Electrical and gas accidents 2017 annual report

Our 2017 annual report analysing trends and highlighting risks in electrical and gas accidents.

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Electrical and gas accidents annual report - 2017 (PDF 591 KB)

1. Executive Summary

Overview of 2017

During 2017 a total of 23 notifiable accidents and 24 non-notifiable gas and electricity accidents were reported to WorkSafe Energy Safety (ES) comprising of:

One notifiable non-fire electrical accident, which didn’t cause a fatality but one person was injured.
Three notifiable and ten non-notifiable natural gas accidents, none of which resulted in fatalities or injuries.
12 notifiable and 14 non-notifiable LPG accidents, which altogether resulted in no fatalities but caused injury to 11 people.

High-Risk Areas 1993-2017

Electrical and gas (natural and LPG) accident information from the last 25 years (1993-2017) has been categorised into relevant groups before being analysed for trends, frequency, and common causes. The information has also been also analysed for the severity and frequency of total accident occurrences for each of these groups.

Electrical accidents

The previously known general public accidents (1993-2008) and all public electrical accidents investigated since 2009 by Energy Safety are aggregated as a single electrical accident category to enable analysis.

Two categories of particular interest for WorkSafe Energy Safety are accidents involving young people and electrical safety in domestic residential environments.

Young people (aged 17 years and less)

In the last 25 years, young people were involved in 36% of general public accidents (289), of which there were 17 fatalities and 96 injuries.

Domestic environment

Over half (52%) of accidents involving the general public in the last 25 years occurred in domestic environments. There were 28 (58% of total) fatalities and 124 (48% of total) people injured from accidents in domestic environments.

Natural gas accidents

Equipment

Cookers and ovens

18% of the notifiable accidents involved cookers or ovens. 12 of the 37 notifiable accidents resulted in one fatality and injury to 14 people.
Cookers and ovens accounted for 11% of reported non-notifiable accidents.

Space heaters

27% of the notifiable accidents involved space heaters. 14 of the 56 notifiable space heater accidents resulted in three fatalities and injury to 13 people.
Space heaters accounted for 20% of reported non-notifiable accidents.

Water heaters and boilers

34% of the notifiable accidents involved water heaters or boilers. 15 of the 69 notifiable water heater and boiler accidents resulted in one fatality and injury to 18 people.
Water heaters and boilers also accounted for 5% of reported non-notifiable accidents.

Liquefied petroleum gas (LPG)

Equipment Cookers and ovens

29% (122) of the 424 notifiable LPG accidents involved cookers or ovens. 87 of the 122 notifiable accidents involving cookers and ovens resulted in 17 fatalities and injury to 116 people.
Cookers and ovens accounted for 16% of reported non-notifiable LPG accidents.

Cabinet heaters

34% (143) of the notifiable LPG accidents involved cabinet heaters. 66 of the 143 notifiable cabinet heater accidents resulted in 13 fatalities and injury to 67 people.
Cabinet heaters accounted for 30% of reported non-notifiable accidents.

Containers (Refillable)

7% (30) of the notifiable accidents involved LPG refillable containers. 16 of the 26 notifiable container accidents caused four fatalities and injury to 19 people.
Refillable containers accounted for 17% (91) of reported non-notifiable accidents.

Environment

Caravans and campervans

11% (46) of the 424 notifiable LPG accidents occurred in caravans or campervans. 33 of the 46 notifiable accidents in caravans or campervans caused 11 fatalities and injury to 39 people.

2. Background

Energy Safety is part of WorkSafe New Zealand and is responsible for the administration of electricity and gas safety and related matters under the Gas Act 1992 and the Electricity Act 1992. Our aim is to bring a clear focus to safety, supply quality and measurement across the electricity and gas sectors.

In January 2009, responsibility for the investigation and reporting of worker and workplace accidents in the electricity and gas sectors, transferred from Energy Safety (ES) to the Labour Group (formerly The Department of Labour and now WorkSafe New Zealand).

