1、Designation: C 1055 03Standard Guide forHeated System Surface Conditions that Produce ContactBurn Injuries1This standard is issued under the fixed designation C 1055; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers a process for the determination ofacceptable surface operating conditions for heated systems.The human
3、burn hazard is defined, and methods are presentedfor use in the design or evaluation of heated systems to preventserious injury from contact with the exposed surfaces.1.2 Values stated in SI units are to be regarded as standard.1.3 The maximum acceptable temperature for a particularsurface is derive
4、d from an estimate of the possible or probablecontact time, the surface system configuration, and the level ofinjury deemed acceptable for a particular situation.1.4 For design purposes, the probable contact time forindustrial situations has been established at 5 s. For consumerproducts, a longer (6
5、0-s) contact time has been proposed byWu (1)2and others to reflect the slower reaction times forchildren, the elderly, or the infirm.1.5 The maximum level of injury recommended here is thatcausing first degree burns on the average subject. This type ofinjury is reversible and causes no permanent tis
6、sue damage.For cases where more severe conditions are mandated (byspace, economic, exposure probability, or other outside con-siderations), this guide may be used to establish a second, lessdesirable injury level (second degree burns), where somepermanent tissue damage can be permitted. At no time,h
7、owever, are conditions that produce third degree burns rec-ommended.1.6 This guide addresses the skin contact temperature de-termination for passive heated surfaces only. The guidelinescontained herein are not applicable to chemical, electrical, orother similar hazards that provide a heat generation
8、 source atthe location of contact.1.7 A bibliography of human burn evaluation studies andsurface hazard measurement is provided in the list of refer-ences at the end of this guide (1-16).1.8 This standard does not purport to address all the safetyconcerns, if any, associated with its use. It is the
9、responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to its use.2. Referenced Documents2.1 ASTM Standards:3C 680 Practice for Estimate of the Heat Gain or Loss andthe Surface Temperatures of Insu
10、lated Flat, Cylindrical,and Spherical Systems by Use of Computer ProgramsC 1057 Practice for Determination of Skin Contact Tem-perature from Heated Surfaces Using a MathematicalModel and Thermesthesiometer3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 skin:3.1.2 epidermisthe
11、outermost layer of skin cells. Thislayer contains no vascular or nerve cells and acts to protect theskin layers. The thickness of this layer averages 0.08 mm.3.1.3 dermisthe second layer of skin tissue. This layercontains the blood vessels and nerve endings. The thickness ofthis layer averages 2 mm.
12、3.1.4 necrosislocalized death of living cells. A clinicalterm that defines when permanent damage to a skin layer hasoccurred.3.1.5 burns:3.1.6 first degree burnthe reaction to an exposure wherethe intensity or duration is insufficient to cause completenecrosis of the epidermis. The normal response t
13、o this level ofexposure is dilation of the superficial blood vessels (reddeningof the skin).3.1.7 second degree burnthe reaction to an exposurewhere the intensity and duration is sufficient to cause completenecrosis of the epidermis but no significant damage to thedermis. The normal response to this
14、 exposure is blistering ofthe epidermis.3.1.8 third degree burnthe reaction to an exposure wheresignificant dermal necrosis occurs. Significant dermal necrosis1This guide is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on I
15、nsulationSystems.Current edition approved Oct. 1, 2003. Published October 2003. Originallyapproved in 1986. Last previous edition approved in 1999 as C 105599.2The boldface numbers in parentheses refer to the list of references at the end ofthis guide.3For referenced ASTM standards, visit the ASTM w
16、ebsite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United S
17、tates.has been defined in the literature (3) as 75% destruction of thedermis. The normal response to this exposure is open sores thatleave permanent scar tissue upon healing.3.1.9 contact exposurethe process by which the surface ofskin makes intimate contact with a heated surface such that noinsulat
18、ing layer, film, moisture, etc., interferes with the rapidtransfer of available energy.3.1.10 insulation systemthe combination of an insulationmaterial or jacket, or both that forms a barrier to the rapid lossof energy from a heated surface. The insulation system mayinvolve a broad range of types an
