Rotorcraft - Emergency Breathing Systems (EBS) - Requirements, testing and marking

This document specifies requirements for Emergency Breathing Systems (EBS) for use by helicopter crew and passengers in the event of a ditching or water impact, to ensure minimum levels of performance. It applies to EBS for use by adults only.
Two categories of EBS are addressed by this standard; Category A EBS capable of being successfully deployed in air and underwater and Category B EBS capable of being successfully deployed in air but not underwater.
This document is applicable to compressed air, rebreather and hybrid rebreather designs of EBS.

Drehflügler - Notfallbeatmungssystem (EBS) - Anforderungen, Prüfung und Kennzeichnung

Dieses Dokument legt Anforderungen an Notfallbeatmungssysteme (EBS) fest, die von der Hubschrauberbesatzung und Passagieren im Falle einer Notwasserung oder dem Aufprall auf Wasser verwendet werden, um Mindestniveaus für die Leistung sicherzustellen. Es gilt für EBS nur die Verwendung durch Erwachsene.
Diese Norm befasst sich mit zwei Kategorien von EBS; EBS der Kategorie A, die erfolgreich in der Luft und unter Wasser eingesetzt werden können, und EBS der Kategorie B, die erfolgreich in der Luft, aber nicht unter Wasser eingesetzt werden können.
Dieses Dokument ist anwendbar für Druckluft , Kreislaufatemgerät  und hybride Kreislaufatemgerät-Auslegungen von EBS.

Giravion - Système de ventilation d'urgence (EBS) - Exigences, essais et marquage

Le présent document spécifie les exigences relatives aux systèmes de ventilation d'urgence (EBS) destinés à être utilisés par l'équipage et par les passagers des hélicoptères en cas d'amerrissage forcé ou d'impact avec un plan d'eau, afin de garantir des niveaux minimaux de performance. Elle s'applique uniquement aux EBS destinés à être utilisés par des adultes.
La présente norme couvre deux catégories d'EBS : l'EBS de catégorie A pouvant être correctement déployé à l’air libre et sous l'eau, et l'EBS de catégorie B pouvant être correctement déployé à l'air libre mais pas sous l'eau.
Le présent document s'applique aux modèles d'EBS à masque à recirculation et à masque à recirculation hybride, tous deux à air comprimé.

Rotoplani - Sistem prezračevanja v sili (EBS) - Zahteve, preskušanje in označevanje

Ta tehnični dokument določa zahteve za sisteme prezračevanja v sili (EBS), ki jih uporabljajo helikopterske posadke in potniki v primeru pristanka v sili ali vdora vode, da se zagotovi minimalna raven zahtevanih lastnosti. Velja samo za sisteme prezračevanja v sili (EBS), ki jih uporabljajo odrasli.
Ta standard obravnava dve kategoriji sistemov za prezračevanje v sili; EBS kategorije A, ki se lahko uspešno uvede pod vodo, in EBS kategorije B, ki se lahko uspešno uvede v zraku, ne pa pod vodo.
Ta tehnični dokument se uporablja za modele EBS dihalnih aparatov na stisnjen zrak, z zaprtim krogom in hibridne dihalne aparate z zaprtim krogom.

General Information

Status
Published
Publication Date
11-Dec-2018
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
12-Dec-2018
Completion Date
12-Dec-2018

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SLOVENSKI STANDARD
SIST EN 4856:2019
01-marec-2019
5RWRSODQL6LVWHPSUH]UDþHYDQMDYVLOL (%6 =DKWHYHSUHVNXãDQMHLQ
R]QDþHYDQMH

Rotorcraft - Emergency Breathing Systems (EBS) - Requirements, testing and marking

Rotorkraft - Notfallbeatmungssystem (EBS) - Anforderungen, Prüfung und
Kennzeichnung

Giravion - Système de ventilation d'urgence (EBS) - Exigences, essais et marquage

Ta slovenski standard je istoveten z: EN 4856:2018
ICS:
49.095 Oprema za potnike in Passenger and cabin
oprema kabin equipment
SIST EN 4856:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 4856:2019
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SIST EN 4856:2019
EN 4856
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2018
EUROPÄISCHE NORM
ICS 49.095
English Version
Rotorcraft - Emergency Breathing Systems (EBS) -
Requirements, testing and marking