At that time, the Labour Group assumed responsibility as lead agency for investigating and reporting on all workplace related gas and electrical accidents. Energy Safety remains the lead agency responsible for the investigation and reporting of non-workplace accidents involving members of the public and consumers.

WorkSafe and Energy Safety maintain an arrangement by which accidents notified to one agency is, where relevant, relayed to the other.

In 2013 Energy Safety became part of WorkSafe New Zealand with the same previous function and responsibility.

To maintain assurance of the safe supply and use of gas and electricity, Energy Safety conducts a range of functions under energy-related legislation. These include monitoring and enforcement, investigation of accidents, development and the promulgation of safety standards and information.

Energy Safety has published annual summaries of notifiable accidents since 2001, covering a period from 1998. The summaries provided regulatory agencies and industry participants with access to standardised summary accident information, and an analysis that highlights trends and risks. While the focus of the annual analyses has been on notifiable accidents, trends in non-notifiable accidents have also been examined.

Energy Safety replaced the annual summaries with quarterly publications at the beginning of 2009 to provide this information on a more frequent basis. The quarterly publications cover the notifiable accident investigations completed in that quarter.

The annual analyses complement the quarterly accident summaries. It examines accident data and trends related to accidents that occurred in that year.

3. Accident data collection and recording

Certain accidents have to be notified to Energy Safety¹. These are generally high consequence accidents. This obligation falls on participants in the energy industry in the first instance. Notifications of gas and electricity related accidents also come from consumers and other agencies, such as the Fire and Emergency New Zealand (FENZ) or through WorkSafe New Zealand, or local body Health and Safety Inspectors.

WorkSafe Energy Safety investigates accidents in line with its responsibilities, and records at least a basic set of data on all reported accidents, regardless of the scale of the investigation. In general, more comprehensive information is recorded for the more intensive investigations that follow significant accidents.

Because there is no obligation, and no rationale that is consistently applied for industry or industry sectors to report non-notifiable accidents to WorkSafe Energy Safety, a low proportion of these accidents are reported. There have been instances where an organisation has, for a limited period, reported all accidents to WorkSafe Energy Safety that have come to its attention. This ‘bulk-reported’ data has been removed for analysis, particularly trend analysis.

WorkSafe Energy Safety does not, in general, conduct in depth investigations of electrically-caused fires unless there is evidence of equipment failure. This is because a significant number of fires that are related to the supply or use of electricity are either not reported or are not reported in a timely manner that allows for a meaningful investigation to be completed. In any case, many electrical fires, although covered by the Electricity Act, occur from incorrect operation or misuse of electrical equipment.

The definitions of “accident” are similar in the Electricity Act and the Gas Act. However there are significant differences in the collection and recording of electrical and gas accident data that affect the analysis of accidents and trends:

Electrically-related fires are not included for analysis. As outlined above, there is evidence that there has historically been under-reporting to Energy Safety of less significant electrically-related fires. In addition our focus has been on electrical accidents² other than fire.
Energy Safety investigates and records gas-related accidents that involve fire, explosion, or gas ‘poisoning’³. Only those accidents that involve deliberate inhalation of LPG are excluded from analysis.
The electrical accident database in use up until 2008 allowed investigators to record only one likely major cause for an electrical accident. The database used for gas investigations allowed investigators to record up to four likely causes or factors for a gas-related accident. The accident investigation database that has been in use since the beginning of 2008 allows a range of factors to be considered and identified.

Natural gas and liquefied petroleum gas (LPG) have different characteristics as fuels and differing distribution and utilisation patterns so they are recorded and analysed separately.

The gas accident database contains information about fatalities, injuries, fires, explosions and minor accidents for natural gas and LPG. These accidents have been analysed for severity⁴ and frequency of similar types of accidents.

Accident analysis

To identify trends and risk areas, this analysis examines data collected since 1993 on notifiable electrical accidents other than fires and both notifiable and non-notifiable gas accidents.

Since the implementation of the Electricity Act and the Gas Act came into force, comparisons have been made between five year periods.

