LEV), the next option in the hierarchy of controls if capture and destruction units cannot assure safe exposure levels (SHTM, 3.5)	Insufficient evidence to support purchase, installation and maintenance (SHTG)

What the SHTG review found (May 2024)

SHTG identified four studies of the two VCT systems available in NHSScotland, all small and preliminary and described in letters to journals. Two UK bench studies, without patients, reported that one system captured approximately 95% of available volatile gases; two studies with patients reported capture efficiencies of 25% (Germany, n=80) and 51% (UK, n=50).
It found no economic evaluations of VCTs, and called for more evidence on capture efficiency in clinical settings and for robust life-cycle assessments.
Desflurane, reported as the most polluting of the three agents, was decommissioned in NHSScotland in March 2023, and NHSScotland reduced volatile gas emissions by 82% between 2018/19 and 2021/22. Topic experts stressed reducing the volume of gas used in the first place, for example with low fresh gas flows.
The SHTG Council noted that the evidence is rapidly evolving and that the use case may need to be revisited. One of the experts it heard noted that hospital AGSS require energy to run, so VCT systems that do not rely on a hospital AGSS could potentially boost their relative environmental benefit.

Where capture technology sits in the guidance

NHS Scotland's SHTM 02-01 Part A (Version 2, August 2026), 3.5: where nitrous oxide and anaesthetic agents are available, the informed design process determines what COSHH compliance requires, which for certain low-flow and total intravenous anaesthesia applications may not be a piped service; if anaesthetic gas capture technology and destruction units cannot assure safe exposure levels, LEV is the next option. Its design checklist asks whether capture technology has been considered.
SHTM 02-01 Part A also asks for existing AGSS to be reviewed to confirm they remain functional and suitable, given reduced fresh gas flow rates and the adoption of anaesthetic agent harvesting and capture technologies.
NHS England's HTM 02-01 Part B (2026): the exhaled waste gas relies on an AGSS to remove it to a safe location, and reducing or removing nitrous oxide does not remove the need for the AGSS, as it also removes anaesthetic agents (10.41). It notes that technologies are available for the removal and decomposition of anaesthetic gases (10.38).

ULTRASEG

ULTRASEG, the Ultra Controlo AGSS, is an active system based on the suction of anaesthetic gas mixtures, at a suction level of minus 0.2 bar, and complies with EN ISO 7396-2 according to its datasheet; its modular construction allows one pump to run while the other is on standby or in maintenance.