Giravion - Système de ventilation d'urgence (EBS) - Rotorkraft - Notfallbeatmungssystem (EBS) -

Exigences, essais et marquage Anforderungen, Prüfung und Kennzeichnung
This European Standard was approved by CEN on 8 July 2018.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4856:2018 E

worldwide for CEN national Members.
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EN 4856:2018 (E)
Contents
Page

European foreword ....................................................................................................................................................... 3

Introduction .................................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 6

4 Classification ..................................................................................................................................................... 8

5 Performance requirements ...................................................................................................................... 10

6 Testing .............................................................................................................................................................. 15

7 Marking ............................................................................................................................................................ 27

8 Information supplied by the manufacturer ........................................................................................ 28

(normative) Rating of breathing effort ............................................................................................ 29

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European foreword

This document (EN 4856:2018) has been prepared by the Aerospace and Defence Industries

Association of Europe - Standardization (ASD-STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this Standard has

received the approval of the National Associations and the Official Services of the member countries of

ASD, prior to its presentation to CEN.

This document shall be given the status of a national standard, either by publication of an identical text

or by endorsement, at the latest by June 2019, and conflicting national standards shall be withdrawn at

the latest by June 2019.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
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Introduction

This document prescribes the minimum standards of design and performance for rotorcraft emergency

breathing systems (EBS), used to reduce the risks of drowning in the event of submersion. An

emergency breathing system is a form of personal protective equipment that provides the user with a

means to breathe underwater, thereby improving the probability of successfully escaping from a

submerged rotorcraft cabin. If used correctly, EBS should mitigate the risk of drowning.

This document aims to ensure that the equipment user is able to carry out the necessary emergency

procedures whilst being provided with an appropriate level of protection under foreseeable conditions

of use. It also aims to ensure that the equipment presents a minimal hazard in relation to escape from

the rotorcraft, and that the equipment has no detrimental effect on the health and safety of the user or

on the performance of other equipment.

This document is applicable to all rotorcraft. Rotorcraft include helicopters, tilt rotor/wing and

gyroplanes. For the purpose of this standard the term helicopter is used generically hereinafter.

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1 Scope

This document specifies requirements for Emergency Breathing Systems (EBS) for use by helicopter

crew and passengers in the event of a ditching or water impact, to ensure minimum levels of

performance. It applies to EBS for use by adults only.

Two categories of EBS are addressed by this standard; Category A EBS capable of being successfully

deployed in air and underwater and Category B EBS capable of being successfully deployed in air but

not underwater.

This document is applicable to compressed air, rebreather and hybrid rebreather designs of EBS.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

International standards

EN 250, Respiratory equipment — Open-circuit self-contained compressed air diving apparatus —

Requirements, testing and marking
EN 12021, Respiratory equipment — Compressed gases for breathing apparatus

EN 14143:2013, Respiratory equipment — Self-contained re-breathing diving apparatus

EN ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests (ISO 9227)

EN ISO 12894, Ergonomics of the thermal environment — Medical supervision of individuals exposed to

extreme hot or cold environments (ISO 12894)
EASA publications

EASA, Certification Specifications and Acceptable Means of Compliance for Large Aeroplanes CS-25,

Book 1 — Appendix F
EASA, ETSO-2C502, Helicopter crew and passenger integrated immersion suits

EASA, ETSO-2C503, Helicopter crew and passenger immersion suits for operations to or from helidecks

located in a hostile sea area

EASA, ETSO-2C504, Helicopter constant-wear lifejackets for operations to or from helidecks located in a

hostile sea area

NOTE In the near future it is anticipated that ETSO-2C502, ETSO-2C503 and ETSO-2C504 will be revised and

that the revised documents will make reference to two new standards: prEN/EN 4862 Rotorcraft — Constant

Wear Lifejackets — Requirements, testing and marking and prEN/EN 4863 Rotorcraft — Immersion Suits —

Requirements, testing and marking. It is intended that when these new documents are published they should be

used in place of the ETSO documents currently referenced.
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Other publications

World Medical Association Declaration of Helsinki — Ethical principles for medical research involving

human subjects (as amended): URL https://www.wma.net/policies-post/wma-declaration-of-helsinki-

ethical-principles-for-medical-research-involving-human-subjects/
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
Emergency Breathing System
EBS

system that allows a person to breathe underwater, overcoming the need to breath-hold for the

complete duration of an underwater escape from a helicopter, that can be deployed under emergency

conditions
3.2
rotorcraft

heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or

more rotors
3.3
helicopter

rotorcraft that, for its horizontal motion, depends principally on its engine-driven rotors

