For products and workplaces to be safe and competitive, they must be designed against anthropometric data that are consistent with those of the current population. However, the characteristics of the human body have changed significantly over recent years. This is particularly true of the dimensions of breadth, depth, girth and weight. In recent decades, updates to the data have been prompted primarily by changes in length measurements. Significant changes in these dimensions are now no longer being observed. KAN has adopted a position paper on the anthropometric situation (pdf, not eAccessible) in conjunction with the DIN Ergonomics standards committee.
Product standards are often based on data that are outdated or of uncertain origin. This may result in products not being safe for certain user groups. Some examples relevant to occupational safety and health:
- Body weight: It becomes an issue for occupational safety and health when the design of products intended to bear or restrain persons is based upon an assumed weight of the intended users that is too low. In some cases, the maximum permissible weight is also simply not evident. Should the requirements of the standards or the specified tests be based on a weight of 75 kg, the resulting products may present a hazard when used by persons whose weight exceeds this figure. Ambulances are an example: specifically, the anchor points for the stretcher are tested for the weight of the stretcher and a dummy with a weight of 75 kg lying upon it. Should an accident occur and the patient weigh significantly more than 75 kg, an additional safety risk may arise if this causes the anchor point to fail. KAN has tasked DIN Software GmbH with reviewing documents (standards and EU documents) to determine whether they contain specifications for the weight of persons. At a KAN expert discussion of the weights of persons, over 30 experts from the accident insurance institutions, social partners, the relevant DIN standards committees and the research community discussed the results of the review. A one-size-fits-all solution evidently does not exist: substitution of 75 kg – a value specified in the most diverse of standards – with a higher value throughout does not necessarily always improve safety. For products designed to carry or restrain persons, however, the value has a bearing upon safety and must be reviewed. Where test methods simulating the weight of persons are described in standards, they must also be scrutinized. The long-term goal is to launch the search for solutions tailored to each particular standard, based on up-to-date body weights. KAN also seeks to raise awareness in standardization bodies for up-to-date anthropometric data which are already available in standards, for example those of the Ergonomics standards committee.
- Access/passage openings: A range of workplaces feature openings with dimensions selected on the basis of human body dimensions. These include emergency exits. For example, KAN has commented on a draft standard governing the driver's cab of locomotives. The main points of criticism were the insufficiently high dimensions of doors and emergency exits (e.g. clear passage heights of less than 1.70 m for doors, and minimum inside dimensions of only 40 cm for emergency exits). In the view of the occupational safety and health community, these dimensions must be selected in consideration of current scientific and technical knowledge. Up-to-date anthropometric data must be used for calculation of the required dimensions. More information on this subject can be found in the article by Dr Anja Vomberg in Eisenbahntechnische Rundschau (pdf, not eAccessible) (in German).
- Personal protective equipment (PPE): As a rule, the fit of PPE is important for the protection it provides. Failure to consider increases in the dimensions stated can result in the PPE ceasing to afford protection and being suitable for use. On the subject of infection protection masks, for example, the need for standards to consider different head dimensions is a topic of discussion. OSH stakeholders are represented on the national and European standardization committees. KAN supports their work and will continue to monitor the standardization project in order to submit OSH concerns as effectively as possible. You can find more information on the subject in KANBrief 1/22, Standardization of infection protection masks.
- Important controls and actuators within reach: Whether controls and actuators (such as emergency-stop actuators or vehicle pedals) are situated within reach is often dependent upon users assuming standard sitting or standing positions. This may no longer be possible when the breadth, depth and/or girth dimensions have increased substantially (for example when a driver's seat is moved backwards to accommodate greater abdominal girth, as a result of which the length of the legs, which has not increased, may no longer be sufficient for the pedals forward of the driver to be reached reliably).
- Test finger: A test finger can be used to test whether the enclosures of machines and installations are designed to prevent persons coming into contact with dangerous parts. However, an assessment commissioned by KAN has found that test fingers to EN 60529 do not always assure this protection, as they are not consistent with the latest anthropometric data on finger length. KAN has been campaigning for some years for the dimensions in the standard to be adjusted. Further information is available in a leaflet (pdf, in German).
- Safety of seating furniture: Here too, a failure to take account of increases in body dimensions gives rise to problems. Standards governing seating furniture must not only consider the increase in weight with respect to the seats' load-bearing capacity: they must also adjust the seat surface area and allow for the changes in seat tipping characteristics when heavier persons rise from the seat.
- Dimensioning of escape and rescue routes: The maximum dimension of the body girth to be considered for the dimensioning of escape routes has risen substantially in recent years. As a result, it can be assumed that the limits currently being applied are not adequate.
- Work in healthcare/patient handling: No requirement exists for the working load limit to be marked on products used in healthcare/patient handling (e.g. lifting equipment). According to reports by the German Social Accident Insurance Institution for the health and welfare services (BGW), the marking of equipment for bearing or restraining patients is wholly inadequate in practice. This constitutes a major problem for the nursing sector. Not only may failure of the product present a risk of accident for nursing staff, it may also be a source of mental stress. Since information on use is often unavailable, liability issues may require clarification. The provision of information in the instructions for use is not sufficient, as the persons using the equipment and the patients on which they are used often change frequently. KAN advocates that equipment intended to bear or restrain patients or users be marked with the maximum safe working load on the equipment itself. Marking must be clearly visible and the font size sufficiently large. The durability of marking must take account of adverse effects under the conditions of intended use (e.g. cleaning/disinfection at a change of user). KAN has already issued numerous comments on standards in this area.