Reference Publications

NBSIR 75-791

NAT L INST. OF STAMl>^fe TE^«^

l!ob MM.Ms t :edural Options for

Modification of Architectural

Glass in Residences to Improve

Occupant Safety

S. Wayne Stiefel

Center for Consumer Product Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

December 1975

Final Report

Prepared for Bureau of Engineering Sciences

. np Consumer Product Safety Commission

>401 Westbard Avenue

100 Jethesda, Maryland 20207

.U56

75-791

1975

National Bureau of Standards

Library, £-01 Admin. Bldg.

NBSIR 75-791 OCT 2 5 1982

PROCEDURAL OPTIONS FOR n° h

MODIFICATION OF ARCHITECTURAL

GLASS IN RESIDENCES TO IMPROVE

OCCUPANT SAFETY no, 7 ST 74/

S. Wayne Stiefel

Center for Consumer Product Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

December 1975

Final

Prepared for Bureau of Engineering Sciences

Consumer Product Safety Commission

5401 Westbard Avenue

Bethesda, Maryland 20207

/ W \

\ apa s

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

James A. Baker, III, Under Secretary

Dr. Betsy Ancker-Johnson, Assistant Secretary for Science anal Technology

NATIONAL BUREAU OF STANDARDS. Ernest Ambler, Acting Director
i
Acknowledgment

The author wishes to thank Mrs. Ruth Warnock for

her assistance and patience in the preparation of this

manuscript

.

ii

SUMMARY

Background

The U.S. Consumer Product Safety Commission (CPSC) has the responsibility for developing and promulgating mandatory safety standards for

products which pose unreasonable risks of injury for consumers. One of

the first products selected for development of a safety standard under the

Consumer Product Safety Act of 1972 (CPSA) was architectural glass. The

prospects for regulation of many other residential unit component parts are wide open. Nevertheless, the initial impact of the adoption of a mandatory

standard for architectural glass would be rather limited. The limited

impact is largely due to the fact that people will continue to occupy

existing housing that will not be immediately subject to the new rule.

Thus some attention must be given to steps that might be taken to reduce

the risk to which these people are exposed.

Obj ective

The objectives of the project were to identify alternative retrofit

options intended to ameliorate the hazards associated with existing

installations of architectural glass, to evaluate the various options

from the standpoint of accident reduction and associated costs, and finally

to recommend, to CPSC, a set of feasible approaches to implement the most

promising retrofit options.

Analysis

Safety motivated modification of existing installations of architectural glass include the use of visual cues, barriers, replacement with

safety glazing material, and application of organic coatings. These

actions should be selectively applied to specific products based on their

ability to: (1) ameliorate the hazard conditions contributing to injury;

(2) perform effectively preventing the injury from being experienced, and

(3) introduce no new types of injury potential of any significance.

A set of modifications was developed for specific products by reviewing

in-depth accident reports and selecting modification concepts appropriate,

depending upon the predominant set of circumstances associated with injuries.

The architectural glass products for which retrofit approaches were

developed included eight NEISS categories: bathtub and shower enclosures,

prime windows, glass storm doors, glass panel (fixed window wall), storm

windows, jalousie glass doors, jalousied glass windows and glass doors

(not otherwise specified)

.

A benefit- cost analysis of modifications for these products based

upon averted injury medical costs yielded only one option which met the

conventional decision point of 1.0. This retrofit is the application of

decals to patio sliding glass doors, which is at the point of indifference

(benefit-cost very close to 1.0). Therefore, for a household which considers

itself as having a higher risk than average, the application of decals would

iii
be warranted. Also for higher risk households, the replacement of the

annealed glass lower panel of storm doors with hardboard might be con- sidered, since its benefit-cost ratio was 0.85. Additional analyses were

performed to determine the magnitude of other factors , e.g., averted injuries not treated in emergency rooms, allowances for "pain and suffering,"

and avoided lost time from work, which would be necessary to improve the

benefit-cost relationship sufficiently to justify recommendation of

additional modifications. It is unlikely that these other factors would

increase benefits sufficiently to justify additional modification options,

since it was shown that quadrupling the calculated benefits would not

achieve a 1.0 benefit-cost ratio.

Findings and Recommendation

The study found that in addition to the application of decals to

patio sliding glassdoors, and possibly the replacement of annealed glass

in the lower panel of storm doors with hardboard for high risk households,

consumers should be encouraged to correct improper operation of all architectural glass products and to store unused glass panels out of traffic.

For these recommendations the use of an informational and educational

approach by the CPSC stands out among the implementation alternatives

considered.

An informational campaign could bring to the public's attention the

hazards associated with storm doors and patio glass doors . A fact which

might be emphasized during any such campaign is, for both patio sliders

and storm doors, children are subjected to many more injuries than can be

accounted for by population alone. Such emphasis would bring the problem

to the attention of parents and alert them to the possibility that, although

they "respect" these products, their children may not have knowledge of the

hazard. The Commission should consider a dual approach to attempt implementation of safety modifications by consumers through both information dissemination and education efforts.

Any education effort must recognize that the problem involves alerting

children and adults to the proper approach for using architectural glass

products. Adults must be influenced to make the necessary safety modifications , and they must be given adequate information with which to make

products safer. In addition to efforts designed to educate the general

public, some effort is warranted to educate the editors of interior

design and home-oriented magazines. Articles illustrating attractive

decoration of patio sliders with decals could contribute toward consumer

acceptance of this idea.

iv
Contents

Page

Executive Summary iii

Abstract 1

1. Introduction 1

1.1. Project Background 1

1.2. Problem 2

1.3. Objectives and Scope of Project 3

1.4. Description of Report Contents 3

2. Architectural Glass Injury Data Analysis 4

2.1. NEISS Data and Analysis 4

2.2. Population of Annealed Architectural Glass Products 8

2.3. Relation of Injuries to Population of Products 8

3. Modification Options Suggested by Accident Pattern Review 12

3.1. Effectiveness of Safety Modifications in Reducing

Injuries 12

3.1.1. Amelioration of Hazard Pattern 12

3.1.2. Performance of Retrofit Alternatives 13

3.1.3. Potential Retrofit Injury Causation 16

3.2. Retrofits Developed from In-Depth Investigations 16

3.2.1. Bathtub and Shower Enclosures 16

3.2.2. Window and Window Glass Other Than Storm Windows. 17

3.2.3. Glass Storm Doors (Annealed Glass) 18

3.2.4. Glass Panel, Fixed (Window Walls) 19

3.2.5. Glass Panels, Sliding (Patio Doors) 19

3.2.6. Storm Windows 20

v
Contents (continued)

Page

3.2.7. Jalousie Glass Doors 20

3.2.8. Jalousie Glass Windows 20

3.2.9. Glass Doors, Not Otherwise Specified 21

4. Benefit-Cost Model 22

4.1. Benefit of Averted Medical Injury Costs 22

4.2. Cost Derivation for Retrofits 23

4.3. Computation of Benefits for Retrofits 24

4.4 Analysis of Benefit -Cost Derivation 28

4.5 Approaches for Encouraging

Architectural Glass Safety 31

5. Conclusions 32

Appendix A. Derivation of Population Estimates for

Annealed Glass Products A-l

Appendix B. Derivation of the Benefit Equation and

Computation of Averted Injury Medical Costs B-l

Appendix C. Implementation Approaches for Encouraging

Safety Modification of Hazardous Architectural

Glass Products C-l

vi
Tables

Page

Table 2.1.1. NEISS Matrix Report Injury Totals by Age Group,

Sex and Selected Injury Types (7/1/72-12/31/74) 5

2.1.2. Projection of NEISS Architectural Glass Data to All

Hospital Emergency Rooms for a One-Year Period 6

2.1.3. Percentages of Injuries for Each Architectural Glass

Product Across Age Groups 7

2.1.4. Relative Indices of the Ratios of NEISS Injury

Percentages Divided by the General Population Percent

s

for Each Architectural Glass Product by Age Group.... 9

2.2. Estimates of Annealed Glass Products 10

2.3. Estimated Annual Injuries in All Hospital Emergency

Rooms per Product for Architectural Glass Products ... 11

3.1.1. Use of Modification Concepts to Ameliorate Injury

Circumstances 14

4.2. Estimated Costs for Product Specific Retrofits 25

4.3.1. Data for Annealed Glass Products Required to Compute

Benefits 26

4.3.2. Calculated Averted Injury Medical Costs Attributable

to Product Retrofits. 27

4.4.1. Estimated Benefit-Cost Ratios for Product Specific

Retrofits 29

4.4.2. Additional Analysis for Product Specific Retrofits:

Multiplier of Benefit-Cost Value to Achieve 1.0

Benefit-Cost 30

B. Computation of Benefit Derived from Averted Medical

Injury Costs Using a 10 Percent Discount Rate over

a Fifty Year Period B-4

C. Potential Implementation Approaches for Safety

Modification of Architectural Glass Products C-2

vii

PROCEDURAL OPTIONS FOR MODIFICATION OF ARCHITECTURAL

GLASS IN RESIDENCES TO IMPROVE OCCUPANT SAFETY

S. Wayne Stiefel

The U.S. Consumer Product Safety Commission has the responsibility for developing and promulgating mandatory safety standards

for products which pose unreasonable risks of injury for consumers. One of the first products selected for development of a safety

standard under the Consumer Product Safety Act of 1972 was architectural glass. The prospects for regulation of many

other residential unit component parts are wide open. Nevertheless, the initial impact of the adoption of a mandatory standard

for architectural glass would be rather limited. The limited

impact is largely due to the fact that people will continue to

occupy existing housing that will not be immediately subject to

the new rule.

This report documents the second and final phase of a project

which considered the possible modifications for architectural

glass products and the means for encouraging their implementation.

The report evaluates available injury data, defines the population

of hazardous architectural glass products and compares the

relative level of hazard among the products. A set of possible

retrofit options is presented, suggested by accident pattern

review, and criteria are developed, which are useful in assessing

their effectiveness. A model has been developed and exercised

to calculate benefit-cost ratios for retrofit modification

based upon averted injury medical costs attributable to injuries

prevented by product modification. A set of implementation

approaches has been postulated for consideration by the CPSC,

for encouraging safety modifications of component parts of

residential units.

Key words: Architectural glass products; Consumer Product Safety

Act; residence-related products; residential safety modification;

safety implementation approaches.

