Assessing the Root Cause of Metalcasting Injuries


The metalcasting industry continues to be challenged with higher injury rates than other manufacturing sectors, and this has been true for many years. According to the U.S. Bureau of Labor Statistics, foundry injury rates have been and continue to be much more than those for all private manufacturing.

This continuing disparity in injury rates should create a strong motivation to focus on injury prevention and the institution of measures designed to reduce foundry injury rates and the human suffering that these rates represent.

In a search for the cause of industrial injuries, it is common to cite the highly influential and groundbreaking work of pioneering safety scientist Herbert William Heinrich. Heinrich’s work, Industrial Accident Prevention: A Scientific Approach, first published in 1931, would become the foundation for safety science over at least the next 50 years. Five editions of the book were published by McGraw Hill, the latest in 1980.

Heinrich’s work, while not in print today, continues to influence the thinking of modern safety professionals and plant managers. His work is often remembered for two fundamental concepts: the ratio of causation of injuries between unsafe acts and unsafe conditions and his accident pyramid, expressing a statistical likelihood of minor safety events to major events.

Heinrich’s own view was accident prevention should focus on man failures and employ psychological methodologies to reduce industrial injuries. Heinrich wrote, “In the occurrence of accidental injury, it is apparent that man failure is the heart of the problem; equally apparent is the conclusion that methods of control must be directed toward man failure.”

The perspective that human error, arising from the person and ultimately the ancestral and social baggage that a person brings with them to work, is the proper focus and cause of industrial injury was not limited to Heinrich. As generations of safety professionals and manufacturing managers were taught this concept, it has found its way into the belief system of individuals and influential organizations.

Why Human Error Is Not a Root Cause
Human acts are involved in a majority of metalcasting injuries. Seldom is it true that a worker, properly engaged in their duties, is suddenly and without his/her own action injured by their environment. The question is whether the actions of the worker are the root cause of such injury. To assist in making this distinction Heinrich’s dominoes can be examined using a common quality problem solving tool of why-why analysis.

With an examination of Heinrich’s theory via why-why analysis, it is clear why Heinrich recommends various psychological and awareness strategies to the correction of industrial accidents. He recognizes he cannot address the true root cause (in his view) of the background of the employee, their upbringing and socialization prior to coming to work for a company, so he must attack the problem at the next level up: the employee himself.

But the tacit assumption in Heinrich’s view is the prevailing influence on employee behavior is already established prior to their hire, external to the organization and that this influence is largely a detriment to good safety performance. This ignores the massive amount of current research on the significant correlation between an organization’s culture and the safety performance of that organization. Heinrich’s link between employee act and past social environment and ancestry also ignores the structural influences that exist through management choices that directly or indirectly influence worker behavior.

Organizational culture can be defined as the shared perceptions among employees concerning the procedures, practices and kinds of behaviors that get rewarded and supported with regard to a specific strategic focus. These shared perceptions are driven by contributing factors such as:

Leadership values and consistency of action.
Supervisory communication and follow up.
Reward systems.
Measurement systems.
Processes for investigation, communication and closure of incidents.

The practical experience of many foundries has supported the link between safety climate/culture and the safety performance of their organizations and specifically the safety-oriented behaviors of individual employees.

From the perspective of a quality engineer, the analysis of the root cause of a human behavior looks for specific structural elements in the environment that may lead to the worker’s actions. This follows from the fundamental orientation that the worker’s actions—or the worker himself—is never the root cause of any problem since management is responsible for the decisive factors in worker performance.

Several structural elements can influence worker safety behavior, including the environment, process layout, documented method, available process time (perceived or actual), tools provided to the worker and type and nature of the personal protective equipment (PPE) provided.

Environment
The physical environment, specifically temperature, humidity and air quality have a direct impact on worker fatigue, which leads to compensation strategies as workers cope with the environmental stress. Fatigue also has been demonstrated to lead to a reduction in vigilance. Vigilance is a necessary part of worker safety to ensure safety checklists for example, are used in job preparation, various safety protocols are engaged prior to work and conditions are observed that might signal a safety risk.

Process Layout
Ergonomic safety is related to the physical manipulations required of the worker by the process layout. Examples include the relative heights of work tables, tools and materials, the relative spacing and positions of these objects, and the weights and forces involved in the process. These physical characteristics of the workplace also contribute to the fatigue and vigilance decay noted earlier. Process layout also can lead to an injury or accident that on a superficial analysis might be attributed to worker inattentiveness or other character trait.

For example, at one jobsite, the scrap tub at an inspection station was located across an aisle with heavy fork truck traffic. Workers were required to turn around, carry the scrap part to the scrap bin and then return. This process required extreme vigilance to avoid the traffic on the aisle. This was an accident waiting to happen that could not be blamed on worker inattention and no amount of warning or signage could compensate for the lack of safety oversight and poor planning in the layout.

Documented Method
Workers generally follow documented instructions and training provided to them. Including appropriate safety precautions and describing a safe and practical method in the instructions will reduce the frequency of problems resulting from these operations. However, when metalcasting operations do not subject their work instructions to a safety-specific review and do not create instructions that accurately represent the real world, safety performance problems will result. Impractical or wrong instructions lead workers to improvise and establish non-standard work practices that can often be detrimental to safety. Work instructions written primarily from a quality perspective (not safety) or not reviewed by workers and/or a safety professional can be the cause of foundry accidents and injuries. These may look like purely worker decision errors, but could have been prevented by adequate planning and instruction.

Process Time
The time available to the worker is a structural element in his/her environment. This time may be dictated by the machine cycle time, the overall pace of work or other constraints. Fast pacing leads to fatigue and compensation techniques where safe work practices may be compromised deliberately to keep up, get a scheduled break on time, etc. Fast pacing may simply not leave adequate time for the specified safe work practice to be carried out.