3.4
ditching

controlled emergency landing on water, deliberately executed in accordance with Rotorcraft Flight

Manual procedures, with the intent of abandoning the rotorcraft as soon as practical

3.5
water impact

helicopter contact with water that is unintentional or exceeds the ditching capability of the helicopter

for water entry
3.6
mouthpiece

device that goes into the mouth of the user, usually held by the teeth, sealing against the lips and

through which a breathable gas is inhaled and exhaled
3.7
nose occlusion system
means of preventing water from entering the nose
Note 1 to entry: A nose clip is one example of a nose occlusion system.
3.8
demand regulator
device which consists of a pressure reducer connected to a demand valve
3.9
medium pressure hose

hose with an interface connection at each end, between the pressure reducer and a demand valve

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3.10
breathing hose

flexible hose connecting a counterlung to the mouthpiece of a rebreather EBS, at approximately ambient

pressure
3.11
pressure indicator
device to indicate to the user the pressure of gas in a cylinder
3.12
purging device

part of the demand regulator that can be operated manually to deliver breathable gas, intended to force

water out of the mouthpiece
3.13
dead space

volume of the cavity formed between the mouth and the inhalation and exhalation parts

3.14
activation device

mechanism which switches breathing from the atmosphere to the counterlung of a rebreather EBS

3.15
counterlung
variable volume container for the user to exhale to and inhale from
3.16
breathable gas
gas that will support life under the intended conditions of use
3.17
work of breathing

work expended during one breathing cycle which is proportional to the area bounded by the pressure

volume diagram divided by the tidal volume
Note 1 to entry: Measured in Joules per litre.
3.18
respiratory pressure

differential pressure at the mouth relative to the no flow pressures measured at the end of inhalation

and exhalation
3.19
hydrostatic imbalance

difference at end exhalation no flow between the pressure at the mouth and that at the lung centroid

reference point
3.20
tidal volume

volume of breathing gas displaced by the breathing simulator during one half cycle (inhalation or

exhalation)
Note 1 to entry: Measured in litres.
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3.21
respiratory minute volume
product of the tidal volume and breathing frequency
Note 1 to entry: Measured in litres per minute.
3.22
useable volume of air

volume of breathable air available to the user while the demand regulator is operating within the

specified breathing performance
3.23
rated working pressure
maximum working pressure of the respective components
3.24
pressure volume diagram

diagram generated during one breathing cycle by plotting the respiratory pressure against the

displaced (tidal) volume
3.25
elastance
change in pressure that results from a given volume change of the human lung
Note 1 to entry: Measured in kPa.L

Note 2 to entry: This is a typical term for the elastic behaviour of a breathing system.

3.26
reference pressure

equilibrium pressure which exists in the mouthpiece when there is no respiratory flow at the end of

exhalation
3.27
escape buoyancy

buoyancy of the combination of an EBS, uninflated lifejacket and immersion suit (as appropriate) to be

overcome when escaping from an immersed helicopter

Note 1 to entry: Escape buoyancy includes the inherent buoyancy of the components of the suit system and

entrapped air but excludes the inflated buoyancy of an inflatable buoyancy element when fitted to the suit.

3.28
crew member
person assigned by an operator to perform duties on board an aircraft
4 Classification
4.1 Design types
4.1.1 Compressed air EBS

A compressed air EBS is a system where air or some other breathable gas is supplied to the user on

demand from a high pressure gas cylinder, the period of breathing being limited by the volume of

useable gas.
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The apparatus shall comprise at least the following components:
 mouthpiece;
 medium pressure hose;
 gas cylinder;
 demand regulator;
 pressure indicator;
 purging device;
 nose occlusion system.
4.1.2 Rebreather EBS

A rebreather EBS is a system with a counterlung which allows the user to move air out of and back into

their lungs, the period of rebreathing being limited by a build-up of carbon dioxide and a reduction in

oxygen concentration.
The system shall comprise at least the following components:
 mouthpiece;
 breathing hose;
 counterlung;
 activation device;
 nose occlusion system.
4.1.3 Hybrid rebreather EBS

A hybrid rebreather EBS is a rebreather system that incorporates a compressed gas cylinder, allowing a

small volume of air or other breathable gas to be introduced into the counterlung, the period of

rebreathing being limited by a build-up of carbon dioxide and a reduction in oxygen concentration.

