Annual Report on Liquefied Petroleum Gas (LPG)
Related Accidents(2013 version)

The High Pressure Gas Safety Institute of Japan (KHK)
Information Services & Research Department
International Affairs Office
4-3-13 Toranomon, Minato-ku, Tokyo 105-8447
TEL: +81-3-3436-2201 FAX: +81-3-3438-4163
Web: http://www.khk.or.jp/english/index.html
MAIL: oversea@khk.or.jp

1. Introduction
This Annual Report contains accidents that occurred in 2013 related to facilities for supplies and consumptions ofLPG at home or on business, which are regulated by the Act on the Securing of Safety and the Optimization ofTransaction of Liquefied Petroleum Gas (hereinafter, the “LPG Act”). This report also contains analyses the data of
the accidents in 2013 by comparing with those in the last nine years (2004 to 2012).

2. Definitions
2.1 Definition of accidents(1) LPG accidents[1] Leakage

A case in which liquefied petroleum gas (hereinafter, “LPG”) leaked, but it did
not catch fire and cause human damages such as poisoning and asphyxiation.
However, in this report, leakage of a very little amount of LPG from joints aslittle as soap bubbles formed when those of threaded parts or rubber tubes are
soaked by soap water is excluded.

[2] Leakage andexplosion

Cases in which LPG leaked, and it resulted in an explosion or a fire caused by
the explosion, as follows.
A. Leakage and explosion, when the explosion resulted from leaked gas only.
B. Leakage, explosion and fire, when a fire broke out following explosion
caused by leaked gas.

[3] Leakage andfire

A case in which a fire that is not limited to that recognized as a fire by the fire
department resulted from leakage of LPG excluding those covered by [2]above. Here, a fire without leakage, which is caused by the overheating or thefailure of LPG appliances including their accessories or by spreading of flames
from a cooking oven, grill, etc., is not classified as a LPG accident.

[4] Poisoning andasphyxiation

A case in which human damages of CO poisoning and asphyxiation arecaused due to incomplete combustion, leakage of LPG, or leakage of exhaustgas from exhaust pipes, etc., at LPG consumption facilities.

(2) Other accidents (not classified as LPG accidents)[1] Accidents caused by suicide, damage by intention, mischief, theft, or other similar causes[2] Accidents resulting from a natural disasterExample)

Accidents caused by facilities’ damages resulting from collapse of houses due
to earthquakeExample)

Accidents caused by facilities’ damages resulting from flood and landslide

Even if accidents are resulted from natural disasters, however, those caused by defects in
toppling prevention measures, fallen snow prevention measures (snow shelters, protectiveboards), or other insufficiencies in safety measures, are classified as LPG accidents.
[3] Accidents involving portable cooking stoves and gas cartridges[4] Other accidents not categorized in the LPG accidents of (1) above
2.2 Classification of human damages
Classified as follows according to the level of damage.
Death:

when a person was confirmed to have died within about five days from thetime of accident

Seriously injured: when a person suffered an injury at the time of accident that took 30 days ormore for full recovery
Slightly injured:

when a person suffered an injury at the time of accident that took less than 30days for full recovery

Copyright © The High Pressure Gas Safety Institute of Japan1

3. LPG accidents
3.1 Occurrences of accidents in the past
900

Number of accidents
800

Number of injuries
Number of deaths
700

Number of accidents and casualties

600

It is noted a characteristic of accidents data inJapan that the number of leakage of gas,
which has not caught a fire and caused nocasualties due to poisoning or asphyxiation, iscounted as a LPG accident.

500

400

300

200

1000
1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997199920012003200520072009

2011

2013

Figure 1: Accident occurrences and casualties by year

Table 1: Change in the number of accidents and casualties by year
YearNumber ofaccidents
Rate to theprevious year

1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

167112

170

217

217

299

368

540

497

581

638

570

793

761

570

559

545

496

34 ▲3352280382347 ▲81710 ▲1128▲4 ▲6 ▲20714▲2▲3▲9515

401

4 ▲2282881016875

79

78

87

90

120

105

105

219

▲3 ▲22 ▲14 ▲26 ▲25 ▲23 ▲27390

306

262

194

146

112

715 ▲33

105▲212333 ▲130109239234

9 ▲2185

204

227

259

▲21101114 ▲20206

Number of deaths
Number ofinjuries

33

38

69

44

33

52

59

74

40

65

56

72

63

60

50

43

51

36

35

42

29

37

36

27

13

31

73

12

146

958

24

7

2

10

4

4

4

5

1

13

271

146

236

283

301

398

389

679

543

523

684

640

825

758

723

650

645

529

550

477

381

336

327

233

171

162

135

83

80

109

6482

6673696486885878987914883888552Copyright © The High Pressure Gas Safety Institute of Japan2

