The IEC 60601-1-8 is a collateral standard to the IEC 60601-1, the standard containing the general specifications. The IEC 60601-1-8 sets out requirements for alarm systems and their documentation and testing. It gives manufacturers specific instructions on the specification and for designing your medical devices.
Manufacturers, however, need to be familiar with the large number of terms that the standard defines. They should also know and implement the expanded requirements set out in amendment 2 to achieve conformity of their products and avoid problems with audits and authorizations. This can be achieved in 12 steps.
Alarms are often the last chance to prevent damage to patients, users, and third parties.
Alarms indicate a potential or actual dangerous situation (patient, operator, device) for which attention or a response from the operator is required. Since the extent of the damage generally increases over time, alarms provide the necessary leeway to avoid serious damage.
Alarms are therefore actions to reduce the risk (in this case the probability). The effectiveness of the alarms must therefore be proven in the usability assessment (see section 4 e)).
It is therefore necessary to minimize the risks which occur if these alarms
The IEC 60601-1-8 aims to minimize precisely these risks and to contribute to making alarms a risk control measure that is as effective as possible.
The IEC 60601-1-8 is a collateral standard to the IEC 60601-1. It therefore also targets medical electrical (ME) devices and systems made of ME equipment.
This collateral standard specifies requirements for ALARM SYSTEMS and ALARM SIGNALS in ME EQUIPMENT and ME SYSTEMS.
“combination, as specified by its MANUFACTURER, of items of equipment, at least one of which is MEE to be inter-connected by FUNCTIONAL CONNECTION or by use of a MULTIPLE SOCKET-OUTLET”
Examples of ME equipment include the medical devices mentioned above: ventilators, dialysis machines, infusion pumps, monitoring systems, and distributed alarm systems. These can be classified into:
The standard therefore relates to those parts of ME equipment (ALARM SYSTEMS) which detect alarm statuses and generate alarm signals, in other words all statuses which require immediate action by the operator.
The standard included non-ME equipment in distributed alarm systems, e.g. standalone software in a patient monitoring center or dismissed alarm displays. It does not, however, set out any technical requirements of the functioning of alarm systems of this type.
Manufacturers of standalone software that runs on generally available devices (e.g. smartphones, pagers) and forward on alarm statuses or display them remotely should also take the standard into account.
The article on IEC 60601-1 (german) is a quick introduction to the world of ME equipment.
The IEC 60601-1-8 sets out the requirements for alarms:
The standard does not set out:
The standard helps with the definition of terms as presented by Chapter 2 of this article.
Manufacturers and operators need to take into account other standards in the case of distributed alarm systems in particular. The following figure provides an overview.
The standard defines a large number of terms which are difficult for laypeople to differentiate, but they don’t need to be understood to make a decision about when which requirement of the standard needs to be complied with.
You can check whether or not you know and have understood all of the terms if you cover the right-hand column of the table in Chapter 2 d) and find the matching terms yourself.
The IEC 60601-1-8 does not define the term alarm. It makes a distinction between alarm systems and alarm signals. It also differentiates between several types of alarm conditions.
An alarm system is defined as follows:
“ALARM SYSTEM parts of ME EQUIPMENT or a ME SYSTEM that detect ALARM CONDITIONS and, as appropriate, generate ALARM SIGNALS”
What would commonly be understood as an alarm is defined by the standard as an alarm signal.
“type of signal generated by the ALARM SYSTEM to indicate the presence (or occurrence) of an alarm condition”
The IEC 60601-1-8 distinguishes between physiological and technical alarm conditions.
“ALARM CONDITION arising from a monitored PATIENT-related variable”
A cardiac arrest, oxygen saturation that is too low or a drop in blood pressure are examples of physiological alarm conditions of this type.
A technical alarm condition, meanwhile, is caused by a technical problem in the equipment being monitored.
“ALARM CONDITION arising from a monitored equipment-related or ALARM SYSTEM-related variable”
Examples of these technical alarm conditions include:
In addition to alarm signals, there are also other signals:
“any signal that is not an ALARM SIGNAL or a REMINDER SIGNAL”
Examples of information signals:
Information signals relate to the patient, the equipment or the workflow. They are not, however, indicators of possible damage and fundamentally do not require the operator to act, they merely require attention. An alarm condition, however, requires the operator to act and interrupt their work.
Amendment 2 introduces a special case within these information signals, advisories.
