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Introduction

In-house transport and materials handling (storage and transfer of goods), either manual or mechanical are carried out to some extent in almost all workplaces. These activities bring about risks such as slips, trips and falls, vehicle and pedestrian collisions, falling objects, musculoskeletal disorders, etc. Furthermore, in large warehouses in the logistics sector automated systems such as automated guided vehicles and digital order picking (picking by voice, picking by vision) create specific risks such as risks linked to cognitive ergonomics.

Accident risks of in-house transport and handling

In almost all workplaces activities related to warehousing and workplace transport take place such as deliveries, transferring goods, dispatching, storage, etc. In addition, there is the logistics sector which covers a wide range of activities such as container reception, transport and logistic centres. The items to be transferred may vary, but the accident risks are mainly the same regardless of the product being transferred. Recognising and assessing the risks associated with in-house transport and materials handling is key for preventing injuries and health-related problems. Based on a risk assessment preventive measures have to be implemented to prevent and control the risks.

Common risk factors of in-house transport are listed in table 1.

Table 1. Overview of risk factors of in-house transport and handling

 Risk factor
Human
Equipment
  • Vehicles, Automated guided vehicles
  • Automated warehousing, collaborative robotics
  • Racking and shelving, pallets, containers, bins
  • Conveyors, overhead cranes
  • Lifting aids, trolleys, carts, hoists
  • Input devices, code scanners, voice/vision picking
  • Use of other tools, e.g. cutter
Environment
  • Indoor air quality
  • Temperature, draught
  • Noise
  • Lighting
  • Layout of the warehouse, traffic routes, pedestrian ways
  • Layout of loading bays
  • Markings, pictograms, signs
  • Condition of floorings, buildings, doors, etc.
  • Weather conditions
Product
  • Handling of hazardous chemicals, fumigated containers
  • Handling of hazardous waste
  • Characteristics of the load (weight, shape, stability)
  • Handling of valuables (security)
Organisation
  • Planning, deadlines, peak moments, organisation of deliveries
  • Working time, work schedules, shift work
  • Organisation of transport flows, separation of vehicles/pedestrians
  • Staffing levels, distribution of tasks, job design
  • Training, information
  • Procedures
  • Maintenance programmes, tidiness, housekeeping

Risks of manual handling and in-house transport

Manual material transfer is a common cause of workplace injuries [1]. Typical manual material transfer injuries are related to the way the materials are handled, to job design and to the physical condition and characteristics of individual workers. Risk factors involved in manual materials handling include the characteristics of the load, the physical effort to move it, the working environment, and the requirements of the handling activity [2]. Typically, accidents related to material transfers, such as falling from a height and injuries caused by falling and collapsing objects, cause more serious damages to the workers and the physical environment than other accidents (not related to transfer) in the workplace. In addition, manual material transfers cause many minor accidents, mostly due to over-extension when reaching for objects [3]. The risks are similar for both in-house transport and any other transport.

Manual handling operations are hazardous, typically causing musculoskeletal problems especially to the lower back [4]. Working with loads which require that both hands are above shoulder height may cause a loss of balance [5]. The most common risk factors in manual materials handling are as follows [6]:

  1. Characteristics of the load to be handled:
    • Weight and shape (too heavy or too large, unwieldy or difficult to grasp),
    • Stability (unstable or has contents likely to shift, positioned in a manner requiring it to be held or manipulated at a distance from the trunk of the body, or with a bending or twisting of the trunk),
    • Potentially damaging (likely, because of its contours and/or consistency, to result in injury to workers, particularly in the event of a collision)[6],
  2. Physical effort required:
    • Too strenuous,
    • Only achieved by a twisting movement of the trunk,
    • Likely to result in a sudden movement of the load,
    • In an unstable posture.
  3. The requirements of the handling activity:
    • Over-frequent or over-prolonged physical effort involving in particular the spine,
    • An insufficient bodily rest or recovery period,
    • Excessive lifting, lowering or carrying distances,
    • A rate of work imposed by a process which cannot be altered by the worker.
  4. Individual factors when the worker:
    • Is physically unsuited to the task,
    • s wearing unsuitable clothing, footwear or other personal effects,
    • Does not have adequate or appropriate knowledge or training [6][2].

