What tannery ergonomics covers
A tannery transforms hides and skins through preparation, tanning and finishing operations. Its ergonomic assessment needs to follow material from receipt to dispatch because the same piece changes in moisture, stiffness and ease of handling. Working a wet hide across a surface, feeding a machine and grading finished leather are not equivalent exposures. Tanning must also be distinguished from the subsequent manufacture of footwear or leather goods.
The ILO’s 2022 sectoral code places design and organisation among the determinants of ergonomics. Applying that principle to an individual plant requires identifying who moves each piece, which equipment is used and how long the activity lasts. The sequence described here is a framework for observation, rather than a claim that every factory uses identical processes. The initial inventory should identify the stages actually present, those that are automated and those undertaken by external businesses.
Wet hides, stacks and transfers
At receipt and preparation, representative pieces should be measured and their condition described. Irregular dimensions, folds and a wet surface can make gripping difficult; a nominal average weight is insufficient. Observation should establish the starting and destination positions and whether each piece is lifted, dragged or turned. As a stack becomes lower during a shift, an initially convenient pickup can become repeated trunk bending.
A useful analytical proposal is to map each transfer and identify handling that could be eliminated by bringing processes together or introducing compatible equipment. Improvement does not simply mean making batches larger, because subsequent movements may then become harder. Containers, trolleys and supports need to suit the material while allowing cleaning, stability and safe access. When hides stick together, sudden forceful pulling should not become an accepted routine. That event calls for a review of storage arrangements and the separation method before the next batch is processed.
Machine feeding and finishing
Mechanical processes may require workers to present, spread, orient and remove pieces. Observation must distinguish the effort of supporting material from the machine’s movement: effective protection against entrapment does not demonstrate that reach distances are acceptable. Equally, improving access does not authorise removal of guards or bringing hands closer to rollers or blades. Any modification requires checks of safety, compatibility and operating conditions.
At grading and manual finishing stations, review the usable surface height, distance to the inspection area and location of tools and containers. Where a product requires reaching across a large table, changing its presentation or providing safe access from multiple sides may be more appropriate than expecting repeated stretching. Test the proposal with different sizes and grades. An arrangement that works for a small piece may fail when the material is broad, flexible or difficult to orient, especially if inspection and handling must occur at the same time.
Assessing posture, force and repetition
A useful assessment combines tasks, duration and variability. Include normal production, batch changes, replenishment and material removal without staging a hazardous manoeuvre for a recording. Workers can help identify short bursts of effort that a brief observation would miss. Record which hand supports the piece, how the wrist is held and whether the body presses against an edge.
MAC can support analysis of lifting and carrying; ART addresses repetitive upper-limb tasks, while RAPP covers pushing and pulling. These tools have different applications. Their scores should neither become diagnoses nor be added together as if they measured one quantity. Where material is deformable or force varies considerably, state the limitations and supplement the assessment with competent technical judgement. The outcome should support a specific decision about improvement. Assigning a coloured risk category without explaining the task, evidence and proposed control leaves the employer without a practical basis for action.
Workstation design and handling aids
Priority should be given to eliminating unnecessary transfers and reducing the need to support or move material with the body. Adjustable tables, presentation supports and transport systems may be considered, but a commercial description does not establish suitability. Check rated capacity, compatibility with moisture and substances, piece stability and maintenance requirements. The arrangement must also protect the people loading, cleaning or clearing the equipment.
An acceptance trial can compare the same operation before and after modification using representative materials and workers with different characteristics. Observe reach, force, visibility and foot space as well as cycle time. If a change enables faster output but keeps the same exposure present for longer, the expected benefit may be reduced. Acceptance should therefore depend on observed results and the updated risk assessment, rather than a generic ergonomic label. Record any difficulties discovered during the trial and who is responsible for resolving them.
Trolleys, routes and floor surfaces
Moving hides on a trolley may eliminate lifts while introducing pushing demands. Review actual loading, handle height and grip, wheels, braking, slopes and thresholds. A result obtained with an empty trolley on a clean floor may not represent a shift involving a full load, water or residues. HSE identifies limitations of RAPP for equipment with small wheels and irregular surfaces.
