ISO 8185:1988

IS0
INTERNATIONAL STANDARD
First edition
1988-03-15
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
ORGANISATION INTERNATIONALE DE NORMALISATION
MEXAYHAPOAHAR OPrAHL43A~MR il0 CTAH/JAPTMSAUMM
e
Humidifiers for medical use - Safety requirements
Humidificateurs médicaux - Exigences de sécurité
O
Reference number
IS0 8185 : 1988 (E)
IS0 8185 : 1988 (E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
(IS0 member bodies). The work of preparing International
national standards bodies
Standards is normally carried out through IS0 technical committees. Each member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council. They are approved in accordance with IS0 procedures requiring at
least 75 % approval by the member bodies voting.
International Standard IS0 8185 was prepared by Technical Committee ISO/TC 121,
Anaesthetic and respiratory equipment.
Users should note that all International Standards undergo revision from time to time
and that any reference made herein to any other International Standard implies its
latest edition, unless otherwise stated,
O International Organization for Standardization, 1988 0
Printed in Switzerland
IS0 8185 : 1988 (E)
Contents
Page
O Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Sections
One - General . 1
O
Two - Safety requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Three - Protection against electric shock hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Four - Protection against mechanical hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Five - Protection against hazards from unwanted or excessive radiation . . . . . . . . 10
Six - Protection against the hazards of explosions in medically used rooms . . . . . 10
Seven - Protection against excessive temperatures, fire and other hazards, such
as human errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Eight - Accuracy of operating data and protection against incorrect output . . . . . 13
Nine - Fault conditions causing overheating and/or mechanical damage;
environmental tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Ten - Constructional requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Annexes
Flammability tests for anaesthetic agents to establish their suitability for use
N
with equipment not classified "AP/APG" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Rationale statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
O
I
IS0 8185 : 1988 (E)
INTERNATIONAL STANDARD
Humidifiers for medical use - Safety requirements
It has not been found possible to include guidance on the matter
O introduction
of droplet size in the case of nebulizing humidifiers.
Humidifiers are used to raise the water content of gas delivered
to the respiratory tract of patients, since the gases generally A rationale for the most important requirements is given in
available for medical use lack sufficient moisture to be annex O. It is considered that a knowledge of the reasonsfor the
physiologically acceptable to the respiratory tract. Heat may be requirements will not only facilitate the proper application of this
employed to increase the water output of the humidifier and International Standard, but will expedite any subsequent re-
vision. This annex does not form an integral part of thestandard.
0 thereby enhance patient comfort.
Section one - General
1 Scope and field of application Requirements for heat and moisture exchangers are given in
IS0 9360 (in preparation).
IS0 8185 is one of a series of International Standards based on
IEC Publication 601-1; in IEC Publication 601-1 (the "General
2 References
Standard"), this type of International Standard is referred to asa
"Particular Standard". As stated in 1.3 of IEC Publication 601-1,
IS0 2882, Rubber, vulcanized - Antistatic and conductive pro-
the requirements of this International Standard take precedence
ducts for hospital use - Electrical resistance limits.
over those of IEC Publication 601-1.
IS0 3744, Acoustics - Determination of soundpower levels of
Humidifiers may be gas-powered, electrically powered or both.
noise sources - Engineering methods for free- field conditions
However, this International Standard has been prepared as a
over a reflecting plane.
Particular Standard based on IEC Publication 601-1, which gives
general requirements for all aspects of safety, not only electrical
IS0 5356, Anaesthetic and respiratory equipment - Conical
safety, and many of the requirements are therefore applicable to
-
connectors
humidifiers not powered by electricity. Where this International
0 Part 7 : Cones and sockets.
Standard specifies that a clause of IEC Publication 601-1 applies,
it means that the clause applies only if the requirement is relevant
Part 2: Screw-threaded weight-bearing connectors.
to the humidifier under consideration.
IS0 5367, Breathing tubes used with anaesthetic apparatus and
The scope and object given in clause 1 of IEC Publication 601-1
ventilators.
applies except that LI shall be replaced by the following :
79, Electrical apparatus for explosive gas
IEC Publication
This International Standard specifies requirements for the
atmospheres -
safety of vaporizing and nebulizing humidifiers, including
Part 3 : Spark test apparatus for intrinsically-sa fe circuits.
those suitable for inclusion in breathing systems, for use with
both intubated and non-intubated patients.
Part 4: Method of test for ignition temperature.
This International Standard also includes requirements for
IEC Publication 601, Safety of medical electrical equipment -
delivery tubes and accessory devices intended to control
Part I : General requirements. 1
humidifier or delivery tube heaters.
Part 2: Particular requirements for safety of baby incu-
Devices commonly referred to as "room humidifiers" and
bators. 2)
humidifiers used in heating, ventilation and air conditioning
systems are outside the scope of this International Standard.