Risks of mechanical handling and in-house transport

Mechanical transfer also poses a high risk to workers [3]. Mechanical transfers are conducted by vehicles and transport systems such as conveyors. Examples of vehicles used in in-house transport include fork-lift trucks, pallet stackers, reach trucks, pedestrian controlled pallet trucks, etc. Vehicles can also be based on an automatic system (automatic guided vehicles). The most serious risks occur due to the interaction between pedestrians and vehicles. Drivers of vehicles such as forklifts are often involved in accidents such as vehicle overturns, falls from vehicles, collisions with obstacles, etc. Inadequate training and warning signs, poor truck maintenance, insufficient lighting and lack of space increase the likelihood of accidents [2]. Speed, even low speed, is a risk factor in mechanical in-house transport [3]. Velocity typically increases level of the damages.

Musculoskeletal disorders, such as lower back problems, are also a risk in mechanical transfer: Sitting for prolonged periods is risky for workers, and when stepping on or off the vehicle there is a risk of hurting one’s feet.

The characteristics of the load in mechanical transfers cause additional risks, if:

  • the load is not straight and stable,
  • the height of the load exceeds the limit of the height of the shelves,
  • the weight of the load exceeds the capacity of the vehicle.

Other risks

Risks of dangerous substances for in-house transport

Lack of awareness of the nature of transported products, ignorance due to lack of training and poor labelling, inappropriate storage and handling may, for example, cause risks for in-house transport of dangerous substances. The key is to have appropriate storage and transport design and have those employees involved in the transport and handling of dangerous products trained in the safe handling of these products ([7].

Risks of storage systems

Warehouses and storage rooms are often organised in aisles and (pallet) racks for storing goods. These racking systems have to be properly installed and maintained to avoid any collapse or falling objects. All racking systems have a maximum safe working load which should never be exceeded. Several EN standards provide technical specifications for the design and installation of storage systems, e.g. EN 15512: Steel static storage systems – adjustable pallet racking systems – principles for structural design. More information is available at the website of the FEM Racking & Shelving European materials handling federation.

Mental risks of in-house transport

Excessive pressure at work can lead to stress, and undermine work performance and cause health risks to the workers and cause risks due to unsafe behaviour at the workplace. For example, not enough time to pick materials for transport or prepare deliveries, poorly arranged work schedules and resources may cause stress for people in in-house transport work ([7]. Furthermore, the use of input devices, tablets, scanners and also order picking technologies such as picking by voice or vision, can increase the mental workload.

Risk prevention of in-house transport and handling

 

Key measures for preventing the risks of in-house transport and materials handling are:

  1. Avoiding the hazards if possible,
  2. Conducting a risk assessment of hazardous tasks that cannot be avoided,
  3. Taking action to reduce the risks of injury [8].

This means that when in-house transport requires manual handling, then if one adopts an ergonomics approach that these tasks should be planned in such a way as to minimise carry distances, decrease the weight of the load, decrease the frequency of manual handling tasks, etc.. In addition, adequate technical devices and lifting aids should be provided, and the working environment should be designed and maintained to minimise the risks of manual handling (even, non-slippery floors, sufficient visibility, good indoor air quality, etc.). Varying tasks with other tasks (requiring no manual handling) may further reduce the risks. [2][9].

The responsibility for employers to provide a safe working environment and for the workers to respect the safety procedures of their workplace are included in the European legislation. Methods for preventing in-house transport risks include ergonomic and technical solutions, providing workplace and task specific training and organisational measures (e.g. safety plans, guidance) and co-operating with all actors in the workplace/environment. These are described in the following sub-chapters. [9]

Legislation

European legislation and strategies aim to protect workers' safety and general health, such as the Council Directive 89/391/EEC [10], and council Directive 89/654/EEC on workplace requirements [11], regardless the specific sector of work. European legal requirements relating to musculoskeletal disorders (MSDs) define conventions and standards for manual materials handling during in-house transport activities. For example, the Council Directive 90/269/EEC on manual handling of loads [6] focuses on reducing the risk of musculoskeletal diseases in handling of loads. The Directive states: "Where the need for the manual handling of loads by workers cannot be avoided, the employer shall take the appropriate organizational measures, use the appropriate means or provide workers with such means in order to reduce the risk involved in the manual handling of such loads". In addition to the directives at the European level, there are also national laws which aim to reduce the risk of diseases and injuries at work [2] [9][12].

Work environment

An appropriate working environment is crucial for safe in-house transport and material handling. Material transfer requires space and a tidy work environment, and suitable lighting, proper signs and markings for transport routes in order to be performed safely. For example, in the construction industry, it has been proved that almost half of the accidents, this includes in-house and in-site transport work, occurred partly because of poor housekeeping and problems with the site layout and lack of space available for working [13]. In addition, the maintenance and cleaning of transport routes need to be performed in such a way that does not cause slipperiness. Routes (both outside and in-house) also need to have even, undamaged surfaces, or if damaged, they need to be fixed in such a way that the surface is even. It is also essential to take the climate conditions, and possible sudden changes in the weather into consideration when planning in-house transport. Visibility should be checked in order to ensure safe passage through the workplace and to eliminate potential risks in hazardous places, such as junctions. Health risks caused by noise can be prevented by providing adequate personal protective hearing equipment in cases when the noise cannot be eliminated or reduced.

