ISO/TC 159/SC 5 - Ergonomics of the physical environment

This document specifies different methods for the determination of metabolic rate in the context of ergonomics of the thermal working environment. It can also be used for other applications, e.g. the assessment of working practices, the energetic cost of specific jobs or sport activities and the total energy cost of an activity. The methods are classified in four levels of increasing accuracy: level 1, Screening, with a table giving examples of activities with low, moderate and high metabolic rates; level 2, Observation, where the metabolic rate is estimated by a time and motion study; level 3, Analysis, where the metabolic rate is estimated from heart rate recordings or accelerometers measurements; and level 4, Expertise, where more sophisticated techniques are described. The procedure to put into practice these methods is presented and the uncertainties are discussed.

This document provides guidelines for extending the definition of equivalent temperature to predictive purposes and specifies a standard prediction method for the assessment of thermal comfort in vehicles using numerical calculations. Specifically, this document sets forth a simulated numerical manikin as a viable alternative to the thermal manikin for the purpose of calculating the equivalent temperature.

This document describes general ergonomics requirements in relation to dynamic signs, as this responsive information presentation technology changes depending on the environmental conditions in which it is used (e.g. environmental illumination, density of people). Dynamic signs are presented adaptively to those environmental conditions. The general requirements for dynamic signs consist of visibility (divided into conspicuity, distinctiveness, legibility and comprehensibility), visual image safety and accessibility. The requirements and recommendations for each are also described. This document does not cover static signs. This document does not include requirements for safety signs for the marking of escape routes. NOTE There are some related recommendations in ISO 30061.

This document presents principles and examples of practical application for the construction of appropriate subjective scales for use in the assessment and evaluation of the physical environment. It does not standardize particular scales. It considers scales of perception, comfort, preference, acceptability, expression form and tolerance, and environmental components such as thermal, visual, air quality, acoustic and vibration. It does not consider other scales such as: — scales related to the effects of the environment on the ability to read displays or signs, on manual performance or on psychological conditions such as mood, etc.; — scales related to pain or scales related to stimuli that can lead to injury. This document does not present principles of surveys (see Note) or questionnaire design. However, the scales that are developed using this document can be incorporated into surveys or questionnaires. NOTE Environmental surveys are described in ISO 28802. ISO 28802 includes scales that are complementary to, and based upon, the principles of scale construction that are described in this document.

ISO 7243:2017 presents a screening method for evaluating the heat stress to which a person is exposed and for establishing the presence or absence of heat stress. It applies to the evaluation of the effect of heat on a person during his or her total exposure over the working day (up to 8 h). It does not apply for very short exposures to heat. It applies to the assessment of indoor and outdoor occupational environments as well as to other types of environment, and to male and female adults who are fit for work.

ISO 24505:2016 provides a method for creating conspicuous colour combinations for use in visual signs and displays taking into account viewer age. It is based on the perceived similarity of colours at photopic and mesopic lighting conditions. ISO 24505:2016 applies to the design of visual signs and displays in which multiple colours are used so that the colours are conspicuous to people of any age, including older people who do not have deficient colour vision. The method and data in this International Standard are not applicable to the design of visual signs and displays for people with colour deficiencies or medical disorders affecting vision. Basically, this International Standard applies to the reflective or object mode colours, but may apply to self-luminous mode colours if the colour coordinates are appropriately transferred to those of the object mode colours.

ISO 24504:2014 specifies methods to determine an appropriate sound pressure level range for spoken announcements in environments where ambient noise is less than 80 dB. The specified methods follow the concepts of ISO/IEC Guide 71 and includes consideration of older persons with decreased hearing ability to determine sound pressure levels of spoken announcements. The spoken speech levels specified are for products and public-address systems. ISO 24504:2014 is applicable when a loudspeaker producing a spoken announcement is located a short distance from the user in an environment where the sound pressure level with a standard frequency weighting A of ambient noise does not exceed 80 dB. It is applicable to spoken announcements that are audible to persons with normal hearing for their age when presented by a target product under quiet and anechoic conditions, and for both recorded voice and synthetic speech announcements. It is not applicable to products providing private information such as automated teller machines in public spaces, nor to spoken announcements heard through headphones or earphones, or with the ear close to the speech sound source such as ear speakers. It does not specify the sound pressure levels of spoken announcements for systems with automatic sound pressure level control to compensate for fluctuating ambient noise levels, nor those presented in emergency situations such as signals for fire alarms, gas leakage and crime prevention (covered in ISO 7240‑16 and ISO 7240‑19), or in automobiles (covered in ISO 15006). It considers only the audibility of speech and not the process of speech understanding.

