NBSIR 75-969^)

Accidents Involving Several

Selected Appliances: Summary

and Descriptive Analysis

Mary E. Stefl

P. Clare Goodman

Ann M. Ramey

Fran D. Bents

Human Factors Section

Product Systems Analysis Division

Center for Consumer Product Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

December 1975

Final Report

Prepared for Consumer Product Safety Commission

Washington, D. C. 20207

NBSIR 75-969

ACCIDENTS INVOLVING SEVERAL

SELECTED APPLIANCES: SUMMARY

AND DESCRIPTIVE ANALYSIS

Mary E. Stefl

P. Clare Goodman

Ann M. Ramey

Fran D. Bents

Human Factors Section

Product Systems Analysis Division

Center for Consumer Product Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

December 1975

Final Report

Prepared for Consumer Product Safety Commission

Washington, D. C. 20207

it.

•"•tAU 0« '

U.S. DEPARTMENT OF COMMERCE, Rogers C.B. Morton, Secretary

James A. Baker, III, Under Secretary

Dr. Betsy Ancker-Johnson. Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Acting Director

TABLE OF CONTENTS

Page

List of Tables v

List of Figures ix

Executive Summary xi

1.0 INTRODUCTION 1

2.0 NIETHODOLOGY 3

2.1 Procedure 3

2.2 Limitations and Qualifications 5

3.0 RESULTS 5 3.1 General Trends 5 3.2 Space Heaters and Heating Stoves 11

3.2.1 Victim Characteristics 11

3.2.2 Injuries 16

3.2.3 Behavioral Classification 16

3.2.4 Product Factors 19

3.2.5 Injury/Hazard/Activity Sequences 19

3.3 Kitchen Ranges 20

3.3.1 Victim Characteristics 20

3.3.2 Product Factors 20

3.3.3 Injuries 20

3.3.4 Behavioral Classification 24

3.3.5 Injury/Hazard/Activity Sequences 28

3.4 Wringer Washers 31

3.4.1 Victim Characteristics 31

i, 3.4.2 Injuries 34

3.4.3 Behavioral Classification 34

3.4.4 Injury/Hazard/Activity Sequences 34

3.5 Hot Water Heaters 36

3.5.1 Victim Characteristics 36

I 3.5.2 Injuries 36

i 3.5.3 Behavioral Classification 39

I 3.5.4 Injury/Hazard/Activity Sequences 39

j 3.6 Irons 41

[ 3.6.1 Victim Characteristics 41

3.6.2 Injuries 41

3.6.3 Behavioral Classification 43

I 3.6.4 Injury/Hazard/Activity Sequences 43

' 4.0 DISCUSSION 43

4.1 Problems 45

4.2 Implications 46

4.3 Recommendations 47

i

TABLE OF CONTEM^S (Continued)

Page

References 49

Appendix 51

iii

LIST OF TABLES

Table Title Page

1 Appliance Items Selected for Study 2

2 Distribution of All Appliance Accident Victims (FY 73 NEISS)

by Age and Sex 6

3 Distribution of all IDIR Appliance Accident Victims by Age

and Sex 9

4 Distribution of Accident Severity as a Function of

Appliance Products 10

5 Distribution of all Accident Victims (IDIR's) by Age and

Hospital Disposition 12

6 Distribution of Type of Injury Incurred by Appliance Product 13

7 Distribution of Space Heater 5 Heating Stove Accident

Victims by Age and Sex (FY 73 NEISS) 14

8 Distribution of Space Heater d, Heating Stove Accident

Victims by Age and Sex (IDIR's) 15

9 Distribution of Space Heater Accident Victims (IDIR's) by

Age and Hospital Disposition 17

10 Behavioral Classification of Space Heater Pi Heating Stove

Accidents 18

11 Distribution of Range Accident Victims by Age and Sex

(FY 73 NEISS) 21

12 Distribution of Range Accident Victims by Age and Sex

(IDIR's) 23

13 Distribution of Range Accident Victims (IDIR's) by Age and

Type of Injury 25

14 Behavioral Classification of IDIR and FFACTS Range Accidents

(Flammable fabric related accidents only) 26-27

15 Behavioral Classification of IDIR Range Accidents

(Non-flammable fabric- related accidents) 29

16 Behavioral Classification of all IDIR Range Accidents by

Range Type 30

V

LIST OF TABLES (Contined)

Table Title Page

17 Distribution of Wringer Washer Accident Victims by Age and

Sex (FY 73 NEISS) 32

18 Distribution of Wringer Washer Accident Victims by Age and

Sex (IDIR's) 33

19 Behavioral Classification of IDIR Wringer Washer Accidents

by Age of Victim 35

20 Distribution of Hot Water Heater Accident Victims by Age

and Sex (FY 73 NEISS) 37

21 Distribution of Hot Water Heater Accident Victims by Age

and Sex (IDIR's) 38

22 Behavioral Classification of IDIR Hot Water Heater Accidents 40

23 Distribution of Iron Accident Victims by Age and Sex

(FY 73 NEISS) 42

24 Behavioral Classification of IDIR Iron Accidents by Age

of Victim 44

vii

LIST OF FIGURES

Figure Title Page

1 Accident Occurrence by Age and Sex of Victim for all

Appliances Combined (FY 73 NEISS) 8

2 Frequency of NEISS Range- related Accidents as a Function

of Victims ' Age and Sex 22

ix

EXECUTI\T SIMIARY

The Problem

In FY 74, the former Technical Analysis Division of the National

Bureau of Standards (NBS) undertook a human factors analysis of

appliance-related accidents for the Consumer Product Safety

Commission (CPSC) . Appliance products listed in the top 50 of

the then- current CPSC Hazard Index were chosen for initial study.

Thus, space heaters and heating stoves, kitchen ranges, wringer

washers, hot water heaters, and irons were included.

Three data sources were available:

a. In-Depth Investigative Reports (IDIR's),

b. National Electronic Injury Surveillance System (NEISS) , and

c. Flammable Fabrics Accident Case and Testing System (FFACTS)

Methodology

All IDIR case histories were read and summarized. Categories

were developed to describe the behavior sequences of victims just

prior to accidental injury. A series of cross tabulations between

victim's age, sex, injury type and severity, and antecedent activity

were then constructed in an attempt to identify product hazards and

uncover accident patterns common to all the appliances investigated.

Product factors were also considered.

NEISS and FFACTS data were used to si^jplement and verify trends

reported in the IDIR's.

xi
Results

The original attempt to develop generic patterns of injury, product

hazard, and victim activity was not successful. However, the following

general trends were noted:

a. Children were over- represented as accident victims in all data

bases and for all appliance products

b. The elderly (66+ years) appeared to suffer injuries of

the greatest severity.

c. Thermal bums were by far the most common injury.

Other accident trends are presented individually by appliance type.

Notable product -specific injuries, hazards, or antecedent activities

are discussed.

Discussion

The difficulties encountered in the present approach to productspecific accident analysis are noted. A limited number of generic

hazards, i.e., those liazards observed across appliance types, are

identified.

Specific recommendations are made to:

a. Expand the data bases to include information describing the

interface between product and product user.

b. Intensify research on product exposure patterns so that a

perspective will exist on which to assess current trends in

accident occurrence.

c. Re-examine age based priorities. Future research and prevention

programs might accrue the greatest societal gains by focusing on

the elderly.

xii
ACCIDENTS INVOLVING SB^ERAL SELECTED APPLIAN^:ES:

SUMMARY AND DESCRIPTIVE ANALYSIS

1.0 INTRODUCTION

Household appliances are used regularly by a majority of the consumer

population and are involved in a great number o£ accidental injuries.

During FY 1974, the former Teclmical Analysis Division of the National

Bureau of Standards (N^S) was asked by the Consumer Product Safety Commission

(CPSC) to analyze appliance- related accidents from a human factors

point of view. Investigation was to focus on those accidents related to

products listed among the top 50 of the then-current Hazard Index. The

appliance products involved, together with their liazard ranking, are

sho\%Ti in Table 1

Case histor)^ investigations of accidents related to these products

were studied in an atten^Dt to better understand the sequence of events

leading to an appliance accident. This effort was aimed at developing a series of injur>Vhazard/activit>^ cross tabulations or relationships which

would characterize accident patterns common to all the appliances

included. It was hoped that such patterns would reveal generic hazards

which, combined with specified product- related human behaviors, produce a predictable type of accident and injur)'. Accident prevention could then

focus on intern^Dting the accident sequence by removing the generic

hazard or redesigning the product in ways which would inhibit the

human activity identified in the cross -tabulations as hazardous.