1. INTRODUCTION

1.1. Project Background

The use of sliding glass doors by the building industry has been

increasing since their introduction in the 1940' s. The very appearance of

spaciousness created by glazing panels, which increase their demand as a building material, unfortunately contributes to the likelihood of unexpected

contact. The Consumer Product Safety Commission (CPSC) estimated that

in 1973, 180 thousand persons sought medical treatment in hospital

emergency rooms for injuries associated with architectural glass. 1

1 Based on a projection of the National Electronic Injury Surveillance System

statistics.
Previous surveys reveal additional factors associated with architectural

glass injuries. Glass doors and windows were involved in 25 percent of

all home fixture accidents, according to the 1969 survey by Teledyne

Brown Engineering. 2 A 1963 glass door survey, for the Public Health

Service, indicated that about three-quarters of the reported injuries

occurred in the home. Further analysis of the NEISS data (collected

from July 1972 to January 1974) indicates that 40 percent of injured

persons admitted to hospital emergency rooms are under fifteen years of

age (this age group accounts for 27 percent of the population) and

approximately 60 percent of persons admitted are males.

The CPSC effort to develop and promulgate a regulation for architectural glazing follows several significant attempts to establish a voluntary

standard for safety glazing, and to promote mandatory use of the ANSI

standard for architectural glazing at the state level. 3 This standard was

developed to approve safety glazing of various types and fail annealed

glass; it was modified and made more rigorous in 1972. Another recent

effort is that of the Consumer Safety Glazing Committee (formed in 1969

during the hearings of the National Commission on Product Safety and

consisting of representatives from glass manufacturers, fabricators and

representatives of affected unions) which developed a Model Bill to Require

Safety Glazing in Hazardous Locations . This bill, intended for enactment

by state legislatures, references ANSI Standard Z-97. 1-1972, and is applicable to "hazardous locations in residential, industrial, commercial and

public buildings." Albeit slow, progress is being made; as of May 1974,

32 states, representing 75 percent of the U.S. population, had adopted a mandatory code or law which incorporates ANSI Z-97. 1-1972. 4

1.2. Problem

The CPSC is now reviewing a proposed standard for architectural

glazing developed by the Consumer Safety Glazing Committee, under the

procedures of Section 7 of the Consumer Product Safety Act. The Commission

may promulgate a standard in the near future applicable to glazing

materials used in new or replacement architectural products, and

although this action is intended to decrease the incidence and severity

of injuries caused by architectural glazing, its initial impact will be

rather limited. This is largely due to the fact that people will

continue to occupy existing housing that will not be immediately subject

to the new rule.

2Teledyne Brown Engineering, A Design Guide for Home Safety , PB- 211 709,

January 1972.

3 The American National Standards Institute developed and published ANSI

Z-97.1, Performance Specifications and Methods of Test for Transparent

Safety Glazing Materials Used in Buildings" in 1966.

4 Sanford C. Adler and R. Tibbot, "Background Report on Architectural

Glass," NBS Interagency Communication, June 28, 1974, p. 20.

2
The National Commission on Product Safety recognized that product

safety standards for architectural glass products would not ameliorate the

hazards for existing homes. 5

"The glass door is a classic example of a product which will be

'misused.' As misuse is foreseeable and the danger avoidable,

the risk is unreasonable. The millions of panels of annealed

glass now in use, unfortunately, are an endemic menace which

grows yearly because, with age, annealed glass becomes weaker.

Even if new construction complies with such state or local

standards as now exist, the residual hazard in annealed glass

already installed will persist for many years."

Adler6 speculates that the initial effect of a CPSC architectural glass

standard may in fact increase injuries.

"If consumer expectations of safety glazing performance are applied

to older glazing materials, the number of glass related injuries

may increase. Individuals may treat existing glazing less

cautiously as they are more frequently exposed to safety glazing."

Therefore, efforts aimed at decreasing the incidence and severity of

injuries caused by architectural glass must address both the obvious and

obtuse hazards associated with glazing materials in existing residences.

Fortunately, there are retrofit options for annealed glass products

which will reduce both accident occurrence and injury severity once an accident occurs. These options have been available to consumers but have

achieved a very limited use. The Commission requires a set of alternative

actions which will result in increased public awareness of the architectural

glass problem, with a corresponding interest in taking appropriate

preventive measures.

1.3. Objectives and Scope of Project

The objectives of the project were to identify alternative retrofit

options intended to ameliorate the hazards associated with existing

installations of architectural glass, to evaluate the various options

from the standpoint of accident reduction and associated costs, and

finally to recommend, to CPSC, a set of feasible approaches to implement

the most promising retrofit options.

1.4. Description of Report Contents

This report documents the second and final phase of project work

and deals with each of the project objectives as described above. Section 1

of this report outlines the project's background and scope. Section 2 evaluates the injury data, defines the population of architectural

5 Final Report of the National Commission on Product Safety , June 1970, p. 13.

6Adler, op. cit., p. 164.

3
glass products, and compares the relative level of hazard among the products.

Section 3 presents retrofit options suggested by accident pattern review and

develops criteria useful in assessing effectiveness in reducing injuries.

Section 4 discusses a model for calculating a benefit -cost ratio for

retrofit modifications. Benefits are defined as potentially averted

injury medical costs attributable to injuries prevented by product

modifications. Section 5 identifies implementation approaches for

consideration by the CPSC, which are appropriate for encouraging safety

modifications of architectural glass products.

2. ARCHITECTURAL GLASS INJURY DATA ANALYSIS

2.1. NEISS Data and Analysis

The Commission's National Electronic Injury Surveillance System (NEISS) was the major source of data for the analyses which follow. Table 2.1.1.

summarizes data collected from July 1972 through December 1974 for the

following nine product categories of architectural glass: bathtub and

shower enclosures, window and window glass, glass storm doors, glass

panels (fixed), glass panels (sliding), storm windows, jalousie glass

doors, jalousie glass windows and glass doors (not otherwise specified).

It is obvious from the data that windows and window glass (prime

windows) products account for more than half of all the injuries related

to architectural glass (as reported by NEISS) . This product category

contributes to injuries at a rate of almost four times as much as the

next highest ranking product- -glass storm doors, and over five times as much as the third highest product category- -glass doors, not otherwise

specified.

Of course, the NEISS totals apply only to those emergency rooms participating in the surveillance program. The CPSC's Bureau of Epidemiology

has, by applying weighting factors to the various hospital emergency room

reports, made projections of total hospital emergency room cases. These

results are presented in Table 2.1.2.

Architectural glass product injury data was examined to determine

injury incidence by age and sex. Table 2.1.3 presents the percentages

of injuries associated with these nine products, broken down by the

indicated age groups. These age groupings are similar to those given

in the NEISS Matrix Report Summaries covering the 2 1/2 year period

July 1, 1972 to December 31, 1974. 7 The percentages in the body of

Table 2.1.3 were derived from these summaries and were used, in

conjunction with comparable statistics based upon the number of people

in the general population, to establish ratio indices for the different

age groups and products.

7 It was necessary to pool the lowest two age groups (0-2 and 2-4) to

match the available population data given at less than 5. 4
Table 2.1.1. NEISS Matrix Report Injury Totals by Age Group,

Sex and Selected Injury Types (7/1/72 - 12/31/74)

Age Group 0690 1 1815 2 1823 3 182414 1825 5 1826 6 1835 7 1836 8 1837 9 Sums %

0-2 12 239 81 13 33 20 0 3 43 444 2.11

2-4 48 775 509 47 74 91 13 19 254 1830 8.68

5-9 43 1276 811 75 99 143 26 37 442 2952 14.00

10-14 43 1643 587 87 112 166 19 55 412 3129 14.89

15-19 41 2304 368 93 98 156 11 49 354 3474 16.47

20-24 57 2046 233 66 68 147 15 41 261 2934 13.91

25-34 56 1956 329 86 82 201 11 30 297 3048 14.45

35-44 36 869 183 46 57 106 7 20 124 1448 6.87

AC C A XQJO joo 1 1 A 114 jy 97L 1 DO A lb lUo yyo 4 . 1 L 55-64 19 248 52 18 15 58 3 2 45 460 2.18

65+ 25 194 39 17 14 38 4 5 35 371 1.76

Unknown 0 10 0 0 0 0 0 0 0 10 0

Total N 418 12,145 3306 587 679 1192 113 276 2375 21091

Male 252 7873 1871 375 401 703 67 178 1427 13147 62.33

Female 166 4267 1433 212 278 489 45 98 947 7935 37.62

Not Stated 5 2 1 1 9

% each product 1.98 57.58 15.67 2.78 3.22 5.65 0.54 1.31 11.26

1 0690 Glass Bathtub § Shower End. 6

XO£.\J Storm Windows

2 1815 Windows § Window Glass 7 1835 Jalousie Glass Doors

3 1823 Glass Storm Door 8 1836 Jalousie Glass Windows

k 1824 Glass Panel, Fixed 9 1837 Glass Doors, NOS

5 1825 Glass Panel , Sliding

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Table 2.1.3. Percentages of Injuries for Each Architectural Glass

Product Across Age Groups

(NEISS Matrix Report Data: 7/1/72 - 12/31/74)

Age Proc uct Codes Percent of

Tnfjil Pnni i 1 a 1" i nn ^ 06091 1815z 1823* 18244 1825b 1826b 1835' 1836H 1837y

<5 14.35 8.35 17.85 10.22 15.76 9.31 11.50 7.97 12.51 8.42

5-9 10.29 10.51 24.53 12.78 14.58 12.00 23.01 13.41 18.61 9.87

10-14 10.29 13.53 17.76 14.82 16.49 13.93 16.81 19.93 17.35 10.26

15-19 9.81 18.97 11.13 15.84 14.43 13.09 9.73 17.75 14.91 9.45

20-24 13.64 16.85 7.05 11.24 10.01 12.33 13.27 14.86 10.99 7.93

25-34 13.40 16.11 9.95 14.65 12.08 16.86 9.73 10.87 12.51 12.23

35-44 8.61 7.16 5.54 7.84 8.39 8.89 6.19 7.25 5.22 11.38

45-54 9.09 4.82 3.45 6.64 3.98 5.54 3.54 5.43 4.55 11.39

55-64 4.55 2.04 1.57 3.07 2.21 4.87 2.65 .72 1.89 9.18

65+ 5.98 1.60 1.18 2.90 2.06 3.19 3.54 1.81 1.47 9.89

Male 60.29 64.85 56.63 63.88 59.06 58.98 59.82 64.49 60.11 48.66

Female 39.71 35.15 43.37 36.12 40.94 41.02 40.18 35.51 39.89 51.34

Total N 418 12,155 3,306 587 679 1,192 113 276 2,375 21,091

1 0690 Glass Bathtub § Shower End.

