EFFECTS OF COUNTERMEASURES FOR SCAFFOLD-RELATEDFALLS IN JAPANKatsutoshi Ohdo
National Institute of Occupational Safety and Health, 1-4-6 Umezono, Kiyose,Tokyo 204-0024, Japan

Fall accidents are a serious problem in the construction industry in Japan, driving
the Japanese government to introduce and strictly enforce countermeasures for
reducing falls from scaffolds. Among the preventive strategies formulated arevarious safety guidelines, such as the Occupational Safety and Health Regulations.
Despite these initiatives, however, mortality rates due to fall accidents remain high.
To further strengthen the fall prevention measures, the Japan Ministry of Health,Labour, and Welfare established a committee in our institute, tasked to investigate
the safety regulations applied overseas. In accordance with the guidelines issued by
the government, the committee also evaluated the current construction methods andfall protection system adopted in the country. On the basis of the results anddiscussion, the Occupational Safety and Health Regulations were amended in 2009.
The current study investigates the effects of these amended measures, which werefound effective in preventing most fall accidents from scaffolds.

Introduction
Frequent fall accidents are severe problems encountered in construction industries, with approximately
40% of fatal accidents during construction attributed to workers’ falls. In Japan, countermeasures for falls
from scaffolds had been strengthened through systematization in official guidelines. Although these
efforts reduced the rate of scaffold-related fatal falls, the overall percentage remains high—an issue thatelevated possible countermeasures to the main agenda of the 11th Labour Accidents Prevention Plan inJapan. To develop additional preventive measures for scaffold-related falls, the Japanese Ministry ofHealth, Labour, and Welfare established a committee at our institute. This committee was mandated toinvestigate the safety regulations applied in construction industries overseas and to evaluate various
Japanese construction methods in accordance with present safety guidelines.
The results and discussion show that workers sometimes fall from the space between
guardrails and work platforms. Preventing falls of this nature necessitates compressing this space.
The experiments conducted by the committee also indicate that scaffold sheeting, which is used
to cover scaffolds and is widely used in Japan (Figure 1), contributes to worker safety; that is, it
protects them from falls (Ohdo et al., 2009).

Experimental method and results
The effect of scaffold sheeting was experimentally examined using a human dummy. Table 1 lists
the experimental cases. An experiment with a used plastic sheet (Case 8) was carried out todetermine the strength of a deteriorated sheet. In all the experiments, the human dummy did not fallfrom the scaffolds, leading to the conclusion that plastic sheets are effective fall protection measures.

- 135 -Figure 1. Scaffolds covered with sheeting
Table 1. Experimental cases
Type of Photos
Case Posturescaffold
7
Prefabri
Sitting andcatedfall to 1 musing slide

CasePosture

1Standing2

Crawl onhands andknees

Prefabri
cated8

Sitting andfall to 1 musing slide

3

Sitting andfall fromback

Prefabri
cated9

Sitting andfall to 1 musing slide

4Standing

Pipe

10

5

Crawl onhands andknees

Pipe

11

Prefabri
Crawl onhands and catedknees, andfall to 0.2 m
using slide
Sitting and Prefabri
fall fromcatedfront6

Sitting andfall fromback

Pipe

Amendment of regulations

Type of Photos
scaffoldPrefabri
catedPrefabri
catedUsedsheeting
Pipe

Nonetheless, occasional falls from the space between work platforms and scaffold sheeting
continued to occur. Such incidents are attributed to space expansion stemming from the pressure
exerted by workers’ weights (Figure 2). When workers reach down to the sides of scaffolds to
conduct repairs, they push the sheeting to make room for movement, thereby widening the space
between the platform and the sheet. To prevent workers from suffering fall accidents, theOccupational Safety and Health Regulations were amended in 2009 (Figure 3). In this study, theeffects of the amended regulations were investigated on the basis of the accident reports provided
by the Labour Standard Office of Japan.

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Figure 2. A worker making room for movement by pushing the sheeting
GuardrailMore than 750 mm
from platform

GuardrailMore than 850 mm
from platform

Work platform

Mid-rail
From 350 to 500 mm
from platform
Work platform
Toe boardMore than 150 mm
from platform

Pipe scaffolds
Brace

Work platform
Work platform

orLower bar
From 150 to 400 mmfrom platform
Work platform

Prefabricated scaffolds
Old regulations

orAdvanced guardrail

Amended regulations

Figure 3. Fall protection as outlined in the amended regulations

Overall findings
Frequency of injury accidents

Labor accidents, in which workers are killed or required to rest for more than three days because
of injury, are documented by the Labour Standard Office. These injury accident reports wereexamined in relation to falls from scaffolds (Japan Ministry of Health, Labour, and Welfare,2013). Table 2 shows the changes in the number of injury accidents from 2007 to 2011. From2008 to 2009, the number of scaffold-related fall accidents drastically decreased from 1,227 to828. This finding confirms the effectiveness of the amended regulations in decreasing accident
frequency.
Table 2. Changes in the number of injury accidents from 2007 to 2011 (persons)
2007
2008
2009
2010
2011
All accidents
143,529
132,609108,081
110,441
113,097
Fall
24,38322,52918,721
18,315
19,145
Fall from scaffolds
1,552
1,227
828
718
871

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Factors contributory to falls from scaffolds

The injury accident reports were also analyzed to determine other factors that contribute to falls
from scaffolds. Figure 4 shows the classification of factors that caused fall accidents in 2011.
Approximately 90% of the accidents (378 persons) occurred in work environments characterizedby illegal conditions. Most of these fall accidents can be prevented by compliance with theamended regulations. Additionally, 42.2% of the accidents (38 + 140 = 178 persons) occurredbecause of unsafe acts. Aside from compliance with the amended regulations, therefore, risk
assessment or safety education should be executed more.
Subject of investigation During assembling or dismantling of scaffolds: 118
Work on scaffolds: 304
422 accidents

Fall protection by regulations
Compliance, 44 (10.4 %)Unsafe acts
Existed, 38

Unsafe acts
Existed, 140

Unsafe acts
Did not exist, 238

33.2 %: Accidents can beprevented by safety educationand compliance with theregulations, etc.

56.4 %: Accidents can beprevented by compliancewith the regulations, etc.

Unsafe acts
Did not exist, 6

9.0 %: Accidents can beprevented by risk assessment
or safety education, etc.

Fall protection by regulations
Non-compliance, 378 (89.6 %)Figure 4. Factors that contribute to fall accidents from scaffolds

Concluding remarks
The developments on safety in Japan’s construction industry are summarized as follows.
z The Occupational Safety and Health Regulations were amended in 2009 to prevent scaffoldrelated fall accidents.
z The effects of the amended regulations were investigated on the basis of injury accident
reports.
z Most fall accidents from scaffolds can be prevented through compliance with the amendedregulations.
z Among the total number of accidents, 42.2% occurred as a result of unsafe acts, indicating
the importance of awareness programs, such as risk assessment or safety education.

References
Ministry of Health, Labour, and Welfare, Japan. (2013). Reports of the committee forinvestigation of the effect of the fall protection from the scaffolds. Retrieved 26 August 2013,
from http://www.mhlw.go.jp/stf/shingi/2r98520000035cmr-att/2r98520000035co8.pdf (inJapanese).
Ohdo, K., Toyosawa, Y., Takanashi, S., Hino, Y., & Takahashi, H. (2009). Study on Mitigationof Fall Risk from Scaffolds in Construction Industry. Proceedings of the Tenth International
Conference on Structural Safety and Reliability (pp. 187-192). Osaka: Kansai University.

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