The safety triangle, commonly known as the safety pyramid or accident pyramid, has recently come under attack from safety professionals. It was originated in 1931 by H.W. Heinrich and detailed in his book, Industrial Accident Prevention: A Scientific Approach. Widely accepted for over 70 years, the safety triangle serves to illustrate Heinrich's theory of accident causation: unsafe acts lead to minor injuries and, over time, to major injury. The accident pyramid (Figure 1) proposes that for every 300 unsafe acts there are 29 minor injuries and one major injury.

Since unsafe acts are difficult to record accurately and Heinrich's theory seems logical, the safety pyramid remained unchallenged for decades. Its widespread acceptance sent safety managers and company presidents in pursuit of unsafe acts under the assumption that if they could control unsafe behavior then the major injury would not occur. In the end, despite targeting unsafe acts through behavioral systems and a variety of difficult-to-administer programs, the major injury still occurred, given enough manhours.

Over the years, a number of safety managers modified the safety pyramid to create a more quantifiable construct based on Heinrich's theory, as illustrated in Figure 2.

Over time, a greater accumulation of accident data suggested that the pyramid is not an equilateral triangle at all; depending on a company's safety culture, it may take any one of a variety of shapes, as identified in Figure 3. For example, companies that attribute blame to employees for incidents tend to have fewer minor and more major injuries.

In some cases, the diagrams began to look more like inverted pyramids or even squares. Stated in a not-so-delicate manner in numerous articles was the observation that Heinrich's theory was just that — ‘theory.’ The hypothesis of the safety triangle was apparently never tested. Although the logic of his theory seems indisputable, Heinrich did not cite studies or provide supporting data.

A March 2003 Journal of Professional Safety article, entitled “Severe Injury Potential,” by the highly esteemed safety consultant Fred Manuele indicates that safety professionals should indeed focus on preventing fatal accidents as well as the unsafe act. He says, “Many accidents that result in severe injury are unique and singularly occurring events in which a series of breakdowns occur in a cascading effect.”

While few safety professionals doubt that many factors contribute to the occurrence of an incident, the key elements or indicators of fatal accidents in the concrete products industry have been related to the following:

1. Not following lockout/tagout procedures, or not establishing lockout procedures for employees to follow.
2. Not having established, written, safe operating procedures in place for a given function, e.g., a laborer enters the top of a silo to break loose bridged-over material.
3. Not having adequate physical safeguards in place for a given process, such as unguarded bottom-feeding stockpiles.
4. Conducting unsafe practices for convenience, since the risk is perceived as insignificant.
5. Operating mobile equipment in an unsafe manner (perhaps previously allowed, or ignored, by supervisors).
6. Traffic accidents.

Each of the above indicators includes multiple underlying causes. These factors suggest that preventing the fatal accident does not depend primarily upon plant inspections in order to write up a mundane list of small items, such as frayed wires and machine guards. While frayed wires and machine guards in need of replacement can result in serious accidents, the fact remains: they seldom do. The focus of this type of inspection is typically not the prevention of the rare fatal incident, but rather, OSHA compliance. Easy-to-remedy and cheap-to-repair items are generated by safety supervisors who know the potentially severe, adverse political effects of identifying underlying management error, the need for possibly expensive training, failures with orientation, and similar costly issues.

The problem of ignoring the causes of fatal accidents is compounded when management becomes obsessed with the accident record — the dreaded lost-time accident count! Usually considered a freak incident, the rare fatal injury may be excluded from the accident count by one means or another. Many safety professionals are now focusing their efforts on preventing the fatal injury, i.e., focusing on Heinrich's incident pyramid from the top down rather than the bottom up.

Renowned safety consultant and professor Dan Petersen wrote in his second edition of Safety Management: “If we study any mass data, we can readily see that the types of accidents resulting in temporary total disabilities are different from the types of accidents resulting in permanent partial disabilities or in permanent total disabilities or fatalities. The causes are different.”

Focusing on the top down, however, can be expensive. Such an approach means conducting a thorough evaluation and step-by-step Job Safety Analysis (JSA) followed by the development of a written Safe Operating Procedure (SOP) for every job in each plant. Because plants are seldom identical in equipment or production demands, a qualified safety professional should spend time with crew members evaluating and documenting their specific duties. Accordingly, employee training should be conducted on the basis of the JSA and SOP so that the requirements of each job are thoroughly understood.

Whenever an employee is observed not using a safety procedure, the oversight should be addressed immediately. As well, the supervisor should practice self-examination: Is the employee performing out of urgency to meet stringent production demands perceived as required by management. A more action-oriented pyramid could be developed as indicated in Figure 4.

FIGURE 4: Identify a level of importance in preventing catastrophic injury

Importance	Action
Most important	• Evaluate equipment and provide all available safety equipment and process equipment necessary to eliminate hazards
	• Evaluate processes and procedures, developing detailed Job Safety Analyses and Safe Operating Procedures
Least important	• Provide training
	• Develop a written safety program for compliance

Developing the JSA and SOP are not desk jobs. If JSAs and SOPs are poorly developed merely to satisfy an administrative requirement, more damage can be done to the safety effort than if they were omitted completely.

A practice that sorely damages a safety effort is blaming all injuries on the employee. Another of Heinrich's theories is “multiple causation,” i.e., all accidents occur as a result of many factors or multiple causes. Based on this theory is the “Root Cause Analysis” used in incident investigations whereby the obvious physical circumstance of the incident is investigated to determine its cause, and what led to that, and so forth, until no further upstream or lateral factors can be identified. To avoid litigation and the obvious political ramifications of following the cause upstream, many companies simply identify the cause of most incidents as employee error or failure to follow safety rules. This simple — and somewhat dishonest defense — is brutal to employees and their families and may generate long-term “attitude” problems among other employees.

NFPA 70E PROTECTS PLANT ELECTRICIANS

The Occupational Safety and Health Administration now considers the voluntary consensus standard, NFPA 70E Standard for Electrical Safety Requirements for Employee Workplaces, which became effective on February 2000, a “recognized industry practice.” Accordingly, inspectors are allowed to issue citations under the general duty clause for violations of the standard. NFPA 70E requires employers to assess the potential flash hazard for workers and provide the appropriate PPE or “clothing resistant to flash exposure to an electric arc flash.”

Each task requires an assessment of the hazard risk category (HRC), which varies from 0 to 4. This assessment can be conducted with a chart provided in the standard that lists common tasks an electrician or maintenance worker would perform. After the HRC is established, a matrix for protective clothing is provided based on hazard/risk. Each HRC has a corresponding minimum arc rating, known as Arc Thermal Performance Value (ATPV) or Energy Break-open Threshold (Ebt), which fire-retardant clothing must meet.

Many companies have decided to simplify NFPA 70E compliance by implementing fire-resistant uniform programs for maintenance workers and electricians. The uniforms are selected to meet the requirements of HRC 0, 1, and 2 for a single layer of material. Flash suits can be used for HRC 3- and HRC 4-level tasks. Smaller plants are simply contracting electrical work and leaving the compliance requirements to the electrical contractor.