Medical devices in a medical gas installation — table of classes, gas produced in the hospital as a medicinal product

The acceptance binder is often thick and yet empty: a certificate for the pipeline system, declarations from the manufacturers of the compressor, the dryer and the air receiver, test reports — and no answer to the question of which of the dozen or more devices in that installation has which declaration of conformity, to which standard and in which class. I have described separately why the system certificate does not cover the supply sources. Here I set out what the acceptance committee and the procurement department need on the table: a table of devices with standards and classes, the status of gas from the plant room as a medicinal product, and a check question for the EUDAMED database.

Which elements of a medical gas installation are medical devices?

All those that have their own manufacturer, their own intended purpose and their own product standard — from the plant room to the outlet in the wall of a patient room. The table brings them together in one place: device, standard, CE marking and the typical class with its rule from Annex VIII to Regulation (EU) 2017/745.

Two caveats before anyone treats the right-hand column like a price list. The class follows from the intended purpose declared by the manufacturer and from Annex VIII — the assignment in the table is typical, not automatic. Each notified body may approach the matter individually; the practice of EUDAMED entries is still taking shape, and other assignments are also encountered in the database. In Poland, a dispute between a manufacturer and a notified body over the application of Annex VIII is resolved by the President of the Office for Registration of Medicinal Products, Medical Devices and Biocidal Products by way of an administrative decision — Article 51(2) of Regulation 2017/745 in conjunction with Article 28(8) of the Act of 7 April 2022 on medical devices.

Device (installation element)	Product standard	CE marking	Typical class and rule
Oxygen supply source: cryogenic tank with pressure-reducing assembly, high-pressure cylinder manifold	ISO 7396-1	yes	IIb, rule 12
Oxygen concentrator plant (oxygen 93)	ISO 7396-1	yes	IIb, rule 12
Nitrous oxide supply source, carbon dioxide supply source	ISO 7396-1	yes	IIb, rule 12
Medical compressed air supply source (complete)	ISO 7396-1	yes	IIa or IIb, rule 12
Synthetic air supply source — mixing of oxygen and nitrogen	ISO 7396-3	yes	IIb, rule 12
Medical vacuum supply source (complete plant)	ISO 7396-1	yes	IIa, rule 12
Anaesthetic gas scavenging system supply source	ISO 7396-2	yes	IIa, rule 12
Manifold and line pressure regulators	ISO 10524-2	yes	IIb, rule 12
Area valve service unit in a box enclosure	ISO 11197	yes	IIa or IIb, rule 2 or 12
Gas status indicator panel, alarm system	ISO 7396-1 clause 6	yes	IIa or IIb
Medical supply unit: bed-head unit, ceiling pendant, ceiling bridge	ISO 11197	yes	IIa or IIb
Terminal unit for medical gases and vacuum	ISO 9170-1	yes	IIa or IIb, rule 2 or 12
Anaesthetic gas scavenging system terminal unit	ISO 9170-2	yes	IIa, rule 2
Copper tube for medical gases and vacuum	EN 13348	yes	IIa, rule 2
Brazed connectors and fittings	EN 1254-1 / EN 1254-4	yes	IIa, rule 2
Low-pressure hose assemblies	ISO 5359	yes	IIa, rule 2
Complete installation as an assembly of devices	ISO 7396-1 (design, testing, acceptance)	no — statement under Article 22(1)–(2)	not applicable

It is worth pausing on the last row: the complete installation is the only item in the list with “no” in the “CE marking” column — instead of a CE marking, a statement by the person combining the devices is drawn up under Article 22(1)–(2). Everything above it has its own declaration of conformity, and that is what the committee asks about.

Where do rule 12 for supply sources and rule 2 for tubes come from?

From the function the element performs in relation to the gas. The MDCG 2021-24 guidance assigns to rule 12 pressure regulators for medical gases, medical gas mixing devices and oxygen concentrators (IIb), and to rule 2 tubing acting as a channel in an active drug-delivery system (IIa). This division is visible in the right-hand column of the table; for the area valve service unit and the terminal unit the table gives both rules.

Why are medical air and oxygen 93 from the plant room medicinal products?

Because gas produced in a hospital plant room does not cease to be a medicinal product on account of where it is produced. Medical air is described in the Polish Pharmacopoeia XIII (2023) monograph “Aer medicinalis” (Ph. Eur. 07/2022:1238), and oxygen 93 in Ph. Eur. monograph 2455 “Oxygenium 93 per centum”, which refers expressly to gas produced in single-stage concentrators. These are not generalities: for medical air the monograph sets the oxygen content and the impurity limits, which have to be tested, not assumed.

Medical air parameter	Requirement of the “Aer medicinalis” monograph
Oxygen content	20.4–21.4 % (V/V)
Carbon dioxide (CO₂)	not more than 500 µL/L
Carbon monoxide (CO)	not more than 5 µL/L
Sulphur dioxide (SO₂)	not more than 1 µL/L
Nitrogen oxides (NO and NO₂ combined)	not more than 2 µL/L
Water	not more than 67 µL/L
Oil	not more than 0.1 mg/m³

The standard follows the same line. Clause K.1 assigns responsibility for the safety, quality and efficacy of gases produced on site to the healthcare facility and indicates to whom it is to be entrusted: a designated person within the facility, who is usually the chief pharmacist. The subsequent clauses spell out the rest: K.3 requires a quality system consistent with GMP principles, K.4 separates production responsibility and quality control between independent persons, and K.5 calls for calibrated on-line analysers and an alarm on deviation from the quality level.