IEC Publication 651, Sound level meters.
1) Cross-references to specific clauses, sub-clauses, etc. in IEC Publication 601-1 apply to the first edition published in 1977 and Amendment No. 1 to
IEC Publication 601-1 published in 1984.
2) At present at the stage of draft [reference No. : 62D(C.O.)381.
IS0 8185 : 1988 (E)
3.13 liquid container: The container incorporated in the
3 Definitions
humidifier which is the direct source of liquid for the
humidification chamber.
NOTE - Attention is drawn to the definitions given in IS0 4135,
Anaesthesiology I- Vocabulary.
NOTE - The liquid container may be detachable for filling.
For the purposes of this International Standard, the definitions
given in clause 2 of IEC Publication 601-1 apply except that the
3.14 liquid output: The total mass of liquid present in
definition given in 2.1.5 shall be replaced by the following :
the inspired gas, expressed in milligrams per litre or in grams
per cubic metre.
applied part: The delivery tube outlet or, if a delivery tube
is not normally fitted or used, the humidifier outlet.
3.15 liquid reservoir: A reservoir from which the liquid
container may be replenished or which, in the absence of a
For the purposes of this International Standard, the following
additional definitions also apply : liquid container, supplies liquid directly to the humidification
chamber.
3.1 absolute humidity: The mass of water vapour
present in unit volume of moist gas, expressed in milligrams
3.16 operating volume: The volume of liquid intended
per litre or in grams per cubic metre.
to be contained by the liquid container during normal use.
3.2 accessible surface temperature : The temperature
3.17 maximum operating pressure : The maximum
of any surface which can be touched by a hand or finger
pressure in the humidification chamber during normal use.
during normal use, including filling and refilling of the
humidifier .
3.18 nebulizing humidifier: A humidifier from which
the liquid output is predominantly in the droplet phase.
3.3 delivered gas temperature : The temperature of the
gas, or aerosol, or both, that is being delivered to the
NOTE - Because the droplets themselves evaporate, there is also
patient, measured at the patient end of the breathing
some liquid in the vapour phase.
system.
3.19 operator control : A control, usually a knob, push-
delivery tube: The tube conveying humidified gas
3.4 button or lever, provided to enable the user to cause the
from the humidifier outlet.
humidifier to perform its intended function without the need
for tools.
delivery tube heater: A device to add heat to gas in
3.5
the delivery tube.
operator indicator : A means provided to indicate a
3.20
mode, state or condition of operation to the operator.
delivery tube outlet: The termination of the delivery
3.6
tube to which the patient connection may be made.
3.21 relative humidity: The water vapour pressure at a
particular temperature expressed as a percentage of the
3.7 heat and moisture exchanger: A device which saturation vapour pressure over a plane water surface at the
preserves a portion of the expired humidity and heat energy same temperature.
and returns it during inspiration.
3.22 saturation vapour pressure : The partial pressure
3.8 humidification chamber: That part of the
of water vapour at a given temperature at a liquid-gas inter-
humidifier from which water or water-based medicament,
face when free evaporation ceases.
referred to in this International Standard as "liquid", is im-
mediately derived for the humidification of inspired gas.
3.23 thermal hazard : A hazard resulting from fire,
excessive surface temperature, excessive delivered gas
3.9 humidifier: A device to add water to the inspired
temperature, or all three.
gas, in addition to that already in the breathing system.
NOTE - Any toxic materials resulting from abnormal temperatures
NOTE - This term includes both nebulizing and vaporizing
also constitute a thermal hazard.
humidifiers.
3.24 usable capacity of the liquid container : The dif-
humidifier heater : A system designed to provide
3.10
ference, in millilitres, between the maximum and minimum
heat to humidifier fluids.
operating volumes.
3.11 humidifier outlet: The port of the humidifier from
vaporizing humidifier: A humidifier from which
3.25
which gas flows.
the liquid output is predominantly in the vapour phase.
3.12 humidifier outlet temperature : The temperature
NOTE - Condensation of vapour results in some of the liquid out-
of the humidified gas, measured at the humidifier outlet.
put not being in the vapour phase.
IS0 8185 : 1988 (E)
3) in the heated and unheated modes, if the
4 General requirements and general
humidifier is designed to operate in both modes; if
requirements for tests
the humidifier is heated, the temperature measured
at the datum plane of the test shall be recorded con-
The requirements given in clauses 3 and 4 of IEC Publi-
tinuously for the duration of the tests.
cation 601-1 apply except for the following additions and
modifications :
The following measuring equipment shall be used :
i)
- amend as follows:
1) gas-flow-measuring equipment calibrated to an
accuracy of f 5 % of the reading in the range
The ambient temperature for the duration of tests shall
1 I/min to 200 I/min, corrected for the test
be between 17 OC and 25 OC.
temperature;
-
in 4.6, add the following items:
-
2) an oxygen analyser with an accuracy of
k 1 % ( V/ V) of oxygen or better.
e) The test gas shall be either air or oxygen at a known
concentration. The humidity of the test gas shall not
O, 12 mg/l (0,12 g/m3), equivalent to a dew point
exceed
5 Classification
of - 40 OC (see table below).