This analysis includes the latest information available at the time of preparation. In some cases, the investigations are complex and may not have been completed at the time of publication. This means that each annual analysis has to review previous years’ cases when further information has been obtained.

This accident analysis does not set out to explain the reasons behind the trends and variations found. These trends may be influenced by any number of factors, including changes in the way accidents are reported, reporting level, or actual improvements in safety or safety practices.

Establishing the reason behind these trends would require detailed analysis of comprehensive data that is not always available and some of which may or may not exist.

WorkSafe Energy Safety uses a system called Energy Safety Intelligence (ESI), which was introduced at the beginning of 2008. This system integrates case management of electricity and gas operational activities, and stores electricity and gas accident information in a single database. This system has more data fields and a more consistent classification facility than was previously used. However, its introduction meant there were some unavoidable inconsistencies between data held on the new system and the data held on the previous systems. This, in turn, places constraints on the analysis.

4. Electrical accidents

This section deals with notifiable non-fire electrical accidents affecting members of the public which were reported to Energy Safety. In a typical non-fire electrical accident the victim receives an electric shock which requires medical treatment. In general these accidents are due to contact with, or coming into proximity with live electric lines, equipment or components. Fire-related electrical accidents and accidents that involve workers are not included in this analysis.

Electrical accidents prior to 1 January 2009 (when the Department of Labour, as it was at the time, assumed responsibility for investigating workplace accidents) were categorised under three main occupational headings: electrical workers, workers in other (non-electrical) occupations, and the general public. Generally about 50% of accidents involved electrical workers, 30% involved workers in other occupations, and 20% involved members of the public.

The definition of notifiable electrical accident of the Electricity Act is modified by the Health and Safety at Workplace Act in 2016^⁵. The threshold for the electrical notifiable accident is raised so now less number of electrical accidents is qualified as notifiable accidents.

This analysis examines accidents involving members of the public for 2017 and gives an overview for the 25 year period from 1993 to 2017.

It also compares rolling averages for the five-year base period (1993–1997) and the current five-year period (2013–2017).

One area of interest for electrical safety is protection of young people and the elderly age groups. This section examines the number of accidents involving young people in age groups up to 17 years old and elderly people in the 65 year and older age group.

Current trends

During 2017:

There were no fatal electrical accidents and one accident resulting in injury. Over the past 25 years there has been an average of 1.9 fatalities per year.
There was a single non-fire electrical accident involving members of the public, injuring one person. Over the past 25 years the average is 9.9 accidents per year.
This injury notifiable accident involved 230 volt (standard low voltage) systems. The average number of accidents involving 230 volt systems over the past 25 years is 6.5 per year.

Longer term trends

Observations based on analysis of trends, consequence, and frequency for the 25 year period between 1993 and 2017:

There were 289 accidents involving members of the public which resulted in fatalities or injuries to 306 people (see Table 1).
48 of these were fatal accidents, each of which involved a single fatality. In six of the fatal accidents there was at least one other person injured.
There were 247 injury accidents causing injury to a total of 258 people.
Graph 1a shows considerable year-on-year variation in the number of fatal and injury accidents and there is no obvious significant trend in the annual number of fatal and injury accidents in this period. A five year rolling average accident number shows some reduction over the last 25 years.
113 (37%) of the total 306 victims are young people (aged 17 years and less), see Graph 1b.

	Accidents	Casualties
Fatality	42	42
Fatality and injury	6	13
Injury	241	251
Total	289	306

Table 1: Notifiable Electrical Accidents and Casualties

Graph 1a Notifiable electrical accidents involving the general public — Graph 1a: Notifiable Electrical Accidents involving the General Public

Graph 1b Notifiable electrical accidents by victim age — Graph 1b: Notifiable Electrical Accidents by Victim Age

Age group

Accident data includes the general age group of involved parties (see Table 2) where it is known, or a reasonable estimate can be made.