Data for the present effort were derived from three sources : the

National Electronic Injury Surveillance System (NEISS) , In-Depth

Investigative Reports (IDIR's), and the Flammable Fabrics Accident Case

and Testing System (FFACTS) . A brief description of each of these systems

follows

NEISS. Operated by the CPSC's Bureau of Epidemiology, NEISS is a telecommunication network connected to 119 hospital emergency rooms throughout the country. These hospitals represent approximately

two percent of all U.S. hospitals having emergency rooms and were

chosen as a statistically representative sample.

NEISS surveys only product -related accidents. The t>'pe of product

involved, the age and sex of the victim, the type of injury, the body

part involved, and the hospital disposition of the victim are among the

data recorded and transmitted daily via computer terminals to CPSC

headquarters

NEISS includes only injuries treated in hospital emergency rooms. However, where and how an accident is treated may depend upon a number

of factors (e.g., family income level, distance to nearest hospital,

age of victim) , all of which introduce a definite but unspecified bias

into the NEISS data.
Appliance Items Selected

for Study

FY74

Hazard Index IDIR's

Product Ranking Reviewed

Space heaters ^ heating stoves 15 186

Kitchen ranges 17 401

Wringer washers 28 120

Hot water heaters 39 69

Irons 47 37

Total 813

2
IDIR's . The National Injury Infomiation Clearinghouse at CPSC

maintains a system of In-Depth Investigative Reports dealing with productrelated accidents. Essentially, IDIR's are the result of personal

interviews conducted with accident victims or their families by local

contractors scattered across the country. To insure most accurate recall,

interviews are performed, whenever possible, within 10 days of the

accident occurrence. Many IDIR's are drawn from cases reported in

NEISS, but other sources, such as the news media, are also tapped.

No claim is made that IDIR's are representative of the population of

accidents or the rat^d hazard of any given product. Bias is introduced

in a number of ways. IDIR's are often collected on a demand basis.

That is, if a hazard is suspected for a particular product, a directive to

collect IDIR's may be issued by CPSC irrespective of the total number of

accidents associated with that product. The directive may be even more

specific, aimed, for exanple, at a particular age group of accident

victims. In addition, the use of the news media may introduce bias since

only the most severe and/or unusual accidents are deemed newsworthy.

FFACTS . FFACTS data were maintained by NBS' former Fire Technology

Division (FTD) and includes case histories similar to IDIR's. Limited

in scope to flammable fabrics fire accidents , FFACTS reports pertain to

only three of the appliance products studied: kitchen ranges, space

heaters and heating stoves, and hot water heaters.

As with the IDIR system, no claims are made for the statistical

validity of FFACTS. Indeed, the use of FFACTS case histories was not

enphasized in the present study since an acknowledged but undefined

overlap exists between FFACTS and both the NEISS surveillance and the

IDIR data. Reservation must therefore be exercised in the interpretation

of any results based on this set of data.

Bias is obviously inherent in all three of the data bases. Unfortunately,

no other known sources contain either the broad range of product- related

accident statistics or the behavioral activity information essential to

a human factors analysis. However limited, these data bases supply

the best information currently available.

.2.0 METHODOLOGY

2.1 Procedure

Because they attenpt to include the total sequence of events leading

to an accident, IDIR's conprised the primary data source for this study.

All available IDIR's dealing with the products involved were consequently

obtained from the CPSC. The number of IDIR's provided, by appliance

type, is shown in Table 1.

"All comments here and below refer only to the IDIR's used in the

preparation of this report, i.e., those available as of January 1974.

The authors acknowledge that substantive changes and inprovements have

occurred in the data base since then.

3
NBS staff members read each case history and extracted the following

information

1. Age of injured

2. Sex of injured

3. Type of injury

4. Bodily location of injury

5. Hospital disposition of victim

6. Product or products involved

7 . Location of accident in the home

8 . Behavioral data (narrative of accident sequence)

An attempt was then made to categorize the behavioral data (Item 8) based

on the victim's activity just prior to injury. For exanple, victims

were often found to be "leaning over" a range top or "pulling the cord"

of a hot iron. Unfortunately, the availability of these data was somewhat

limited. Information was frequently inconplete and occasionally missing,

and in other cases, inpossible to procure. For example, a young child

or the victim of a severe accident often cannot report or recall events

just prior to injury. In addition, the quality and completeness of

the accident narrative varied greatly from interviewer to interviewer.

Finally, a series of cross -tabulations or relationships among the

various data listed above was developed for each product type.

For exanple, the victim's age and sex was conpared to the type of injury

incurred, the severity of the injury (as judged by hospital disposition)

and the victim's antecedent behavior. Special attention was directed

towards those cross -tabulations including behavioral sequences (Item 8

above)

NEISS data served a secondary function in the present study. At

the time the study was undertaken, NBS was just developing its ability

to access the FY 73 NEISS data. Its use in the present analysis was therefore minimal, limited to distributions of accident victim's age

and sex. For each appliance product, the age and sex trends observed

in FY 73 NEISS were conpared to those of the IDIR sample. A crude

assessment of the representativeness of the sample IDIR data could thus

be made. However, future accident analyses should make full utilization

of the NEISS data, examining entrees for injury type and bodily location,

hospital disposition, and injury severity as well as age and sex of

the accident victims. The present effort was weakened by the unavailability

of such information.

It was beyond the scope of the present study to read and review all

relevant FFACTS studies. Since the NBS Human Factors Laboratory staff

had performed a human factors analysis of FFACTS range-related accidents

at an earlier date (Pezoldt, Persensky, and Peiser, 1973) those

results, where appropriate, are noted in the present research. For

both space lieaters and heating stoves and water heaters , FTD made

available summary data indicating the victim's age and sex, type and

extent of injury, and hospital disposition. In many cases, a short

behavioral description of the victim's activity at the time of the

accident (e.g., "leaning over pilot light") was also included. Such

information was utilized whenever possible.

4
2.2 Limitations and Qualifications

The limitations o£ the behavioral information found in the IDIR's

have already been noted, yet a thorough human factors analysis of

appliance- related accidents requires rather conplete activity sequence

information. Neither NEISS, which contains no behavioral data, nor

FFACTS, which is limited in scope, could adequately supplement or

substitute for the widespread "gaps" found in the IDIR's.

The development of conprehensive injury/hazard/activity cross

tabulations was also hampered by the broad nature of the products

themselves. In the course of the study it became obvious that some products (irons, wringer washers) are "use" products, usually requiring

continual liuman involvement. Others (space heaters and heating stoves

and hot water heaters) are "functional" products operating in the absence

of human interaction. Still other appliances (kitchen ranges) operate

in both modes. The accidents and injury/hazard/activity relationships

associated with such a wide range of man-machine interfaces necessarily

differ greatly.

Thus the initial attenpt to develop accident patterns generalizable

to all appliance products was abandoned. Instead, each appliance product

was "analyzed" separately and a series of relationships between product

hazards, injury, and human behavior was generated for each product.

\Vhenever possible, general relationships or trends were developed across

all appliance types; in no case, however, was it possible to incorporate

behavioral infomiation in these general relationships . What has emerged

is in descriptive terms, that is, general relationships and averages are reported but no statistical inferences are made. Percentage figures,

which inply a certain degree of statistical authority, are limited to

discussions of the NEISS data. Trends observed in both the IDIR's

and FFACTS, where sampling bias is known to exist, are reported in

only the most general terms.

Finally, a brief note on how to use this report is in order. The

results are presented first an general terms. Accident trends and

statistics are combined and reported for all products. Thereafter, a separate subsection of the results section is devoted to each appliance

item studied. Thus, the reader interested in only one of the appliances

reviewed should read first Section 3.1 (General Trends) and then consult

that subsection dealing with the appliance of interest.

3 . 0 RESULTS

3.1 General Trends

While the majority of results apply to individual appliances, a few general observations can be made.

For exanple, the victim of an appliance accident was slightly more

likely to be female. Table 2 illustrates that 56.2 percent of the

FY 73 NEISS victims were female and only 43.8 percent were male when

all appliances were combined.

5
TABLE 2

Distribution of All Accident

Victims (FY 73 NEISS) by Age and Sex

Percent of

Percent of Total U.S.