The classification given in clause 5 of IEC Publication 601-1
Table - Vapour pressures and quantities of water
applies except that the following addition shall be made to __ 5.2:
vapour above ice as a function of the temperature
In general, conduction paths will exist and an electrically
Temperature Pressure Humidity
powered humidifier shall not be type BF or type CF equip-
OC Torr 1)
ment unless there are instructions against any connection
4,579 which may provide an electrical path to earth.
O
4,s
-5 3,008 3.24
2,17
- 10 1,95
6 Identification, marking and documents
- 15 1,24 1,38
- 20 0,77
0.88
The requirements given in clause 6 of IEC Publication 601-1
- 25 0.47 0,55
apply except for the following additions and modifications :
- 30 0,28 0,33
- The following additional general requirement also
- 35 0,17 0,206
applies :
- 40 0,093 0,115
0,052 0,066
- 45
All markings pertaining to the operation of the humidifier
-50 0,029 0,038
(e.g. filling lines of the liquid container, venturi
adjustments, etc.) shall be legible to an operator having
1 Torr = 1 mmHg = 133,322 Pa
1)
visual acuity, corrected if necessary, of at least 1 seated
or standing 1 m from the humidifier at an illuminance of
f) The liquid container, if provided, shall be filled
215 Ix.
initially to the maximum operating volume with distilled
or deionized water at the ambient test temperature. The
NOTES
liquid reservoir, if provided, shall be filled with distilled or
deionized water in accordance with the manufacturer’s
1 Marking should not be obscured by the hand normally used
to operate the associated controls.
instructions.
2 All markings should have a luminance contrast of at least
g) The datum plane for measurements shall be a
50 % when compared with the surrounding background
transverse plane within 10 mm of the inlet of a test
materials.
chamber having a wall thickness of between 2 mm and
3 mm and being in the form of a tube of polycarbonate -
In __ 6.1 e), add the following :
or acrylic resin with a smooth interior surface and
55 2 5 mm in length. The internal diameter of the
The humidifier shall be marked with its country of origin.
chamber shall be approximately that of the internal
-
diameter of the delivery tube outlet (or humidifier outlet, In __ 6.1, add the following additional item :
if appropriate).
y) The marking on the outside shall also include the
following :
h) Tests shall be performed for all the possible com-
binations of the following :
1) The maximum and minimum liquid levels, if
these are necessary for the correct operation of the
1) for the inlet flow: minimum, mean and maximum
values of the recommended usable flow; humidifier,
2) The direction of flow, in the case of flow-
2) for operator control settings: the minimum,
mean and maximum values for all operating controls; direction-sensitive humidifiers. 7)
See also annex O (in this International Standard).
1)
4.5
IS0 8185 : 1988 (E)
3) If a pressure-relief mechanism is provided, the In 6.8.3a), add the following :
range of pressures, in kilopascals or conventional
centimetres of water, at which it opens. This marking The technical description shall also include the following
shall be on or near the relief device. 1) information :
4) If the humidifier is driven by compressed gas, the 1) The intended use of the humidifier (e.g. in
anaesthesia, in respiratory care, at home or in
ranges of the supply flows or pressures that are re-
quired. hospital) : whether or not the humidifier is suitable for
use with intubated patients or for inclusion in ven-
5) If the humidifier is capable of producing a water tilator or other positive pressure breathing systems. 1)
content greater than 44 mg/l(44 g/m3), thewarning :
2) The usable capacity, in millilitres, of the liquid
"CAUTION - EXCESSIVE QUANTITIES OF container of the humidifier and that of the liquid
WATER CAN BE DELIVERED" reservoir, if provided.
3) The statement "THE CONTAINERS AND
-
In - 6.3, add the following additional item :
RESERVOIRS OF HUMIDIFIERS INTENDED FOR
USE IN HOSPITAL SHOULD BE FILLED WITH
f) The effect of movement of all controls shall be in-
STERILE LIQUID".
dicated by either the position of the control or a coupled
indicator.
4) The warning "THE TEMPERATURE OF LIQUID
INTRODUCED INTO THE LIQUID CONTAINER
NOTE - The direction of control movement necessary to cause
OR RESERVOIR DURING FILLING SHALL NOT
the controlled function to increase should be clearly marked on
EXCEED 37 OC".
or next to the control.
