ASTM C1055-99
(Guide)Standard Guide for Heated System Surface Conditions That Produce Contact Burn Injuries
Standard Guide for Heated System Surface Conditions That Produce Contact Burn Injuries
SCOPE
1.1 This guide establishes a process for the determination of acceptable surface operating conditions for heated systems. The human burn hazard is defined, and methods are presented for use in the design or evaluation of heated systems to prevent serious injury from contact with the exposed surfaces.
1.2 The maximum acceptable temperature for a particular surface is derived from an estimate of the possible or probable contact time, the surface system configuration, and the level of injury deemed acceptable for a particular situation.
1.3 For design purposes, the probable contact time for industrial situations has been established at 5 s. For consumer products, a longer (60-s) contact time has been proposed by Wu (1) and others to reflect the slower reaction times for children, the elderly, or the infirm.
1.4 The maximum level of injury recommended here is that causing first degree burns on the average subject. This type of injury is reversible and causes no permanent tissue damage. For cases where more severe conditions are mandated (by space, economic, exposure probability, or other outside considerations), this guide may be used to establish a second, less desirable injury level (second degree burns), where some permanent tissue damage can be permitted. At no time, however, are conditions that produce third degree burns recommended.
1.5 A bibliography of human burn evaluation studies and surface hazard measurement is provided in the list of references at the end of this guide (1-16).
1.6 This standard does not purport to address all the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to its use.
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Designation: C 1055 – 99
Standard Guide for
Heated System Surface Conditions
That Produce Contact Burn Injuries
This standard is issued under the fixed designation C 1055; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This guide establishes a process for the determination of 2.1 ASTM Standards:
acceptable surface operating conditions for heated systems. C 680 Practice for Determination of Heat Gain or Loss and
The human burn hazard is defined, and methods are presented the Surface Temperatures of Insulated Pipe and Equipment
for use in the design or evaluation of heated systems to prevent Systems by Use of a Computer Program
serious injury from contact with the exposed surfaces. C 1057 Practice for Determination of Skin Contact Tem-
1.2 Values stated in SI units are to be regarded as standard. perature from Heated Surfaces Using a Mathematical
1.3 The maximum acceptable temperature for a particular Model and the Thermesthesiometer
surface is derived from an estimate of the possible or probable
3. Terminology
contact time, the surface system configuration, and the level of
injury deemed acceptable for a particular situation. 3.1 Definitions of Terms Specific to This Standard: Descrip-
tions of Terms Specific to This Standard:
1.4 For design purposes, the probable contact time for
industrial situations has been established at 5 s. For consumer 3.1.1 skin:
3.1.2 epidermis—the outermost layer of skin cells. This
products, a longer (60-s) contact time has been proposed by
Wu (1) and others to reflect the slower reaction times for layer contains no vascular or nerve cells and acts to protect the
skin layers. The thickness of this layer averages 0.08 mm.
children, the elderly, or the infirm.
1.5 The maximum level of injury recommended here is that 3.1.3 dermis—the second layer of skin tissue. This layer
contains the blood vessels and nerve endings. The thickness of
causing first degree burns on the average subject. This type of
injury is reversible and causes no permanent tissue damage. this layer averages 2 mm.
3.1.4 necrosis—localized death of living cells. A clinical
For cases where more severe conditions are mandated (by
space, economic, exposure probability, or other outside con- term that defines when permanent damage to a skin layer has
occurred.
siderations), this guide may be used to establish a second, less
desirable injury level (second degree burns), where some 3.1.5 burns:
3.1.6 first degree burn—the reaction to an exposure where
permanent tissue damage can be permitted. At no time,
however, are conditions that produce third degree burns rec- the intensity or duration is insufficient to cause complete
ommended. necrosis of the epidermis. The normal response to this level of
exposure is dilation of the superficial blood vessels (reddening
1.6 A bibliography of human burn evaluation studies and
surface hazard measurement is provided in the list of refer- of the skin).
3.1.7 second degree burn—the reaction to an exposure
ences at the end of this guide (1-16).
1.7 This standard does not purport to address all the safety where the intensity and duration is sufficient to cause complete
necrosis of the epidermis but no significant damage to the
concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and dermis. The normal response to this exposure is blistering of
the epidermis.
health practices and determine the applicability of regulatory
limitations prior to its use. 3.1.8 third degree burn—the reaction to an exposure where
significant dermal necrosis occurs. Significant dermal necrosis
has been defined in the literature (3) as 75% destruction of the
This guide is under the jurisdiction of ASTM Committee C-16 on Thermal
dermis. The normal response to this exposure is open sores that
Insulation and is the direct responsibility of Subcommittee C16.24 on Health and
leave permanent scar tissue upon healing.