2 1815 Windows § Window Glass

3 1823 Glass Storm Door

' k 1824 Glass Panel, Fixed

5 1825 Glass Panel, Sliding

6 1826 Storm Windows

7 1835 Jalousie Glass Doors

8 1836 Jalousie Glass Windows

9 1837 Glass Doors, NOS

*U.S. Bureau of the Census, Census of Population 1970, General Social and

Economic Characteristics Final Report, PC(1)-CL, United States Summary,

Table 85.

7
The values in Table 2.1.4 were obtained by dividing the percent in

each cell of Table 2.1.3 by the percent of the corresponding age group.

The resultant quotients of these ratios provided a relative indication

of the relationship between the NEISS sample population and the general

population. For any given product and given age group, if the proportion

of injured people is the same as the proportion of people in that same age group for the general population, then the index will be 1.0. Values

larger than 1.0 indicate a higher proportion in the sample than in the

general population for the same group. Values less than 1.0 indicate the converse. The magnitude of the index denotes its relative seriousness.

A cursory examination of Table 2.1.4 reveals that, in general,

injuries involving architectural glass products tend to be more prevalent

among males and among people under 25 years of age.

2.2. Population of Annealed Architectural Glass Products

Since 1971 various states have implemented controls over the use

of annealed glass in "hazardous locations," including entrance and exit

doors, storm doors, and bathtub/shower enclosures. 8 Unfortunately

the ability to accurately estimate the number of products in use, and to

differentiate between annealed glass and tempered or other safety glazing

is difficult. The estimates which follow are documented in Appendix A

and have been principally based upon an analysis of the estimates made

by the Architectural Glass Project's Consumer Safety Glazing Committee

Economic and Environmental Subcommittee's Final Report of February, 1975.

The subcommittee's sources included Census Bureau reports on construction,

surveys performed for various industries and estimates from several trade

associations.

A ranking of the number of architectural products containing annealed

glass, in Table 2.2 places prime windows first, followed by storm windows,

entrance/exit doors, storm doors, patio sliding doors and finally bathtub

and shower enclosures. Estimates were not found for fixed glass panels,

jalousie glass doors or jalousie windows used in residential units.

2.3. Relation of Injuries to Population of Products

It has been pointed out that prime windows account for well over

half of the injuries sustained from architectural glass products. A

measure of injuries per product would provide an additional perspective

into the problem. Table 2.3 was derived from Table 2.2, Estimate of Annealed

Annealed Glass Products, and Table 2.1.5, Projection of NEISS Architectural

Glass Data to All Hospital Emergency Rooms. Table 2.3 includes only those

products which are predominately found in the home. Products for which

no population estimates were available were excluded. Bathtub and

shower enclosures have the highest value in terms of injuries per product,

8Approximately 80 percent of the U.S. population resides in states which

have adopted safety glazing legislations or made it a requirement in

mandatory state codes.

8
Table 2.1.4. Relative Indices of the Ratios of NEISS Injury Percentages

Divided by the General Population Percents for Each

Architectural Glass Product by Age Group

Age Product Codes

Group 06091 18152 18233 18244 1825 b 1826b 1835 7 18368 1837 9

<5 1.70 .99 2.12 1.21 1.87 1.11 1.37 .95 1.49

5-9 1.04 1.06 2.49 1.29 1.48 1.22 2.33 1.36 1.89

10-14 1.00 1.32 1.73 1.44 1.61 1.36 1.64 1.94 1.69

15-19 1.04 2.01 1.18 1.68 1.53 1.39 1.03 1.88 1.53

20-24 1.72 2.12 .89 1.42 1.26 1.55 1.67 1.87 1.39

25-34 1.10 1.32 .81 1.20 .99 1.38 .80 .89 1.02

35-44 .75 .63 .49 .69 .74 .78 .54 .64 .46

45-54 .80 .42 .30 .58 .35 .47 .31 .48 .40

55-64 .50 1.31 .17 .33 .24 .53 .29 .08 .20

65+ .60 .16 .12 .29 .21 .32 .36 .18 .15

Male 1.24 1.33 1.16 1.31 1.21 1.21 1.23 1.32 1.23

Female .77 .68 .84 .70 .80 .80 .78 .69 .73

1 0690 Glass Bathtub § Shower End.

2 1815 Windows § Window Glass

3 1823 Glass Storm Door

4 1824 Glass Panel, Fixed

5 1825 Glass Panel, Sliding

6 1826 Storm Windows

7 1835 Jalousie Glass Doors

8 1836 Jalousie Glass Windows

9 1837 Glass Doors, NOS

9
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•rH (/) r-1 00 CM to •H LO vO CM cn

rH i—rH LO

nj i—

CM rH o 00 vD rH

Tot (Mi rH

rH

tO

PH

t-> _V)

I—

tM, o o

rH to U MI—

En ia i i +-*

+-> u •H u rH k>

tO M-i s

o t/i O •H H

Jg t_, M •d O t/J CO /—

H

/—v fH .5

•H u J rH u> r—

CO V-/ r-i 1) 1§ r1 n rH O rH •H rH X o o +-> +-> 4-> Pr St CO Pa Si

10
Table 2.3. Estimated Annual Injuries in All Hospital Emergency Rooms

per Product for Architectural Glass Products

Bathtub/Shower

Enclosures

Prime Windows

Storm Doors

Glass Panels, Sliding

Patio Doors

Storm Windows

Total

Products

(Millions)

2.38

1,156

70.3

9.1

562

Estimated Annual Ratio of Injuries

Injuries

per Product

(xlOOO)

1.293*

0.080

0.485

0.594

0.020

per Product

with Bathtub/

Shower Enclosures

1.000

0.062

0.375

0.460

0.015

^Estimated Annual Total Injuries * Total Products (millions) , therefore,

3,077 * 2,380,000 = 0.001293.

11
more than twice that occurring for the next highest product,

patio sliding glass. The last column of Table 2.3 compares injuries per

product for each of the products with bathtub and shower enclosures.

Depending upon the objectives of the Commission, Table 2.3 serves

to illustrate that different emphasis would be placed upon efforts to

reduce injuries associated with these products. For example, if total

numbers of injuries were the basis for selection, then clearly prime

windows would be the major candidate. However, if the incidence of

injury per product was the criteria selected, bathtub/shower enclosures,

when compared to prime windows, account for about sixteen times as many

injuries per product.

3. MODIFICATION OPTIONS SUGGESTED BY ACCIDENT PATTERN REVIEW

3.1. Effectiveness of Safety Modifications in Reducing Injuries

A recommendation to utilize a specific safety retrofit for an architectural glass product would depend upon satisfying three basic

criteria for evaluating safety effectiveness:

(1) that the retrofit concept ameliorates the hazard pattern or circumstances responsible for injury or death;

(2) that the product after retrofit actually performs in a safer

manner (effectively preventing experienced injury patterns)

and

(3) that the retrofit, although preventing the type of injury

previously being experienced, does not introduce a significant

number of new types of injuries.

The modifications for architectural glass products can be grouped

into four categories:

(1) visual cues to call attention to the existence of the glass

thus reducing the risk of unexpected contact;

(2) coatings (painted on or applied films) which either strengthen

the glass or hold glass fragments together if breakage occurs;

(3) barriers such as screens or bars to restrict direct contact

with the glass; and

(4) replacement of annealed glass with safety glazing materials or non-glazing materials.

3.1.1. Amelioration of Hazard Pattern

The selection of the retrofit concept appropriate for an architectural glass product depends upon the predominant set of circumstances

associated with the injuries. For example, injuries resulting from a

slip or fall could probably not have been prevented through increased

glass visibility. Barriers to keep a person away from the glass surface

would probably prevent such injury, or at least result in a less severe

injury. Tempered glass would have a similar effect. Patio sliding doors or window walls, on the other hand, seem to provide accident circumstances

12
where in many circumstances additional visual cues alert the person

that the glass was present, thus averting injury.

Table 3.1.1 matches architectural glass products with appropriate

modification concepts. Where "yesM is indicated, the in-depth reports

provided a subjective basis to believe that the injury circumstances can

be modified by the retrofit classification to significantly lower the level

of injuries. The concept of changing the physical characteristics of the

glass product, so that it breaks at the higher energy levels and after

breaking presents a less hostile edge for cutting or penetrating, is

represented by both of the retrofit concepts of coatings and the replacement

with safety glazing. There seems to be general agreement that the concept

of safer break characteristics is the most effective measure in preventing

injuries. The architectural glass standard, under development, bases its

rationale upon this concept, and, as Table 3.1.1 indicates all architectural

glass products could effectively utilize these approaches. 9

The use of barriers would also be effective for all products except

storm windows or prime windows. The barriers would significantly interfere

with the windows' function either by reducing light transmitted or by

impairing operation.

Visual cues provide an appropriate preventive concept for fixed

glass panels, sliding patio doors and doors which are predominantly glass.

These products are involved in accident sequences in which often the injured

person does not perceive the product's presence.

3.1.2. Performance of Retrofit Alternatives

The ability to quickly perceive a glass barrier would reduce

injuries for products such as patio doors, fixed glass walls and

predominantly glass doors. Such visual cues can be provided by the

simple addition of decals at eye height for both adults and children.

More complex schemes could use optical effects such as lighting or possible

distortion of the glass only when the person is in motion. An evaluation

of what fraction of the injuries could be prevented by increased visibility was not possible from examining the NEISS data. In-depth reports

indicated that for those products mentioned, visibility was a factor in

several of the accident occurrences.

Barriers to prevent the transfer of a person's kinetic energy to

the architectural glass product appears to be an effective measure to

reduce injuries. The barriers, however, must be designed to account for

children as well as adults and must prevent circumstances where body parts

are diverted over or under a barrier into the glass. Again, no statistical

evidence is available to support the use of barriers.

9 See Section 1.1 of the proposed "Safety Standard for Glazing Materials

Used in Certain Architectural Products," January, 1975.

13
Table 3.1.1. Use of Modification Concepts to Ameliorate

Injury Circumstances

Architectural Glass Product

Visual

Cues Coatings* Barriers

Replace With

Safety Glazing

Bathtub/Shower Enclosures no yes yes yes

Window § Window Glass no yes no yes

Glass Storm Doors no yes yes yes

Glass Panels, Fixed yes yes yes yes

Glass Panels, Sliding

Patio Doors yes yes yes yes

Storm Windows no yes no yes

Jalousie Glass Doors no yes yes yes

Jalousie Glass Windows no yes yes yes

Glass Doors Not Otherwise

Specified yes yes yes yes

Doors with Some Vision Panel no yes yes yes

*Assuming coatings to provide additional strength to the glass when broken

do not allow penetration of the body part or if penetration occurs do

not cause more damage than annealed glass alone.