5) If the humidifier includes an integral mechanism
-
Replace - 6.7 by the following1):
air for the purpose of diluting oxygen,
which entrains
or if it can be supplied with supplementary oxygen, a
If visual indicators used on the humidifier are not ident-
recommendation that the oxygen concentration
ified by marking, with the exception of alphanumeric
should be measured at the point of delivery to the
displays, their colouring shall conform to the following
patient.
requirements :
6) If the humidifier is powered by pressurized gas,
II Continuous red shall be used to indicate to the
the recommended ranges of flows or supply
operator that the humidifier or a portion of it has
pressures and method(s1 of connection.
failed.
7) The maximum operating pressure,
2) Flashing red shall be used to denote an emerg-
ency condition requiring an immediate response by
8) If the humidifier is intended to deliver a mean gas
the operator, e.g. in the case of a potential thermal
flow in excess of 30 I/min, the recommended
hazard. Flashing red indicators shall be regularly
minimum and maximum gas flows. 1)
intermittent.
9) If the humidifier is intended for use with a spon-
be used to denote a condition in
3) Yellow shall
taneously breathing patient, the pressure drop, in
which there is need for caution or re-check, or in
kilopascals or conventional centimetres of water, as a
which an unexpected delay is experienced, e.g. when
function of flow, at the minimum and maximum
the liquid reservoir requires filling.
flows recommended by the manufacturer and at one
intermediate flow.
Green shall be used to indicate that the humidi-
4)
fier is ready for use or in use.
IO) The gas leakage, in millilitres per minute, of the
humidifier at the maximum operating pressure.
5) Blue shall be used only as an advisory indicator.
11) If the tidal volume of the patient can be
Compliance shall be checked by functional test and
influenced by the inclusion of the humidifier in a
inspection.
breathing system, the internal compliance (sub-
tracting gas leakage) of the humidifier and, if pro-
-
In 6.8.2, replace item d) by the following : vided, its delivery tube. If the internal compliance can
be affected by a change in the volume of liquid in the
if the humidifier, its delivery tube or its breathing system liquid container, the compliance at the maximum and
components, if provided, are re-usable, the instructions
minimum operating volumes shall be stated in
for use shall contain details of suitable cleaning, disinfec- millilitres per conventional centimetre of water or
tion and sterilization techniques. millilitres per kilopascal. 1)
See also annex O (in this International Standard).
1)
IS0 8185 : 1988 (E)
20) Instructions for the operating and maintenance
12) The liquid output of the humidifier, in milli-
of the humidifier (including calibration if this is to be
grams per litre or in grams per cubic metre, within the
carried out by the user).
operating range of gas flows and temperatures.
21) A statement as to whether or not the humidifier
NOTE - This may be expressed conveniently in the form of
is intended for single use.
a graph comprising at least three points and including
approximations of the maximum, mean and minimum
22) Filling instructions and the need for sterility.
flows.
23) If particular agents, such as anaesthetic gases
and vapours, impair the performance of the humidi-
If relative humidity is used as an index of liquid out-
fier outside the requirements of this International
put, the temperature and the point of measurement
Standard, a statement to that effect.
shall be stated.
If the humidifier is intended for use with a delivery
13) If the humidifier can deliver a liquid output
tube, the manufacturer shall either identify at least
greater than 44 mg/l (44 g/mJ), the conditions under
one accessory delivery tube which does not impair
which this occurs.
the performance of the humidifier or shall state the
performance of the humidifier with a designated
14) If the use of delivery tubes other than those
delivery tube.
supplied or recommended by the manufacturer will
NOTE - The manufacturer or supplier should provide
impair the safety or effectiveness of the humidifier,
examples of the different functions of the humidifier under
the statement "THE USE OF DELIVERY TUBES NOT
e typical operating conditions.
RECOMMENDED FOR USE WITH THIS PRODUCT
MAY IMPAIR ITS PERFORMANCE AND SAFETY".
24) Unless it can be demonstrated that the
humidifier is not susceptible to electromagnetic inter-
15) For a heated humidifier, the warm-up time re-
ferenCe, the instructions for use shall include the
quired for it to reach operating temperature from a
statement "FUNCTION OF THIS HUMIDIFIER MAY
starting temperature of 21 IT 2 OC.