“An ADVISORY is a type of INFORMATION SIGNAL notifying the OPERATOR of a condition of the PATIENT or ME EQUIPMENT providing contextual awareness that is intended to improve the clinical workflow or understanding of the PATIENT condition, the awareness not being intended as a means of RISK CONTROL”
Examples of advisories:
It is often difficult to differentiate alarms from advisories, and this is sometimes fluid. A rule of thumb may be able to help here:
Alarms are always needed when a specific action is necessary as otherwise damage may occur. Advisories, meanwhile, should explicitly suppress behavior that is being considered or has been started (e.g. opening a cover on equipment that is switched on).
Manufacturers often get creative with their choice of words so they do not have to meet the requirements of the standard. It is, however, the purpose that is critical rather than the term used. The standard also mentions this in the new amendment.
Finally, the IEC 60601-1-8 also defines a reminder signal:
“periodic signal that reminds the OPERATOR that the ALARM SYSTEM is in an ALARM SIGNAL inactivation state”
The English language differentiates between “alarm” and “alert”. It is particularly important to distinguish between the two.
“synonym for the combination of:
IEC 60601-1-8 AMD2:3.41
The authors combine alarms and advisories in the term alert. The authors wish to make clear that the use of the term alert instead of alarm does not per se exclude the applicability of IEC 60601-1-8.
Systems which only provide advisories or information, however, are not in the scope of the IEC 60601-1-8.
The IEC 60601-1-8 merely requires alarms to be clearly differentiated to prevent confusion. Requirements of the presentation of advisories and information can be found in the basic standard IEC 60601-1 or in the individual standards IEC 60601-2-X.
The IEC 60601-1-8 uses the term Indicator Lights. However, it does not define the term.
Indicator lights are a visual addition to the acoustic alarms or can be used as an advisory of an intentional dangerous situation (not fault). Examples of this include:
Indicator lights related to alarms are referred to in the IEC 60601-1:AMD2 as Alarm Indicator Lights. These indicator lights must always flash. Advisory indicator lights, meanwhile, must be constantly illuminated (see Table 2, IEC 60601-1:AMD2).
The IEC 60601-1:AMD2 counts advisory indicator lights as information signals (see Table 2 and blog article AMD2).
Indicator lights used as warning and caution advisories (see examples) are treated as safety marks. The requirements of the advisory indicator lights are can therefore be found in the basic standard IEC 60601-1 and some of the individual standards. The requirements of the alarm indicator lights (flash frequency) can be found in IEC 60601-1-8.
A cardiopulmonary bypass machine is used as an example to assign the correct terms to the various types of information.
Type of information
Term, consequence, danger
Air in the system
Air can lead to an embolism
Advisory: Next replacement of the oxygenator in 4 h
Information (no alarm)
Failure of the air bubble detector
Air bubbles not detected, embolism
Battery display showing remaining charge
Oxygen saturation display
Attention of the operator
Blood temperature display
Attention of the operator
Level falls below limit
Failure of the alarm system
Power failure display
Equipment fails, no function
Area of the speed display marked in red
Display that the speed set is too high for a patient
If damage results from this:
Display that the speed set is too high for a patient
If no damage results from this:
Actual speed deviates from the TARGET set
Error cannot be identified can leads to damage
Heating and cooling unit in operation
Information (green indicator light)
The standard sets out specific requirements of the alarms. These include:
Amendment 2 even provides specific examples of undulations (see below).
The IEC 60601-1-8 sets out specific specifications for manufacturers for the documentation including accompanying documentation.
To be documented
List of the risks for which an alarm is the measure that should be used to manage the risk
Risk management files
Technical description of the function (algorithms, design, statuses etc.) of the alarms
System Requirements Specification, system architecture
The prioritization of the alarms (primarily by severity and speed of occurrence of damage)
System Requirements Specification
Factors for the sensitivity of an alarm (sensitivity, specificity)
System Requirements Specification
Disclosure of the algorithms and functionality of the alarm system
Instructions for use
The IEC 60601-1-8 also sets out specific specifications for the testers (e.g. a test laboratory). The tests must comprise:
The IEC 60601-1-8 was most recently amended in  by Amendment 1. It is also referred to as “version 2.1”. Since then there have been other proposed changes, 20 of which were classed by the European Commission as urgent. These were included in Amendment 2 in 2020, also known as “version 2.2”.
All of the remaining points (“long list”) are to be included in a third version which is planned for 2024 or later.
The scope of 62 pages alone is enough of an indication of how important and extensive the changes are. They include:
The following sections address some of these points.