For purchasing and maintenance, define the route on which the equipment will operate and the arrangements for withdrawing it when it no longer rolls properly. Temporary storage should not narrow passageways or require manoeuvring between people and machines. Review drainage and cleaning so that a transport improvement does not increase slipping hazards. Gloves and footwear must be selected against actual risks; they cannot compensate for a poorly designed route or defective trolley. The trial should include turning, stopping and positioning at the destination, rather than considering straight-line travel alone.
Links with hygiene and machinery safety
Biomechanical loading must be coordinated with biological control of animal-derived raw materials and chemical assessment of the products used. These are separate issues: reducing bending does not necessarily eliminate contact exposure, and treated leather cannot automatically be assumed free of every hazard. Assessment identifies substances, stages and exposure routes without transferring conclusions from receipt to finishing without justification.
This coordination has practical consequences for equipment selection. A support that improves reach but makes a surface difficult to decontaminate needs reconsideration. A glove suitable for a particular agent can change grip and should be tested during the task. Mixing products or changing formulations is not proposed as an ergonomic solution. Equipment interventions must retain guards and established isolation procedures. Where a blockage requires access to a dangerous area, the activity is no longer ordinary material handling and requires its own authorised procedure, competent personnel and the relevant safeguards.
Organisation, participation and adjustment
Exposure depends on how batches, production pace and recovery are organised. Rotating between two jobs with similar wrist gripping or shoulder elevation can change the job title without changing the load. Rotation needs a description of each activity’s demands and evidence that the alternation reduces the relevant exposure. It does not replace redesigning an unsuitable operation.
Worker participation should include different shifts and levels of experience, with a channel for reporting difficulties without penalty. A newly appointed worker needs training on the actual equipment and time to become familiar with it. A health limitation requires assessment of adjustments by the competent professionals. Age or sex alone does not establish that someone is unable to perform a task. Adjustments should respond to individual characteristics and observed working conditions, while checking that the remainder of the team does not silently absorb a more demanding workload as a result.
Example of improvement and verification
Hypothetical example: a plant identifies that grading requires repeated turning between a low stack and a high table. The team examines several batches and establishes that pieces differ in size and ease of separation. An adjustable presentation support and a revised output arrangement are proposed before deciding whether further handling assistance is required.
The trial compares the complete operation, including loading the support and cleaning it. Bending, reaches, gripping difficulties and worker feedback are recorded alongside batch identity and observed conditions. If a new difficulty appears, the arrangement is corrected before wider introduction. No percentage reduction in injuries is attributed to this illustration: it is neither a study nor a real case. Its purpose is to show what evidence an organisation could collect to decide whether a modification works in its own process. The trial should also identify the person responsible for checking that the improved arrangement remains in use.
Records and follow-up indicators
Prevention records should identify the task and process stage, observed materials, assessment method, limitations, measures, responsibilities and subsequent checks. Suggested tannery indicators include manual transfers eliminated, handling aids available and usable, wheel defects, outstanding adjustments and operations reassessed after changes in batches or equipment. None alone establishes that musculoskeletal disorders have disappeared.
Reported symptoms warrant appropriate healthcare and preventive examination of the job while maintaining confidentiality. An organisational dashboard needs aggregated conclusions and actions, rather than individual diagnoses visible to everyone. The LPRL and royal decrees cited belong to the Spanish legal framework; HSE and ILO materials are technical references requiring contextual interpretation. Review must respond to relevant changes, harm or evidence that controls are insufficient. It should not be closed merely because a form has been signed or training recorded. Retaining the original observations makes it possible to understand why a measure was selected and whether later operating conditions still match its intended use.
Frequently asked questions
Is there a universal safe weight for hides?
No. Weight, dimensions, grip, moisture, frequency, posture and route must be assessed together; a single number does not establish safety.
Does a mechanical aid eliminate every risk?
It may reduce handling, but loading, cleaning, maintenance, entrapment and effects on preceding and subsequent tasks still require assessment.
Does ergonomics replace biological exposure control?
No. Animal-derived raw material handling requires a specific hygiene assessment coordinated with ergonomics and machinery safety.
Is job rotation sufficient?
It can help only if relevant demands change and recovery is possible; it does not replace correcting a hazardous task.