BE ADVERSELY AFFECTED BY THE OPERATION
OF HIGH-FREQUENCY SURGICAL APPARATUS
16) For a heated humidifier, the range of delivery
OR SHORT-WAVE OR MICROWAVE EQUIPMENT
tube outlet temperatures at a stated ambient
IN THE VICINITY".
temperature ( f 2 OC) between 17 OC and 25 OC, and
25) Details of all materials used in the construction
advice that the user should monitor the delivered gas
of the humidifier which may come into contact with
temperature. The manufacturer shall draw the atten-
respirable gases delivered to the patient.
tion of the user to any circumstances during the per-
formance of the tests given in 42.3.3, 42.3.4, 42.3.5
NOTE - In some countries there are national regulations
and 50.5 (in this International Standard) in which the
concerning the biocompatibility of materials used in
temperature exceeds 41 OC. He shall advise the user
anaesthetic equipment.
to monitor the gas temperature continuously at the
26) A statement as to whether or not the humidifier
delivery tube outlet (or, if the humidifier is intended
is suitable for use with anaesthetic agents.
for use without a delivery tube, at the humidifier
outlet) using a device, which may be free-standing,
In 6.8.4, add the following :
___
giving auditory and visible high-temperature alarms
when the temperature exceeds 41 OC.
The additional information required to be given in the
O
technical description as specified in 6.8.3a) items 91, lo),
17) If the manufacturer supplies a delivery tube
11 1, 15) and 18) (in this International Standard), shall be
heater, which delivery tube(s) to use and whether or
obtained by carrying out the tests described in 6.8.4.1
not degradation of anaesthetic agents is liable to take
to 6.8.4.5.
place.
6.8.4.1 Flow resistance
18) If, when tested under the conditions given in
4.6 h), the temperatures of any of the accessible sur- Measure the pressure drop between plane A and plane B
faces of the humidifier exceeded 55 OC, if metal, or as shown in the figure. If the humidifier is intended for
I
75 OC, if non-metal. use with a delivery tube, fit a delivery tube rec-
ommended by the manufacturer for the duration of the
19) If, when tested as described in 6.8.4.5, the
test. Plane A shall be a maximum of 10 mm from the
A-weighted sound pressure level exceeds 60 dB, the
humidifier inlet and plane B shall be a maximum of
circumstances under which this occurs. 1)
10 mm from the humidifier outlet or, if the humidifier is
I
intended for use with a delivery tube, from the delivery
NOTE - If an attachment intended for a particular
tube outlet.
therapeutic application reduces the A-weighted sound
The internal diameters of any adaptors used in the test
pressure level to 60 dB or below, the manufacturer should
shall be not less than the internal diameters of the
state in which part of parts of the operating range this
occurs. humidifier inlet and outlet ports.
See also annex O (in this International Standard).
1)
IS0 8185 : 1988 (E)
Dimensions in millimetres
High-pressure gas inlet (applicable only to
humidifiers which use additional driving gas
to nebulize the liquid)
p1 ca>,31-\
II
\
Inlet from atmosphere or
patient connection port -e
or breathing machine
PlaneA
b- Plane B
10 max.
L 10 max.
I
Figure - Test apparatus for flow resistance in a humidifier through which a patient may breathe spontaneously
(see 6.8.4.1 )
6.8.4.2 Gas leakage gas temperature (or humidifier gas outlet temperature, if
appropriate) recommended by the manufacturer.
Occlude all ports of the humidifier except one. Apply the
Elapsed time from switch-on to attainment of the set
maximum operating pressure, as stated by the manufac-
temperature shall be measured. The measurement shall
turer, plus 10 % (i.e. 1,l times maximum operating
be made in the datum plane of the test chamber.
pressure) to the open port by injection of air from a
graduated syringe. The pressure shall be confirmed by a
6.8.4.5 Noise
gauge accurate to at least f 1 % of the reading. Deter-
mine the gas leakage, in millilitres per minute, from the
6.8.4.5.1 Measuring instruments
change in volume (corrected for the compliance of the
A precision sound level meter complying with the re-
humidifier and necessary test attachments) when the
quirements for a type 1 instrument specified in IEC
50 'XO of the initial value.
pressure has fallen to
Publication 651 shall be used. Measurements shall be
taken using the frequency-weighting characteristic A and
6.8.4.3 Internal compliance
the time-weighting characteristic S of the sound level
meter. The sound level meter shall have been calibrated in
Occlude all orifices except one and eliminate all leaks.
accordance with the manufacturer's instructions.
Pressurize the humidifier by injecting air through the
open port from a graduated syringe or similar volumetric
6.8.4.5.2 Test environment
device to a pressure of 2,5 kPa (25 cmH2O). Record the
volume change when a steady state has been attained.
Measurements shall be taken in a free field over a reflect-
Calculate the compliance (the change in volume per unit
ing plane as specified in IS0 3744.
change in pressure), correcting for the compliance of the
test apparatus. Carry out the test at both the minimum
NOTE - The necessary conditions may be achieved econ-
and maximum operating volumes, if applicable, and
omically on a hard, flat surface outdoors, in a large room or in a
express the results in millilitres per conventional smaller room with sufficient sound absorptive materials on its
centimetre of water or millilitres per kilopascal. Repeat walls and ceiling.
the test at pressures of 5 kPa, 7.5 kPa and 10 kPa
6.8.4.5.3 Ambient conditions
(50 cmH20, 75 cmH20 and 100 cmH20).