The system shall comprise at least the following components:
 mouthpiece;
 breathing hose;
 counterlung;
 gas cylinder with gas release system;
 activation device;
 nose occlusion system.
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4.2 Performance levels
4.2.1 Category A EBS

Category A systems have the capability to be rapidly deployed and used both in air and underwater.

These designs of EBS are suitable for use when capsize and/or sinking occurs immediately after the

helicopter makes contact with the water.
4.2.2 Category B EBS

Category B systems have the capability to be deployed in air and used both in air and underwater.

These designs of EBS are suitable for use where there is sufficient time to deploy the equipment prior to

any subsequent submersion. Category 'B'B systems have limited capability in water impact accidents as

capsize and/or sinking is likely to occur immediately after the helicopter makes contact with the water.

5 Performance requirements
5.1 General

5.1.1 Where applicable, EBS shall be tested in combination with associated equipment, including a

constant wear aviation lifejacket and/or constant wear immersion suit that it is intended to be worn

with, in accordance with 6.8. It shall be deployed in the same manner as it would be in normal service,

and from the intended stowed position (6.1 and 6.8.3).

5.1.2 If a compressed breathable gas other than air is used, additional assessment and testing might be

required. This shall be determined following visual inspection in accordance with 6.1.

5.2 Design

5.2.1 The EBS shall be practicable in use and light in weight without prejudice to the design strength

and performance. Testing shall be carried out in accordance with 6.1 and 6.8.

5.2.2 The EBS shall be simple to deploy and capable of being operated with either hand. The number

of deployment actions shall be minimized; for example, no more than one action should be required to

activate a rebreather system on submersion, i.e. opening the valve of the counterlung. Testing shall be

carried out in accordance with 6.1, 6.8.3 and 6.8.4.

5.2.3 The equipment shall not have any sharp edges or protruding parts which might injure the user,

or damage the lifejacket, immersion suit or other emergency equipment. Testing shall be carried out in

accordance with 6.1 and 6.8.

5.2.4 Compressed air EBS shall provide the user with a minimum useable volume of air of 50 L

Standard Temperature and Pressure Dry (STPD), meeting the requirements of EN 12021. Testing shall

be carried out in accordance with 6.1 and 6.5.

5.2.5 Where a counterlung is incorporated into a rebreather system, the counterlung shall have

sufficient breathable capacity to accommodate an expired volume of at least 6 L (STPD). In the case of a

hybrid rebreather EBS, additional capacity shall be provided equivalent to the volume of breathable gas

discharged into the counterlung from the gas cylinder. The counterlung shall be designed to prevent

collapse, taking panic breathing into account. Testing shall be carried out in accordance with 6.1 and

6.6.
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5.2.6 In EBS designed for underwater deployment (Category A), the design shall minimise the amount

of water that can enter the mouthpiece (dead space). It shall be possible to expel this water from the

mouthpiece. Testing shall be carried out in accordance with to 6.1, 6.8.3.2, 6.8.4.4, 6.8.4.6 and 6.8.4.7.

5.2.7 Subjects shall be provided with a means to prevent water entering the nose that is easy to deploy

and effective when used underwater. Nose occlusion systems (including nose clips) shall be designed to

fit a wide range of user sizes. Nose clips shall be easy to open with either hand and shall be permanently

attached to the EBS, on or adjacent to the mouthpiece. Testing shall be carried out in accordance with

6.1 and 6.8.

5.2.8 Where an EBS includes a harness to fit the EBS to the body, this shall allow correct positioning

on the body when used according to the manufacturer's instructions. Testing shall be carried out in

accordance with 6.1 and 6.8.

5.2.9 Gas cylinders and connections with demand regulators shall comply with the appropriate

European specifications and shall be approved and tested with respect to the rated working pressure.

Testing shall be carried out in accordance with 6.1.

5.2.10 Leakage from compressed air EBS shall not exceed 10% of the initial cylinder pressure, in any

single case, when tested in accordance with 6.5.6.
5.3 Materials

5.3.1 The materials used shall have adequate mechanical strength to resist damage. Testing shall be

carried out in accordance with 6.1, 6.5, 6.8.3, 6.8.4 and 6.9.

