ANALYSIS ON CHARACTERISTICS OF FALL ACCIDENTS
IN CONSTRUCTION INDUSTRY
Tetsuo Hojo1 and Katsutoshi Ohdo212

Institute of Technologists, 333 Maeya, Gyoda, Saitama, 361-0038, Japan
National Institute of Occupational Safety and Health, 1-4-6 Umezono, Kiyose,Tokyo 204-0024, Japan

Falling accidents are a serious problem in the construction industry in Japan, it isimportant to analyse the factor to take steps to meet the situation. In this study, firstly
the injury accident reports by Labour Standard Office in Japan were investigated.
Next, the details of the work of the fall accidents was analysed based on the result of
the investigation. It was found that the fall accidents from elevation in constructionindustry were mainly happened in wooden house constructions and building
constructions, and that fall from scaffolds were the most frequent fall accidents inboth constructions. In order to investigate the details of the cause of the disaster inthese two construction works, fall accidents from elevation according to the places andthe height, where workers fell, were analysed. From the results of this analysis,
characteristics of the cause of disaster were clarified by the type of construction works
and by the seriousness of the accidents.

Introduction
Falling accidents are a serious problem in the construction industry in Japan. Approximately 40%of fatal construction accidents are caused by falls. Therefore, MHLW (the Ministry of Health,Labour and Welfare, Japan) has introduced and strictly enforces countermeasures to reduce falls
from scaffolds with various safety guidelines, e.g., the Guideline for Advanced Guardrail
Installation Method for work requiring scaffold erection. These countermeasures have resulted in areduction in fatalities caused by workers falling.
However, the rate of fatal accidental falls is still high in the construction industry, and possible
countermeasures became the main issue of the 11th Labour Accidents Prevention Plan in Japan.
Therefore, in this study, the injury accident reports by Labour Standard Office in Japan wereinvestigated. More than 1800 reports were checked and classified into the places, where workers
fell. From the results of the investigation, the measure for decrease fall risk was examined.

Investigation of Accidents Report
Labour accidents, in which workers were killed or injured with more than three days’ rest, werereported by Labour Standard Office in Japan. This data-base is open to the public on the WEB siteof the Ministry of Health, Labour and Welfare. In this study, these injury accident reports wereinvestigated.
Figure 1 shows the classification of main causes of the labour accidents in 2007 in Japan.
131,478 workers were killed or injured with more than three days’ rest, and 35% of accidents were- 67 -caused by workers’ fall. Fall accidents were classified as “fall on same level” (18%, 23,649workers) and “fall from elevation” (17%, 23,064 workers). In This study, the measure for decrease“fall from elevation” was examined.

Fall on same level
Fall f rom elevation
16%

5%

18%

Caught in or comp ressed by equipment orob jects
Cut or rub

2%

Transportatio n (vehicle)

5%

17%

Struck b y f alling or f lying ob ject

7%

Crush into object o r equipment

7%8%Struck b y object o r equipment

15%

Collapse
OthersFigure 1. Classification of main causes of the labour accidents in 2007 in Japan
Figure 2 shows the classification of the fall accidents from elevation according to industries.
31% of the fall accidents from elevation (7141 workers) were happened in construction industry.
In this study, 1,824 fall accidents from elevation in construction industry were extracted from 7,141
accidents (see Figure 2), and the injury accident reports were investigated in detail.
Figure 3 shows the classification of the fall accidents from elevation in construction industry
according to construction objects. Mainly, the fall accidents from elevation were happened inwooden house constructions (22%, 403 workers) and building constructions (21%, 384 workers),
as shown in Figure 3.

Others,
5409, 23%

Woodenhouses, 403,
22%

Construction

7141, 31%

Commerce,
2344, 10%
Manufacturing

3677, 16%

Others,1037, 57%
Transportation

Buildings,
384, 21%4493, 20%

Figure 2. Fall accidents from elevationaccording to industries 

Figure 3. Fall accidents from elevationaccording to construction objects

Characteristics of Fall Accidents
Fall accidents from elevation according to the places

Figure 4 shows the classification of casualties of fall accidents from elevation in wooden house
constructions according to the places, where workers fell, and Figure 5 shows that of in building
constructions.

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In both constructions, fall from scaffolds were the most frequent fall accidents, and stepladders
were the next. Approximately 40 % of the fall accidents were happened from these two places. The
cause in the third place or less is different according to construction. Fall from the roof is 14% morein the wooden construction. On the other hand, fall from the construction machineries accounted for
6% in building constructions. It is because there are a lot of work on the inclining roof in wooden
construction, and a lot of work to use machineries in building constructions.

Workplatforms
3%
Openings
3%

Others16%Work tables
3%

Others20%

Stairs3%

Trucks3%
Stairs3%

Scaffolds
20%

Stepladders
18%

Beams
10%

Roofs
4%
Openings
4%

Roofs
14%

Trucks5%

Ladders
10%

Figure 4. Casualties according to the places
in in wooden house constructions

Scaffolds
27%

Stepladders
16%

Beams
5%
Machineries6%

Ladders
7%

Figure 5. Casualties according to the placesin building constructions

Figure 6 shows the classification of fatalities of fall accidents from elevation in wooden house
constructions according to the places, where workers fell, and Figure 7 shows that of in building
constructions. In building constructions, fall from scaffolds accounts for 36%, being at the firstplace as well as casualties. On the other hand, in wooden house constructions, fall from beams
occurred most, accounting for 27%, but, fall from scaffolds accounts for 18%, in 3rd place. This isbecause it is hard to take fall protection measures in the work on beams, and when happened it islikely to become a serious accident. Fall from roofs is in 2nd place in both constructions.