This International Standard describes how International Standards concerned with the ergonomics of the physical environment can be applied for people with special requirements, who would otherwise be considered to be beyond the scope of those standards. It has been produced according to the principles of accessible design provided in ISO/IEC Guide 71 and using the data provided in ISO/TR 22411. It is not restricted to any specific environment but provides the general principles that allow assessment and evaluation, and can contribute to the development of standards concerned with specific environments. It is applicable to built environments as well as to other indoor, vehicle and outdoor environments. Nor is it restricted to specific environmental components; it includes assessment of acoustic environments, thermal environments, lighting, air quality and other environmental factors that could be considered to influence the health, comfort and performance of people with special requirements in an environment. It is applicable to all occupants of such environments who can be considered to have special requirements. NOTE This will depend upon context and can, for example, include babies, infants, men or women, people with disabilities, older or ill people. A person could have a special requirement in one type of environment but not in another.

This International Standard provides an environmental survey method for the assessment of the comfort and well-being of occupants of indoor and outdoor environments. It is not restricted to any particular environment, but provides the general principles that allow assessment and evaluation. It presents the principles for conducting an environmental survey to assess the comfort and well-being of people in environments. It gives guidance on the design of the survey, as well as on the environmental measurements used to quantify the environment and the subjective assessment methods used to quantify the occupants' responses to that environment. It does not provide guidance on the design of subjective scales. It is applicable to built as well as other environments, including vehicle and outdoor environments, and to all the occupants of those environments who can be considered as providing valid responses to an environmental survey. There may be specific features of certain types of environment that have to be taken into account; however, the general principles it outlines will apply. This International Standard is not restricted to specific environmental components. It includes assessment of thermal environments, the acoustic environment, the visual and lit environment, air quality and other environmental factors that could be considered to influence the comfort and well-being of the occupants of an environment. It is a basic ergonomics standard which can contribute to the development of standards concerned with specific environments such as those found in buildings. It is intended to be used by people involved in the general assessment and evaluation of physical environments, including general ergonomics practitioners as well as those who develop standards and guidelines for specific applications. NOTE The results of the environmental survey produced by the application of this International Standard may identify specific problems that require expert advice.

ISO 24501:2010 specifies methods for determining the sound pressure level range of auditory signals so that the users of consumer products, including people with age-related hearing loss, can hear the signal properly in the presence of interfering sounds. Auditory signals, in ISO 24501:2010, refer to sounds with a fixed frequency (also called beep sounds) and do not include variable frequency sounds, melodic sounds, or voice guides. ISO 24501:2010 is applicable to auditory signals which are heard at an approximate maximum distance of 4 m from the product, as long as no physical barrier exists between the product and the user. It is not applicable to auditory signals heard through a head receiver or earphones, or to those heard with the ear located very near to the sound source because of the interference of the head with sound propagation. ISO 24501:2010 does not specify the sound pressure level of auditory signals regulated by other statutes, such as those for fire alarms, gas leakages and crime prevention, nor does it specify auditory signals particular to a communication tool such as telephones. ISO 24501:2010 does not specify auditory danger signals for public or work areas which are covered in ISO 7731, ISO 8201, and ISO 11429.

ISO 24502:2010 specifies the age-related luminance contrast of any two lights of different colour seen by a person at any age, by taking into account the age-related change of spectral luminous efficiency of the eye. ISO 24502:2010 provides a basic method of calculation that can be applied to the design of lighting, visual signs and displays. It applies to light, self-luminous or reflected, in visual signs and displays seen under moderately bright conditions called photopic vision and whose spectral radiance is known or measurable. It does not apply to light seen under darker conditions called mesopic or scotopic vision. ISO 24502:2010 specifies the luminance contrast for people aged from 10 to 79 years who have had no medical treatment or surgery on their eyes that may affect their spectral luminous efficiency. ISO 24502:2010 does not apply to visual signs and displays seen by people with colour defects whose spectral luminous efficiency is different from those with normal colour vision, nor those seen by people with low vision.

ISO 24500:2010 specifies the auditory signals used as a means of feedback for operations or conditions of consumer products when used by a person with or without visual or auditory impairment. It is intended to be applied as appropriate to such products depending on the product type and its conditions of use. It is applicable to auditory signals of a fixed frequency used in general applications (also called “beep sounds”), but not to variable frequency or melodic sounds. It does not specify fire or gas leak alarm sounds or crime prevention alarm sounds (determined by other laws and regulations), electronic chimes, voice guides or other sounds particular to communication instruments such as telephones; nor is it applicable to auditory danger signals for public or work areas (covered in ISO 7731, ISO 8201, and ISO 11429). It is not applicable to machines and equipment used for professional work; nor does it specify the sound pressure levels of auditory signals from the consumer products (for the determination of these levels, taking into consideration accessible design, see ISO 24501).