Age Group Male Female Total Total

0-12 mos. 158 102 260 9.6

13-18 mos

71 41 112 4.2

19 mos . - 2 yrs

129 106 235 8.7

3-5 yrs. 177 145 322 11.9

Population

0-5 yrs. 535 394 929 34.4 (10.32)

6-10 124 119 243 9.0 (10.05)

11-15 58 91 149 5.5 (10.11)

16-20 83 150 233 8.6 ( 9.12)

21-26 102 196 298 11.1 ( 9.08)

27-35 77 160 237 8.8 (10.61)

36-45 73 105 178 6.6 (11.48)

46-55 58 115 173 6.4 (11.25)

56-65 38 73 111 4.1 ( 8.87)

66+ 32 111 143 5.3 ( 9.12)

Unknown 1 1

No victim 1

TOTAL 1180 1515 2696

Percent of Total 43.8 56.2 100.0*

* Due to rounding errors, percentages may not always sum to exactly 100.0. ** 1970 Census.

6
It should be noted tliat the data in Table 2 are divided into 10

major age-groins, each representing approximately 10 percent of the

total U.S. population according to the 1970 census. The farthest

column on the right of Table 2, "Percent of Total U.S. Population," gives

the exact population percentages by age categories . This same breakdown

by age vd.ll be used consistently tlirougliout tlic report but the "Percent

of Total U.S. Population" column will not be repeated. Due to the large

percentage of accidents involving children under five years of age (34.4%),

this group lias been further divided into four subgroups . The same subgroups \\111 also appear throughout the report. Finally, a category

designated "No Victim" appears in the "Age Group" column. This apparent

inconsistency includes those cases where an accident occurred but the

product user escaped injury. Such cases were included in the data base

when they provided descriptions of the events and behaviors preceding

the accidents

Closer examination of Table 2 suggests an age by sex interaction.

Figure 1 presents these same data in histogram form. Here it is apparent

that younger victims of appliance accidents tend to be male but older

victims are more often female.

A similar age and sex interaction was observed when the IDIR victims

for all types of appliance accidents were combined (see Table 3)

Accident age statistics are often bimodal, that is, the very young

and ver>' old members of the population are typically over -rep resented

(lladdon, Suchman 5 Klein, 1964) as accident victims. The present data

partially supports this model. While children are clearly frequent

accident victims in both the NEISS and IDIR data bases, a similar trend

is not evident for the elderly. The elderly may be construed, however,

as over- represented in terms of accident severity, that is, the injuries

they suffered were of greater apparent severity than any other age group.

Tliis point will be discussed below.

It was noted that the NEISS data available in the present study

were limited to the age and sex distributions of accident victims . The

hospital dispositions recorded in the IDIR's, therefore, were used as a rough gauge of accident severity. Table 4 presents the number of

victims for each category of hospital disposition by appliance product.

Note that the third column from the right, "Total Admissions and/or Deaths,"

represents a composite of all those cases where death or injury requiring

hospital admission resulted. A crude means of assessing a product's

relative accident severity results from comparing the number of "Total

Admissions and/or Deaths" to the total number of victims for that product.

Table 4 also presents each product's ranking on CPSC's Hazard

Index. The Hazard Index attempts to rate product hazard (not accident

severity) by assigning a weighted function of accident frequency, injury

severity and age of victim to each product. Little correspondence

between accident severity (as judged by hospital disposition) and the

7
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Distribution of All IDIR Appliance

Accident Victims by Age and Sex

Age Group 2 1. Male Female Unknown Total

0-12 mos. 29 13 42

13-18 mos. 19 20 39

19 mos. -2 yrs. 34 39 1 74

3-5 yrs. 81 43 124

0-5 yrs. 163 A. %J 1X 27Q

6-10 42 51 93

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16-20 23 35 58

1 c

\j 1 27-35 26 39 65

36-45 22 23 45

46-55 14 18 32

56-65 15 22 37

66+ 16 46 62

Unknown 4 3 7

No victim 4 2 2 8

TOTAL 369 438 6 813

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product's ranked liazard is evident in Table 4, with the possible exception

of irons. This product ranks lowest of all the appliances on the

Hazard Index, and appears to have a low acconpanying severity (e.g.,

four "Admissions and/or Deaths" of a total of 37 victims) as well.

Table 5 conpares hospital disposition to the age of the IDIR victim.

Again, the relative severity of accidents in each age group may be crudely

assessed by conparing the number in the "Total Admissions and/or Deaths"

column to the total number of cases. Note the relatively high severity

of accidents associated with the oldest age group, the group which

also accrues the largest number of fatalities. The youngest age

group, on the other hand, incurs the largest number of total accidents,

but with what appears to be the lowest associated severity.

Finally, Table 6 shows the type of injury sustained as a function

of appliance product. Bums were the most commonly observed injury,

affecting the majority of victims. Bum injuries were not, however,

uniformly distributed across all appliances sanpled. For exanple, only

one bum injury was associated with wringer washer accidents. No

other single injury was coimon to all appliance types.

The results for individual appliances follow. Whenever possible,

verbal descriptions of relationships and trends are minimized, and

reference is made instead to data tables for detail. More attention,

however, is devoted to the delineation of victim activity sequences

and their inplications . Because of the biases and limitations inherent

in the data sample, caution must be exercised in the interpretation

and application of all results

3.2 Space Heaters and Heating Stoves

Ranking 15th on the Hazard Index, space heaters and heating stoves

have long been recognized as hazardous products. The list of

associated hazards includes open flames, high surface temperatures, and

gas accumulation/explosion potential ; the relationship and interaction

between these factors and human behavior, however, has been relatively

unexplored. A total of 186 IDIR's were available for this analysis.

3.2.1 Victim Characteristics

Sex was marginally related to space heater accidents; 45.5 percent of

the FY 73 NEISS victims were female and 54.5 percent were male (see Table 7).

Children, however, were particularly prone to accidents with these

appliances. Nearly one-half (46.6 percent) of the victims were five

years of age or less, and another 9.8 percent were 6-10 years of age.

Thus almost 60 percent of space heater accidents were incurred by the

youngest 20 percent of the population.

Age and sex distributions for the IDIR sanple are presented in

Table 8. The relationships evidenced here are similar to those described

for the NEISS data.

11
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12
TABLE 6

Distribution of Type of Injury Incurred

by Appliance Product

Space Heaters/ Kitchen Wringer Hot Water

Injury Heating Stoves Ranges Washers Heaters Irons Total

Bum 163 373 1 54 36 627

Smoke Inhalation 16 7 23

CO Posioning 14 14

Laceration 4 11 24 39

Contusion 1 53 54

Crush 14 14

Abrasion 13 13

Avulsion 3 3

Sprain 2 2

Fracture 4 3 7

Anputation 2 2

Concussion 1 1

Other/Unknown 1 6 5 1 13

No injury 1

1

TOTAL 186 401 120 69 37 813

13
TABLE 7

Distribution of Space Heater (\ Heating Stove Accident Victims by Age and Sex

(FY 73 NEISS)

Percent

Age Group Male Fenale Total of Total

0-12 mos. 23 12 35 13.2

13-18 mos. 11 6 17 6.4

19 mos. -2 yrs. 15 16 31 11.7

3-5 yrs. 20 21 41 15.4

0- 5 yrs

AO r r bb ^ A A 0-iU Id 9 A ZD

11-15 8 4 12 4.5

16-20 4 8 12 4.5

21-26 12 6 18 6.8

27-35 12 9 21 7.9

36-45 10 12 22 8.3

46-55 6 9 15 5.6

56-65 2 3 5 1.9

66+ 9 2 11 4.1

Total 145 121 266

Percent of total 54.5 45.5 100.0

14
TAl^Li; 8

Distribution of Space Heater ^ Heating Stove Accident Victims by Age and Sex

(IDIR's)

Age Group Male Female iotal

0-12 mos

oo 4 iz

lo-lo mos.

rb

7 IZ

19 mos . - 2 yrs

7/ ZD

3-5 yrs

ZD 1 7

0-5 yrs. 46 46 92

6-10 6 12 18

11-15 2 5 7 16-20 5 8 13

21-26 3 6 9

27-35 12 7 19

36-45 5 2 7

46-55 1 1 2

56-65 2 3 5

66+ 6 7 13

No victim 1

Total 88 97 186

15
Twenty-six IDIR victims of space lieater accidents could be described

as physically or emotionally handicapped. That is, their response

capabilities were inpaired due to alcohol consunption, drug use, fatigue,

seizures, dizziness, or the like. While it may be inferred that such

factors contributed to the sequence of events leading to the accident,

conplete information was usually missing from the case histories. These

data are admittedly difficult to obtain; victims are often reluctant to

reveal such factors for fear of public embarrassment, insurance

cancellations, legal problems, etc. There is a need for skilled IDIR

interviewers who can convince and reassure victims that anonymity will be

maintained.