Stairs3%

Floors3%

Ladders
3%

Beams
27%

Stepladders
4%Work
platforms
3%

Work tables
3%

Others2%

Openings
10%

Scaffolds
36%

Stepladders
5%

Beams
10%

Work
platforms
6%
Openings
6%

Others9%

Scaffolds
18%

Roofs
21%

Figure 6. Fatalities according to the places
in wooden house constructions

Machineries
10%

Roofs
21%

Figure 7. Fatalities according to the placesin building constructions

Fall accidents from elevation according to the heightFigure 8 shows the classification of casualties of fall accidents from elevation in wooden house
constructions according to the height, where workers fell, and Figure 9 shows that of in building
constructions. As for the height data, nearly half was unknown, but it is analysed within theobtained data.

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In wooden house construction, "1-2m"and "2-3m" have occurred most, accounting for 18%,
respectively. Fall from a comparatively low place stands out. In building constructions, "1-2m"
occurred most, accounting for 15%. "5m or more" occupies by as much as 10%, and it is thoughtthat it is because there are a lot of works in a high place compared with wooden house construction.

Figure 8. Casualties according to theheight in wooden house constructions

Figure 9. Casualties according to theheight in building constructions

Figure 10 shows the classification of fatalities of fall accidents from elevation in wooden house
constructions according to the height, where workers fell, and Figure 11 shows that of in building
constructions. It differs from casualties, "5m or more" occupied a lot, and it reached 56%, morethan half, especially in the building construction work.
This result suggests the possibility that severity is increased when it is crashed, when the heightof the work becomes higher. However, since the frequency of occurrence of disaster casualties ishigher crash from low areas, the measures can not be ignored.

Figure 10. Fatalities according to theheight in wooden house constructions

Figure 11. Fatalities according to theheight in building constructions

Measure for decrease fall risk from scaffolds
In order to examine further countermeasures to decrease such fall accidents from scaffolds, MHLW
established a committee to evaluate various construction methods according to present safety
guidelines. From the results of the committee, the Occupational Safety and Health Regulation andthe Guideline for Advanced Guardrail Installation Method were amended in 2009.
Figure 12 shows the prefabricated scaffolds erected by the method, and Figure 13 shows the- 70 -

installation method for using the advanced guardrails. In the method, the upper guardrails arealways set from the lower platforms using the advanced guardrails. In using the method, workers
are always protected from a fall by the advanced guardrails at the top of the previously erectedscaffolds in all construction stages of the scaffolds, i.e. assembling of the scaffolds, work on thescaffolds, and dismantling of the scaffolds.
MHLW aimed to spread the use of this method through their safety guidelines and investigated
the use rate of this method on 6,433 construction sites. The result showed that only 31% ofconstruction sites use this method, and it was found that the use of the method was not widespreadyet. Therefore, it is necessary to use this method more widely for decrease fall risk from scaffolds.

Figure 12. Prefabricated scaffolds erected by theAdvanced Guardrail Installation Method

Advanced guardrail

Figure 13. Advanced Guardrail Installation Method- 71 -Conclusions
In this study, the injury accident reports by Labour Standard Office in Japan were investigated, andthe measure for decrease fall risk was examined. The results are summarized as follows.
1) In japan, 131,478 workers were killed or injured with more than three days’ rest by the labour
accidents in 2007, and 35% of the accidents were caused by workers’ fall.
2) 31% of the fall accidents from elevation were happened in construction industry.
3) Mainly, the fall accidents from elevation in construction industry were happened in wooden
house constructions and building constructions, and fall from scaffolds were the most frequent
fall accidents in both constructions.
4) In order to decrease such fall accidents from scaffolds, the Occupational Safety and HealthRegulation and the Guideline for Advanced Guardrail Installation Method was amended byMHLW in 2009.
5) However, only 31% of construction sites use this method, and it was found that the use of themethod was not widespread. Therefore, it is necessary to use this method more widely for
decrease fall risk from scaffolds.

Acknowledgement
This study was supported by Grants-in-Aid for Scientific Research in 2013 from the Ministry ofEducation, Culture, Sports, Science and Technology of Japan.

References
Ministry of Health, Labour and Welfare, Japan, (2009), Occupational safety site, Retrieved 2010,
from http://anzeninfo.mhlw.go.jp/ (in Japanese).
Ohdo,K.and Hojo,T.,(2012) Investigation on fall accidents and measure for decrease fall risk feom
scaffolds, Proc. of the 10th International Conference Occupation Risk Prevention, Bilbao,Spain, CD-ROM.
Ohdo,K., Hojo,T.and Hirokane,M., (2013), Factor analysis on fall accident in construction industry
using web-based Labour accidents data, Proc. of Annual conference of Japan Society of Civil
Engineers, CD-ROM, (in Japanese)
Ministry of Health, Labour and Welfare, Japan, (2009), Guideline for Advanced Guardrail
Installation Method, Retrieved 2009, fromhttp://www.mhlw.go.jp/bunya/roudoukijun/anzeneisei26/dl/09.pdf (in Japanese).
Ministry of Health, Labour and Welfare, Japan, (2011), Report on examination for effect valuationof fall preventive measure, (in Japanese).

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