ISO 15743:2008 presents a strategy and practical tools for assessing and managing cold risk in the workplace, and includes: models and methods for cold risk assessment and management; a checklist for identifying cold-related problems at work; a model, method and questionnaire intended for use by occupational health care professionals in identifying those individuals with symptoms that increase their cold sensitivity and, with the aid of such identification, offering optimal guidance and instructions for individual cold protection; guidelines on how to apply thermal standards and other validated scientific methods when assessing cold‑related risks; a practical example from cold work. It is applicable to both indoor and outdoor work situations — indoor work includes work done inside vehicles, outdoor work both inland and offshore work — but is not applicable to diving situations or other types of work performed underwater.

ISO 11079:2007specifies methods and strategies for assessing the thermal stress associated with exposure to cold environments. These methods apply to continuous, intermittent as well as occasional exposure and type of work, indoors and outdoors. They are not applicable to specific effects associated with certain meteorological phenomena (e.g. precipitation), which are assessed by other methods.

ISO 9920:2007 specifies methods for estimating the thermal characteristics (resistance to dry heat loss and evaporative heat loss) in steady-state conditions for a clothing ensemble based on values for known garments, ensembles and textiles. It examines the influence of body movement and air penetration on the thermal insulation and water vapour resistance. It does not deal with other effects of clothing, such as adsorption of water, buffering or tactile comfort, take into account the influence of rain and snow on the thermal characteristics, consider special protective clothing (water-cooled suits, ventilated suits, heated clothing), or deal with the separate insulation on different parts of the body and discomfort due to the asymmetry of a clothing ensemble.

ISO 14505-1:2007 gives guidelines for the assessment of thermal stress inside vehicles used for land, sea and air operation. It offers information about the assessment of hot, cold as well as moderate thermal environments by referring to different methods, as specified in International Standards, and specifying the constraints and necessary adjustments needed for the special case of vehicle climate assessment.

ISO 14505-2:2006 provides guidelines for the assessment of the thermal conditions inside a vehicle compartment. It can also be applied to other confined spaces with asymmetric climatic conditions. It is primarily intended for assessment of thermal conditions, when deviations from thermal neutrality are relatively small. Appropriate methodology as given in ISO 14505-2:2006 can be chosen for inclusion in specific performance standards for testing of HVAC-systems for vehicles and similar confined spaces.

ISO 15536-1:2006 provides temperature threshold values for burns that occur when human skin is in contact with a hot solid surface. It also describes methods for the assessment of the risks of burning, when humans could or might touch hot surfaces with their unprotected skin. In addition, ISO 13732-1:2006 gives guidance for cases where it is necessary to specify temperature limit values for hot surfaces, but does not set surface temperature limit values. ISO 13732-1:2006 deals with contact periods of 0,5 s and longer. It is applicable to contact when the surface temperature is essentially maintained during the contact. It is not applicable if a large area of the skin (approximately 10 % or more of the skin of the whole body) can be in contact with the hot surface. Neither does it apply to skin contact of more than 10 % of the head or contact which could result in burns of vital areas of the face. ISO 13732-1:2006 is applicable to the hot surfaces of all kind of objects: equipment, products, buildings, natural objects, etc. It is applicable to hot surfaces of products that may be touched by healthy adults, children, elderly people and also by people with physical disabilities. For the purposes of simplification, it mentions only products; nevertheless, it applies to all other objects as well. It is applicable to products used in any environment, e.g. in the workplace, in the home. It does not provide data for the protection against discomfort or pain.

ISO 14505-3:2006 gives guidelines and specifies a standard test method for the assessment, using human subjects, of thermal comfort in vehicles. It is not restricted to any particular vehicle but provides the general principles that allow assessment and evaluation. The method can be used to determine a measure of the performance of a vehicle for conditions of interest, in terms of whether it provides thermal comfort to people or not. This can be used in vehicle development and evaluation. ISO 14505-3:2006 is applicable to all types of vehicles, including cars, buses, trucks, off-road vehicles, trains, aircraft, ships, submarines, and to the cabins of cranes and similar spaces. It applies where people are enclosed in a vehicle and when they are exposed to outside conditions. For those exposed to outside conditions, such as riders of bicycles or motorcycles, drivers of open sports cars and operators of fork lift trucks without cabins, vehicle speed and weather conditions can dominate responses. The principles of assessment, however, will still apply. ISO 14505-3:2006 applies to both passengers and operators of vehicles where its application does not interfere with the safe operation of the vehicle.