3.2.2 Injuries

Bums were the most frequently observed result of space heater

accidents, involving 163 of the 186 IDIR victims. Another 16 victims

suffered inhalation poisoning, and the remaining seven victims (all

children five years of age or less) incurred lacerations, contusions, or

concussions after "Falling into" a heating unit.

Eleven deaths resulted from space heater accidents and another

49 of the total 186 IDIR victims required hospitalization.

While the oldest group (66+ years) was not over- represented in

accident occurrence, the injuries incurred by these victims were more

severe than average. As Table 9 illustrates, five of the 13 victims

in this age group were fatalities and another three were hospital

admissions

3.2.3 Behavioral Classification

Activities preceding space heater accidents were divided into four

major categories. Table 10 lists these activities, along with the

associated number of IDIR victims. The two most frequently observed

categories of behavior, "Interacting with" and "Occupied near" were

further classified into more explicit descriptions of the victim's

antecedent behavior.

Only 59 of the 186 IDIR victims were injured while directly "Interacting

with" the heater, that is, while engaged in activities related to the unit's

heating function. Another 94 victims were injured while engaged in nearby

unrelated activities, and seven victims were sinply "Passing by" the unit.

The inplication is, of course, that space heater hazards do not relate only

to the direct operation of the space heater.

The fourth category, "No causative activity," refers to those

behaviors prior to the accident that could not be integrated into the

accident sequence. Sleeping victims of carbon monoxide poisoning are an exanple.

Summaries of 122 FFACTS were classified according to the same behavioral categories . The results of this effort are also shown in

Table 10.

16
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17
TABU: 10

Behavioral Classification of

Space Heater and Heating Stove Accidents

Ml ITTlKfiT' INLUIUJCI

L X V -L L V TDTR ' <;

Xii LCI cLL' L J-i WX Lil J t) iigntmg 0 0

- wamiing io

- place object on 1 0

- sit on 2 1

- touch purposely 10 1

Occupied near 94 65

- standing 5 35

19 4

- working 3 4

using riaiiuiiaDies 10

- fell into 50 4

- lean over heater 3 2

Passing by 7 10

No causative activity 24 8

Other/unspecified 2 13

TOTAL 186 122

18
Certain age-related activities were observed. All 10 IDIR victims

whose behavior was described as "Using: touched purposely" were children

five years of age or less. All but one victim injured while "Passing by"

was 10 years old or less. These trends imply that some children

are not cognizant of space heaters as a hazard and that the units

are not (or cannot be) located outside a child's sphere of activity.

Similarly, 36 of the 50 victims who were "Occupied near: fell into"

were children.

3.2.4 Product Factors

Due to the large number of IDIR accidents that occurred without the

victim actually using the heater, an effort was made to assess the

condition of the unit itself. Heating units were judged to "Need repair" or be characterized by "Poor design" according to the guidelines listed

in the Appendix. Even though insufficient data often made classification

difficult, 118 of the units in the IDIR sarple were judged in "Satisfactory"

condition. Another 51 units showed "Poor design," 16 were shown to

"Need repair," and no decision could be made in one instance.

Accidental injury seems to have occurred far more frequently with

gas space heaters and heating stoves than any other type. Of the 186

sample IDIR's, 131 cases involved gas, 19 involved electric, 10 involved

oil or kerosene, and the remaining 26 cases concerned heating units of

an unspecified nature.

3.2.5 Injury/Hazard/Activity Sequences

Two coimonly observed accident sequences were noted:

1. While using a space heater to warm themselves, individuals

moved too close to the gas heater's exposed flame. Clothing

ignition and bum injuries resulted i

2. While engaged in unrelated "play" activities nearby, children

fell into the heating unit and incurred relatively minor

contact bums.

Some of the hazards associated with space heaters and heating stoves

have already been noted; these include an exposed flame, gas explosion/

accumulation potential, and high surface tenperatures . In addition, the

present data suggest that the presence of the unit itself may be

hazardous, for a relatively large number of victims (94) were injured

while engaged in activities adjacent but unrelated to the heating unit.

Whether or not these accidents can be linked to the portability of

many of the units (which implies that the user can position it

"hazardously") is a topic for further study.

19
3.3 Kitdicn Ivingcs

Kitchen ranges rank 17th on the CPSC listing of hazardous products.

A total of 401 IDIR's dealing with range-related accidents were available

for NBS use. Both gas and electric ranges were included.

3.3.1 Victim Characteristics

According to the NEISS data, more females than males were injured in

range-related accidents. As shown in Table 11, 59.2 percent of the

victims were female and 40.8 percent were male.

This sex distribution is not consistent across all age groins,

as Figure 2 illustrates. Notable exceptions occur:

- in the youngest age group (0-5 years) where the majority of

the victims, 58.9 percent, were male.

- in the 21-26 year old age group. Here 71.8 percent of these

victims were female, many of whom were probably young

liomemakers interacting extensively with a kitchen range for

the first time.

- in the oldest age group (66+) where 72.4 percent of the

victims were women. At this age level, however, the majority

of the total population is female.

The age distribution for the victims of kitchen range accidents

was similar to the age distribution for all appliance accidents

combined. Again, a relatively large percent of the injured, (27.0

percent of the NEISS victims) were drawn from the youngest 10 percent

of the population (see Table 11)

Table 12 presents the IDIR data for kitchen ranges. The age

and sex trends correspond well to those reported in FY 73 NEISS,

suggesting that the sample studied was representative, at least with

respect to these factors, of the overall surveillance system data.

3.3.2 Product Factors

The data suggest that gas ranges are more hazardous than electric

ranges. While the Gas Appliance Manufacturers Association, Inc. reports

(NEISS News , April 1975) a nearly equal number of gas and electric

ranges in residential use in 1974, gas range accidents outnumbered

electric range accidents 2.6 to 1 in the IDIR's sampled. Even higher

ratios between gas and electric range-related accidents were reported in

FY 73 NEISS (3.0 to 1) and FY 74 NEISS (2.8 to 1).

3.3.3 Injuries

Bums were the most commonly observed injury associated with kitchen

ranges, affecting 373 of the 401 IDIR victims.

20
TABLE 11

Distribution of Range Accident

Victims by Age and Sex

(FY 73 NEISS)

Percent

Age Group f^le Female Total of Total

0-12 mos. 92 60 152 11 . / 13-18 mos. 22 16 38 2.9

19 mos. -2 yrs. 51 28 79 6.1

3-5 yrs. 41 40 81 6.3

0-5 yrs. 206 144 350 27.0

6-10 45 28 73 5.6

XX X J 77

XQ- LV XUJ 1 t^t; XOD X z. . u 21-26 53 135 188 14.5

27-35 35 97 132 10.2

36-45 33 58 91 7.0

46-55 35 70 105 8.1 . 56-65 27 38 65 5.0

66+ 16 42 58 4.5

Unknown 1 1 0.1

No victim 1 0.1

Total 529 766 1296

Percent of total 40.8 59.2 100.0

21

TABLE 12

Distribution of l^nge Accident Victims

by Age and Sex

(IDIR's)

Age Group Male Female Total

0-12 mos. 13 3 16

13-18 mos. 8 9 17

19 mos. -2 yrs. 13 10 23

3-5 yrs. 18 13 31

0-5 yrs. 52 35 87

6-10 12 23 35

11-15 18 21 39

16-20 13 22 35

21-26 12 36 48

27-35 9 18 27

36-45 13 17 30

46-55 10 16 26

56-65 12 16 28

66+ 7 32 39

Unknown 1 0 1 No Victim 4 2 6

Total 163 238 401

23
Bums were inflicted in three basically different ways. Many

(170 of the cases) victims were burned by direct contact with flames,

often following flammable fabric ignition. Others (108 victims) received

contact bums from a hot surface or were bumed by the heat from a gas range explosion (92 victims)

The type of injury incurred as a function of the IDIR victim's age

is shown in Table 13. Since no relationship between age and range type

was apparent, gas and electric ranges have been coml)ined. Note that one- half of the victims of contact Imms were children five years of age or younger.

Of the 401 victims of kitchen range accidents, 245 were treated

and released from a hospital emergency room, and 89 retjuircd hospitalization

but survived. A total of 32 fatalities (48 were observed in the overall

IDIR sample) were associated with kitchen ranges.