The worker’s perception of available time is dictated by a number of signals from the work environment, including:
The rate at which other workers are progressing.
Implicit or explicit messages from supervision that a faster rate or greater work output is needed to satisfy customer demand or some target of performance.
Bonus programs that reward higher worker output regardless of what might be physically appropriate for ergonomic or physical safety.
Tools

Generally, tools are provided in the foundry to increase the efficiency of the work and improve the capability of the worker to perform the task. In a comparable way to work instructions, poorly planned or reviewed tools can lead to a variety of impromptu decisions on the part of workers that do not optimize safety.

“Failure to follow instructions” is perhaps the most frequent attribution to cause of industrial accidents. This statement is clearly pointing to a human failure—the worker himself is responsible.

A few examples in the tool category help illustrate the need to dig deeper than blaming the worker.

A worker in a cleaning room received burns on his fingers from contact with a hot casting. The worker had defeated the protection of his right hand by cutting off the fingers of his glove. Upon investigation, it was discovered the actuator switch for a tool he was required to use had a guard that had inadequate clearance for a gloved finger. The worker had compensated for the poorly designed tool by cutting the glove’s fingers off, permitting him to use the tool as intended.

A worker in the melt shop fell and was injured during fluxing and dross-off of an aluminum holding furnace. Investigation revealed he had been issued a drossing tool that had a relatively short handle, creating substantial heat burden on the worker. The melt shop employees had welded an extension to the handle to allow the worker to be farther away from the melt. This had broken suddenly during operation resulting in a fall and fracture.

A worker in a rework area was struck by an overhead fixture and required stitches to his head. The worker, to reduce the trip hazard from the excessively long hose/cable connections to his tool, had wrapped them around a fixture on his work station to get them out of the way. Fatigue on the fixture from the cabling and hoses finally overcame the fixture attachment and it struck the worker while falling.

In each of these cases, a poorly reviewed tool was provided to the worker. The worker, faced with the dilemma of his desire to do the job well while still using the deficient tool, made the situation work until the safety risk and probability caught up. Only with the most superficial of analyses can these cases be designated as worker-caused injuries.

Personal Protective Equipment
Management is responsible to provide appropriate personal protective equipment to workers. Workers are required to wear this equipment and failure to do so is normally attributed as a worker responsibility. Yet management also has an obligation to make the PPE fit properly and be wearable for the duration required, instruct on proper fitment and sizing, and provide accommodation in the job routine for the limitations and constraints associated with PPE use. Injuries where PPE was not worn must be investigated beyond the simple observation that proper PPE was not worn.

Workers must be able to do the task (repetitively) with the PPE in place; it must work as required and not entail other problems that drive workers to compensate. For example, poorly designed or ill-fitting eye wear leading to fogging or unstable fit with head gear will only be periodically worn (or perhaps completely ignored) by workers.

Harm in the Belief of Human Error Causality of Injury
Failure to identify and address the root cause of any problem means the problem will recur. Just as clipping the top off a dandelion growing in a garden will only have a short-term effect, so too problems that are addressed only at a symptomatic level will happen again. Tragically, recurrence of the problems in a foundry is tallied in a human cost, not just time wasted weeding again.

Recurrence of safety problems wastes valuable people resources by implementing programs that are ineffective, misguided and sedative in their effect, meaning short term improvements often result from a focus on safety performance and operator attention and vigilance will increase temporarily. This leads the organization into the false belief that this improvement is sustainable and early results will continue long term. Often this experience leads organizations to try another program with similar emphasis thinking it was a flaw in the implementation or the particular character of the individual program that caused initial results to fade rather than rethinking the premise behind such programs.

Beyond recurrence, belief that the workers themselves are the primary focus in preventing injury shifts responsibility for correction from management to the worker. This permits management to evade its true responsibility, namely to provide that which their workers need to be safe and successful. Executive management has a stewardship responsibility for the people they employ, not just for their company reputations and their capital investments. If top management views safety performance as the one area where their actions are ultimately ineffective because it relies on the “ancestry and social environment” workers bring into the workplace ala Heinrich, then the most powerful change agent in the building has been effectively negated.

When problems are not effectively addressed by hard work and sincere effort, or when problems appear out of effective reach, a frustration and belief forms that not all injuries can be prevented. If a widespread belief is held that workers themselves are diligent and precise about their work or are careless and lazy, then it follows that the key attribute of safety performance depends on a character attribute that cannot be filtered by the hourly hiring process. Belief that some people are just “injury prone” leads to employment practices that tend to seek those individuals who have had frequent first aid or recordable injuries and remove them from the team. This is logical if one believes worker behavior can only be demonstrated in practice and that unsafe behavior results largely from the worker himself. These beliefs when widespread harm a true evaluation of the root cause of injuries. They also lead to a focus on a “compliance to regulations” mentality that follows the law but goes no farther because results beyond that rely on worker attitudes rather than a cultural or structural element in the foundry environment.

Heinrich’s idea that worker behaviors are part of the chain of cause and effect leading to workplace injuries was largely correct but did not go far enough and left safety practitioners with the notion that prevention of injury requires the right kind of worker. These ideas persist with harmful consequences for organizations and individuals in the metalcasting industry and in the manufacturing sector as a whole.

As the foundry industry searches for improvement in its safety performance going forward, it must look beyond behavior and the social and cultural backgrounds of its workers to the company cultural and environmental elements of the workplace. Management must lead the effort, authorizing it by personal presence and practical support, such that the root causes of unsafe behaviors are addressed.

This article is based on Paper 17-069 originally presented at the 121st Metalcasting Congress in Milwaukee in April 2017.