ISO 13732-3:2005 provides methods for the assessment of the risk of cold injury and other adverse effects when a cold surface is touched by bare-hand/finger skin. It provides ergonomics data for establishing temperature limit values for cold solid surfaces. The values established can be used in the development of special standards, where surface temperature limit values are required. Its data are applicable to all fields where cold solid surfaces cause a risk of acute effects: pain, numbness and frostbite, and are not limited to the hands but can be applied in general to the healthy human skin of male and female adults.

ISO 7730:2005 presents methods for predicting the general thermal sensation and degree of discomfort (thermal dissatisfaction) of people exposed to moderate thermal environments. It enables the analytical determination and interpretation of thermal comfort using calculation of PMV (predicted mean vote) and PPD (predicted percentage of dissatisfied) and local thermal comfort, giving the environmental conditions considered acceptable for general thermal comfort as well as those representing local discomfort.

ISO 7933:2004 specifies a method for the analytical evaluation and interpretation of the thermal stress experienced by a subject in a hot environment. It describes a method for predicting the sweat rate and the internal core temperature that the human body will develop in response to the working conditions. The various terms used in this prediction model, and in particular in the heat balance, show the influence of the different physical parameters of the environment on the thermal stress experienced by the subject. In this way, this International Standard makes it possible to determine which parameter or group of parameters should be modified, and to what extent, in order to reduce the risk of physiological strains. The main objectives of ISO 7933:2004 are the following: the evaluation of the thermal stress in conditions likely to lead to excessive core temperature increase or water loss for the standard subject; the determination of exposure times with which the physiological strain is acceptable (no physical damage is to be expected). In the context of this prediction mode, these exposure times are called "maximum allowable exposure times". ISO 7933:2004 does not predict the physiological response of individual subjects, but only considers standard subjects in good health and fit for the work they perform. It is therefore intended to be used by ergonomists, industrial hygienists, etc., to evaluate working conditions.

ISO 15265:2004 describes a strategy for assessing and interpreting the risk of physiological constraints, or of discomfort, while working in a given climatic environment. It is applicable in any working situation with steady or varying conditions of the climate, metabolic rate or clothing. ISO 15265:2004 does not describe a single procedure, but a strategy in three stages that can be used successively to gain deeper insight in the working conditions, as it is needed to draw the most appropriate conclusions about the risk involved and identify the best control and prevention measures. It is definitely oriented towards the prevention and/or control of these working problems in the heat or cold. The risk of heat or cold disorders and/or discomfort is therefore assessed only to the extent that it is required to reach this goal.

ISO 9886:2004 describes methods for measuring and interpreting the following physiological parameters: body core temperature; skin temperatures; heart rate; body-mass loss.

ISO 7731:2003 specifies the physical principles of design, ergonomic requirements and the corresponding test methods for danger signals for public and work areas in the signal reception area and gives guidelines for the design of the signals. It may also be applied to other appropriate situations. ISO 7731:2003 does not apply to verbal danger warnings (e.g. shouts, loudspeaker announcements). ISO 9921 covers verbal danger signals. Special regulations such as those for a public disaster and public transport are not affected by this International Standard.

ISO 9921:2003 specifies the requirements for the performance of speech communication for verbal alert and danger signals, information messages, and speech communication in general. Methods to predict and to assess the performance in practical applications are described and examples are given.

ISO/TR 19358:2002 deals with the testing and assessment of speech-related products and services, and is intended for use by specialists active in the field of speech technology, as well as purchasers and users of such systems.

This part of ISO/TS 13732 presents principles and methods for predicting the thermal sensation and degree of discomfort for people where parts of the body are in contact with solid surfaces at moderate surface temperatures (approximately 10 °C to 40 °C). It deals with the thermal sensation for contacts of the hand, foot and for the sitting position on the floor.

Specifies a system of danger and information signals taking into account the different degrees of urgency. Applicable to all danger and information signals which have to be clearly perceived and differentiated as specified in ISO/TR 12100-2. Does not apply to certain fields covered by specific standards.

Describes criteria for the perception of visual danger signals in the area in which people are intended to perceive and to react to such a signal. Specifies the safety and ergonomic requirements and the corresponding physical measurements.