No accident severity trends were observed by range type, age group, or sex.

3.3.4 Behavioral Classification

Classifying victim behavior just prior to an accident is one of

the most crucial features of a human factors approach to acccident research.

At an earlier date NBS staff had performed a behavioral analysis of

kitchen range accidents using FFACTS data (Pezoldt, Persensky, and Peiser,

1973) . The activity sequences developed at that time were applied to

all comparable IDIR's in the present study, that is, those 215 case studies involving flammable fabric related fires. New behavioral

categories were developed for the remaining data.

'Ihe behavioral classification of flammable fabric range accidents

is shown in Table 14. Five of the nine categories encompassed

behavior broad enough to require further subdivision. Table 14 depicts

the number of accidents associated with each activity sequence for

both the flammable fabric related IDIR's and FFACTS case histories

analyzed earlier.

Similar relationships were found in both data bases. For example, 33 of

the 215 subsample IDIR victims and 44 of the 285 FFACTS victims were

injured while "Leaning against the range." Similarly, 38 of the IDIR

and 43 of the FFACTS victims were injured while "Occupied near the range."

These similarities sipport the validity of the activity sequences

identified. However, a notable discrepancy exists for the "Reaching

across the range" category. Here, 103 of the 285 FFACTS victims, but

only 42 of the 215 IDIR victims were injured in this manner.

Many range- related accidents do not occur during range use, as an examination of Table 14 reveals . None of the activities described

in Categories IV or V ("Occupied near range" and "Climbing onto or around range") involved use of the range for cooking or meal preparation.

Together these categories encompass a substantial number of cases in

both data bases (50 IDIR's, 62 FFACTS).

24
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If)

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25
TABLE 14

Behavioral Classification of IDIR and FFACTS

Range Accidents

(Flammable fabric related accidents only)

Subsample Total

Behavioral Category IDIR's FFACTS

I. Reaching Across Range ^ 42 103

A. To set controls 6 11

B. To back burner, front burner

energized 2 14

C. To item on range surface 12 13

D. Accidentally energizing burner 0 3

E. I\'hile standing on chair 2 6

F. Contact with pilot 0 4

G. Other, cooking 17 52

H. Unaware burner was on 3 0

II. Reaching Above Range 14 21

A. Into cupboard/shelf above 6 7

B. Other than into cupboard 2 6

C. Accidentally energizing burner 1 2 D. While standing on chair 5 6

III. Leaning Against Range 33 44

A. Using range as support 11 . 13

B. Unaware burner was activated 1 4

C. Falling, fainting, tripping, etc. 12 6

D. Using range as heater 9 21

IV. Occupied Near Range 38 43

A. Walking near range 8 6

B. Standing in close vicinity 16 29

C. Standing on chair near range 8 8

D. Using range as heater 6 0

V. Climbing Onto or Around Range 12 19

A. Directly on range 9 12

B. On adjacent counter 2 7 C. To keep warm 1 0

26
TABLE 14 (Con't)

Subsample Total

Behavioral Category iniR's FFACTS

VI. Flammable Solvent Used Near Range 17 9

VII. Physical or Emotional Problem 5 7

VIII. Grease Related " 17 19

IX. Other 37 20

A. Upset pan on range 3

B. Testing to verify if burner

is on 2 C. Accidentally energized burner 3

D. Touching hot cooking surface 4

E. Misc/unknown 25

TOTALS 215 285

27
The remaining 186 IDIR's (tliose not involving flammable fabric

fires) are classified by activity sequence in Table 15. Nearly half

(86) of the victims of these accidents were injured by gas range

explosions. Another 49 victims, most of whom were children, received

contact bums after touching a hot surface.

Items III and IV on Table 15 are "catch-all" categories, encompassing

Hie rather small number of "Non-bum" injuries and "Others." In both

Tables 14 and 15, "Others" refers either to those accidents which were in

some way unique or for which little or no behavioral information was

available

Finally, the activity sequences identified for all 401 IDIR's are shown as a function of range type in Table 16. Categories VIII and IX,

"Flammable solvent used near range" and "Explosion" are limited to gas

ranges. The majority of the other behavioral categories involved more

gas than electric ranges, a finding in consonance with the overall

ratio of gas to electric range-related accidents reported above. The

"Climbing onto or around range" and "Grease related" categories are exceptions, for they involve electric ranges more often than gas.

3.3.5 Injury/Hazard/Activity Sequences

Bums were the usual injury resulting from kitchen range accidents in

the IDIR data; the overwhelming majority of victims (393) suffered some

sort of bum injury. A variety of hazard/activity sequences, however,

were noted.

Fabric ignition was the hazard most frequently encountered. More

than lialf of the surveyed victims were injured after some part of their

clothing ignited, usually following contact with an energized surface

element. The activities related to this hazard usually involved

reaching across or above the range while cooking. More often that not,

a loose-fitting sleeve or shirt tail was involved.

The exposed pilot light on gas ranges was also identified as hazardous. In this case, the accident sequence often included attempts

to light an oven or bumer pilot. Other injuries resulted from the use of volatile liquids in the vicinity of an exposed pilot light.

Finally, hot surface tenperatures on both types of ranges were

found hazardous, especially to children. An activity sequence commonly

associated with this hazard involved a young child, just leaming to

walk, using the fronts of kitchen cabinets and appliances for support.

A child who encounters a hot oven door in this manner often does not

possess the motor skills which would enable him or her to move

quickly enough to avoid injury. It is noteworthy, however, that the

injuries related to hot surfaces were not as severe as those associated

with kitchen ranges in general.

28
TABLE 15

Behavioral Classification of IDIR Range Accidents

(Non-flammable fabric -related accidents)

No. of

Category Incidents

I. Explosions 86

A. Lighting the oven, explosion

occurs 66

B. Lighting the burner, explosion

occurs 14

C. Range explosion, other/unknown

pilot 5 D. Microwave explosion 1

II. Touching hot surface

(e.g., oven door) 49

III. Non-Burn 23

A. Cleaning oven 3

B. Lost balance, fell 5 C. Bumping into range 2 D. Closing oven or broiler door

on hand 2 E. Laceration on other range-part 3

F. Smoke inhalation 1 G. Gas leak (inhalation) 7

IV. Other 28

A. Climbing on oven or broiler 4

B. Moving grease 4

C. Camp stove related 6

D. Unspecified 14

TOTAL 186

29
TABLE 16

Behavioral Classification by All IDIR

Range Accidents by Range Type

Range Type

Other/

Activity Pattern Gas Electric Unspecified Total

I. Reaching across range 23 17 2 42

II. Reaching above range 11 3 0 14

III. Leaning against range 20 12 1 33

IV. Occupied near range 22 13 3 38

V. Climbing onto or around range 4 7 1 12

VI. Grease related 5 9 3 17

VII. Physical or emotional problem 5 0 0 5

VIII. Flammable solvent used near range 17 0 0 17

IX. Explosions 85 0 1 86

X. Touching hot surface 18 9 22 49

XI. Non-bum injuries 18 3 2 23

XII. Other 29 23 13 65

TOTAL 257 96 48 401

30
Several measures may be taken to alleviate or reduce these

hazards. For exanple, the surface temperatures on oven doors may be

reduced. Backsplash controls can be placed high enough above the

range top to reduce the probability that loose-fitting garments will

touch an energized burner. Both measures have, in fact, been addressed

by the latest revisions (effective September 30, 1975) to the

Underwriters' Laboratory Standard (#858) for kitchen ranges.

Other safety measures might include shielding a gas burner pilot

from any possible contact with the range user's clothing. Reminding

parents of the dangers of storing substances attractive to children

above, in, or nearby the range would be helpful and the designers of

future kitchens should insure that cabinets or shelves are not built

directly above the range. The relatively large number of gas

explosions resulting in accidental injury are of particular concern. Unfortunately, whether these accidents may be attributed to product

factors or human factors is generally unknown.

3.4 Wringer Washers

A total of 120 IDIR's were summarized concerning washing machines

with wringers, the 28th most hazardous product according to the CPSC

Hazard Index. FY 73 NEISS data was also available for this product.

3.4.1 Victim Characteristics

Tables 17 and 18 show the age and sex distributions of wringer

washer accident victims for NEISS and the IDIR's, respectively.

While no sex differences were observed for IDIR victims, nearly

two- thirds (62.1 percent) of the victims reported by NEISS were female.