Safety Hazard Potentials.
Current edition approved March 10, 1999. Published May 1999. Originally
published as C 1055 – 86. Last previous edition C 1055 – 92.
The boldface numbers in parentheses refer to the list of references at the end of
this guide. Annual Book of ASTM Standards, Vol 04.06.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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C1055–99
3.1.9 contact exposure—the process by which the surface of 4.2.4 If the injury level exceeds that specified, further
skin makes intimate contact with a heated surface such that no analysis of the system is required using either the thermesthe-
insulating layer, film, moisture, etc., interferes with the rapid siometer (a direct method) or an additional calculation. Both
transfer of available energy. methods are described in Practice C 1057.
3.1.10 insulation system—the combination of an insulation 4.2.5 If after this additional analysis the system still exceeds
material or jacket, or both that forms a barrier to the rapid loss the injury level criterion, then the system is unacceptable for
of energy from a heated surface. The insulation system may the criterion specified and the design should be revised.
involve a broad range of types and configurations of materials.
5. Significance and Use
3.1.11 jacket—the protective barrier placed on the exposed
side of an insulation to protect the insulation from deterioration 5.1 Most heated apparatus in industrial, commercial, and
residential service are insulated, unless thermal insulation
or abuse. The jacket material can be made of paper, plastic,
metal, canvas cloth, or combinations of the above or similar would interfere with their function; for example, it is inappro-
priate to insulate the bottom surface of a flatiron. However,
materials.
3.1.12 thermesthesiometer—a probe device developed by surface temperatures of insulated equipment and appliances
may still be high enough to cause burns from contact exposure
Marzetta (13) that simulates the thermal physical response of
the human finger to contact with heated surfaces. under certain conditions.
5.2 This guide has been developed to standardize the
4. Summary of Guide determination of acceptable surface operating conditions for
heated systems. Current practice for this determination is
4.1 This guide establishes a means by which the engineer,
widely varied. The intent of this guide is to tie together the
designer, or operator can determine the acceptable surface
existing practices into a consensus standard based upon scien-
temperature of an existing system where skin contact may be
tific understanding of the thermal physics involved. Flexibility
made with a heated surface.
is retained within this guide for the designer, regulator, or
4.2 The process used in the analysis follows the outline
consumer to establish specific burn hazard criteria. Most
listed below:
generally, the regulated criterion will be the length of time of
4.2.1 The user must first establish the acceptable contact
contact exposure.
exposure time and the level of acceptable injury for the
5.3 It is beyond the scope of this guide to establish appro-
particular system in question.
priate contact times and acceptable levels of injury for particu-
4.2.2 Secondly, the user determines the maximum operating
lar situations, or determine what surface temperature is “safe.”
surface temperature. This determination is made either by
Clearly, quite different criteria may be justified for cases as
direct measurement (if possible) or by use of a calculation at
diverse as those involving infants and domestic appliances, and
design conditions using a method conforming to Practice
experienced adults and industrial equipment. In the first case,
C 680.
no more than first degree burns in 60 s might be desirable. In
4.2.3 Next, utilizing the contact time (4.2.1), the maximum
the second case, second degree burns in 5 s might be
surface temperature (4.2.2), and the graph, Fig. 1, the user
acceptable.
determines the potential injury level. If the operating point falls
below the injury level specified (4.2.1), then no further analysis
NOTE 1—An overview of the medical research leading to the develop-
is required. ment of this guide was presented at the ASTM Conference on Thermal
FIG. 1 Temperature-Time Relationship for Burns
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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C1055–99
Insulation, Materials and Systems on Dec. 7, 1984 (14).
6.3.2 The second step is to determine the temperature of the
system surface at the worst design condition by one of the
5.4 This guide is meant to serve only as an estimation of the
following methods.
exposure to which an average individual might be subjected.
6.3.2.1 Insert the system dimensions, material properties,
Unusual conditions of exposure, physical health variations, or
and operating conditions into an analysis technique conforming
nonstandard ambients all serve to modify the results.
to Practice C 680. This technique should be used during design
5.5 This guide is limited to contact exposure to heated
or where the system surface temperatures cannot be physically
surfaces only. It should be noted that conditions of personal
measured at worst case conditions.
exposure to periods of high ambient temperature or high
6.3.2.2 Direct contact thermometry (thermocouple or resis-
radiant fluxes may cause human injury with no direct contact.
tance device) or infrared, noncontact thermometry.