The layout of the workplace must allow everyone (workers, customers, suppliers) to enter, exit, move about and work without risk to health and safety. This requires adequate planning and design of the workplace and traffic routes. The basic principles include: - Segregation of the traffic routes for pedestrians/vehicles - Segregation of the various traffic flows (pick-up/delivery; goods/persons). The traffic routes should be sufficiently wide (taking into account the vehicles, the loads) and adequate (limit the number of curves, slope levels, etc.).

Many of the risks caused by use of transport vehicles can be prevented with correct work environment design and training workers in safety behaviour. Examples of these preventive methods are:

  • To avoid the need for reversing,
  • Ensure safe loading and unloading space,
  • Segregate pedestrian and vehicle traffic routes,
  • Ensure that suitable safety features, such as speed limit signs and pumps, edges of loading bays clearly marked, etc.,
  • Ensure that vehicles are properly maintenance, e.g. pre-check of brakes and lights [2].

In many workplaces the environment is challenged and changing due to changes in production process or design of the workplace layout. Especially in warehouses the working environment changes often as new items are stored, and this poses risks for both company workers and for those delivery workers who occasionally visit the site. This is why marking stored items clearly and in a consistent manner is a key safety action; the delivery workers need to find the correct place without searching and causing risks to other workers while moving in the work area. In addition, all site workers and delivery personnel need to be kept informed by the site supervisor which routes to use (see more under the following “Cooperation” chapter).

Ergonomics of material transfers

In-house transport and materials handling should be performed safely and also by following the rules of ergonomics, since these can help to prevent musculoskeletal disorders. The use of transfer devices is important in preventing over-exertion by workers [14]. Pulling and pushing and lifting and carrying poses the greatest strain on the human musculoskeletal system. Manual transfer aids used for assisting in lifting or decreasing the need for carrying loads also have to be considered as long as they are ergonomically sound [9].

Mechanical devices can reduce the physical risk of over-exertion [15]. In addition, mechanical aids reduce the force required to shift heavy loads. The decision between choosing manual or mechanical materials handling is sometimes complex: (1) On one hand, manual material transfer causes lower back problems, for example because of heavy loads and the strain the weight placed on the human body. (2) On the other hand, mechanical material transfer can also cause lower back problems. For example, forklift drivers experience lower back problems because their work involves long-term sitting positions and vibration [16]. Mechanical material transfers also include other risks [16], such as crashing to other vehicles or people.

Technical devices

Material transfers can be performed more safely by using adequate technical devices, such as forklifts, pallet wagons or cranes [17]. Tasks that demand frequent lifting are associated with an increased risk of lower back pain [18]. The safety of in-house transport and materials handling can be improved by undertaking a thorough planning of lifting operations and adequate training for those using the lifting equipment. It is also essential to pay attention to selecting, inspecting and maintaining the lifting equipment or any other mechanical work device.

Technical help devices should be taken into use in order to avoid needless manual transfers [14][19]. Machinery to support handling of loads and lifting aids need to be taken into use and workers need to be trained to use these aids in a correct way. The maintenance of the technical devices need to have a procedures as well in order to avoid the risks of using damaged devices[2].

Lifting equipment need to be inspected and maintained regularly. The maintenance should be extended to the lifting chains as well in order to prevent using dirty and corroded lifting chains. When lifting work is performed, the work area needs to be closed off from other traffic in order to prevent accidents caused by falling objects or collisions.

Safe use of forklift trucks should be ensured by providing adequate training for forklift users. Forklift trucks need regular maintenance. In addition, working environment should be planned in a way that there is enough space for forklift trucks to manoeuver[9].

Training

The employer should also provide appropriate training for personnel, because material transfer -related accidents can be prevented by improving work methods and learning better ways to operate with the others in the work team. Training workers to adopt correct positions when lifting objects can help to avoid back injuries [14]. For example, preferring two person manual transfer techniques and using appropriate tools and devices for material transfers at workplaces are simple ways to prevent the risk of injury. However it needs to be noted that having two persons transfer materials may pose additional risk factors which will need further consideration.

Training workers in the correct way of using the devices and vehicles increases the safety of in-house transports. Training should be provided for all workers who use the vehicles and devices, and it is important that the employers ensure that the training procedures are kept up-to-date, and that all vehicle and device users should have adequate skills for using the equipment[9].