Alarm signals improve the perceptibility of an alarm situation (dangerous situation) and therefore have a significant impact on the clinical management and the patient risk. Alarm signals are generally characterized by their presentation (acoustic, visual, acoustic + visual) in combination with the task requirement (priority).
The authors identified two problems linked to the alarms in various tests:
Alarm fatigue is increased by
The standard wants to increase manufacturers’ awareness of the known problem of alarm fatigue and asks manufacturers to take the effect into account when designing the alarm user interface.
The standard generally views alarms as part of a risk activity. There would therefore be a positive risk/benefit ratio if an alarm system only indicated clinically relevant alarm situations that require an action within an appropriate amount of time. The standard calls these alarms “clinically actionable”.
The effectiveness of the risk activity should therefore not be reduced by too many or incorrect alarms. In this context, the standard introduces the following new terms:
The standard does not set out specific requirements for technologies such as intelligent alarm systems or the accuracy and correctness of alarms. Manufacturers must rather take these aspects into account when designing the alarm system (performance specification) and in the risk analysis.
No alarm when there is an alarm situation
Operator does not notice a patient’s critical condition or only notices too late. Can lead to frustration and decreased user acceptance.
Specifying limits between false negative and true negative
Alarm when there is no alarm situation
Are not clinically relevant and are disruptive (NUISANCE ALARM SIGNAL) and lead to delayed, unnecessary, inappropriate, or no user actions and worsen attention (ALARM FATIGUE). In some cases, users may turn the alarm off.
Improved algorithms, delays in alarms
Alarm when there is an alarm situation
Too many (disruptive) alarms (ALARM FLOOD) which do not require immediate action (CLINICALLY NONACTIONABLE) because the priority has been incorrectly assessed or the user is already aware of the situation can lead to inappropriate user actions or worsen attention (ALARM FATIGUE).
Improved algorithms, discussing the relevance of the alarms with users (considering the risks/benefits)
No alarm when there is no alarm situation
(Point 5 of the list in section 4 b))
Acoustic signals are often not sufficiently effective because they are either
The acoustic alarm signals are the first and often only indicator for the perceptibility of an alarm situation. Accordingly, the acoustic alarm signals have a particular importance in the standard and must also meet the usability requirements as part of the user interface (auditive interface).
Relevant criteria for the usability of acoustic signals are:
To date, the standard has set out melodic tone sequences for the coding of the information (perceptibility) in an alarm signal (see Annex F).
In various tests the authors determined that the melodic alarm signals (Annex F) only fulfil the above-mentioned criteria for usability to a certain extent and do not correspond to the latest technology (and science).
Scientific tests in other areas (avionics, engineering) show how effective, usable acoustic interfaces can be designed. This has led to the development of further techniques, e.g.:
The basic idea is to create a link between an acoustic signal and a known reality, such as a coughing sound which indicates dangerous levels of carbon monoxide.
From an evolutionary perspective, our hearing is able to differentiate complex noises and cognitively process them.
The authors therefore introduced the Auditory Icons and Auditory Pointer in Amendment 2. These are briefly presented below.
“sound that creates a strong semantic link to the category it represents”
Auditory Icons have a much stronger link to the alarm condition than abstract sounds, are easier to localize and more resistant to masking. The selection of specific AUDITORY ICONS for specific functions means that confusion with noises which naturally occur in a clinic environment is avoided.
The authors are so convinced of the applicability of the Auditory Icons that they claim that a user who has not perceived the Auditory Icons would not have perceived the conventional alarm signals either.
Table G.4 shows a list of the Auditory Icons that have already been validated for the most common alarm conditions.
Table G.4 – Characteristics of the AUDITORY ICON
SOURCE of the ALARM CONDITION
AUDITORY ICON metaphor
AUDITORY ICON description
File name of AUDITORY ICON
“Lup-dup” ; heartbeat sound
A stylized, square/triangle wave-based “ heartbeat“ sound with no discernible frequency. Six PULSES formed from three 2- PULSE “lup-dup” sequences
Liquid disturbance, water churning, bubbles
Two approximately 1 s sequences of a strong water bubbling sound, separated by silence
A single inhale followed by an exhale
A 1 s inhaling sound (like white noise), followed by a 0.5 s gap, followed by a slow exhale with a long tail
Irregular, stylized dripping/saturation
Stylized irregular temporal pattern with some discernible pitch; a two-tone sequence superimposed on the six-tone pattern
Complex sound including high frequency harmonics, rising slowly over approximately 2 s
Drug or fluid delivery/administration
Shaking pill bottle
Two 0.8 s sequences of a 4-rattle shaking sound
Equipment or supply failure
Starting up a motor that shuts down suddenly
Spectrally complex sound of a motor revving up (increasing in frequency) over approximately 1.2 s then an abrupt stop tailing off for approximately 0.5 s
See for yourself whether you can correctly assign the alarms. The standard also provides the examples.