14
The use of safety glazing materials, such as tempering, imbedding

wire, organic coating, or lamination, as a replacement for annealed glass

would significantly reduce injuries.* 0 The effectiveness would of course depend upon the performance characteristics of the material selected; the

ability to withstand impact and resistance to shattering. These characteristics vary among safety glazing material. It is assumed that any

recommended replacement material would meet the standards established

for new installations being developed by CPSC for glazed architectural

products

.

Organic coatings applied over annealed glass have been used widely

to stop flying glass after explosions. More recently, claims have been

made that organic-coated glass has injury preventing safety properties

when persons impact the product. Organic glass is available with

coatings already applied to annealed glass, ready to cut to size and

install. Also, organic coatings are available in sheets of mylar which

can either be applied professionally or on a do-it-yourself basis and as paint-on plastic coatings. The application of either mylar films or paint-on plastics has particular appeal as a retrofit option since the

glass would probably not have to be removed from its frame.

However, very limited tests of mylar coatings performed at NBS

proved to be inconclusive. The coatings appeared to work well when it

remained adhered to the glass, but during some tests the coating separated

from the glass and did not hold the glass fragments in place. Other

tests indicated that in instances where a penetration does occur, there

is a likelihood that the jagged fragments held by the coating may entrap

the body member making extraction difficult or impossible without additional

injury. Some glass breaking tests using simulated arm and other tests

using a lead shot-filled punching bag impactor, showed that this phenomena

actually did occur.

Therefore, additional information is needed to assess the effective- ness of organic coatings. Investigations are required to establish:

(1) How much of an increase in breaking resistance is provided to

the glass (of several representative thicknesses)?

(2) What are the break patterns at energy levels just sufficient

to break the glass?

(3) What are the break patterns and entrapment characteristics

at increasing energy levels?

(4) What are the factors involved in "successfully" applying the

organic coatings? and

(5) How well do the coatings hold up under various types of

environmental conditions, both in performing their safety

function as well as optical degradation over time?

10U.S. Consumer Product Safety Commission, Bureau of Epidemiology, Hazard

Analysis Injuries Involving Architectural Glass , November, 1974, p. 1.

15
3.1.3. Potential Retrofit Injury Causation

In-depth investigations of accidents reported in NEISS have indicated

that the handling of annealed glass materials has caused injury. Therefore,

options incorporating replacement or coatings, which by their nature

require glass handling, are potential injury producers. The ability among

individuals to perform retrofits varies with their skill, background and

training, as well as the particular tasks involved in performing the

modification. The extent to which additional injuries might be produced

by safety modification was not assessed in this report.

A controlled experiment to monitor the performance of retrofit

tasks by individuals of varied skill levels may reveal a significant

potential for injury. Results from such experiments could lead to hints

for performing injury-free modifications or recommendation that only

qualified professionals perform certain modifications. In addition to

the production of injuries during safety related modification, injuries

of another mode are possible following product modification. For example,

tempered glass resists breakage and can absorb higher energy levels than

annealed glass. The individual who falls and strikes his head on tempered

glass will probably avoid lacerations but may sustain impact type injuries,

such as fractures, contusion or concussion.

There exists potential abuse which could result from a CPSC

recommendation to use a safety retrofit. Those retrofits which do not

reduce injury could cause consumers to (1) spend money needlessly, (2)

subject themselves to the hazard of installing an ineffective retrofit, or (3) install a product which could result in a more hazardous annealed

glass product following retrofit installation. To reduce the likelihood

of such occurrences the Commission could require that products which are intended to improve safety properties of annealed glass be required to

meet a set of standards established by the Commission.

3.2. Retrofits Developed from In-Depth Investigations

In-depth investigation reports provide insights into the sequence

of actions resulting in an injury. Although they do not facilitate a statistically valid explanation of all NEISS injuries, the in-depths do

report on the circumstances surrounding accidents and give information

necessary to take corrective action. The modification options which follow

were suggested by reviewing the in-depth reports and combining this

information with suggestions presented in the Teledyne Brown Engineering,

A Design Guide for Home Safety and a draft NBS report to the CPSC, Making

Your Doorways Safer . 1

In most cases only one of the suggested options

would be applied; however, in some circumstances several may be compatible.

3.2.1. Bathtub and Shower Enclosures

The NEISS data indicated that injuries sustained in bathtub

and shower enclosure accidents were more severe than injuries

C. Johnson and R. Wehrli, Making Your Doorways Safer , February 4, 1975.

16
sustained from other architectural glass products. The in-depth

reports indicated that most accidents occurred when a person slipped and

fell against the enclosure, breaking the glass. In many instances the

person received injury to many areas of the body. Table 2.1.4 indicated

that children under 5, and adults between 20 and 25 years old sustained

75 percent more injuries than would be predicted by population statistics

alone. Fifty-eight percent of all accidents occurred to persons under 25

(accounting for only 46 percent of the population) . The following options

are suggested:

(1) Replace all annealed glass with safety glazing.

(2) Paint on plastic coatings or apply adhesive mylar over the

annealed glass.

(3) Install secure grab bars and non-slip tread surfaces in and

around bathtub and shower.

(4) Replace annealed glass enclosure with a rod and shower

curtain.

3.2.2. Window and Window Glass Other Than Storm Windows

The Bureau of Epidemiology's publication Hazard Analysis - Injuries

Involving Architectural Glass , November 1974, listed a set of patterns

identified with window injuries; these were:

• loss of balance

• intentional contact with window by opening or closing window;

knocking or banging on windows

• contact with glass broken prior to accident, and

• accidents not involving broken glass

Table 2.1.4 indicates that persons 15 to 25 received twice as many

injuries as their frequency in the population would indicate.

The Consumer Safety Glazing Committee did an analysis which indicated that increasing the energy required to break glass would substantially reduce injury incidence. "As we understand the results of the study

(special in-depth study on windows and storm windows) the use of glazing

material, which can withstand a 5 ft. lb. impact would eliminate

approximately 50 percent of the injuries, and the use of glazing material

which can withstand an impact of 12 ft. lbs. or more would eliminate

approximately 75 percent of injuries associated with windows and storm

windows." 12

The following suggestions are intended to reduce accident occurrence,

both for injuries which involve contact with glass as well as accidents

not involving broken glass:

(1) Replace pitted, crazed or cracked glass with safety glazing

or double strength glass.

12Comments of A. J. Bartosic, Rohm and HAAS Company, Risk of Injury

Subcommittee, meeting, January 16, 1975.

17
(2) Correct any improper operation or installation;

- sticking

- need for more than usual force to open or close

- slamming shut

- loose or broken putty or moldings.

(3) Install lifting handles on bottom half of double-hung windows.

(4) Paint on plastic coating or apply adhesive mylar on annealed

surface

.

(5) Remove broken glass immediately from frame and dispose of

properly. Do not leave in or around house.

3.2.3. Glass Storm Doors (Annealed Glass)

In-depth investigations of glass storm door injuries indicated the

most common pattern of injury involved the opening or closing of the door. 1 Accidents involved either pushing on the glass or following too closely

behind another person and being struck by the door upon closing. Haste

was a predominant factor in this type of occurrence. A second pattern

involved loss of balance and tended to be more serious. Less common

events included slamming the door, knocking on the glass and contacting

glass that was already broken.

Referring to Table 2.1.3, it can be noted that about 60 percent of

the injuries involving storm doors concerned the lower 3 age groups, i.e.,

children under 15 years of age, who account for only 28 percent of the

general population. Children of this age typically run in and out of

residences frequently, or at least, more often than adults. Since most

storm doors are constructed with an upper and lower panel , it may be

reasonable to assume that most of the injury- causing breakages involve the

lower panel which is more easily contacted by children due to their smaller

height. Therefore, a substantial increase in safety may be expected if at

least the lower annealed glass panel was replaced with safety glazing or even plywood, hardboard or equivalent product. The preferred retrofit

would be to have safety glazing in the upper panel also. The likelihood

of bodily contact with storm doors (which are usually spring loaded and

many slam shut) suggests that the replacements for annealed glass just

mentioned would be much more desirable from a safety standpoint than

applying decals to annealed glass in these types of doors.

The following suggestions are applicable to storm doors:

(1) Replace annealed glass with safety glazing

(a) tempered glass

(b) acrylic plastic

(2) Correct any improper operation or installation of door

- sticking

- need for more than usual force to open or close

- slamming shut.

i 3 Bureau of Epidemiology, U.S. Consumer Product Safety Commission, Hazard

Analysis, Injuries Involving Architectural Glass , November, 1974, p. 15.

18
(3) Provide proper bedding for all glazing to avoid direct glass

to metal contact.

(4) Replace at least the lower half of a door with plywood, hardboard or equivalent product.

(5) Provide a structurally supported plate to cover an area of

glass on the door around the handle.

(6) Install metallic impact bars of grillwork over inside glass

to at least shoulder height (95 percentile man). Installation

to be hinged to permit easy cleaning of glass.

(7) Attach clear adhesive mylar to inside of glass.

3.2.4. Glass Panel, Fixed (Window Walls)

A finding of the in-depth reports was that "while sliding glass

door injuries usually occurred at home, those reported for fixed panels

usually happened in public buildings such as hotels, stores, or office

buildings."* 4

However, since window walls are present in residences the following

suggestions may be useful to those individuals having such fixed glass

panels.

(1) Replace all pitted, crazed or cracked glass panels with

safety glazing.

(2) Install impact bars or latticework to a height of at least

46 cm (18 inches) from the floor on the inside. This installation should be 5 to 8 cm (2 to 3 inches) from the glass

panel to permit access space for cleaning glass.

(3) Locate planters or furniture adjacent to fixed glass panels

to make accidental contact with them impossible or unlikely.

(4) Drape heavy curtains next to window walls, for a measure or protection when curtains are drawn closed.

(5) Paint on plastic coatings or apply adhesive mylar.

(6) Apply decals at appropriate eye levels for children and adults.

3.2.5 Glass Panels, Sliding (Patio Doors)

Patio door injuries occurred most often when the injured person

was unaware of the presence of the glass and ran or walked into the door.