5.3.2 The materials used shall have sufficient resistance to changes caused by the effects of

temperature. There shall be no signs of degradation to the materials and the EBS shall remain

functional following temperature cycling, when tested in accordance with 6.4.

5.3.3 Any fabric integral to the EBS and not part of a lifejacket or suit system, used to cover, retain or

secure the EBS on the user shall be of low flammability.

The cover fabric shall as a minimum meet the vertical test of CS-25 Appendix F Part 1 (a)(1)(ii) (or as

amended). Fabrics used to retain or secure the EBS on the user shall as a minimum meet the horizontal

test of CS-25 Appendix F Part 1 (a)(1)(iv) (or as amended).

5.3.4 All metallic components shall be made of corrosion-resistant materials or be protected from

corrosion. Metallic components shall not be significantly affected by corrosion when tested in

accordance with the neutral salt spray (NSS) test of EN ISO 9227 for a period of 160 h.

The EBS shall not affect a magnetic compass by more than 1° when placed 300 mm from the compass.

Testing shall be carried out in accordance with 6.3.

5.3.5 Any high or medium pressure parts and connections shall meet the requirements of EN 250.

5.3.6 All parts that have to be cleaned and/or disinfected shall be easy to clean, be insensitive to the

cleaning agents and disinfectants recommended by the manufacturer and remain functional after

having been cleaned or disinfected. Recommended cleaning or disinfectant products shall not be known

to have any adverse effect on the user. Testing shall be carried out in accordance with 6.1.

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5.4 Compatibility

5.4.1 EBS intended for use by crew members shall be designed such that, when stowed, the crew

member shall be able to carry out all normal and emergency procedures, without undue impediment or

discomfort. Testing shall be carried out in accordance with 6.10.

5.4.2 The EBS shall not impair the performance of a seat harness or hinder harness release. The EBS

shall not impede or prevent escape from a submerged helicopter. Testing shall be carried out in

accordance with 6.8.3, 6.8.4 and 6.10.

5.4.3 The EBS shall not impede or prevent the boarding of a helicopter liferaft. At least two thirds of

the test subjects shall be able to board the liferaft without assistance, and the remaining test subjects

shall be able to board the liferaft with the assistance of no more than one other test subject, with the

EBS worn as used. Testing shall be carried out in accordance with 6.8.4.8.

5.4.4 The EBS shall not impair the performance of, and shall be compatible with, any lifejacket or

immersion suit that is intended to be worn with it. The performance of the EBS, immersion suit and/or

lifejacket combination shall be tested in accordance with 6.1, 6.8.1.2, 6.8.3, 6.8.4, 6.8.5 and 6.10 of this

standard, and the compatibility requirements of ETSO-2C502, ETSO-2C503 or ETSO-2C504, as

appropriate.

5.4.5 Potential snagging hazards shall be reduced to a minimum. Any part of the EBS that might pose a

snagging hazard during flight, emergency evacuation, escape or rescue shall be suitably covered,

protected or restrained. Testing shall be carried out in accordance with 6.1, 6.8.4.5, 6.8.4.6, 6.8.4.8,

6.8.4.9 and 6.10.
5.5 Breathing performance
5.5.1 General

The work of breathing, respiratory pressures, hydrostatic imbalance and extreme cold water

requirements specified in 5.5.2 to 5.5.5 shall be met under the following conditions:

 simulated breathing using a sinusoidal waveform, with respiratory minute volumes as shown in

Table 1;
0

 in water at a temperature of (4 ) °C, and extreme cold water (5.5.5) if specified by the

manufacturer;

 simulated orientations of vertical (pitch +90°), inverted (pitch −90°) and face-down (pitch 0°) with

zero roll.
NOTE Pitch and roll definitions are as described in EN 14143.

When tested in accordance with 6.5, dynamic performance shall be determined from a pressure volume

diagram (see Figure 1 and Figure 2) generated by plotting pressure against displaced volume.

5.5.2 Work of breathing
−1 −1

Work of breathing shall not exceed 3,0 JL at ventilation rates up to and including 62,5 L.min ATP.

The EBS shall remain functional at ventilation rates up to 75 L.min ATP. Testing shall be carried out

in accordance with 6.5.1, 6.5.2, 6.5.3 and 6.5.4.
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5.5.3 Respiratory pressures

Peak-to-peak respiratory pressure shall be determined as shown in Figure 1 (compressed air EBS) or

Figure 2 (rebreather and hybrid rebreather EBS), expressed as b, and shall not exceed 5,0 kPa

(50 mbar).