For age, however, both data bases show distinctive age biases. Fiftyseven of the 120 IDIR victims were children five years or less and another

31 victims were 6-10 years old. NEISS reports percentages of 38.5 percent

and 20.0 percent

, 'respectively , for these same age groups.

Once the high incidence of injuries to the two youngest age

groups was noted, the case histories were reread to determine whether

or not a supervising adult had been present v^en the accident occurred.

For those 88 IDIR cases involving children ten years of age or less,

19 occurred in the presence and 46 in the absence of adult supervision.

Even though no classification could be made for the remaining 23 cases

,

the data clearly suggest that wringer washers pose a greater hazard

for an unsupervised child as for a si^jervised child.

Finally, an age by sex interaction was observed for the victims

of wringer washer accidents. An examination of both Tables 17 and 18

reveals that younger wringer washer victims tended to be male but

older victims were more often female. Societal sex roles suggest a possible

31
TABLE 17

Distribution of Wringer Washer

Accident Victims by Age and Sex

(FY 73 NEISS)

Percent

Age Group Male Female Total of Total

0-12 mos. 2 1 3 0.7

13-18 mos. 4 2 6 1.3

19 mos . - 2 yrs22 10 32 7.1

3-5 yrs. ,78. 54 132 29.4

0-5 yrs. i(.)0 0/ I / J oo . 5 0-iU A 1 41 4y 90 20 .

11-15 8 13 21 4.7

16-20 • 2 9 11 2.4

21-26 2 18 20 4.5

27-35 . 1 18 19 4.2

36-45 S 11 16 3.6

46-55 1 19 20 4.5

56-65 1 17 18 4.0

66+ 3 58 61 13.6

Total 170 279 449

Percent of total 37.9 62.1 100.0

32
TABLE 18

Distribution of Wringer Washer

Accident Victims by Age and Sex

(IDIR's)

Age Group Male Female Total

0-12 mos.

13-18 mos.

19 mos. -2 yrs. 9 7 16

3-5 yrs. 29 12 41

0-5 yrs. 38 19 57

6-10 18 13 31

11-15 5 5

16-20 2 2 4

21-26 1 1

27-35 8 8

36-45 3 3

46-55

56-65 3 3

66+ 7 7

IMknown 1 1

Total 59 61 120

Percent of total 49.2 50.8

33
explanation. Young boys are more likely than girls to be attracted by

the "mechanical" nature of the washer's moving wringers and to be

injured while exploring the machine's workings. Older victims, on the

other liand, are most often housewives injured while using the machine.

3.4.2 Injuries

Almost all of the IDIR wringer washing machine accidents involved

tlie machine's moving wringer. It is not surprising, then, that 53 of the

120 resultant injuries were contusions. Lacerations were also common

(14 cases), as were crushes (14 cases) and abrasions (13 cases).

Injury type was apparently not age-related.

3.4.3 Behavioral Classification

"Feeding clothes through the wringer" was the most common activity

preceding a wringer washer accident in the IDIR data. As Table 19 indicates,

a substantial number (50) of victims, including most of the adults, were

injured in this manner, that is, while using the machine for its intended

purpose.

Twenty- six children aged ten or under were also injured while

"feeding clothes through the wringer," but many of these young victims

were described as mimicking or attenpting to help their mothers or caretakers.

Most other children were injured after "Touching the roller" or "Playing" with the machine. IDIR interviewers frequently attributed

the former activity to the child's curiosity. Indeed, careful

reading of the case studies suggests strongly that the moving wringers

hold an inherent fascination for children. Those victims described as "Playing" were often trying to feed an object other than clothes

(e.g., toys) through the wringer.

3.4.4 Injury/Ilazard/Activity Sequences

A common injury/hazard/activity sequence to emerge from the

Wringer washer data involved a young child, usually a boy, who was fascinated by the movement of the wringer on the washing machine. When

his or her caretaker was somehow distracted or absent, the child touched

the wringer, or attenpted to put some object through it. The child's

arm was drawn into the wringer and the resulting injury involved a bruised, crushed, or lacerated arm.

The most hazardous aspect of a wringer washer appears to be the wringer

itself. It is related to both product use and product abuse injuries.

Some product use injuries might be prevented by added safety features.

An emergency release button, already present on some models, is an

exanple. Underwriters' Laboratory Standard #560 (Electric Homelaundry Equipment), already specifies that the roller system be designed

such that it disengages whenever a force greater than 20 pounds is

34
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35
applied in a direction other than that which feeds the roller. The

adequacy of this 20 pound requirement should be examined in light of

the relatively large number of injuries still occurring during proper

product use.

Since abuse injuries with wringer washers seem to involve mostly

children, the prevention of these injuries could focus on making the

wringer's operation somehow less appealing. A possible but untested

solution would involve designing a shield to obscure the moving rollers

from young observers. Since a number of children were injured after

activating the wringer themselves, the operation of the wringer could

be made more conplicated. For exanple, the continual depression of a foot pedal could be required for operation. Careful positioning of this

pedal could ensure that the average child could not simultaneously

depress it and still reach the wringer.

3.5 Ifot Water Heaters

Water heaters rank 39th on the CPSC Hazard Index. Wliile these

appliances are fueled in a variety of ways, utility gas and electricity

are, of course, the most common methods. The Census Bureau reports

(July 1972) that approximately 35.0 million gas and 16.1 million

electric water heaters are currently in use. Ibwever, only two of

the 69 available IDIR's dealing with water heater accidents involved

electrically fueled units. The remainder were powered by natural

gas (43 cases), bottled gas or oil-fired fuel (16 cases), or by an

unknown or unspecified agent (8 cases).

3.5.1 Victim Characteristics

Sex of the victim was a factor in hot water heater accidents. Table 20

shows that 66.8 percent of the FY 73 NEISS victims were male and 33.2 percent

were female. The IDIR sanple also reflects this sex trend. As shown

in Table 21, 40 of the 69 hot water heater victims were male and only

24 were female (the sex of the remaining five victims was unspecified)

Children were again over -represented as accident victims. Here,

22.4 percent of the NEISS and 19 of the 69 total IDIR victims were five

years of age or less

It should be noted that the correspondence between the IDIR sample

and the NEISS surveillance system data is not as high for hot water

heaters as for the other appliances studied. The small sanple size

also suggests that all reported relationships be considered cautiously.

3.5.2 Injuries

Bums and carbon monoxide poisoning were the only two types of

injuries reported in the IDIR's: 54 and 14 hot water heater victims,

respectively, incurred these injuries. Type of injury was not related

to the victim's age and sex in the IDIR sanple.

36
tabu: 20

Distribution of Hot Water Heater

Accident Victims by Age and Sex

(FY 73 NEISS)

Percent

Arrp nTnun Male Femal

Total of Total

0-17 mos 6 5 11 4 9

13-18 mos 5 4 9 4 0

19 mos -2 yrs. 15 7 22 9.9

3-5 yrs. 6 2 8 3.6

0-5 yrs. 1 o lo bU LL A

D-10 1 A 14 / Zl y .4

11-15 9 2 11 4.9

16-20 16 5 21 9.4

21-26 21 8 29 13.0

27-35 17 17 34 15.2

36-45 18 7 25 11.2

46-55 13 4 17 7.6

56-65 7 4 11 4.9

66+ 2 2 4 1.8

Total 149 74 223

Percent of total 66.8 33.2 100.0

37
TAIME 21

Distribution of Hot Water Heater

Accident Victims by Age and Sex

(IDIR's)

Age Group Male Female Unknown Total

0-12 mos. 4 2 6

13-18 mos. 1 1 2

19 mos . - 2 yrs

4 1 1 6

3-5 yrs

4 1 5

0-5 yrs. 13 5 1 19

6-10 2 3 5

11-15 5 2 7

16-20 3 2 5

71-76 c D 27-35 5 6 11

36-45 4 1 5

46-55 3 3

56-65 1 1

66+ 3 3

Unknown 1 3 4

No victim 1 1

TOTAL 40 . 24 5 69

38
Five fatalities were reported and anotJier 22 of the 69 IDIR victims

were hospitalized. Note, however, tliat tlie hospital disposition of

12 victims, a relatively large proportion of the sample, was not known.

None of the victims suffering from carbon monoxide posioning required

hospitalization.

3.5.3 Behavioral Classification

The precipitating activity sequences for hot water heater IDIR

accidents are shown in Table 22. In 20 of the 69 cases the victim's

activity was judged "Irrelevant to the accident" suggesting that

product, rather than human, factors were involved in the causal

chain of events precipitating the accident. Typical product factors

could include design defects or malfunction.