Purpose is to specify information which will allow the correct, effective and practical use of International Standards concerned with the ergonomics of the thermal environment. Describes the underlying principles concerning the ergonomics of the thermal environment.

ISO 14415:2005 provides background information on the thermal responses and needs of groups of persons with special requirements so that International Standards concerned with the assessment of the thermal environment can be appropriately applied for their benefit.

The metabolic rate, as a conversion of chemical into mechanical and thermal energy, measures the energetic cost of muscular load and gives a numerical index of activity. Metabolic rate is an important determinant of the comfort or the strain resulting from exposure to a thermal environment. In particular, in hot climates, the high levels of metabolic heat production associated with muscular work aggravate heat stress, as large amounts of heat need to be dissipated, mostly by sweat evaporation. ISO 8996:2004 specifies different methods for the determination of metabolic rate in the context of ergonomics of the climatic working environment. It can also be used for other applications -- for example, the assessment of working practices, the energetic cost of specific jobs or sport activities, the total cost of an activity, etc.

Provides a method for prediction of the effectiveness of speech communication in the presence of noise generated by machinery as well as in noisy environment. Parameters are the ambient noise at the speaker's position, ambient noise at the listener's position, distance between the communication partners and a great number of physical and personal conditions.

Covers the construction and use of judgement scales for use in providing reliable and comparative data on the subjective aspects of thermal comfort or thermal stress.

Gives methods for estimating the thermal characteristics (resistance to dry heat loss and evaporative heat loss) in steady-state conditions for a clothing ensemble based on values for known garments, ensembles and textiles. Does not deal with other effects of clothing, such as adsorption of water, buffering, tactile comfort. Does not take into account the influence of rain and snow on the thermal characteristics. Does not consider special protective clothing. Does not deal with the separate insulation on different parts of the body and discomfort due to the asymmetry of a clothing ensemble.

The purpose is to present a method for predicting the thermal sensation and the degree of discomfort (thermal dissatisfaction) of people exposed to moderate thermal environments and to specify acceptable environmental conditions for comfort. Applies to healthy men and women and was originally based on studies of North American and European subjects but agrees also well with recent studies of Japanese subjects and is expected to apply with good approximation in most parts of the world. Applies to people exposed to indoor environments where the aim is to attain thermal comfort, or indoor environments where moderate deviations from comfort occur.

Proposes methods and strategies to assess the thermal stress associated with exposure to cold environments. Cold stress is suggested to be evaluated in terms of both general cooling of the body and local cooling of particular parts of the body (e.g. extremities and face). The methods apply to continuous, intermittent and occasional exposure and in both indoor and outdoor work. Specific effects associated with certain meteorological phenomena (e.g. precipitation) are not covered and should be assessed by other methods.

Describes methods for measuring and interpreting body core temperature, skin temperature, heart rate, and body mass loss. Annex A presents a comparison of the different methods concerning their field of application, their technical complexity, the discomfort and the risks. The measurement techniques are described in annex B, limit values are proposed in annex C.

Specifies methods for determining the metabolic rate, but can also be used for other applications, e.g. for the assessment of working practices, the cost of specific jobs or sport activities, the total cost of activity, etc. Annexes A to G contain: classification of metabolic rate for kinds of activities, classification of metabolic rate by occupation, data for standard person, metabolic rate for body posture, type of work and body motion related to work speed, metabolic rate for typical activities, example of calculation of the average metabolic rate for a work cycle, examples of calculation of the metabolic rate based on measured data.

Identifies the parameters that influence visual performance. It also presents the criteria that have to be satisfied in order to achieve an acceptable visual environment. Is applicable to working areas in industrial buildings, offices and hospitals, but not to those working areas of low luminance used for such activities as projection, viewing of transparencies, and handling of photosensitive materials.

Gives a method, which can easily be used in an industrial environment for evaluating the stresses on a individual. It applies to the evaluation of the mean effect of heat on man during a period representative of his activity but it does not apply to very short periods, nor to zones of comfort.

Describes a method of calculating the heat balances as well as the sweat rate that the human body should produce to maintain this balance in equilibrium. The various terms used show the influence of the different physical parameters. It does not predict the physiological response of individual subjects, but only considers standard subjects in good health and fit for the work they perform.

Specifies the safety requirements and the corresponding test methods for work places in the signal reception area and gives guidelines for the design of the signals. May also be applied to other appropriate situations. Does not apply to verbal danger warnings. Special regulations such as those for a public disaster and public transport are not affected.