For compressed air EBS peak expired respiratory pressure, expressed as c in Figure 1, shall not exceed

2,5 kPa (25 mbar) and peak inspired respiratory pressure, expressed as d in Figure 1, shall not exceed

2,5 kPa (25 mbar).

For rebreather EBS (including hybrid rebreather EBS) the elastance of the system, determined as

−1 −1
shown in Figure 2 and expressed by c/a, shall not exceed 1 kPa.L (10 mbar.L ).
For compressed air EBS the demand regulator shall not free-flow during testing.
Testing shall be carried out in accordance with 6.5.1, 6.5.2, 6.5.3 and 6.5.4.
5.5.4 Hydrostatic imbalance

For rebreather EBS (including hybrid rebreather EBS), hydrostatic imbalance shall be between

+2,5 kPa (+25 mbar) and −2,5 kPa (−25 mbar) relative to lung centroid pressure. Testing shall be

carried out in accordance with 6.5.5.
5.5.5 Extreme cold water temperatures

If the EBS is intended for use in water temperatures less than 4 °C the manufacturer shall state the

minimum operational temperature. The breathing performance of the EBS shall also be tested and meet

the requirements of 5.5.2 to 5.5.4 at the surface (immersed to a depth sufficient to preclude surface

effects) at that temperature. Testing shall be carried out in accordance with 6.5.

5.6 Safety devices

5.6.1 For a compressed air EBS, a pressure indicator shall be provided to confirm that there is

adequate gas in the cylinder. An indicator shall be provided to show that the system is ready for use.

Testing shall be carried out in accordance with 6.1.

5.6.2 For hybrid rebreather EBS, the gas cylinder shall have a status indicator to show that the gas

release system is in a ready to use condition. Testing shall be carried out in accordance with 6.1.

5.6.3 For rebreather and hybrid rebreather EBS, it shall be possible to check that the EBS is ready for

use and has not been tampered with. Testing shall be carried out in accordance with 6.1.

5.6.4 Where a security tag or anti-tamper stitching is used, this shall be a weak link that is easy to

break during emergency deployment. Testing shall be carried out in accordance with 6.1 and 6.8.3.1.

5.6.5 The risk of inadvertent operation or activation by the user shall be minimized, including the

inadvertent release of gas from a cylinder. Testing shall be carried out in accordance with 6.1, 6.8 and

6.10.
5.7 Deployment

5.7.1 It shall be possible to fully deploy Category A EBS in less than 12 s, using one hand only (this

time shall include deployment of the nose occlusion system). This shall be achievable with both the

right hand and the left hand. It shall be possible to deploy the mouthpiece within 10 s (this time may

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SIST EN 4856:2019
EN 4856:2018 (E)

exclude deployment of the nose occlusion system). Testing shall be conducted in dry conditions, in

accordance with 6.8.3.1.

5.7.2 It shall be possible to fully deploy Category B EBS in less than 20 s, using one hand only. This

shall be achievable with both the right hand and the left hand. Testing shall be conducted in dry

conditions, in accordance with 6.8.3.1.

5.7.3 For EBS designed for underwater deployment (Category A EBS) it shall be demonstrated that full

deployment can be achieved, with each hand, following submersion. Test subjects shall be able to clear

water from the mouthpiece if necessary, achieve a good seal at the mouth and breathe from the EBS.

Testing shall be carried out in accordance with 6.8.3.2.

It shall be possible to deploy Category A EBS when inverted underwater following a 180° sideways roll.

Testing shall be carried out in accordance with 6.8.4.4.
5.8 Ease of use and manoeuvrability in water

5.8.1 Test subjects shall be able to achieve a good seal at the mouth, whilst manoeuvring underwater

in different orientations including the face-down (prone) position. This shall be tested in accordance

with 6.8.4.1.

5.8.2 Each test subject shall demonstrate their ability to use the EBS for at least 60 s whilst pulling

themselves along an underwater rail in the face-down position. This shall be tested in accordance with

6.8.4.2.

5.8.3 Each test subject shall demonstrate their ability to use the EBS for at least 60 s whilst inverted.

This shall be tested in
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