19、d configurations of materials.3.1.11 jacketthe protective barrier placed on the exposedside of an insulation to protect the insulation from deteriorationor abuse. The jacket material can be made of paper, plastic,metal, canvas cloth, or combinations of the above or similarmaterials.3.1.12 thermesthe
20、siometera probe device developed byMarzetta (13) that simulates the thermal physical response ofthe human finger to contact with heated surfaces.4. Summary of Guide4.1 This guide establishes a means by which the engineer,designer, or operator can determine the acceptable surfacetemperature of an exi
21、sting system where skin contact may bemade with a heated surface.4.2 The process used in the analysis follows the outlinelisted below:4.2.1 The user must first establish the acceptable contactexposure time and the level of acceptable injury for theparticular system in question.4.2.2 Secondly, the us
22、er determines the maximum operatingsurface temperature. This determination is made either bydirect measurement (if possible) or by use of a calculation atdesign conditions using a method conforming to PracticeC 680.4.2.3 Next, utilizing the contact time (4.2.1), the maximumsurface temperature (4.2.2
23、), and the graph, Fig. 1, the userdetermines the potential injury level. If the operating point fallsbelow the injury level specified (4.2.1), then no further analysisis required. (See Note 1.)NOTE 1The following equations have been developed from theoriginal data used to generate Fig. 1 for easier
24、use of this figure.TA5 15.005 1 0.51907 3 Ln time 3 1000! 1 352.97/Ln time3 1000! (1)TB5 39.468 0.41352 3 Ln time 3 1000! 1 190.60/Ln time3 1000! (2)where:TA= critical contact temperature for complete transepidermal ne-crosis, C.TB= critical contact temperature for reversible epidermal injury,C.time
25、 = elapsed contact time, s.Ln = natural logarithm.4.2.4 If the injury level exceeds that specified, furtheranalysis of the system is required using either the thermesthe-siometer (a direct method) or an additional calculation. Bothmethods are described in Practice C 1057.4.2.5 If after this addition
26、al analysis the system still exceedsthe injury level criterion, then the system is unacceptable forthe criterion specified and the design should be revised.5. Significance and Use5.1 Most heated apparatus in industrial, commercial, andresidential service are insulated, unless thermal insulationwould
27、 interfere with their function; for example, it is inappro-priate to insulate the bottom surface of a flatiron. However,surface temperatures of insulated equipment and appliancesmay still be high enough to cause burns from contact exposureunder certain conditions.5.2 This guide has been developed to
28、 standardize thedetermination of acceptable surface operating conditions forheated systems. Current practice for this determination iswidely varied. The intent of this guide is to tie together theexisting practices into a consensus standard based upon scien-tific understanding of the thermal physics
29、 involved. FlexibilityFIG. 1 Temperature-Time Relationship for BurnsC1055032is retained within this guide for the designer, regulator, orconsumer to establish specific burn hazard criteria. Mostgenerally, the regulated criterion will be the length of time ofcontact exposure.5.3 It is beyond the scop
30、e of this guide to establish appro-priate contact times and acceptable levels of injury for particu-lar situations, or determine what surface temperature is “safe.”Clearly, quite different criteria may be justified for cases asdiverse as those involving infants and domestic appliances, andexperience
31、d adults and industrial equipment. In the first case,no more than first degree burns in 60 s might be desirable. Inthe second case, second degree burns in 5 s might beacceptable.NOTE 2An overview of the medical research leading to the develop-ment of this guide was presented at the ASTM Conference o
32、n ThermalInsulation, Materials and Systems on Dec. 7, 1984 (14).5.4 This guide is meant to serve only as an estimation of theexposure to which an average individual might be subjected.Unusual conditions of exposure, physical health variations, ornonstandard ambients all serve to modify the results.5
33、.5 This guide is limited to contact exposure to heatedsurfaces only. It should be noted that conditions of personalexposure to periods of high ambient temperature or highradiant fluxes may cause human injury with no direct contact.5.6 This guide is not intended to cover hazards for coldtemperature e
34、xposure, that is, refrigeration or cryogenic appli-cations.5.7 The procedure found in this guide has been described inthe literature as applicable to all heated surfaces. For extremelyhigh-temperature metallic surfaces (70C), damage occursalmost instantaneously upon contact.6. Procedure6.1 This proc