	Fatal Consequence⁶ (Frequency)		Injury Consequence (Frequency)
Age groups	1993-2017	2013-2017	1993-2017	2013-2017
Young people (0-17)	17 (17)	1 (1)	96 (91)	8 (8)
Child (0-4)	4 (4)	0 (0)	15 (15)	2 (2)
School age (5-12)	5 (5)	1 (1)	53 (53)	4 (4)
Adolescent (13-17)	8 (8)	0 (0)	28 (26)	2 (2)
Adult	29 (29)	2 (2)	127 (126)	19 (18)
Elderly (65+)	2 (2)	0 (0)	13 (12)	1 (1)
Total	48 (48)	3 (3)	258 (247)	30 (29)

Table 2: Age breakdown for notifiable electric shock accidents involving members of the public

35% of fatal accidents (17 fatalities) involved young people. One of these has occurred in the last five years.
91 injury accidents involved 96 young people and eight of these accidents, injuring eight, occurred in the last five years.
There has been a significant reduction in the number of young people who were injured in electrical accidents during the current period compared with the base period. In the current period eight (27%) out of 30 injuries involved young people compared with 30 (45%) out of 67 injuries in the base period.
Only 5% (14) of the total 289 accidents involved people aged 65 years or over. This is a relatively small number compared with the age profile of the population as a whole. As numbers are small no further analysis has been carried out.

Voltage

The standard voltage in domestic installations is 230 V. This is the voltage that people normally interact with in their homes. About two thirds of accidents involving members of the public involve 230 V (see Graph 1c).
31 (65%) of the 48 fatal accidents and 162 (66%) of the 247 injury accidents involved 230 volt systems; two (4%) fatal accidents and 17 (7%) of injury accidents involved 400 volt systems; and eight (17%) of fatal accidents and 37 (15%) of injury accidents involved 11,000 volt systems (see Table 3).
Of the 48 fatal accidents, 17 of the victims were young people. 11 of these cases involved 230 volt systems.
67 (35%) of the 191 fatal and injury accidents associated with 230 volt systems involved young people.

	Fatal Consequence⁷ (Frequency)		Injury Consequence (Frequency)
Voltage groups	1993-2017	2013-2017	1993-2017	2013-2017
230	31 (31)	2 (2)	165 (162)	23 (22)
400	2 (2)	0 (0)	17 (17)	3 (3)
11,000	8 (8)	1 (1)	39 (37)	4 (4)
25,000	2 (2)	0 (0)	3 (3)	0 (0)
33,000	2 (2)	0 (0)	7 (7)	0 (0)
66,000	1 (1)	0 (0)	1 (1)	0 (0)
110,000	0 (0)	0 (0)	6 (2)	0 (0)
Total	48 (48)	3 (3)	258 (247)	30 (29)

Table 3: Voltage breakdown for notifiable electric shock accidents involving members of the public

Causal factors

Investigations seek to identify a causal factor or factors. These factors fall into one or more broad categories as indicated in Graph 1d. Because there can be a combination of one or more causal factors for an accident, percentages do not add to 100%.

In cases involving members of the public the most common causes of electrical accidents were lack of maintenance in 68 (20%) cases, and misuse actions in 48 (14%) cases (see Graph 1d).
In 11 (23%) fatal electrical accidents, misuse of equipment was identified as the cause.
Table 4 gives the most common causes of electrical accidents over the past 25 years, and over the past five years.

	Period 1993-2017	Period 2013-2017
Main causes	Lack of maintenance – 23% Failure to follow safe work procedures – 22% Misuse – 17%	Lack of maintenance – 17% Failure to follow safe work procedures – 30% Misuse – 23% Exposed to live parts – 23%

Period
1993-2017

Period
2013-2017

Main causes

Lack of maintenance – 23%

Failure to follow safe work procedures – 22%

Misuse – 17%

Lack of maintenance – 17%

Failure to follow safe work procedures – 30%

Misuse – 23%

Exposed to live parts – 23%

Table 4: Factors in notifiable electrical accidents involving members of the public

Graph 1d Notifiable electrical accidents by causal factor — Graph 1d: Notifiable Electrical Accidents by Causal Factor