At the microphone positions, the A-weighted sound
6.8.4.4 Warm-up time
pressure levels of the background noise shall be at least
10 dB below the sound pressure level to be measured.
The warm-up time of a humidifier which is heated or
supplied with a delivery tube heater shall be determined
NOTE - If barometric pressure, temperature or relative hu-
during warm-up from a stabilized starting temperature of
midity deviate excessively from those of standard conditions,
21 & 2 OC to the maximum stable delivery tube outlet appropriate corrections may be required.
.-O
IS0 8185 : 1988 (E)
plane, with the axis of the delivery tube vertical and
6.8.4.5.4 Humidifier installation
150 mm from the microphone on the axis between the
The humidifier shall be mounted as recommended in the humidifier and the microphone. If the length of the
instructions for use or in a manner typical for its intended delivery tube does not allow this set-up, move the
microphone towards the humidifier until the distance
use. If it is intended to be table-mounted, the table top
shall be a hard, acoustically reflecting surface, unless a between it and the delivery tube outlet is 1% mm.
resilient pad is recommended in the installation instruc-
If the manufacturer recommends or supplies attach
tions. If it is wall-mounted, the wall shall be of a hard,
ments for particular therapeutic applications and states
acoustically reflecting material.
that these reduce the A-weighted sound pressure level
to 60 dB or less, repeat the measurements with the
6.8.4.5.5 Measurements
attachments fitted. If any such attachment incorporates
a port intended for connection to a tracheal or
Operate the humidifier over its normal working range, in
tracheostomy tube, connect a tube of an internal
addition to the settings specified in 4.6h) (in this Inter-
diameter equal to or greater than that of the port and a
national Standard). Place the microphone at the position
length such that its other end will be sufficiently distant
of maximum sound pressure level in the horizontal plane
from the sound level meter not to interfere with the noise
passing through the geometric centre of the humidifier
measurements.
and at a radius of 1 m.
At each setting, if the humidifier is intended for use with
7 Power input
a
a delivery tube, take a second measurement using the
recommended delivery tube. The delivery tube outlet
The requirements given in clause 7 of IEC Publication 601-1
shall be placed so as to lie on the specified horizontal
apply.
IS0 8185 : 1988 (E)
Section two - Safety requirements
8 Basic safety categories 11 Special measures with respect to safety
The requirements given in clause 8 of IEC Publication 601-1 The requirements given in clause 11 of IEC Publication 601-1
do not apply as they are not relevant to humidifiers.
apply.
9 Removable protective means
12 Single fault condition
The requirements given in clause 9 of IEC Publication 601-1
apply.
The requirements given in clause 12 of IEC Publication 601-1
apply.
10 Special environmental conditions
The requirements given in clause 10 of IEC Publication 601-1
apply.
Section three - Protection against electric shock hazards
13 General 18 Earthing and potential equalization
The requirements given in clause 18 of IEC Publication 601-1
The requirements given in clause 13 of IEC Publication 601-1
apply.
apply.
19 Continuous leakage currents and patient
14 Requirements related to classification
auxiliary currents
The requirements given in clause 14 of IEC Publication 601-1
The requirements given in clause 19 of IEC Publication 601-1
apply.
apply except that the following addition shall be made
to 19.4hi :
15 Limitation of voltage and/or current
The patient leakage current shall be measured from the
humidifier outlet port and from any parts of the humidifier
The requirements given in clause 15 of IEC Publication 601-1
that, in normal use, are fitted between the humidifier outlet
apply.
port and the patient. All these parts, including the outlet
port, shall be connected together electrically, with the
exception of parts connected electrically to the protective
16 Enclosures and protective covers
earth terminal.
The requirements given in clause 16 of IEC Publication 601-1
Parts not connected together electrically shall be tested
apply.
separately.
17 Insulation and protective impedances
20 Dielectric strength
The requirements given in clause 17 of IEC Publication 601-1 The requirements given in clause 20 of IEC Publication 601-1
apply. apply.
IS0 8185 : 1988 (E)
Section four - Protection against mechanical hazards
-
In 24.4, __ add the following additional item :
21 Mechanical strength
The requirements given in clause 21 of IEC Publication 601-1 f) Fill the liquid container and liquid reservoir to their
maximum recommended levels. Connect the humidifier
apply except that 21.2, 21.3 and 21.4 shall be deleted and the
following addition shall be made to 22: to a breathing system and tilt the humidifier through 20°,
or through 30° if the humidifier is intended for use during
The humidifier shall be filled with water to its maximum
transport of patients, and check that no liquid from the
operating volume prior to carrying out each drop test.
liquid container or liquid reservoir enters the breathing
system.