Organisational measures

The employer can improve the safety of material transfers by recognising and eliminating the hazards associated with in-house transport and materials handling [19].

Any incidents that occur during material transfers provide information that can reduce future manual transfer accidents, and it is important that all accidents and near misses are reported and analysed by the safety management team. For example, in order to decrease the risk of accidents in material transfers, it might be possible to reduce the object weights or strength requirements of a task, and to increase the frequency of rest breaks [13].

An important issue in improving occupational safety in in-house transport and material handling is managing the transfers. Over-exertion is a common type of injury related to in-house transport and material handling. It has been studied that using appropriate devices in material transfers on a construction site can increase ergonomics, safety and efficiency [17]. Careful planning of the transfers and maintenance of transportation equipment are essential when the target is improving safety.

The prerequisite for safe in-house transport and materials handling is that the work is adequately organised. Organising work includes also planning of breaks which is an important point when attempting to prevent accidents [20]. There are a variety of guidelines and checklists for employers and managers, for example provided by EU-OSHA [2][9] and the national occupational safety and health actors [14][7][19], to identify possible risks and improve the work environment and methods of in-house transport and materials handling.

Co-operation

Co-operation between various operators is important since it can improve the transfer of information about accident risks of in-house transport and manual handling. The occupational safety and health unit often holds the information of accidents and work-related diseases of the employees. Medical checks of workers could also include the consultation of possibilities to perform safer material transfers. Thus co-operation between the occupational safety and health unit, employer and employees could be one way to improve working conditions into safer direction. (Occupational safety and health units are more common in large scale organisations, however small-scale enterprises (SMEs) may co-operate with outside service providers. This varies in different countries).

Material transfer related accidents should not be seen as an inevitable part of workers' "bad luck", because these accidents are more likely to be caused by operations that can be improved. Once the occupational health care has the information about accidents and health status of the workers, the health care unit should use this information in consultation with the employer for example about the importance of work time arrangements and appropriate materials transfer equipment [20].

Workers from different employers may be performing tasks within each workplace, for example trucks bring and pick up materials. The trucks are in most cases driven by external workers, but they need to access to workplaces and they use the routes utilized by permanent workers. In addition to driving, drivers face accident risks in loading and unloading operations in clients’ workplaces and the working environment may not be familiar to the drivers. Site rules should be generally known and accepted by all who work in the area. The importance of the clear signs where to stop the vehicle for loading or unloading decrease the need of unnecessary driving in the client's workplace area. If the driver has to concentrate on looking for the right place to unload, this may decrease his/her attention to the other areas where there maybe workers. In addition to unfamiliar working environment, loading and unloading are often performed under tight schedules and quickly, possibly without appropriate devices, all of which may increase risk-taking behaviour. The co-operation of companies that operate in the same area needs to be considered carefully in order to create a safe and risk free work environment for all parties operating in the site. Within a workplace, the common rules should be clear for all workers who are working in the area, including the subcontractors [19].

Conclusions

Safety issues of in-house transport and materials handling are more and more relevant in today’s changing business world. The life cycle of products is shorter than ever before and the current trend is to replace damaged or broken items by new ones instead of fixing the old ones. Companies are using subcontractors and even the smallest parts may need to be transferred for production from one place to another. This increases the amount of in-house transport and material handling in the workplace.

The wide variety of different materials makes it complicated to recognise how each one should be handled. Many products need unique means of transportation. This increases the importance of better and more focused risk assessment in order to recognise the OSH risks associated with handling different types of materials.

Each workplace has its unique challenges in managing the safety of in-house transport and materials handling. The presence of several contractors and subcontractors working in the same location clearly raises the need for unambiguous site rules. Information should be clearly available about core issues, e.g. which routes to use, which devices and vehicles are on the site, when devices can be on-site, etc. Careful planning of the logistics increases the safety of site workers, also of those workers who are only temporarily visiting the site.

Références

[1] Davies, J., Kemp, G., Frostick, S., Dickinson, C. & McElwaine, J. Manual handling injuries and long term disability', Safety Science 41, 2003, pp. 611-625.