The injuries resulted in many severe lacerations generally to the lower

leg, thigh or face. Examination of Table 2.1.4 indicates children and

young adults under 25 received many more injuries than could be accounted

for by population alone. The following suggestions provide for either

replacement, improved annealed glass break characteristics, physical

barriers or visual cues intended to reduce injury occurrence.

(1) Replace annealed slider with tempered glass.

(2) Correct any improper operation or installation of sliding

glass panels.

lt+ Ibid. , p. 30.

19
(3) Apply decals at appropriate eye heights for children and

adults

.

(4) Create an optical imperfection such that it causes a ripple

effect in glass when a person is moving, but not when standing

still.

(5) Install resilient impact bars at about mid-height of the door.

(6) Paint on plastic coatings or apply adhesive mylar.

(7) Replace pitted, crazed or cracked glass with safety glass.

3.2.6. Storm Windows

The hazard patterns for storm windows were similar to prime windows

except that additional patterns were found associated with installation or

removal of the glass and with the storage of unmounted glass. The age

groups most expected to handle various aspects of storm window maintenance,

from ages 14 through 34, received higher accident ratios (Table 2.1.4)

than other age groups. The following options for modification are applicable

to storm windows:

(1) Replace all pitted, crazed or cracked storm windows with safety

glazing.

(2) Correct any improper operation or installation of storm windows.

(3) Install proper bedding for all glass to avoid direct glass

to metal contact.

(4) Paint on plastic coatings or apply adhesive mylar.

(5) Store windows in areas out of traffic pattern.

3.2.7. Jalousie Glass Doors

Very little information is available for injuries associated with

jalousie glass doors. CPSC files included only two in-depth reports; one involved a non-glass injury and the other involved a cut caused by an edge

of glass which slipped from metal clamps. The following suggestions, although

not based upon any injury data, appear to be reasonable.

(1) Replace all pitted, crazed or cracked glass with safety glazing.

(2) Cover inside of glass louvers with grillwork. This installation

should be placed to allow operation of the louvers.

(3) Paint on plastic coatings.

(4) Correct any improper operation of door.

3.2.8. Jalousie Glass Windows

No in-depth information is available for jalousie glass windows.

A possible problem, similar to jalousie doors, is the edge of glass which

is exposed when the windows are opened. The following would possibly

reduce injuries associated with the product.

(1) Replace all pitted, crazed or cracked glass with safety glazing.

(2) Locate planters or furniture adjacent to fixed jalousie glass

windows to make accidental contact with them impossible or

unlikely.

20
(3) Drape heavy curtains next to jalousie glass windows for a measure of protection when curtains are drawn closed.

(4) For floor to ceiling windows, install impact bars and latticework to a height of at least 46 cm (18 inches) from the floor

on the inside. This installation should be far enough out

to permit operation of the louvers.

(5) Paint on plastic coatings.

3.2.9. Glass Doors, Not Otherwise Specified

Injury patterns reported for this category of data were similar

to those reported for storm doors, e.g, lost balance- -fell against door,

pushed on glass, slammed door, etc. These doors were primarily exterior

glass doors located in stores, schools, office buildings or homes.

The Bureau of Epidemiology has found that none of the glass door

categories "adequately described doors (primarily exterior doors) that

contain one or more small glass panels or doors that consist of a wood

or metal panel in the lower half and a glass panel in the upper half." 15

While Product Code 1805 is intended to include these doors, hospitals have

not been consistent in coding injuries attributable to such products

under category 1805. Therefore, surveillance data for these doors cannot

be considered reliable.

Although many of these doors are not located in the home, modifications which follow are intended to provide for safer exterior doors in

homes

.

(1) Replace glass with plywood, hardboard or equivalent product

(if visibility through door is not necessary)

.

(2) Replace all cracked, broken or pitted panes with safety

glass (laminated; tempered; plastic).

(3) If glass is near a handle" or push plate replace glass

with safety glass. (Making less harmful if broken.)

(4) Hang clear plastic vinyl (.010") over glass on outside and

batten down edge with wooden strips; hang cloth or place tie

curtains over glass on inside, attached top and bottom.

(Vinyl can also be battened on both sides.)

(5) Cover glass with grillwork on both sides using wood, masonite,

metal or wire mesh. Openings in grillwork should not be large

enough to put a fist or hand through. Installation should be

hinged or easily removable for clearing glass.

(6) Attach clear adhesive mylar to inside of glass.

(7) Paint plastic coating onto glass.

(8) Correct improper installation of the door if it sticks or

if slamming of door is necessary to close it; or install

checking device if door normally slams shut.

15 Ibid., pp. 6-7.

21
4. BENEFIT-COST MDDEL

The purpose of calculating a benefit -cost ratio for the retrofit

modifications is to determine whether proposed costs can be justified

considering present medical costs and other calculable costs for annealed

glass products. The model assumes, for analysis purposes only, that

retrofits are accomplished immediately, and therefore all projected

injuries which would have occurred are avoided. The results obtained

apply to the average product being modified; that is, an implicit assumption is made that all installations have an equal probability of being

involved in an injury causing accident. 16

A benefit-cost approach considers the costs of making modifications

to annealed glass products, and the benefits expected (the return expected

by virtue of injuries avoided because of the modification). In order to

obtain such information it is necessary to examine the circumstances or patterns of injuries, and to discover which modifications would be effective

in reducing injuries. The cost of such modifications must also be estimated.

A benefit-cost model for modification of existing architectural glass

products (annealed) follows:

4.1 Benefit of Averted Medical Injury Costs

Consider a modification which essentially elminates all injuries

attributable to a product. 17 The injuries averted would equal a projection of injuries expected over the entire life of the product.

The life of glass products is influenced by two major factors:

(1) Breakage - which may or may not cause injury, and

(2) House obsolescence - the house is either destroyed or renovated resulting in replacement of the product.

1

G

The data indicate that products used by high risk segments of the

population (i.e., children) appear to be involved in a greater proportion

of injuries. Therefore, when interpreting the results, families with

children should consider making changes for lower benefit-cost ratios

that households solely composed of adults.

17 It is recognized that annealed glass is not the sole contributing factor

in injuries for these products, and therefore the accuracy of this assumption depends upon the fraction of injuries attributable to other product

characteristics

.

Additionally, the assumption that retrofits are 100 percent effective

can not be valid and so modifications would not eliminate all injuries.

The assumption permits an analysis which results in an overestimation of

benefits, therefore low benefit-cost ratios resulting from analyses

using this assumption are beyond consideration.

22
The following equation (derivation given in Appendix B) was applied:

P = P (1 + rA - r - A) n

where P is the number of architectural glass products remaining in n year n after breakage and removal of obsolete housing,

and where P

q

= number of products at the start,

r = annual rate of product breakage, and

A = annual rate of removal of obsolete housing.

From this equation it is possible to predict the products remaining

in any year, once estimates are obtained for the initial number of products,

the rate of product breakage and the rate of housing obsolescence. The

total number of product related injuries over time can be estimated using

the above equation and assuming a proportional decrease in injuries as potentially hazardous products are removed or replaced.

The conversion of the number of injuries in any year to a monetary

value for medical costs can be accomplished based on an average medical

cost value per injury. Since these injuries may be occurring in any year

after the starting point of the analysis, the monetary value of medical

costs must be discounted 18 in order to compare these values with the costs

of retrofits. The net sum of avoided injury costs over the life time of

products approximates the benefit derived from modifying products at the

initiation of the analysis to prevent future injuries. The sum represents

avoided injury medical costs attributable to the expenditures made to make

products safer. The benefits can be divided by the total products at the

start (P ) to yield the benefits expected per product.

4.2 Cost Derivation for Retrofits

The cost side of the equation is derived from knowledge of the number

of products containing annealed glass and the approximate costs required to

modify each product. It was assumed, for compatibility with benefit

assumptions, that the entire population of products was modified, and

therefore future injuries due to annealed glass were totally avoided.

The cost equation is represented by:

TC = P CM

o where TC = total costs for product modification,

P

Q

= number of products at the start, and

CM = average modification cost per product.

18Discount rates are intended to permit the evaluation of alternative

investments with expenditures occurring at different points in time and

reflect the long term borrowing rate of investment capital.

23
The average modification costs of the retrofit options suggested in

Section 4.1 depend upon many variables, among which are the price of

necessary materials (e.g., tempered glass) and whether the services of

professionals are required to make the modifications. Because of price

differentials between retail establishments and the uncertainty associated

with who will perform the retrofit, it is not possible to associate a firm

cost to the retrofits. A rough estimate was obtained by sampling a few

retail establishments and ascertaining their charges for materials and

services associated with the proposed retrofits. These cost estimates

are shown in Table 4.2.

4.3 Computation of Benefits for Retrofits

Table 4.3.1 provides the data required to calculate the benefits of

retrofit (the potentially averted injury medical costs) . Estimates for

breakage rates for the various products as well as estimated average

medical costs came from the Consumer Safety Glazing Committee Economic

and Environmental Subcommittee's Final Report, February 7, 1975. 19

The averted injury costs computation used a 10 percent discount rate

and an assumed annual housing obsolescence rate of 1.0 percent. 20 > 21

Computations were carried out for a 50 year period. 22 The benefit computations assume that injury costs are based solely on the total estimated

hospital emergency visits and applies the average medical cost of treatment. Table 4.3.2 presents the results and permits consideration of the

expenditures per product for retrofits which are benefit-cost defensible

based upon averted medical costs.

Since the computation only considers medical costs of emergency room

cases, it does not include injuries treated elsewhere, an allowance for

pain and suffering, nor did it include lost time from work. Also ex- cluded from the computation are benefits derived from saving lives or preventing permanent physical impairments and associated retraining costs.

The computation does not attempt to project any changes in medical costs.

The averted injury medical costs in Table 4.3.2 are for an average product

modification without consideration of the household members.

19The committee derived its medical cost estimates from A Procedure for

Estimating the Costs of injuries Associated with Household Products . J. Wulff, National Commission on Product Safety, March 1970, and updated

the medical costs to October 1974 using the Consumer Price Index for

Urban Wage Earners and Clerical Workers, Medical Care - Series F.

20 The discount rate of 10 percent was chosen to conform to Office of

Management and Budget Circular No. A- 94, March 1972.

21 The Economic and Environmental Subcommittee used both a 1.0 percent and

a 0.6 percent rate of obsolete housing. The 1.0 percent rate assumption

agrees with the fraction of the total housing units removed from the inventory

from 1960 to 1970, according to the U.S. Census of Housing: 1970, Components

of Inventory Change , Final Report HC(4)-1, 1973.