22 Moving parts
25 Expelled parts
22 of IEC Publication 601-1
The requirements given in clause
apply.
The requirements given in clause 25 of IEC Publication 601-1
apply.
23 Surfaces, corners and edges
26 Vibration and noise
The requirements given in clause 23 of IEC Publication 601-1
apply.
The requirements given in clause 26 of IEC Publication 601-1
shall be replaced by the following requirement :
24 Stability and transportability
If humidifiers are intended to be used in association with
incubators complying with the requirements of the par-
The requirements given in clause 24 of IEC Publication 601-
ticular standard for the safety of baby incubators (IEC
apply except for the following additions and modifications :
Publication 601-2-?), attention is drawn to the noise level re-
- quirements given in that standard.
Replace 24.3 by the following 1) :
When the humidifier is tilted through 20° in any direction
from its normal operating position, there shall be no 27 Pneumatic and hydraulic power
spillage from the liquid ccjntainer or liquid reservoir into
The requirements given in clause 27 of IEC Publication 601-1
the breathing system. If the manufacturer states that the
humidifier is intended for use during the transport of
apply.
patients (e.g. movement by ambulance from one lo-
cation to another), the humidifier shall be capable of
withstanding a tilt of 30° in any direction from the
28 Suspended masses
normal operating position without allowing liquid from
the liquid container or liquid reservoir to enter any part of The requirements given in clause 28 of IEC Publication 601-1
the breathing system.
apply.
See also annex O (in this International Standard)
1)
IS0 8185 : 1988 (E)
Section five - Protection against hazards from unwanted
or excessive radiation
33 Infra-red radiation
29 X-radiation
The requirements given in clause 29 of IEC Publication 601-1
The requirements given in clause 33 of IEC Publication 601-1
apply.
apply.
30 Alpha, beta, gamma, neutron radiation
34 Ultraviolet radiation
and other particle radiation
The requirements given in clause 34 of IEC Publication 601-1
The requirements given in clause 30 of IEC Publication 601-1
apply.
apply.
31 Microwave radiation
35 Acoustical energy (including ultrasonics)
The requirements given in clause 31 of IEC Publication 601-1
The requirements given in clause 35 of IEC Publication 601-1
apply.
apply.
32 Light radiation (including visual radiation
36 Electromagnetic compatibility
and lasers)
The requirements given in clause 36 of IEC Publication 601-1
The requirements given in clause 32 of IEC Publication 601-1
apply.
apply.
Section six - Protection against the hazards of explosions
in medically used rooms
k) A humidifier classified and marked "APG" or "AP"
37 General
shall be provided with an electrostatic charge leakage path
The requirements given in clause 37 of IEC Publication 601-1
between the breathing system input and outlet ports and
together with the following additional sub-clauses apply :
from each of these ports to the protective earth, if provided.
The resistance shall not exceed 106Q. The requirements
37.5 Humidifiers which are suitable for use with anaes-
IS0 2882 shall also apply.
given in
thetic agents but which are not intended for use with flam-
mable anaesthetic agents shall be restricted to use with
Compliance shall be checked by measurement of the
those agents which are not ignited in the flammability tests
resistance.
given in annex N (in this International Standard).
37.6 Electrical circuits which may be a source of ignition
in the gas conducting system of a humidifier not classified
40 Requirements and tests for anaesthetic-
"AP" or "APG" shall meet the requirements given in 43.7
(in this International Standard). proof equipment, equipment parts or
components (AP)
38 Classification, marking and accompanying
The requirements given in clause 40 of IEC Publication 601-1
documents of anaesthetic-proof equipment
apply.
The requirements given in clause 38 of IEC Publication 601-1
apply.
41 Requirements and tests for anaesthetic-
39 Common requirements for "AP" and
proof category G equipment, equipment parts
"APG" equipment
or components
The requirements given in clause 39 of IEC Publication 601-1
apply except that the following additional item shall be added The requirements given in clause 41 of IEC Publication 601-1
to 39.3 :
apply.
IS0 8185 : 1988 (E)
Section seven - Protection against excessive temperatures, fire
and other hazards, such as human errors
3) after exhaustion of the water supply (i.e. when
42 Excessive temperatures
the liquid container and liquid reservoir, if a reservoir
The requirements given in clause 42 of IEC Publication 601-1
is provided, become exhausted during normal use, SC
apply except for the following modifications :
that no liquid is available to the humidification
chamber).
