---
title: "CAT.IDE.A.230 First-aid oxygen — Part-CAT · Avioverse"
description: "Pressurised aeroplanes operated at pressure altitudes above 25 000 ft, in the case of operations for which a cabin crew member is required, shall be…"
url: "https://avioverse.aero/regulations/easa/air-ops/part-cat/subpart-d/cat-ide-a-230"
---

# CAT.IDE.A.230 First-aid oxygen

ANNEX IV (Part-CAT) · Regulation (EU) No 965/2012 · EAR revision 27 Mar 2026

IR Implementing rule

## CAT.IDE.A.230 First-aid oxygen

(a) Pressurised aeroplanes operated at pressure altitudes above 25 000 ft, in the case of operations for which a [cabin crew member](https://avioverse.aero/glossary/easa/cabin-crew-member) is required, shall be equipped with a supply of undiluted oxygen for passengers who, for physiological reasons, might require oxygen following a cabin depressurisation.

(b) The oxygen supply referred to in (a) shall be sufficient for the remainder of the flight after cabin depressurisation when the cabin altitude exceeds 8 000 ft but does not exceed 15 000 ft, for at least 2 % of the passengers carried, but in no case for less than one person.

(c) There shall be a sufficient number of dispensing units, but in no case less than two, with a means for cabin crew to use the supply.

(d) The first-aid oxygen equipment shall be capable of generating a mass flow to each person.

IR · CAT.IDE.A.230 — Regulation (EU) No 965/2012 · Regulation (EU) 2019/1387 · Air OPS Easy Access Rules · EAR revision 27 Mar 2026

GM Guidance material

## GM1 CAT.IDE.A.230 First-aid oxygen

GENERAL

(a) First-aid oxygen is intended for those passengers who still need to breath oxygen when the amount of supplemental oxygen required under CAT.IDE.A.235 or CAT.IDE.A.240 has been exhausted.

(b) When calculating the amount of first-aid oxygen, the operator should take into account the fact that, following a cabin depressurisation, supplemental oxygen as calculated in accordance with Table 1 of CAT.IDE.A.235 and Table 1 of CAT.IDE.A.240 should be sufficient to cope with potential effects of hypoxia for:

(1) all passengers when the cabin altitude is above 15 000 ft;

(2) at least 30 % of the passengers, for any period when, in the event of loss of pressurisation and taking into account the circumstances of the flight, the pressure altitude in the passenger compartment will be between 14 000 ft and 15 000 ft; and

(3) at least 10 % of the passengers for any period in excess of 30 minutes when the pressure altitude in the passenger compartment will be between 10 000 ft and 14 000 ft.

(c) For the above reasons, the amount of first-aid oxygen should be calculated for the part of the flight after cabin depressurisation during which the cabin altitude is between 8 000 ft and 15 000 ft, when supplemental oxygen may no longer be available.

(d) Moreover, following cabin depressurisation, an emergency descent should be carried out to the lowest altitude compatible with the safety of the flight. In addition, in these circumstances, the [aeroplane](https://avioverse.aero/glossary/easa/aeroplane) should land at the first available aerodrome at the earliest opportunity.

(e) The conditions above may reduce the period of time during which the first-aid oxygen may be required and consequently may limit the amount of first-aid oxygen to be carried on board.

GM · GM1 CAT.IDE.A.230 — Regulation (EU) No 965/2012 · ED Decision 2021/005/R · Air OPS Easy Access Rules · EAR revision 27 Mar 2026

AMC Acceptable means of compliance

## AMC1 CAT.IDE.A.230(d) First-aid oxygen

GENERAL

(a) The mass flow of oxygen should be in accordance with CS-25.1443 or equivalent.

(b) The oxygen supply may be calculated by assuming an average flow rate of at least 3 litres standard temperature pressure dry (STPD)/minute/person, or equivalent, as demonstrated during the certification of the dispensing unit.

AMC · AMC1 CAT.IDE.A.230(d) — Regulation (EU) No 965/2012 · ED Decision 2021/005/R · Air OPS Easy Access Rules · EAR revision 27 Mar 2026

[All rules in SUBPART D: INSTRUMENTS, DATA, EQUIPMENT](https://avioverse.aero/regulations/easa/air-ops/part-cat/subpart-d)

Consolidated from the EASA Easy Access Rules (revision 27 Mar 2026, extracted 13 Oct 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.