Figure 1 shows the number of accidents that occurred between 1967 and 2013 and the resultingcasualties. Looking at the data by decade, the number of accidents increased gradually during the 1960s
along with the increase in LPG consumption and diversification of users.
In the 1970s, the number of accidents continued increasing along with the number of households using
LPG and reached a peak in 1979 with 793 accidents, causing 63 casualties. This was the year thatmarked the highest number of casualties, at a level similar to that of 1974.
Soon after entering the 1980s, a large-scale city gas explosion took place that resulted in enormous
human damages marked by 15 deaths and 222 seriously and slightly injured persons. The number ofaccidents was 761 that year. The number of accidents peaked out this year and started showing adownward tendency, reducing greatly to 570 in 1982.
Thereafter, the number of accidents continued declining linearly from the late 1980s, falling below 100 in
1994, to 82.
The year 1997 saw the lowest number of accidents (68) since enactment of the LPG Act. In the 2000s,
the number of accidents remained above 100 until 2013, although the number of deaths has been on thedecrease.

3.2 Accident situations by phenomenon
Looking at the accident situations by phenomenon that occurred in 2013, the number of leakage-onlyaccidents that did not start fire or explosion were more than half of total accidents. The number ofleakage-only accidents was 109, showing a decrease of 50 from the previous year. The number ofleakage and explosion (fire) accidents was 48, showing the same number as the previous year. Thenumbers of accidents by phenomenon in the past decade are shown below.
Table2: Number of accidents by phenomenon
2004

2005

2006

20072008

2009

2010

2011

2012

2013

41

46

137

113

115

84

76

116

159

109

56

46

70

64

53

45

60

55

48

48

12

651

60

42

60

45

44

43

7

11

6

11

6

14

8

11

8

6

105

105

219

239

234

185

204

227

259

206

Leakage
Leakage andexplosion (Fire)
Leakage and fire
(Excluding explosion)
CO poisoning andasphyxiation
Total

4. Analysis of accident situations
The following kinds of LPG accidents that have occurred frequently were analyzed.
(1) CO poisoning accidents
As shown in Table 3 and Figure 2, four CO poisoning accidents occurred in 2013, showing adecrease of four from the previous year. Two of four were Class B accidents, resulting the same
number as the previous year. The breakdown of four accidents is shown below.

[1] Accident caused by use of commercial oven in an unventilated kitchen (two accidents)[2] Accident caused by inadequate ventilation of a convection flue (CF) bath heater
Copyright © The High Pressure Gas Safety Institute of Japan3*CF refers to ventilation system that takes in the air inside a room and discharge exhaust
outdoor through vent by natural ventilation force.
[3] Accident caused by use of commercial dish washing machine in an unventilated dish washingroom
Incidentally, the reason why the number of casualties increased to 88 in 2009 was attributed to thelarge number of casualties per accident in 2013.

Table 3: Number of CO poisoning accidents (excluding asphyxiation) by year and casualties
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Number of Accidents

61051161481084Of the above, the number ofClass B or highr class accidents

1103263322

Number of deaths

0102233

1

1

2

Number of injuries

2122

1329885

1632

37

4

Of the above, the number ofClass B or highr class accidents

700

90

65

716

23

1

100
88

90
Number of accidents
Catualties

80
70
60
50

3840

33
3130

1923
21

20

13
10

10

14
10

11

10
68
5866402004 2005 2006 2007 2008 2009 2010 2011 2012 2013
YearFigure 2: Number of CO poisoning accidents by year and casualties(2) Buried pipes accidents
The pipes that are installed between LPG cylinders and a gas meter are called supply pipes, and are
installed between a gas meter and consumption devices like heaters are called distribution pipes inJapan. Pipes are installed on the ground or underground. The number of supply pipe accidents isgreater than distribution pipe accidents.
Table 4 and Figure 3 show that 25 accidents involving buried pipes took place in 2013, an increaseof nine from the previous year. 20 out of 25 accidents involved supply pipes, in which eight accidents
were increased from the previous year, and the other five accidents involved distribution pipes, inwhich one accident was increased from the previous year. Then one accident of Class B occurred.

Copyright © The High Pressure Gas Safety Institute of Japan4

Causes of accidents include damages in 20 accidents (supply pipes in 18 accidents and distribution
pipes in two accidents) and deterioration due to corrosion in four accidents (supply pipes in twoaccidents and distribution pipes in two accidents).

