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Vol. 44, No. 3 May-June 2008
In the Spotlight
Application of System Safety to Prevention of Falls from Height in Design of Facilities, Ships and Support Equipment for Weapons Systems

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Falls from height are the second leading cause of occupational fatalities, behind only traffic-related fatalities, and account for approximately 700 occupational fatalities annually in the United States [Ref. 1]. The number of such fatalities has continued to rise during the past decade, while most work-related injuries are declining in number. Table 1 summarizes this data. Approximately half of these deaths occur in the construction industry.

Table 1 Fatal Falls in U.S. Private Industry
Year Fatal Falls Total Fatalities
2001 810 (14%) 5,915
2002 714* (13%) 5,524
2003 662 (12%) 5,575
2004 783 (14%) 5,764
2005 735 (13%) 5,734
2006 771* (13%) 5,703*
2007 806* all industry (14%) 5,703

* Data regarded as preliminary at the time of review (Nov. 2007)

Falls from height accounted for 288,500 (6%) of the 4,700,600 OSHA-recordable1 mishaps occurring in 2001 and 2002 tracked by the Bureau of Labor Statistics (BLS) in 2004. In 2006, falls accounted for 234,450 (20%) of 1,183,500 non-fatal mishaps in private industry recorded by the BLS. The general reduction in fall injuries is likely to be related to regulatory requirements and their more stringent enforcement.

Statistics in England are similar, but show fall-related mishaps, rather than traffic-related accidents, as the leading cause of occupational fatalities (Health & Safety Executive, 2003b). Falls accounted for 73 (25%) of 291 occupational fatalities in 2000/2001, but dropped to 46 (22%) of 212 fatalities in 2005/2006.

The 46 fatalities and 3,300 major injuries sustained in 2005/20062 represent some of the lowest figures on record and include a 50% reduction in the rate of fall injuries among workers from 1991/1992 to 2005/2006. This reduction appears consistent with the aggressive campaign undertaken by the Health and Safety Executive to reduce workplace injuries, particularly falls. The English Health and Safety Executive made prevention of fall injuries a top priority in the 2001/2004 strategic program (see

European statistics show a similar trend. Falls from height accounted for approximately 40% of construction industry accidents [Ref. 2].

In 1998, OSHA reported that 150 to 200 workers are killed and 100,000 are seriously injured annually in the construction industry as a result of falls from height. Several high-risk industries suffer the greatest fraction of their occupational fatalities from falls. These include general construction (34%); residential construction (45.5%), carpentry and floor work (53%) and steel erection (81.7%) [Bureau of Labor Statistics (BLS) 2001 data]. Shipyards are categorized within the construction industry, making it difficult to extract fall data for the maritime industry. Review of the narratives from OSHA fatality data between 1991 and 2001 indicates that 20 (16%) of 120 shipyard fatalities recorded appeared consistent with falls from height, but often provided limited detail. Scaffolding and fall protection are the two most commonly cited OSHA violations and garnered the highest penalty amounts in Fiscal Year 20073.

Typical costs for a fatality range from $800,000 to $2,400,000, while the average cost of serious injury is more than $30,000 [Ref. 3]. The Center for Naval Analysis' evaluation of Navy mishap data, using three databases, showed that falls ranged from 15% to 28% of reported total injuries and illnesses [Ref. 4]. This evaluation also identified several shipyards as Navy locations with the higher injury rates and compensation costs.

Testimony provided by workers and personnel in two shipyard safety departments suggested that some mishaps, not reported as falls, resulted when workers "caught" themselves to avert a serious fall at the cost of a lesser injury, such as a strained shoulder. Concurrently, the category of "slip/twist/not falling" accounted for 35% of the Navy-wide summary of fall-related injuries [Ref. 4]. It is likely that similar types of mishaps in other industries account for many other events that were actually averted falls.

Much of the attention has been on use of personal protective equipment and fall-arrest systems retrofitted into existing facilities, often at considerable cost. There has been less focus on initial design and preliminary risk evaluation in design. System safety practitioners have not consistently addressed risks associated with work at elevated locations as a consideration in preliminary hazard assessments or in design requirements.

U.S. Regulatory Requirements and Definitions
Protection against falling from heights during operations conducted at elevation is one of the more intuitively clear safety requirements. The regulatory definition of an elevated work location varies slightly by industry from 4 to 10 feet4. The requirement is five feet or greater within shipyard employment and eight feet or greater within the maritime industry.

OSHA regulations stipulate assured fall protection for elevated work locations that provides a fixed barrier or use as an approved personal fall-arrest system. An assured fall-protection system is defined as a combination of equipment and work practice that either prevents falls by measures such as fixed barriers (preferred) or alternatively, fall-arrest systems.5

1 OSHA Regulations (Standards - 29 CFR 1906) regulate reporting of occupational injury and illness statistics. OSHA-recordable injuries typically involve a loss of greater than one day of work time.
2 U.K. Health and Safety Executive - A Guide to the Work at Height Regulations,
3 Information courtesy of Keller Online (
4 OSHA Regulatory requirements by industry are five feet for shipyard employment (29 CFR 1915.159 and 29 CFR 1915.77c); six feet for construction (29 CFR 1926.501b); four feet for General Industry (29 CFR 1910.23b); 15 feet for Steel Erection (29 CFR 1926.760a); and eight feet for Marine Terminals and Longshoring, 29 CFR 1918 (see for regulations).
5 A personal fall-arrest system includes an approved full-body harness and other equipment designed to provide controlled expansion that limits the impact forces created by a fall on the victim (to 1,800 pounds) and certified anchorages (3,600 pounds). The device providing controlled deceleration may include a lanyard, deceleration device, lifeline or a suitable combination of these. The use of body belts for fall arrest has been prohibited in the U.S. since January 1, 1998.

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