35、edure requires the user to make several deci-sions that are based upon the results obtained. Careful docu-mentation of the rationale for each decision and intermediateresult is an important part of this evaluation process.6.2 The first phase in the use of this guide is to establish theacceptable lim
36、its for contact exposure time and the acceptablelevel of injury for the system in question. Where no availablestandards for these limits are prescribed, the following limitsare recommended based upon a survey of the existing medicalliterature.6.2.1 Acceptable Contact Times:6.2.1.1 Industrial Process
37、5 s.6.2.1.2 Consumer Items60s.6.2.2 Acceptable Injury LevelsThe acceptable injury levelis that of first degree burns as defined in 3.1.6 and is the limitrepresented by the bottom curve in Fig. 1.6.3 The next phase in the process is to establish themaximum operating surface temperature under worst ca
38、seconditions. This evaluation may be made either by directmeasurement (but only at worst case conditions) or by using acalculation approximation. The steps required for determiningthe maximum surface temperature are as follows:6.3.1 The initial step is to establish the operating systemparameters. Th
39、is step provides input information to the analy-sis and may preclude any further work concerning burn hazard.The items that need to be identified and recorded are asfollows:6.3.1.1 System DescriptionShape, size, materials, includ-ing jacket material, thickness, and surface emittance.6.3.1.2 Operatio
40、n ConditionsTemperatures of heated sys-tem, times of year, cycle, etc.6.3.1.3 Ambient ConditionsWorst case design tempera-ture for burn hazards would be summer design dry bulb. Or, forinside conditions, the maximum expected room ambient airtemperature. Include the ambient air velocity, if known.NOTE
41、 3Design conditions for burn hazard evaluation may be differentfrom those used for heat loss analysis. For example, the highest ambientis used for burn hazard analysis versus the lowest for heat loss.6.3.2 The second step is to determine the temperature of thesystem surface at the worst design condi
42、tion by one of thefollowing methods.6.3.2.1 Insert the system dimensions, material properties,and operating conditions into an analysis technique conformingto Practice C 680. This technique should be used during designor where the system surface temperatures cannot be physicallymeasured at worst cas
43、e conditions.6.3.2.2 Direct contact thermometry (thermocouple or resis-tance device) or infrared, noncontact thermometry.NOTE 4(1) Care should be used in attaching measurement devices onhot systems since burns can result; and (2) Proper installation techniquesmust be used with direct contact thermom
44、etry to prevent heat sinking ofthe surface and obtaining incorrect temperature readings.6.4 In many situations, surface temperatures exceed therange of applicability of this guide and thus the evaluation ismade through interpretation of the surface temperature dataand the system properties. The limi
45、ting conditions belowshould first be examined to see if further analysis is required.6.4.1 If the surface temperature is below 44C, no shortterm (that is, less than 6 h) hazard exists and the remainingsections can be ignored.6.4.2 If the surface temperature exceeds 70C and thesurface is metallic, it
46、 may present a hazard regardless ofcontact duration.Attempts should be made to lower the surfacetemperature below 70C. Nonmetallic skins may be safe forlimited exposure at temperatures above 70C. In these cases, aswith all cases between 44C and 70C, the analysis should becompleted.6.5 With the measu
47、rement or estimation of surface tempera-ture for the system in question, utilize the graph (Fig. 1) andcheck if the intersection of the operating surface temperatureand the selected time of contact falls below the thresholdtemperature.NOTE 5The threshold temperature used will depend on the limits of
48、acceptable burn chosen in 6.2.2. If the burn level is first degree, usethreshold line B in Fig. 1. If second degree burns are acceptable, usethreshold line A in Fig. 1.6.6 If the operating surface temperature and time are belowthe threshold (line B) curve, then the system meets the selectedcriteria.
49、6.7 If, however, the point falls above the curve, the systemmay meet the selected criterion only if certain combinations ofC1055033insulation or jacketing, or both, are used. Analysis proceduresfor the jacketing/insulation effects are outlined in PracticeC 1057. Two methods provided in Practice C 1057 are brieflydescribed below.6.7.1 The calculation technique provided in Practice C 1057uses system geometry, material properties, and temperatureconditions to estimate the maximum contact temperature usedin Fig. 1 when the heat capacity effects of t