Table 4: Number of buried pipes accidents by year and casualties
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Number of Accidents

1212172131

24

18181625

Of the above, the number ofClass B or highr class accidents

10

1000000

1

Number of deaths

10000

0000

1

Number of injuries

463

1

20

200

2

Of the above, the number ofClass B or highr class accidents

00

20

0

0

0

0

0

1Catualties

Accidents
3535
Distribution pipes

3030
Supply pipes
8
Number of catualties

25

25
5523
120

20

2020
19

2
5513

131515415
2312101010965553322

100
2004

2005

2006

2007

2008

2009

2010

002011

2012

02013

YearFigure 3: Number of buried pipes accidents by year and casualties(3) Bulk supply accidents
In 2013, six accidents involving bulk supply (supply facilities only) occurred, showing a decrease of
seven from the previous year. The six accidents were as follows.
*Bulk supply refers to supply of liquefied petroleum gas into bulk storage tanks from portable LPG
generators (bulk tank trucks). See Figure 4.
[1]
[2]
[3]
[4]
[5]

Damages caused by snow (two accidents)
Gas leakage caused by error in replacing of regulator
Gas leakage caused by corrosion of supply pipes
Gas leakage from liquid outlet valve
Gas leakage from supply pipes caused by car collision

Copyright © The High Pressure Gas Safety Institute of Japan5Figure 4: Bulk supply system
Protector

Regulator
Release valve
Liquid inlet valve

Gas outletvalve

Safety valve

Liquid outlet valve

Level gauge

Filling port

Figure 5: Bulk storage tank5.

Accident classification

When an accident occurs, it is classified as follows according to the degree of loss.
Contents of loss

Class A(1) Deaths

5 or more(2) Deaths plus serious injuries

10 or more

(3) Casualties (death plus injury) 30 or more
(4) Direct property damage

200 million yen or more

(5) Any accident affecting the public, or which could have developed into a large scale disaster(1) Deaths

Class B

1 to 4(2) Serious injuries

2 to 9(3) Casualties (injury)

6 to 29(4) Direct property damage

200 million yen or more

(5) Accidents repeatedly occurring at the same works(6) Any accident affecting the public, or which could have developed into a large scale of disaster.
Class C

Other than Classes A and B

Copyright © The High Pressure Gas Safety Institute of Japan6

6. List of major accidents that occurred in 2013
Accident title

CO poisoning while using a commercial
oven in an unventilated room

CO poisoning caused by inadequate
ventilation of a convection flue (CF) bathheaterGas Leakage and oxygen deficiency
caused by damaged buried supply pipes
while digging the roadDateJune 12 approx. 15:30

July 5 unknown time

November 16 approx. 9:48

Death/ seriously injuries/
minor injuries

1/0/1

1/0/0

1/0/0

Overall toll

211

Substance nameCO gasCO gas

Oxygen deficiency

Scale---

Primary phenomenon/
secondary phenomenon

CO poisoning / -CO poisoning / -Oxygen deficiency / -Situations of handling

While being operated

While being operated

While being operated

Accident causes (maincauses)/ (secondary causes)

Stagnation of CO gas caused byinappropriate ventilation / -Incomplete combustion caused by drop of
the combustion efficiency/ -LPG leakage / Oxygen deficiency

Ignition source

It was alerted the fire department that twousers were found collapsed on the floor ata bakery. At the hospital where the twowere taken, it was confirmed that one ofthem died due to carbon monoxide
poisoning and the other one was slightly
affected.
At the site of the accident, a commercial
oven was used in a room where allwindows were closed and a ventilation
system was stopped. Under thecircumstances, the cause of the accident isbelieved to be the room filling with exhaustcontaining carbon monoxide caused bylack of ventilation.

One user died from CO poisoning during
taking a bath at an apartment house.
The cause of the accident is assumed tobe the accumulation, in the room, ofexhaust containing carbon monoxide which
generated because of incomplete
combustion that result from drop of the
combustion efficiency by deposit on theheat exchanger of the bath heater.
However, details are unknown.

Accident outline

When a contractor was digging on a roadto bury new gas pipes (polyethylene pipe)
at one meter depth under the ground, hedamaged existing buried supply pipes sogas leakage started. He went into the dughole to stop the gas leakage from thedamaged portion and died because ofoxygen deficiency at a hospital where hewas transported to.
At the site of the accident, he damaged
buried supply pipes by a power shovel andentered the hole to stop gas leakage
without confirmation of gas density of inside
the hole. The cause of the accident is
oxygen deficiency.

Copyright © The High Pressure Gas Safety Institute of Japan7