“sound that attracts attention, denotes the priority and aids in localization of the COMMUNICATOR”
Auditory Pointers “point” to the source of the alarm (type of equipment and which patient) and indicate the priority and criticality (high, medium, low) of the alarm status. An auditory pointer shows spatial parameters as acoustic parameters.
Tables G.1 and G.2 show the spectral, amplitude and time variables for the HIGH PRIORITY, MEDIUM PRIORITY and LOW PRIORITY.
The standard then sets out tone parameters which can be used to model the urgency, audibility, and localizability.
Here, too, the ISO provides examples.
(see 4 c) and 4 d))
The standard suggestions from tables G.1 to G.5 have already been clinically validated by the authors and do not need to be checked again. This also relates to the alarm signals that remain valid according to tables 3 and 4.
The authors tested the Auditory Icons (Annex G) against the melodic alarm signals (Annex F) with user groups in a clinical environment. The Auditory Icons were clearly superior.
This article shows an example of a possible test setup for a formative or summative usability assessment.
If, however, you develop your own alarm signals, Auditory Icons and Pointers, you must validate the effectiveness in a real or simulated clinical environment using the following criteria.
In Annex H, the standard also provides a test framework for the summative assessment and acceptance criteria for the aspects of learnability, localizability, and perceptibility.
Manufacturers who have been manufacturing and distributing their systems for a long time and have not reviewed against the latest technology since 2012 (last amendment to the IEC 60601-1-8) should check their system for conformity and create a PMS report. The following 12 steps are helpful:
In the EU, Amendment 2 is on the list of standards which will be revised and harmonized by May 2024 (see standardisation request-MDR-IVDR).
According to AMD 2, section 22.214.171.124 d) the melodic alarms previously recommended can continue to be used. It is, however, the authors’ intention to make the new ALARM SIGNALS from Annex G compulsory in the next amendment or edition of the IEC 60601-1-8.
The latest deadline for harmonization (EN 60601-1-8:2007+AC:2010+A11:2017+prA2) is planned for May 27, 2024. Version 3.0 of the standard, which plans to make the new alarm signals compulsory, is planned for 2024.
Whether and by when version 3.0 of the standard will be harmonized remains to be seen, but it is not expected to be within the next three years.
IEC 60601-1-8 Edition 2.1 2012
December 17, 2023
FDA recognition of IEC 60601-1-8 Edition 2.1 2012-11 [Rec# 5-76] will be superseded by recognition of IEC 60601-1-8 Edition 2.2 2020-07 CONSOLIDATED VERSION [Rec# 5-131]. FDA will accept declarations of conformity, in support of premarket submissions, to [Rec # 5-76] until December 17, 2023. After this transition period, declarations of conformity to [Rec # 5-76] will not be accepted.
ABNT NBR IEC 60601-1-8:2014
YY 0709-2009 (IEC 60601-1-8:2003)
CAN/CSA C22.2 NO. 60601-1-8:08 + AMD1:2012
JIS T 60601-1-8:2012
The first impulse of many manufacturers is to manage risks through alarms and advisories. The MDR and IVDR set out the order in which actions of this type are to be determined. The inherently safe design is the first priority.
However, if there is no other choice than to manage the risks with alarms and other “signals”, these actions must be effective. A standard such as the IEC 60601-1-8 is therefore helpful because it provides specific specifications about how these alarms and signals should be designed.
These specifications are not constants, they must correspond to the latest technology. The fact that the authors of IEC 60601-1-8 are following the latest technology with the second amendment should therefore be welcomed. They are contributing to the safety of medical devices.
Although the scope of the IEC 60601-1-8 is limited to medical devices such as ME equipment, the specifications of this standard can also be helpful with other medical devices.
Manufacturers should immediately set out to check their conformity with the second amendment. The implementation of the twelve points set out above is helpful for this.
The Johner Institute helps manufacturers to develop safe, high-performance, and effective medical devices which meet the requirements of IEC 60601-1-8:AMD2. Get in touch (e.g. using the contact form) to find out how you can check the conformity of your products quickly and easily, restore this if necessary and document your analysis. Your auditor will value your efforts too.