Table 22 also shows that 17 victims were injured while "Using a flammable substance near a heater." The most typical flammable substance

was gasoline being used as a cleansing agent. Another eight victims

"Upset or spilled a flammable substance" in the vicinity of a heater.

These data suggest a general lack of awareness of the presence of an

exposed flame.

Still another seven victims encountered scald burns, an injury

unique to this appliance judging by the IDIR's. Children who "Contacted

hot water from the faucet" while being bathed were usually involved in

these accidents. A malfunctioning or improperly adjusted thermostat was frequently inplicated.

Because FFACTS deals only with flammable fabric -related accidents,

the activity sequences developed for the IDIR sample were not applicable

to the 75 hot water heater accidents reported in FFACTS. It should be

noted, however, that 47 of the FFACTS cases involved using a flammable

liquid near the heater and another 10 cases involved a spilled or iq)set

flamnable liquid.

3.5.4 Injury/Hazard/Activity Sequences

In the present study, the open flame of a gas pilot light emerged

clearly as a water heater hazard. Bums were the most common and severe of the observed injuries. The most frequently related activity

involved the use of a flammable solvent, usually gasoline. Thus, the

most commonly encountered injury/hazard/activity sequence in the IDIR

data involved the use of a flammable solvent near the hot water heater.

Flames or an explosion resulted, arid the victims suffered bum injuries.

It is apparent that many of the victims of hot water heater

accidents were unaware of the potential hazards associated with this

appliance. Because the operation of the appliance does not require

constant or regular monitoring, the consumer may "forget" that an exposed flame is present when flammable substances are being used.

Other victims reported not knowing that the fumes from a volatile

39
mM\l 22

Beliavioral Classification of IDIR

Hot Water Heater Accidents

Activity Total

Activity- irrelevant (gas or

fume leak) 20

Using flammable substance near

heater 17

Upset or spilled a flammable

substance 8

Lighting pilot light 9

Contact with hot water from

faucet 7

Bunded into hot water heater 3

Other (includes "no injury") 5_

TOTAL 69

40
substance could ignite, and thus perceived no danger in using flammable

liquids in the same room as a gas hot water heater. Here certain

accidents might be prevented by appropriately shielding the heater's

open flame. In addition, highly conspicuous labels depicting the dangers

of an e:5q)osed flame could be affixed to the appliance to "remind" the

user of its inherent dangers.

A relatively large number of hot water heater accidents were

unrelated to the behavior of the victim; as noted above, 20 of the

69 IDIR's could be attributed directly to faulty equipment or gas

leaks . Besides educational programs which stress the inportance of

regular product maintenance and potential ignition hazards , little from

a liuman factors approach can be applied towards water heater accident

reduction

3.6 Irons

Household irons rank 47th on CPSC's Hazard Index. Only 37 IDIR's

dealing with iron-related accidents were available; any reported trends are therefore extremely tenuous

3.6.1 Victim Characteristics

Table 23 shows the age and sex distributions for FY 73 NEISS iron

accident victims. A disproportionately high rate (50.2 percent) of victims

were children five years of age or less. Because of the small sanple

size, an age by sex distribution for iron IDIR's is not included but

an over- representation of the youngest age group was again apparent. Twentyfour of the 37 victims were five years of age or less

Within this youngest age group, no sex differences in relation to

iron- related accident occurrence were observed in either data base.

For all other age groups combined, however, the XEISS victims were

2.5 times more likely to be female than male, a finding in accord with

traditional sex roles.

3.6.2 Injuries

Thirty-six of the 37 IDIR victims of iron accidents suffered bums.

As judged by hospital disposition, these injuries were generally not

severe. Only four victims required hospital admission. Thirty-one

victims were treated and released and the disposition of the remaining

two victims was not reported.

As use patterns would predict, a large proportion of the IDIR ironrelated injuries (10 instances) were concentrated around the hands

or wrist. Another eight injuries involved the feet or legs. No other

isolated bodily part was consistently injured.

41
TABLE 23

Distribution of Iron Accident Victims

by Age and Sex

(FY 73 NEISS)

Percent

Age Group Male Female Total of Total

0-12 mos

35 24 59 12.8

13-18 mos. 29 13 42 9.1

19 mos. -2 yrs. 26 45 71 15.4

3-5 yrs. 32 28 60 13.0

0-5 yrs. 122 110 232 50.2

6-10 11 22 33 7.1

11-15 6 22 28 6.1

16-20 9 25 34 7.4

21-26 14 29 43 9.3

27-35 . 12 19 31 6.7

36-45 7 . 17 24 5.2

46-55 . 3 13 16 3.5

56-65 1 11 12 2.6

66+ 2 7 9 2.0

Total 187 275 462

Percent of total 40.5 59.5 100.1

42
3.6.3 Behavioral Classification

The behavioral categories developed for iron-related accidents are shown in Table 24 as a function of the victim's age. Note that age

groups unrepresented in the IDIR sanple have been ommitted from this

table.

"Pulling the cord" emerged as a frequent activity leading to

an iron accident; 13 of the incidents could be characterized by this

behavior. All victims in this category were children injured by a falling hot iron. Nearly half of these children were infants, 12 months

of age or less.

Another five victims were injured after 'Touching a hot iron"; again

it should be eirphasized that three of these victims were children.

Three accidents may be attributed to product failure and/or design

defect. In these cases, adult victims were burned by emerging steam

while "Examining the bottom of the iron".

Several other cases specified virtually nothing regarding the

victim's specific actions just prior to the accident. The category

'Tlaying" is an example. Since the varieties of children's play

activities are innumerable, the designation of a behavioral sequence

as "Playing" only occurred as a last resort, when no other activities

were specified in the IDIR. This problem could be reduced by training

future interviewers to be more explicit in their behavioral

descriptions of the accident.

3.6.4 Injury/Hazard/Activity Sequences

An accident sequence commonly observed for iron-related accidents

involved a young child (often an infant) pulling the cord of a hot iron and

being injured as the hot iron fell on or next to him or her. With only

one exception, the injured suffered bums; thus the IDIR data suggest

little hazard associated with the mass of the iron itself. No sinple

design modifications are evident which would reduce or prevent the types

of iron-related accidents found in the present data.

4.0 DISCUSSION

Certain relationships or trends have emerged from the data under study;

thus a human factors descriptive analysis by individual appliance product

has not been without merit. At times, hazards have been identified and

possible, but untested, mechanisms to reduce accident occurrence and

severity have been suggested. It is apparent, however, that the original

intent, namely the identification of injury/hazard/activity patterns vdiich

would apply in a generic manner to all home appliances , has not met with

success

43
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44
4.1 Problems

It is instructive to examine the factors working against a more

satisfactory conpletion of this original task. In the first place, the

limitations of the available data for a human factors analysis cannot be

overenphasized. The inconsistencies, omissions, and dubious

representativeness of the IDIR's have already been noted. These shortcomings render any trends described in the results section of questionable

authenticity, though to a lesser degree if that same trend is also discemable

in the available NEISS data.

Beyond these shortcomings, the IDIR's do not systematically record

the right kind of information necessary for a conplete human factors

analysis. It was noted earlier that IDIR's purport to provide a description of the total accident sequence; this was, unfortunately, the

exception rather than the rule, a fact unknown by MBS investigators at

the time the study began. In addition, questions essential to a human

factors approach are not part of the IDIR interviewing procedure.

Information regarding the dimensions of the human victim (e.g., height,

arm span, visual capabilities), the dimensions of the appliance products

(weight, noise level), and the physical and psychological aspects of

the human-product interface (attractiveness, ease of operation) must be

included in the case histories if meaningful analysis is to be accomplished.

Yet inproving the quality of the in-depth interview is not enough.

More basic research is also needed to provide a perspective against which

accident trends may be interpreted. Product use patterns serve as an

example. In the present study, certain appliance -related accidents

were distributed equally by sex. Such a finding can imply either that

both men and women use that particular product equally often, or that some accidents can be attributed to high product exposure and others to

unfamiliarity . Because both explanations are viable, the course of

future research is ambiguous , since redesigning product features which

become hazardous only after prolonged usage is not the same as reducing

hazards due to user inexperience. The knowledge of product use patterns

would reduce the ambiguity and allow for more efficient reduction of

product- related hazards.

A better understanding of how a product is used is also needed.