[2] EU-OSHA – European Agency for Safety and Health at Work. Preventing Vehicle Transport Accidents at the Workplace, Factsheet 16, 2011. Available at: https://www.google.com/url?q=https://osha.europa.eu/en/publications/factsheets/16&sa=U&ei=3Y4tUpz_BeXI4ASsjIHwAQ&ved=0CAcQFjAA&client=internal-uds-cse&usg=AFQjCNEo6B-shRRPP7q0LFflULqJJPbZaA

[3] Perttula P., Kiurula M., Merjama J., Laitinen H., ‘Accidents in materials handling at construction sites’, Construction Management and Economics, Vol. 21, No 7/October, 2003, pp. 729-736. Available at: http://www.tandfonline.com/doi/abs/10.1080/0144619032000087294

[4] Gagnon, M., ‘The efficacy of training for three manual handling strategies based on the observation of expert and novice workers’, Clinical Biomechanics 18, 2003, pp. 601-611.

[5] Denis, D., St-Vincent, M., Imbeau, D., Trudeau, R., ‘Stock management influence on manual materials handling in two warehouse superstores’, International Journal of Industrial Ergonomics (36), 2006. pp. 191-201.

[6] Council Directive 90/269/EEC of 29 May 1990 on the minimum health and safety requirements for the manual handling of loads where there is a risk particularly of back injury to workers (fourth individual Directive within the meaning of Article 16 (1) of Directive 89/391/EEC). Available at: https://osha.europa.eu/en/legislation/directives/6

[7] HSE – Health and Safety Executive, Warehousing and storage, A guide to health and safety, HSE publications, second edition 2007. Available at: http://www.hse.gov.uk/pubns/priced/hsg76.pdf

[8] HSE – Health and Safety Executive, Manual Handling, Manual Handling Operations Guidelines 1992, Guidance on Regulations, third edition, 2004. Retrieved 27 February 2013, from: http://www.hse.gov.uk/pubns/priced/l23.pdf

[9] efact44

[10] Directive 89/391/EEC of 12 June 1989 on the introduction of measures to encourage improvements in the safety and health of workers at work (Framework Directive). Available at: https://osha.europa.eu/en/legislation/directives/the-osh-framework-directive/1

[11] Council Directive 89/654/EEC of 30 November 1989 concerning the minimum safety and health requirements for the workplace. [1989] OJL 393. Available at: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31989L0654:EN:HTML

[12] EU-OSHA – European Agency for Safety and Health at Work, Hazards and risks associated with manual handling of loads in the workplace, E-fact 73, July 3, 2007

[13] Haslam, R., Hide, S., Gibb, A., Gyi, D, Pavitt, T., Atkinson, S. & Duff, A., ‘Contributing factors in construction accidents’, Applied Ergonomics 36, 2005. pp. 401-415.

[14] HSE – Health and Safety Executive, Are you making the best use of lifting and handling tools? First published 09/04. Available at: http://www.hse.gov.uk/pubns/indg398.pdf

[15] Gallagher, S. 2005. Physical limitations and musculoskeletal complaints associated with work in unusual or restricted postures: A literature review. Journal of Safety Research 36, pp. 51-61.

[16] Viruet, H.B., Genaidy, A., Shell, R., Salem, S. and Karwowski, W., ‘Effect of forklift operation on lower back pain: An evidence-based approach’, Human Factors and Ergonomics in Manufacturing, 18, (2), (2008), pp. 125-151.

[17] Perttula, P., Korhonen, P., Lehtelä, J., Rasa, P-L., Kitinoja, J-P., Mäki-mattila, S., Leskinen, T., ‘mproving the Safety and Efficiency of Materials Transfer at a Construction Site by Using an Elevator’, J Constr Engrg and Mgmt, 132(8), 2006, pp. 836-43.

[18] Kuiper, J., Burdorf, A., Frings-Dresen, M., Kuijer, P., Spreeuwers, D., Lötters, F., Miedema, H., Assessing the work-relatedness of nonspecific low-back pain, Scandinavian Journal of Work, Environment & Health, 31, 2005, pp. 237-243.

[19] INRS

[20] Perttula, P., Improving Occupational Safety in Logistics - Accident Risks of Heavy Vehicle Drivers and Material Transfers at Construction Sites, People and Work Research Reports 95, Finnish Institute of Occupational Health, Tampere, 2011.

Lectures complémentaires

EU-OSHA - European Agency for Safety and Health at Work, Practical tools and guidance on musculoskeletal disorders, Available at: [12]

FEM - European manufacturers of materials handling, lifting and storage equipment [13]

HSE - Health and Safety Executive, Warehousing Available at: [14]

BGHW - Berufsgenossenschaft Handel und Warenlogistik, BGHW-Interaktiv, Das sichere Lager in der Warenlogistik. Available at: [15]

 

Contributeur

Karla Van den Broek

Prevent, Belgium

Pia Perttula

Finnish Institute of Occupational Health

Kirsi Koskela