5.6 This guide is not intended to cover hazards for cold
temperature exposure, that is, refrigeration or cryogenic appli- NOTE 3—(1) Care should be used in attaching measurement devices on
hot systems since burns can result; and (2) Proper installation techniques
cations.
must be used with direct contact thermometry to prevent heat sinking of
5.7 The procedure found in this guide has been described in
the surface and obtaining incorrect temperature readings.
the literature as applicable to all heated surfaces. For extremely
6.4 In many situations, surface temperatures exceed the
high-temperature metallic surfaces (>70°C), damage occurs
almost instantaneously upon contact. range of applicability of this guide and thus the evaluation is
made through interpretation of the surface temperature data
6. Procedure and the system properties. The limiting conditions below
should first be examined to see if further analysis is required.
6.1 This procedure requires the user to make several deci-
6.4.1 If the surface temperature is below 44°C, no short
sions that are based upon the results obtained. Careful docu-
term (that is, less than 6 h) hazard exists and the remaining
mentation of the rationale for each decision and intermediate
sections can be ignored.
result is an important part of this evaluation process.
6.4.2 If the surface temperature exceeds 70°C and the
6.2 The first phase in the use of this guide is to establish the
surface is metallic, it may present a hazard regardless of
acceptable limits for contact exposure time and the acceptable
contact duration. Attempts should be made to lower the surface
level of injury for the system in question. Where no available
temperature below 70°C. Nonmetallic skins may be safe for
standards for these limits are prescribed, the following limits
limited exposure at temperatures above 70°C. In these cases, as
are recommended based upon a survey of the existing medical
with all cases between 44°C and 70°C, the analysis should be
literature.
completed.
6.2.1 Acceptable Contact Times:
6.5 With the measurement or estimation of surface tempera-
6.2.1.1 Industrial Process—5 s.
ture for the system in question, utilize the graph (Fig. 1) and
6.2.1.2 Consumer Items—60s.
check if the intersection of the operating surface temperature
6.2.2 Acceptable Injury Levels—The acceptable injury level
and the selected time of contact falls below the threshold
is that of first degree burns as defined in 3.1.6 and is the limit
temperature.
represented by the bottom curve in Fig. 1.
NOTE 4—The threshold temperature used will depend on the limits of
6.3 The next phase in the process is to establish the
acceptable burn chosen in 6.2.2. If the burn level is first degree, use
maximum operating surface temperature under worst case
threshold line B in Fig. 1. If second degree burns are acceptable, use
conditions. This evaluation may be made either by direct
threshold line A in Fig. 1.
measurement (but only at worst case conditions) or by using a
6.6 If the operating surface temperature and time are below
calculation approximation. The steps required for determining
the threshold (line B) curve, then the system meets the selected
the maximum surface temperature are as follows:
criteria.
6.3.1 The initial step is to establish the operating system
6.7 If, however, the point falls above the curve, the system
parameters. This step provides input information to the analy-
may meet the selected criterion only if certain combinations of
sis and may preclude any further work concerning burn hazard.
insulation or jacketing, or both, are used. Analysis procedures
The items that need to be identified and recorded are as
for the jacketing/insulation effects are outlined in Practice
follows:
C 1057. Two methods provided in Practice C 1057 are briefly
6.3.1.1 System Description—Shape, size, materials, includ-
described below.
ing jacket material, thickness, and surface emittance.
6.7.1 The calculation technique provided in Practice C 1057
6.3.1.2 Operation Conditions—Temperatures of heated sys-
uses system geometry, material properties, and temperature
tem, times of year, cycle, etc.
conditions to estimate the maximum contact temperature used
6.3.1.3 Ambient Conditions—Worst case design tempera-
in Fig. 1 when the heat capacity effects of the surface are to be
ture for burn hazards would be summer design dry bulb. Or, for
considered. Once this maximum contact temperature is deter-
inside conditions, the maximum expected room ambient air
mined, the user returns to steps 6.5-6.7 for the refined analysis.
temperature. Include the ambient air velocity, if known.
6.7.2 An alternative to calculation of the contact tempera-
ture is available for those systems
...
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