22By the 50th year using a 10 percent discount rate only 0.23 percent of the

medical costs being incurred would be added to benefit totals, therefore, the

analysis was terminated at this point.

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27
The benefit calculation for each of the products under study assumed,

for the purpose of analysis, that the retrofits were 100 percent effective

in preventing injuries. As a retrofit's effectiveness is lowered the

benefit also is lowered. To the extent that additional behavioral and

engineering knowledge becomes available regarding effectiveness, the

benefit should be adjusted accordingly.

4.4. Analysis of Benefit-Cost Derivation

The benefit-cost ratio derived from the previous equations is equal

to the benefit (the discounted sum of expected injury medical costs)

divided by the total cost for product modification (TC) . The equations

can be modified to include additional information once available, such

as the fraction of injuries actually attributable to annealed glass or

the number of deaths. The benefit-cost values derived can be used to indicate if any of the proposed retrofits are within a reasonable range for

implementation consideration.

The benefit-cost ratios in Table 4.4.1 yield only two retrofit options

with ratios meeting or approaching 1.0. Generally a ratio of benefits to

costs of 1.0 is the lower bound of acceptable values for decisions. Therefore, those retrofit costs per product greatly exceeding the benefits per

product values must be justified on other grounds. If the conventional

benefit-cost decision point of 1.0 is selected to evaluate the results of

Table 4.4.1 only one of the product specific retrofit approaches met the

decision criterion. This retrofit is the application of decals to patio

sliding galss doors, which is at the point of indifference (benefit-cost

very close to 1.0). Therefore, for a household which considers itself as having a higher risk than average, the application of decals would be

warranted. The replacement of the lower panel of storm doors with hardboard might also be considered by high risk households, since its benefitcost ratio is 0.85.

The computations, however, include only those estimated benefits based

on potentially avoided injuries treated in hospital emergency rooms. The

magnitude of additional benefits relating to injuries not treated in

emergency rooms, allowances for "pain and suffering," avoided lost time

from work, saving lives or preventing permanent physical impairments and

associated retraining costs are not easily calculable. Additional analysis

may be performed to indicate what magnitude of benefits these other factors

would have to contribute to achieve the conventional benefit-cost decision

criterion of 1.0. Table 4.4.2 indicates that only one more retrofit option

approaches acceptability even after quadrupling the benefit values. This

retrofit, for bathtub and shower enclosures, involves replacement of the

annealed glass enclosure with a rod and curtain.

For the last retrofit approach in Table 4.4.1, correct improper

operation of the products, costs could not be estimated. Corrective maintenance, however, not only is important for safety reasons but can also

be supported on functional grounds. The recommendations that storm windows

and storm door glass not in use be stored out of traffic patterns and that

broken glass be appropriately disposed of are not easily quantified for

28
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30
benefit-cost calculations. Costs for proper storage and disposal would

depend upon individual's utility values. These computations were not

attempted. Costs estimates were not included! for impact bars which could

be used on bathtub enclosures, storm and patio doors, since standard

hardware was not found to be available.

For prime windows and storm windows the benefit -cost computations

indicate that the only actions appropriate are keeping them in good working

order, properly disposing of broken glass and storing unused panels out

of the way.

4.5 Approaches for Encouraging Architectural Glass Safety

One of the objectives of this project was to recommend feasible

approaches to implement the most promising retrofit options. The project

tasks were divided into two phases, which were carried out simultaneously,

the benefit-cost analysis and the development of approaches suitable

for encouraging safety modifications to architectural glass products in

residences. The study has resulted in a set of alternatives (Appendix C)

which are generally applicable to the implementation of safety oriented

modifications for products existing in the home. These approaches were

developed without the results from the benefit -cost analysis (due to the

parallel timing of these tasks) so they were subsequently reexamined.

Their applicability was reviewed with respect to the two modification

options suggested for patio sliding glass doors and storm doors, as well

as to the concepts of correcting improper product operation and storing

glass panels out of traffic.

A set of potential implementation approaches was selected which

could apply to improving the safety of architectural glass products now

in place in residences. 23 Review of these approaches, in view of the

findings of the benefit-cost analyses, led to the conclusion that it

would be appropriate for CPSC to undertake an informational and educational

approach. lh

An informational campaign would bring to the public's attention the

hazards associated with patio glass doors and storm doors. A fact to be

emphasized during any such campaign is, that for both of these products

,

children are subjected to many more injuries than can be accounted for

The implementation approaches were selected from the set of countermeasures developed during the first phase of this project and documented

in NBSIR 75-651, Procedural Options to Reduce the Risk of Injury from

Products Installed in Residences, June 1975.

2tfNo attempt has been made to develop an analysis of the cost associated

with information and education campaigns by the CPSC or their effective- ness for implementation purposes.

31
by population alone. Such emphasis would bring the problem to the

attention of parents and alert them to the possibility that, although

they "respect" these products, their children may not have knowledge of

product hazards. An education effort must recognize that the problem

involves alerting children and adults to the proper approach for using

architectural glass products. Adults must be influenced to make the

necessary safety modifications, and they must be given adequate information with which to make products safer. In addition to efforts

designed to educate the general public, some effort is warranted to

educate the editors of interior design and home decoration oriented

magazines. Articles illustrating attractive decoration of patio sliders

with decals could contribute toward consumer acceptance of this idea.

5. CONCLUSIONS

The analyses indicated that the only economically justifiable

options are the application of decals to patio sliding glass doors

and possibly the replacement of annealed glass in the lower panel of

storm doors with hardboard for households with higher than average

risk. Further, it is unlikely that the introduction of factors not

included in the analyses would increase benefits sufficiently to

justify consideration of additional options, since even quadrupling

the calculated benefits would fail to produce a favorable benefit-cost

ratio.

Informational and educational campaings by the CPSC were found the

most appropriate of the implementation approaches reviewed. The

potential implementation approaches were considered for their applicability

to the modification options suggested for patio sliding glass doors and

storm doors and to the correction of improper product operation and the

storage of glass panels out of traffic. The Commission should consider

a dual approach to implement safety modifications through both information

dissemination and educational activities. The purpose of the informational campaing would be to bring the hazards associated with architectural glass products to the public's attention. A factor to be emphasized

is the extent to which these accidents involve children. An educational

effort would involve: alerting children and adults to the proper methods

for using and storing architectural glass products, influencing adults

to take actions to make products safer, and providing information which

enables concerned individuals to make products safer.

32
APPENDIX A.

Derivation of Population Estimates for

Annealed Glass Products

The source of information providing the basis for determination of

the product populations was the Final Report of the Architectural Glass

Project's Consumer Safety Glazing Committee's Economic and Environmental

Subcommittee submitted to the CPSC in February, 1975. The subcommittee

compiled statistics and estimates from the U.S. Census Bureau's Structural

Characteristics of Housing and surveys performed for the National Association

of Home Builders, the Architectural Aluminum Manufacturers Association,

the Aluminum Extrusion Council, the National Woodwork Manufacturers

Association and the Consumer Safety Glazing Committee.

A.l. Bathtub Enclosures and Shower Doors

Basis for determination:

Total annealed glass used in bathtubs and showers = 3.62 million m

2 (39 million ft 2

)

Average area of glass panels = 1.22 m

2 (13.1 ft 2

)

Average panels per enclosure unit = 1.25

Analysis:

Number of panels = 3.62 million m

2 = 2.98 million

1.22 m

z /panel

Number of units = 2.98 million panels = 2.38 million

1.25 panels/unit

A. 2. Prime Windows

Basis for determination:

Total glazed area = 966,696,110 m

2 (10,405,430,000 ft 2

)

Single glazed = 878,269,140 m

2 (9,453,610,000 ft 2

)

Double glazed = 88,426,974 m

2 (951,820,000 ft 2

)

Total occupied housing units (1975) = 73,548,000

Analysis:

Assuming average window = 0.836 m

2 (9 ft 2

)

Total windows = 966,696,110 m

2 = 1156 million

.836 m

2 per window

A-1
A. 3. Storm Doors

Basis for determination:

1 and 2 family units

1 and 2 family units in 1970 = 52,235,000 units

2 doors per unit suited to storm doors

66 percent of doors installed prior to 1970 have storm doors

18 percent of new construction install storm doors

Cumulative total of U.S. population requiring safety glazing

by year 1970 to 1975 - see Table 2.1

New housing starts in 1971 = 1,217,000; 1972 = 1,383,000;

1973 = 1,191,000; 1974 = 700,000.

Apartments

Apartment units in 1970 = 13,392,000

Doors per unit suited to storm doors = 1

33 percent of doors suited have storm doors

New apartment units in 1971 = 868,000; 1972 = 995,000;

1972 = 867,000; 1974 = 700,000.

Analysis of Storm Doors Containing Annealed Glass

Year Total Units

Doors/

Unit

Storm Doors/

Door

fraction ot

Population

Not Requiring

Safety Glazing

Annealed Glass

Storm Doors

1 § 2 Family Units

1970 52,235,000 2.0 0.66 1.00 68,950,200

1971 1,217,000 2.0 0.18 0.79 346,600

1972 1.383,000 2.0 0.18 0.66 331,100

1973 1,191,000 2.0 • 0.18 0.31 132,900

1974 700,000 2.0 0.18 0.22 55,400

Total 69,816,200

Apartments

1970 13,392,000 1.0 0.33 1.00 4,419,360

1971 868,000 1.0 0.33 0.79 226,570

1972 995,000 1.0 0.33 0.66 218,350

1973 867,000 1.0 0.33 0.31 88,690

1974 700,000 1.0 0.33 0.22 50,820

Total 5,003,790

Adjustment to compensate for overestimation of apartment doors

suitable for storm doors and fraction of installed units x.l = 500,379

Total units = 69,816,200 + 500,379 = 70,316,579 or about 70 million units

A2
i

A. 4. Storm Windows

Basis for determination:

Single strength glass in use = 469,801,400 m

2 (5,056,900,000 ft 2

)

Analysis

Assuming average window area = 0.836 m

2 (9 ft 2

)

Total storm windows = 469.801,400 m

2 = 562 million

0.836 m per window

A. 5. Patio Sliding Doors

Basis for determination:

Total patio doors in existence

Total panels

Glazing area 57,793,125

Estimated annealed glazing area 39,732,973

Estimated tempered glazing area 17,874,545

Estimated annealed replaced

with tempered (8%) 3,178,585

Total existing annealed 36,554,151

Total existing tempered 21,053,167

Analysis:

Average area of patio door = 57,793,125 m

2 = 4.01 m

2 14,400,000 patio doors

Accounts for 2 panels per door plus a fraction which are double glazed.