-
Amend 42.1 (last entry in table Xa) as follows11 :
42.3.4 If temperature control is derived from a
The requirement for equipment parts which may in
temperature sensor fitted at the delivery tube outlet (or,
normal use have unintended contact with a patient does
if intended for use without a delivery tube, at the
not apply to heated humidifiers; for these humidifiers,
humidifier outlet), carry out the test described in 42.3.3
the maximum enclosure temperature shall be 55 OC, if
under the following conditions :
metal, or 75 OC, if non-metal.
1 ) both open-circuit and short-circuit;
Heated surfaces necessary to the proper functioning of
the humidifier and exposed only during assembly in
2) with the temperature sensor removed from its
preparation for use, dismantling after use or during filling
normal site, if it is detachable or easily dislocated;
procedures are excluded from the requirements in 42.1.
3) with the temperature sensor disconnected from
-
Replace 42.3 by the following : the temperature-control system.
42.3.1 1) In the case of heated humidifiers, either the
42.3.5 The accessible surface temperature of the
gas temperature at the delivery tube outlet (or, if in-
delivery tube shall be measured with an instrument
tended for use without a delivery tube, at the humidifier
capable of indicating temperature to an accuracy of
outlet) shall not exceed 41 OC in normal steady-state use
* 1 OC. Operate the humidifier throughout the range of
or single fault conditions or the gas temperature at the
flows and settings recommended by the manufacturer
delivery tube outlet (or, if intended for use without a
over the ambient temperature range given in 4.5 (in this
delivery tube, at the humidifier outlet) shall be indicated
International Standard) and measure the highest ac-
continuously and the temperature-measuring device
is
cessible surface temperature of the delivery tube that
shall activate auditory and visual alarms when the
obtained.
temperature exceeds 41 OC. If a delayed auditory alarm
is used, the delay shall not exceed 1 min. If a failure of
43 Fire prevention
the temperature-control system can constitute a thermal
hazard, an additional non-self-resetting thermal cut-off
The requirements given in clause 43 of IEC Publications 601-1
shall be provided. The thermal cut-off shall also activate
together with the following additional sub-clauses apply :
a visual indicator. The alarms shall continue until the
fault condition responsible foi. their activation has been
43.3 In order to minimize the risk of fire in normal use or
corrected.
in single fault conditions at least one of the following re-
quirements shall be satisfied :
NOTE - The auditory alarm may be free-standing.
a) electrical components shall be separated from com-
42.3.21) The accessible surface temperature of the
partments in which accumulations of oxygen or mixtures
delivery tube shall not exceed 41 OC within 50 mm of the
of oxygen with anaesthetic agents can occur by a barrier
delivery tube outlet.
complying with the requirements given in 43.4;
Compliance shall be checked by the tests given in 42.3.3
b) compartments containing electrical components
to 42.3.5.
shall be ventilated according to the requirements given
in 43.5;
42.3.3 At the minimum and maximum temperature
c) electrical components which, in normal use or single
control settings and the minimum and maximum flows
fault conditions, can be a source of ignition, shall
recommended by the manufacturer, measure the gas
comply with the requirements given in 43.7.
temperature in the datum plane of the test chamber
under the following conditions :
43.4 Any barrier required under the provision of 43.3a)
1) normal use; shall be sealed at all joints and holes for cables, shafts or
other purposes.
2) starting without liquid (i.e. with no liquid in or
immediately available to the humidification chamber
Compliance shall be checked by inspection and, if
or liquid container);
applicable, by the compliance test described in 43.6.
1) See also annex O (in this International Standard).
IS0 8185 : 1988 (E)
43.5 The ventilation required under the provision of 45 Pressure vessels and parts subject to
43.3b) shall be such that the oxygen concentration in the
pressure
compartment containing electrical components shall not
exceed 4 % ( V/ V) above the ambient level. If this require- The requirements given in clause 45 of IEC Publication 601-1
ment is met by forced ventilation, a failure alarm shall be together with the following additional sub-clauses apply :
provided.
45.11 A means of pressure relief shall be provided if the
Compliance shall be checked by the test given in 43.6. humidifier can be damaged or its performance influenced
adversely by excessive pressure, when it is used in accord-
ance with the manufacturer’s instructions. The means of
43.6 Arrange the humidifier in a test room in which the air
pressure relief shall be self-resetting when the normal
exchange is between 3 and 10 changes per hour. Measure
operating condition is restored.
the oxygen concentration under the following conditions :
Compliance shall be checked by the test given in 45.12.
a) single fault conditions;
45.12 For humidifiers without pressure-relief valves,
occlude all orifices except one. Pressurize the humidifier
bl selection of the least favourable control settings;
through the open orifice to twice the stated maximum
c) supply mains voltage variation of I 10 %. operating pressure and check that the humidifier maintains
mechanical integrity.
The oxygen concentration shall be measured for such a
For humidifiers with pressure-relief valves, occlude all
period tha
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