Let me put it bluntly. The production of medical air, oxygen 93 or synthetic air is subject to pharmacy procedures in exactly the same way as the production of any other medicinal product in a hospital. Nobody would prepare an infusion solution without a specification, testing and release by a pharmacist — yet with gases this standard is often overlooked, even though the product goes straight into the patient’s airways. Why oxygen from the pipeline falls under the pharmacy and not the technical department is the subject of the article: in a hospital, oxygen is a medicinal product.

What are the sampling points on the supply source for?

So that the monograph can be verified rather than merely cited. In designs they are often treated as an add-on or a servicing convenience — whereas they are part of the quality control of a medicinal product: they serve to draw a gas sample and test it against the monograph routinely, according to a schedule set by the person responsible for quality, and not only when something raises doubts. They are sometimes routed to the hospital pharmacy or connected to a certified analyser that measures the gas parameters continuously and relates them to the pharmacopoeial values.

The method is suggested by the pharmacopoeia itself: the monographs provide for the determination of oil in medical air and of carbon monoxide in oxygen 93 using the detector tubes described in chapter 2.1.6. The test takes a few minutes, is carried out at the supply source, and the result goes into the quality documentation. The result is accepted by the pharmacist, not by the installation contractor. That is the difference between technical acceptance and the release of a medicinal product.

Which row of the table has a declaration of conformity?

The contractor need not be taken at their word: the EUDAMED database is public, and the table in this article suggests what to look for in it — the scope of the notified body’s certificate is anchored there in EMDN nomenclature codes.

The check question for every acceptance and every procurement procedure: for which row of the table has the contractor presented a declaration of conformity, and do the type, intended purpose and Basic UDI-DI of that device appear in the list covered by the certificate? The term “medical gas and vacuum pipeline system” does not provide that answer, because the definition of the system encompasses both the compressed air supply source and the anaesthetic pendant. A shared name is not evidence of a shared scope. The check takes a single afternoon.

Frequently asked questions

What medical device class does a medical gas terminal unit have?

Typically IIa or IIb under rule 2 or 12 of Annex VIII to Regulation (EU) 2017/745; the product standard is ISO 9170-1, and for anaesthetic gas scavenging system terminal units ISO 9170-2 (IIa, rule 2). The class is decided by the intended purpose declared by the manufacturer; in Poland, a dispute over the application of Annex VIII is resolved by the President of URPL by administrative decision.

Is medical air produced in a hospital compressor plant a medicinal product?

Yes. It is described in the Polish Pharmacopoeia XIII (2023) monograph “Aer medicinalis” (Ph. Eur. 07/2022:1238), which sets an oxygen content of 20.4–21.4 % (V/V) and impurity limits, including 5 µL/L for carbon monoxide and 0.1 mg/m³ for oil. The place of production does not change the status of the gas — it only changes who is responsible for its quality.

Who in a hospital is responsible for the quality of gas produced on site?

Under clause K.1 of Annex K to PN-EN ISO 7396-1:2016-07, responsibility for the safety, quality and efficacy of gases produced on site rests with the healthcare facility, which entrusts it to a designated person — usually the chief pharmacist. Clause K.4 additionally requires production responsibility and quality control to be separated between independent persons.

What are the sampling points on a medical air supply source for?

To draw a gas sample and test it against the pharmacopoeial monograph according to a schedule set by the person responsible for quality — not only when something raises doubts. The determination of oil in medical air and of carbon monoxide in oxygen 93 is carried out with the detector tubes of chapter 2.1.6 of the Pharmacopoeia, at the supply source, and the result is accepted by the pharmacist, not by the installation contractor.

Basis

PN-EN ISO 7396-1:2016-07 — clause 6; Annex K: K.1, K.3, K.4, K.5.

ISO 7396-2, ISO 7396-3, ISO 10524-2, ISO 11197, ISO 9170-1, ISO 9170-2, EN 13348, EN 1254-1 / EN 1254-4, ISO 5359 — product standards for the devices in the table.

Regulation (EU) 2017/745 of the European Parliament and of the Council on medical devices (MDR) — Article 22(1)–(2), Article 51(2), Annex VIII (rules 2 and 12).

The Act of 7 April 2022 on medical devices — Article 28(8).

MDCG 2021-24 — guidance on the classification of medical devices, examples for rules 2 and 12.

Polish Pharmacopoeia XIII (2023) — monograph “Aer medicinalis” (Ph. Eur. 07/2022:1238); European Pharmacopoeia — monograph 2455 “Oxygenium 93 per centum”; chapter 2.1.6 (detector tubes).

EUDAMED — the European database on medical devices: notified body certificates in EMDN nomenclature.

If, before acceptance, you want the declarations of conformity, classes and EUDAMED entries cross-checked against what actually stands in the plant room and on the wards, we carry out this document verification as part of a medical gas installation audit.

Prepared by: Łukasz Konieczny — Medpipe Sp. z o.o.; member of Technical Committee No 284 for medical equipment and apparatus at the Polish Committee for Standardization (PKN), repeatedly appointed by the courts as an expert witness in medical equipment and devices. An extended version of this text appeared in the quarterly “Wyroby Medyczne” 3/2026 (39).