Number of annealed doors = 36,554,151 m

2 4.01 m /patio door

= 9 million door systems

14,400,000

28,800,000

m

2 (622,080,000 ft 2

) m

2 (427,680,000 ft 2

) m

2 (192,400,000 ft 2

)

m

2

( 34,214,000 ft 2

) m

2 (393,465,600 ft 2

) m

2 (226,614,400 ft 2

)

A-3
A. 6. Entrance and Exit Doors with Glass

Basis for determination:

Total glazing material in use in residential doors = 21,422,391 m

2 (230,803,970 ft 2

) Mean value of glazing area all doors with glass = 0.279 m

2

(3 ft 2

) /door

Analysis

Number of residential doors with glass = 21,442,391 m

2 0.275 m2 /door

= 77 million doors

A. 7. Sidelites

Basis for determination:

One door in 45 is installed in a door frame with sidelites.

Analysis

Residential units with sidelites = 77 million doors = 1.7 million

45 doors/sidelite

A-4
APPENDIX B.

Derivation of the Benefit Equation and

Computation of Averted Injury Medical Costs

B.l. Derivation of the Benefit Equation

The net present value of medical injury costs averted by retrofit

of hazardous products can be calculated by prediction of the injuries,

which would have occurred over the life of the product without the

retrofit, and application of the associated medical cost for each injury.

The net present value computation discounts medical costs occurring in the

future and sums these costs over a fifty year period. The discount

factor permits the comparison of two alternatives: (1) doing nothing,

in which case injuries are expected to occur and accumulate medical costs

over the life of the product; and (2) retrofitting the product to make it

safe, thus avoiding all future injuries but immediately incurring the cost

of retrofit.

The net present value of medical injury costs may be represented by

the algebraic equation

50 . NPV = l P AI AMC d (1)

-i n n

v J n=l

where NPV is the net present value of medical injury costs, P^ is the

number of products remaining in year n, AI is the average annual injury

rate per product, AMC is the average medical cost per injury, and d is

the discount factor in year n. * . .

The derivation of P , the number of products remaining in year n,

depends upon several parameters which will be introduced and defined. The

products remaining at the end of any year depend upon the number of

products in the beginning of the year, the number of products which are broken (replaced with safety glazing), as well as those products which

are eliminated during the year when housing is removed from the inventory.

The products remaining after breakage the first year can be expressed as

Pi = Po (1-r) (2)

where P 0 is the total products initially and r is the annual rate of

removal of products due to breakage.** The removal of products resulting

from housing inventory reduction may be represented by

Pi = Pi Cl-X) (3)

*The computation of NPV of medical injury costs were summed over a fifty

year period. Although, because of discounting, approximately 96 percent

of the costs were incurred by the 25th year.

**The annual rate of removal ,of products due t© breakage (r) has been

treated as a constant over time, although glass is known to become gradually

weaker with age. This is not expected to introduce a significant error,

since the value of r is only an approximation.

B-1
where A is the annual rate of removal of products due to house obsolescence?

Using equation (2) in equation (3) yields

Pi = P0 (1-r) OX). (4)

Continuing to the end of the second year the products remaining after

breakage can be expresses as

P 2 = Pi (1-r) (5)

and after removal of products for house obsolescence

P2 = P\ Or) (1-X). (6)

Using equation (4) in equation (6) yields

P2 - Po (1-r) (1-X) (1-r) (1-X) (7)

or equation (7) may be rewritten as

P2 = P0 (1-r) 2 (1-X) 2

. (8)

During the third year products remaining after breakage and removal due

to house decay may be expressed as

P3 = P2 (1-r) (1-X) (9)

and using equation (8) in equation 9 yields

P 3 = P0 (1-r) 3 (1-X) 3

. (10)

The general form, therefore, is

P

n

= P0 (l-r)

n

(1-X)

n

v^*?SS

or equation (11) may be rewritten as

P

n

= P0 U+rA-r-X)

n

. (12)

Using equation (12) in equation (1) yields

50 n

NPV = Z P0 (1+rA-r-X) AI AMC d (13)

n=l n

and removing the constant terms from the summation

50

NPV = P 0 AI AMC Z (l+rA-r-X)

n

d . (14)

n=l n

*It is recognized the unlike glass, which has a constant rate of breakage over

time, houses probability of being removed from the inventory is not constant

and increases substantially after many years of existence. However, rather

than classify housing by differential removal rates, an average rate of re- moval was selected for simplicity of analysis from U.S. Census data over a ten year period.

B-2
The product P 0 AI, (the initial product times the annual injury rate

per product) equals the annual number of accidents occurring with the

initial population of products. This value may now be set equal to either

the annual number of injuries treated in emergency rooms based upon NEISS

estimates, or the total projected cases in the U.S. per year.

B.2. Computation of Benefits

Table 4.3.1 provides data for annealed glass architectural products

required to calculate benefits using equation (14). In addition, the

computations for all products used a housing obsolescence rate (A)

of 0. 01 and a discount rate (d) of 10 percent. The discount factor

(d ) can be derived from the discount rate (d)

.

n

(l+d) n

Table B presents the results of the benefit computation for bathtub and

shower enclosures, prime and storm windows, storm doors and patio sliding

doors

.

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APPENDIX C.

Implementation Approaches for Encouraging Safety Modification

of Hazardous Architectural Glass Products

This appendix will discuss implementation approaches which are appropriate to consider for encouraging the safety modification of

component parts of residences. Although the implementation approaches

are generally applicable to component parts of residences, the discussion

which follows is structured for application to architectural glass products.

It is intended that the implementation approaches, as discussed in this

appendix, be viewed as a spectrum of options available to the Commission.

The selection of an implementation approach or set of approaches to be

applied would depend upon the results of additional analyses for specific

products, which would consider factors such as retrofit effectiveness and

benefit -cost.

The first phase of work on this project identified, for products

installed in homes, the product history stages, institutional groups,

hazard sources and countermeasures available to the CPSC. 1 The

relationships among these four elements was structured for evaluating

alternative impacts. A review of the list of hazard sources enabled

identification of five hazard sources which correspond to hazard patterns

the in-depth reports indicate are involved with architectural glass

accidents. The five are: (1) improper materials, (2) faulty design,

(3) inadequate maintenance, (4) misuse, and (5) placement of product

such that interactions creates a hazard. Having identifed hazard sources

the document provides a matrix of countermeasure options available to the

Commission corresponding to each hazard source. 2 The scope of this phase

of the project, installed annealed glass architectural products, is much

narrower than the entire spectrum of products for which the matrix was

developed. Those countermeasure options which could apply to architectural

glass products are presented in Table 5.

The practical application of these ten countermeasures will now be

discussed. The discussion will concentrate on the factors which are relevant in considering their use for implementation of safety retrofits.

The ten countermeasures may be classified into three broad types of

activities the Commission may consider.

(1) Mandatory activities intended to fulfill the need to protect

the public through actions which set standards and either remove

or modify unsafe products as warranted by the conditions;

^tiefel, et al., Procedural Options to Reduce the Risk of Injury from

Products Installed in Residences , NBSIR 75-651, June 1975, p. 9.

2 Ibid., p. 22.

C-1
Table G. Potential Implementation Approaches for SafetyModification of Architectural Glass Products

Develop a product safety performance standard for retrofit materials;

Develop model laws, regulations and standards, and encourage

their uniform adoption by state and local governments;

Coordinate and cooperate with other Federal agencies;

Encourage or effect the development and implementation of more

effective maintenance and safety- oriented performance testing

programs

Improve information dissemination or education;

Require informative and truthful labeling of a product, having

safety hazards;

Require public notice of defect or failure to comply with product

safety rule, and/or require individual notice to purchasers pursuant

to Section 15(c) of the Act;

Recall and refund monies to owner;

On-site alteration (retrofiting) to remedy extant defects;

On-site replacement to remove extant defective products.
(2) Voluntary activities which are designed to encourage other

organizations and agencies to take appropriate action perhaps

leading to mandatory requirements by other agencies; and

(3) Information and education activities which are designed to bring

the problem to the public's attention and offer reasonable

approaches to improve safety.

C.l. Mandatory Implementation Approaches

The Commission will probably promulgate a standard for glazed architectural products in the immediate future. The standard will establish

the type of glazing materials to be allowed in the hazardous locations

this study addresses. In addition to establishing requirements for new

products, existing products which are subsequently broken must be replaced

with approved safety glazing materials. This requirement is in effect

in the 32 states which have adopted the previously mentioned Model Bill

to Require Safety Glazing in Hazardous Locations . Still to be addressed

is the question of whether to require the replacement of potentially

hazardous annealed glass products before they are broken or otherwise

made unsafe.

The Consumer Product Safety Act of 1972 broadly establishes the

circumstances for employing the countermeasures which would either require

repair, replacement or refund. A requirement to either repair a product,

replace it or refund the purchase price may be imposed in cases of

substantial product hazards. Section 15 (a) of the Act defines substantial

product hazard as "(1) a failure to comply with an applicable consumer

product safety rule which creates a substantial risk of injury to the public,

or (2) a product defect which (because of the pattern of defect, the number

of defective products distributed in commerce, the severity of the risk or otherwise) creates a substantial risk of injury to the public." The CPSC

would have to make a finding after a hearing that either condition (1) or (2) was supported, and the public interest would be best served by

ordering the manufacturer, distributor or retailer to take which ever action he elects (i.e., to repair, replace or refund the purchase of the

product)

.

The Commission may obtain a similar result (repair, replacement or

refund) through a court order by filing an action in U.S. District Court

under subsection 12(a) (2) of the Act against a manufacturer, distributor

or retailer, claiming and proving commerce of an "imminently hazardous"

consumer product. The Act defines this term as "a consumer product which

presents imminent and unreasonable risk of death, serious illness, or

severe personal injury."

Paralleling the development of a product safety standard for

architectural glazing materials is the question of appropriate action

for retrofit materials specifically designed to modify annealed glass

products. A retrofit's effectiveness in reducing injuries depends upon

a design which must:

C-3
(1) Ameliorate the present hazard conditions leading to an injury;

(2) Perform as expected; and

(3) Not introduce a significant number of injuries through a second

injury mode.

The Commission could consider setting standards for those products

which are specifically designed to modify annealed glass products and

thereby reduce an unreasonable risk of injury. In the case of painted- on plastics and mylar coatings, limited testing has produced inconsistent

results. More information is needed. This retrofit option may be

applied to nearly the entire set of architectural products at lower cost

than replacement with safety glazing materials. Therefore, if the

option is effective in making glass safer, it may prove to be a popular

choice by safety concious consumers.