It is well known that consumer products are not always used in the

designer's intended way; yet, patterns of product abuse and misuse now

become apparent only when accidental injury and emergency room attention

result. Product use and abuse patterns should be studied in their own

right, initially as a function of product user factors such as age

and sex.

Finally, a clear need exists for a better method of indexing

accident severity. The validity of the CPSC Hazard Index currently used

to determine product research priorities is open to question. NEISS

statistics provide the basis for the Hazard Index, and vhile the

intricacies of its confutation are not of concern here, it is inportant

to note that product severity is a weighted function of accident

45
frequency, injury severity, and age of the victim. Higher priorities

are awarded younger victims. Wliile injury severity is rated on a nine

point scale, NEISS statistics are transmitted daily, indicating tJiat

emergency room diagnosis is the only basis for rating severity. 'ITius patients who later die as a result of product -related injury are not

counted as fatalities. Similarly, factors such as length of

hospitalization, the existence of long term and/or permanent

disabilities, and loss of employment are not reflected in the Hazard

Index. Perhaps more inportantly, no account is made for frequency of

product use. Embarrassing questions ensue. For example, are kitchen

ranges (ranked 17th) , v>^ich are used regularly by most people really more

hazardous than wringer washers (ranked 28th) , which are used occasionally

by some people? Once a more acceptable method of indexing severity is

developed, the attempt to identify hazards and hazardous activities associated

with the most severe and debilitating accidents will be more fruitful.

4.2 Inplications

Despite limitations, the present research has identified certain

generic liazards . An open flame, whether associated with a kitchen

range, hot water heater, or space heater or heating stove, is clearly

the most liazardous feature of the appliances studied. Open flames

were related to a variety of accidents, ranging from flammable fabric

fires to gas explosions. Another generic hazard concerned hot surface

temperatures ; here all the studied appliances except wringer washers

were involved. A "behavioral" generic hazard concerned leaving

young children unattended in the presence of an appliance; this

hazard was particularly poignant with wringer washers, but applicable

in some degree to all appliances under study. Because such hazards

cannot be identified within a total accident pattern of injuries,

hazards , and activities , no reasonable recommendation for accident

prevention or severity reduction can be specified generically.

Instead, recommendations must be limited to specific appliances.

In addition to the delineation of generic hazards , the current

results have underscored the strong relationship between age and

accidental injury. The younger age groups are clearly over- represented

as accident victims; so to a lesser extent are the elderly. Childhood

accident proneness may be attributed to a number of factors, including

curiosity, unfamiliarity with the environment and its hazards, and

still developing perceptual/motor response systems. The elderly also

suffer from impaired sensory-motor capabilities, a condition which,

coupled with their decreased agility and increased fragility, renders

them highly susceptible to accidental injury.

The aged experience a special problem regarding accident severity;

half of the accident victims in the oldest ten percent of the population

were fatalities or required hospital admission. It may be assumed

(though such data were not analyzed) that because of their reduced

recuperative abilities, a disproportionate number of long-term

hospital stays are also associated with the elderly. Since the

number and proportion of individuals who reach "old age" in our

4#
society is currently increasing rather dramatically, the magnitude

of problems this group experiences in relation to total product- related

accidental injury will also increase.

4 . 3 Recommendations

In summary, the following recommendations are made:

1. E>q)and the data base. Redesigning the IDIR report form to

include liuman factors data, i.e., information regarding the interface

between the product involved and the human using that product, will

contribute to a better understanding of the total accident sequence. This

is turn can lead to better accident reduction and prevention programs.

There are immediate difficulties with such a suggestion since the

relevant human factors information is often highly product-specific . In

the case of a kitchen range accident, for example, the size of the

range, the control knob location and type, and the armspan of the range

user represent some of the pertinent product-specific human factors

information. Collecting such data implies the preparation of a separate

form, specific to each product, to accompany the general IDIR form.

Wliile such an undertaking is unwieldly, the benefits gained for products

ranking high on the Hazard Index may conpensate for the extra effort

expended

2. Intensify research efforts to describe product exposure and

product use patterns. Answers to questions such as "Who uses the products?"

flow often do they use them?" and "How do they use or abuse them?" are prerequisites to a meaningful application of epidemelogical analyses such

as the present effort, and consequently to any significant strides in productrelated accident prevention and reduction.

3. Re-examine priorities. Product -re lated accident prevention has

typically focused on children to the exclusion of other age groups. Tlie

current data clearly support the high accident-susceptibility of children

but also suggest that their injuries tend to be minor. Perhaps the

increasing percentage of elderly, whose accident -proneness represents more

of a loss to society in terms of severity and time, should receive more

attention.

47

REFERENCES

Bureau of the Census. Detailed Housing Characteristics . United States

Summary . July 1972.

Haddon, William; Suchman, Edward A.; Klein, David. Accident Research:

Method and Approaches . New York: Harper fi Row, 1964.

NEISS News, Vol. 3(3). A Consumer Product Safety Commission Publication,

April 1975.

Pezoldt, V. J. ; Persensky, J.J.; and Peiser, P.C. "A human factors

evaluation of kitchen range accident data," November 1973 report

prepared for Fire Technology Division, National Bureau of Standards

(unpublished manuscript)

49

AI^P]".NniX

Parameters Delineating tlie Condition

of Space Heaters and Heating Stoves

Space heaters and heating stoves were judged to show "Poor Design"

if one or more of the following conditions were observed:

1. An open flame with no protective grill.

2. Materials ignited when near but not touching the heater.

3. The legs were unsteady, or the heater was unbalanced and

frequently tipped over.

4. A victim was burned by coming close to but not touching the

heater

5. Outside air currents could cause the flame size to change.

6. Guard rails became notably hot.

7. There was no safety switch on the pilot light to prevent

gas accumulation.

Units were judged to "Need Repair" if one or more of the conditions

listed below were met:

1. The wiring was worn.

2. Gas leaks were pronounced.

3. The protective glass covering the flames was broken.

4. The flue or internal pipes were disconnected.

Any other space heater or heating stove, which could not be described

by any of these characteristics, was assumed in "Satisfactory" condition.

USCOMM-NBS-DC 51
NBS-lUA (REV. 7-73)

U.S. OEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. I'l Ul.K A riON OR Rl-POR T NO.

NBSIR 75-969

2. (lov't Accession

No.

3. Recipient's Ari.< ssion No.

4. Ti 1 1.I-: AND Sinn ri i.i': ACCIDENTS INVOLVING SEVERAL SELECTED APPLIANCES:

SUMviARY AND DESCRIPTIVE ANALYSIS

5. I'uhl i( ill ion Diitc December 1975

6. I'crforming ( )rgiin i /iil ion ( ode

7. Airi llOK(S)

Mary E, Stefl, P. Clare Goodman, Ann M. Ramey, Fran D. Bents

8. Pt rlorming Orgiiii. Report No.

9. i'i:K I'ORMINCi ORGANIZATION NAMI-l AND ADDRliSS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Proieit /Task/Work Unit No. 4411421

11. ("ontract/Grant No.

12. Sponsoring Organization Namt- and Complete Addres.s (Street, City, State, ZIP)

Consumer Product Safety Commission

Washington, D.C. 20207

13. Type of Report & Period

(-overed

Final

14. Sponsoring Agency ('ode

15. .SUPPI.HMF.NTARY NOTES

16. .ABSTRACT (A 200-word or less (actual summary ol most significant information. If document includes a significant

bibliography or literature survey, mention it here.)

Accident data relating to home appliance products was examined from a human

factors viewpoint. The appliances studied ranked among the top 50 on the

Consumer Product Safety Commission's Hazard Index and included space heaters

and heating stoves, kitchen ranges, wringer washers, hot water heaters, and

irons. The intent to uncover general accident patterns which would relate product

hazards, human activity, and injuries across all appliance products was not

successful. Instead, a number of accident sequences specific to individual

appliances were observed and described. Due to the inherent bias in the "data

base, however, all results must be accepted with reservation. Recommendations

for future research and accident reduction were made.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons)

Accident; human factors; kitchen appliances; safety.

18. AVAILABILITY ^ Unlimited

For Official Distribution. Do Not Release to NTIS

I

' Order From Sup. of Doc, U.S. Government Printing Office Washington, D.C. 20402, SD Cat. No. CU

I

^ Order From National Technical Information Service (NTIS)

Springfield, Virginia 22151

19. SECURITY CLASS

(THIS REPORT)

UNCL ASSIFIED

21. NO. OF PAGES

56

20. SECURITY CLASS

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USCOMM.DC 29042-P74