In-depth accident analysis of electrical fatalities in the construction industry

Abstract

The current study analyzed 255 electrical fatalities in the construction industry. Similar to our previous analysis of fatal falls, each electrical fatality was analyzed in terms of individual factors (age, gender, experience of the victim), task factors (performing task), environmental factors (wet area and confined space), management factors (company size measured by number of workers), source of injury, and causes for these accidents. These electrocution accidents were divided into five accident patterns: direct worker contact with an energized power line, boomed vehicle contact with an energized power line, conductive equipment contact with an energized power line, direct worker contact with energized equipment, and improperly installed or damaged equipment, to identify contributing factors for each. For each accident pattern, accident causes (failure to de-energize electrical systems, failure to maintain safe distances, improper use of personal protective equipment (PPE), poor work practice, accidental contact with exposed electrical parts, defective tools and equipment, lack of effective safety devices or unsafe environment) and prevention measures (safe work practices, insulation, guarding, grounding, and electrical protective devices) were developed based on the identified common scenarios. The current classification scheme can be used as a data-collection instrument that will lead to more precise and effective interventions.

Relevance to industry

The current research develops a coding system that would facilitate the categorization of fatal electrocutions in terms of the cause for electrocution, performing task, source of injury, individual factor, and company size for deriving potential risk factors and effective electrocution protection strategies. Significant accident scenarios and high-risk groups of occupational electrocution were identified based on the analysis of 255 work-related electrocution fatalities.

Introduction

Electrical fatalities accounted for 14.6% of all fatal accidents and were the second leading cause of occupational fatality in Taiwan, following falling fatalities (30%), according to Chi and Wu (1997). Our study of 423 electrical fatalities from the years 1996 to 2002 indicated that the construction industry had 255 fatal electrocutions, which accounted for 60% of the total number of electrical fatalities. Electrical fatalities are second only to falls (2.11 per 100,000 workers) as causes of occupational fatality in the construction industry. The average annual incidence rate—0.78 per 100,000 workers—was relatively high as compared to 0.4 in US (Kisner and Casini, 1998) and 0.49 in Australia (Harvey-Sutton et al., 1992), indicating that occupational electrical fatal injury is a significant problem in Taiwan.

We need to determine the cause of electric shock in order to control the hazard and successful accident prevention relies to a large extent on knowledge about the causes of accidents (Williamson and Feyer, 1998). In seeking to understand the causes of these accidents, epidemiological analyses are of value in revealing the factors associated with fatal injuries. However, care is needed with the choice of classification scheme for the analysis as this can materially affect the outcome (Chi and Wu, 1997). Appropriately defined classification categories are also important in forming a basis for effective accident prevention programs (Hinze et al., 1998).

Classification was a major problem in our previous study. The number of divided categories and the actual cutoffs could have enormous impacts on the result of the analysis, both required extensive literature survey and tradeoffs (Chi and Wu, 1997). As indicated by Hinze et al. (1998), carefully developed categories of accident causation would provide a viable basis for implementing effective accident prevention programs. One major objective of the current research was to develop a coding system that would facilitate the categorization of fatal electrocutions in terms of the cause for electrocution, performing task, source of injury, individual factor, and company size for deriving potential risk factors and effective electrocution protection strategies. The coding framework was developed based on the scenario analysis of Drury and Brill (1983), OSHA (2002)'s three major causes of electrical accidents: unsafe equipment or installation, environment, and work practices, and several other researches for electrical fatalities. The coding scheme was designed to be mutually exclusive individually but complete collectively. A total of 255 fatal electrocutions were coded and analyzed based on a classification scheme that will be described in Materials and Methods. The Finnish multi-linear event-sequencing method (Aaltonen, 1996) and the operationalized model (Tuominen and Saari, 1982), which treat an accident as a flow of events, were adopted to determine potential causes preceding the five accident patterns of electrocution.