Another mandatory option the CPSC could consider is the requirement

to label glazing materials. A labeling requirement for glazing materials

now being sold to the public would yield two immediate results. First

glazing materials not permitted for replacement, i.e., annealed glass

in storm doors, could be labeled to indicate appropriate use. This

would alert the consumer "do-it-yourselfer" to the hazard and would

probably keep him from violating the standard. Second, it would bring

to the public's attention the fact that they now have annealed glass in

locations prohibited by present requirements. Such information could

result in additional caution and possible replacements of or modifications

to hazardous products.

Problems of improper installation and injuries resulting from

installation might be ameliorated through mandatory labeling requirements.

For example, adequate labeling of safety retrofit materials for annealed

glass could provide information needed for safe and effective installation

of these products.

C. 2 . Voluntary Implementation Efforts

A voluntary implementation approach on the part of CPSC may result in

mandatory actions implemented by other agencies at the Federal, State and

local levels of government to impact the safety of existing housing. The

discussion to follow will, for each level of government, explain how the

CPSC can encourage implementation of safety retrofits for architectural

glass products.

C. 2.1. Local Government

Direct contact with each local government is impractical because of

the large number of municipalities in the United States which have the

authority to adopt and enforce building codes. 3 The local governments

3 Allen D. Manuel, Local Land and Building Regulation Research Report , No. 6,

National Commission on Urban Problems, 1968.

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however, rely upon several other organizations in the formulation of the codes

which they adopt. For example, five model building codes have been developed

through four organizations.

• Building Officials Conference of America (BOCA) - Basic Building Code

9 American Insurance Association (AIA) - National Building Code

9 Southern Building Code Congress (SBCC) - Southern Standard Building

Code

a International Conference of Building Officials (ICBO) - uniform

Building Code

• With the cooperation of all four of the above - One and Two Family

Dwelling Code

It is possible that by working with these organizations, annealed glass

retrofits for existing housing could be implemented.

Several communities in Michigan, for example, have legislation which

requires an inspection by building and safety departments prior to any sale

of one or two family dwelling units. If units failed to meet safety and

health standards, deficiencies would have to be corrected before the sale. 5 The significance of the approach was that it allowed an accelerated method

for increasing safety in existing housing. Use of this approach to implement

safer storm doors, would perhaps require that upon resale hazardous annealed

glass panels must be replaced with safety glazing or a non-glazed material.

Housing codes are another type of model code primarily related to the

occupancy requirements of buildings and their maintenance after construction.

Model housing codes are promulgated by the building code organizations.

Because the housing codes influence accepted maintenance practices and

acceptable safety levels, these codes may prove to be an excellent mechanism

for increasing architectural glass safety..

In addition to the model building code organizations, there are associations of public officials which may provide CPSC a forum for the

introduction of ideas to increase the safety of existing housing. Many of

these organizations provide advisory aids to local officials and are viewed as a source for obtaining expert advice and factual information on specific problems. Since research on current problems is an activity of

many of these organizations, the CPSC may provide inputs for their research

and publications. The publications of these associations include newsletters, bulletins, books, monographs, research papers, conference

^See Stiefel, W. , et al., op. cit . Appendix B.4 for a discussion of model

building related code groups, and Appendix B.8 for a discussion of local

government building code regulation.

5National Safety Council, "Technical Topics Concerning Home Safety,"

July 1975, p. 2.

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proceedings and regular and special reports. The following organizations

may be receptive to the Commission's ideas: 6

• American Public Health Association

• International City Management Association

9 National Association of Counties

9 National Association of Housing and Redevelopment Officials

• National League of Cities

» National Municipal League

• U.S. Conference of Mayors

C.2.2. State Government

Like local government, state governments rely upon model building

and housing codes in formulating their housing requirements. 7 In addition,

the National Conference of States on Building Codes and Standards is a forum

for the discussion of mutual problems and the promotion of uniformity

throughout the states in building codes and their enforcement. The

organization offers a point of contact with state government employees with

building regulation responsibilities.

The CPSC's own State Conference on Product Safety offers the

opportunity to make recommendations on a formal (model laws regulations

and standards) or informal (idea provoking presentation) basis to encourage

positive actions at the state level. Additional organizations, composed of

state officials with the responsibility for legislation or administration

impacting existing housing, include the Council of State Governments, the

National Legislative Conference and the National Governor's Conference.

C.2.3. Federal Government

Federal agencies influence housing safety both directly and indirectly. 8 Direct influence is made over Federal public housing projects

administered through HUD as well as housing provided to government employees,

such as military housing. Direct contacts by the CPSC explaining the

nature of the hazard and potential solutions could have an immediate impact.

This type of housing, however, accounts for a very minor segment of U.S.

housing market.

6The list was obtained from reviewing the International City Management

Association's Municipal Year Book 1973 , "Professional and Service Organizations

Serving Local and State Governments,' '"pp. 356-359.

7 See Stiefel, W. , et al., op. cit. Appendix B.7 for a discussion of state

building code enforcement.

8 See Stiefel, W. , ibid., Appendix B, p. B-18 for a discussion of Federal

agencies which deal with building codes and related construction matters.

C-6
The indirect controls have a much wider influence over the private

housing market. The Veterans Administration (VA) acts as a "guarantor"

of mortgages let to veterans. All homes financed under VA guarantee must

meet certain minimum standards, as set by that agency, and compliance is

accomplished through a staff of Federal inspectors. Modifying these

standards to include replacement of annealed bathtub enclosures and storm

door glass, requiring visual cues for patio sliders and window walls,

and proper operation of glazed doors and windows would contribute to a safer house, and is within the VA's prerogative.

The Federal Housing Administration (FHA) offers mortgage insurance

for residences which meet "minimum standards (which) ... assure well planned,

safe, and soundly constructed homes." 9 These standards, which are updated

annually, are based upon current literature and past history. The VA

relies heavily upon the FHA standards in formulating their own standards.

Incorporation of requirements for existing architectural glazed products

could accelerate the process of retrofitting or removing unsafe products

from the home.

The Department of Health, Education, and Welfare's Public Health

Service provides technical assistance in housing quality improvement, code

administration and the training of state and (on an ad hoc basis) local

agencies. Working through the Public Health Service's contacts with the

various health agencies may expedite the process for influencing introduction of safety requirements for existing architectural glazing into housing

codes and standards.

C.3. Informational Implementation Approaches

The purpose of an information compaign is to bring to the public's

attention the hazards associated with architectural glass products. A

fact which might be emphasized during any such campaign is the proportion

of accidents which involve children. Such emphasis would catch the

attention of parents and alert them to the possibility that although

they "respect" a product, such as a storm door, their children may have no

knowledge of its hazard. The Commission could consider a dual approach to

attempt implementation of safety modifications through both information

dissemination and education efforts.

Any education effort must recognize that the problem involves:

alerting children and adults of the proper approach for using architectural glass products; influencing adults that they should take actions to

make products safer; and providing information which enables concerned

individuals to make products safer.

9 Preface to FHA Minimum Property Standards for Multifamily Housing.

C-7
Specific product related retrofits which are candidates for inclusion

in a public information campaign:

(1) Bathtub and shower enclosures

- replacement of annealed glass with rod and shower curtain

- use of non-slip appliques and secured grab bars

(2) Storm doors

- replacement of glass with safety glazing

- replacement of glass with hardboard in lower panel

coupled with a plate covering glass around handle

(3) Patio sliding doors

- use of visual cues such as decals, appliques and lighting

(4) All products

- keep in good working order

- immediately and properly dispose of broken glass, and

- store unused glass panels (storm windows and doors) out of

traffic.

In addition to efforts designed to educate the general public, some effort is warranted to educate editors of interior design and home oriented

magazines regarding the safety of architectural glass. Consumers tend to

emulate the ideas presented in these magazines. The editors, for example,

may be influencial in encouraging consumer use of shower curtains replacing

the older annealed glass tub enclosure. Articles illustrating attractive

decoration of patio sliders with decals could also contribute toward consumer

acceptance of this idea.

USCOMM-NBS-DC

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NBS-1 14A (REV. 7-73)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO.

NBSIR 75-791

2. Gov't Accession

No.

3. Recipient's Accession No.

4. TITLE AND SUBTITLE

PROCEDURAL OPTIONS FOR MODIFICATION OF ARCHITECTURAL

r"T ACC TM DPCTTYPMr'PC: Tn TMDPn\/"P fYVI IDANT QATTPTV (jLAoo 1IN KnolDElNLIlO 1U JJurKUVXl UL.L.U r/VN I af\r£H I

5. Publication Date

6. Performing Organization Code

7. AUTHOR(S) 8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 4411431

11. Contract/Grant No.

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

Bureau of Engineering Sciences

Consumer Product Safety Commission

5401 Westbard Avenue

Bethesda, Maryland 20207

13. Type of Report & Period Covered

Final

14. Sponsoring Agency Code

I 15. SUPPLEMENTARY NOTES

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

bibliography or literature survey, mention it here.)

The U.S. Consumer Product Safety Commission has the responsibility for developing and

promulgating mandatory safety standards for products which pose unreasonable risks of

injury for consumers. One of the first products selected for development of a safety

standard under the Consumer Product Safety Act of 1972 was architectural glass. The

prospects for regulation of many other residential unit component parts are wide open.

Nevertheless, the initial impact of the adoption of a mandatory standard for architectural

glass would be rather limited. The limited impact is largely due to the fact that

people will continue to occupy existing housing that will not be immediately subject to

the new rule.

This report documents the second and final phase of a project which considered the

possible modifications for architectural glass products and the means for encouraging

their implementation. The report evaluates available injury data, defines the populatioji

of hazardous architectural glass products and compares the relative level of hazard

among the products. A set of possible retrofit options is presented, suggested by

accident pattern review, and criteria are developed, which are useful in assessing their

effectiveness. A model has been developed and exercised to calculate benefit -cost

ratios for retrofit modification based upon averted injury medical costs attributable

to injuries prevented by product modification. A set of implementation approaches has

been postulated for consideration by the CPSC, for encouraging safety modification of

component parts of residential units.

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

)

Architectural glass products; Consumer Product Safety Act; residence -related products;

residential safety modification; safety implementation approaches.

18. AVAILABILITY [X Unlimited

|

' For Official Dis tribution. Do Not Release to NTIS

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

I 30 Order From National Technical Information Service (NTIS)

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