ML17277B458
| ML17277B458 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 07/17/1984 |
| From: | Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| GO2-84-427, NUDOCS 8407250381 | |
| Download: ML17277B458 (42) | |
Text
1 II REGULATOR i INFORMATION DISTRIBUTION STEM (RIDS)
ACCESSION NBR:8407250381 DOC ~ DATEe 64/07/17, NOTARIZED: NO DOCKET FACIL:50 397 HPPSS Nuclear Projects Unit 2E Nashington Public Powe 05000397 AUTHNAME AUTHOR AFF,ILIATION SORENSENEG.C, washington Public Power Supply System RECIP,NAME RECIPIENT AFFILIATION SCHl<ENCEREA, Licensing Branch 2 SUBJECT; Discusses replacement of vinyl asbestos tiled floor, w/carpeting to enhance control room condition K improve human performances Proposed carpeting meets or exceeds critical radiant flux ratingiper ASTM E 648 test<
DISTRIBUTION CODE: AOOBS COPIES RECEIYED:LTR ENCL I BIZE:
to NUREG-0737(Generic Ltr 62 33)
TITLE: OR/Licensing Submittal: Suppl 1 NOTES: 05000397 OLe12/20/83 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR NRR LB2 BC 7 7 ENCL'NTERNAL:
IE/DEPER/EPB 3 NRR PAULSONEN 1 1 NRR/DHFS/HFEB 5 5 NRR/DHFS/PSRB 1 1 NRR/DL/ORAB 1 NRR/DL/ORB5 5 5 NRR/DS I/CP8 1 NRR/DSI/ICSB 1 1 NRR/DS I /METB 1 1 NRR/0 /RAB 1 1 NRR/DSI/RSB 1 1 F IL 1 RGN5 1 1 EXTERNAL: LPDR 1 1 NRC PDR 1 1 NSIC 1 1 NTIS 1
.TOTAL NUMBER OF COPIES REQUIRED: LTTR 34 ENCL 34
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Washington Public Power Supply System P.O. Box 968 3000 George Washington Way Richland, Washington 99352 (509) 372-5000 July 17, 1984 840725038i 840717 I G02-84-427 PDR ADOCK 05000397 P PDR Docket No. 50-397 Director of Nuclear Reactor Regulation Attention: Hr. A. Schwencer, Chief Licensing Branch No. 2 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Hr. Schwencer:
Subject:
NUCLEAR PLANT NO. 2 CONTROL ROON FLOOR: ENHANCEHENT OF Review of the WNP-2 control room design has indicated the desirability of replacing the present vinyl asbestos tiled floor covering with carpeting.
Enhancement of the work area to create a pleasant and comfortable setting is advantageous and.desirable in view of the long hours and confining as-pects of the control room operator's job. Beneficial features to be real-ized by this replacement include at a minimum, the following:
1 Background noise. reduction
- 2) Ambience and comfort
, 3) Hinimize fatigue of personnel
- 4) Overall improvement of control room appearance.
This control room enhancement/improvement has been adopted effectively by other operating plants such as Susquehanna, Diablo Canyon, Trojan and LaSalle.
With construction completion and a marked decrease in control room traffic, this improvement is being scheduled at this time to enhance control room conditions and improve human performance.
Current NRC regulations establish carpet flammability criteria on the; basis of the ASTM E-84 "tunnel" test, specifying a maximum flame spread index of 25 and a maximum smoke, developed value of 50. Submitted for your review is a com-parative analysis of the subject floor covering using the "Critical Radiant Flux" test in accordance with ASTH E-648, NVLAP Code 03/F04, and the NFPA 258, ASTH E-662, 79 test for "Specific Optical Density of Smoke Generated".
Since about 1981 carpet manufacturers have used the Floor Radiant Panel Test (ASTH E-648 or NFPA 253) as the nationally recognized standard for evaluating carpet used on, floors. This test more adequately tests the carpet in its actual installation. configuration and is recognized in the 1981 Life Safety
A. Schwencer Page Two July 17, 1984 CONTROL ROOM FLOOR: ENHANCEMENT OF Code (NFPA 101), Section 6-5.2, Interior Floor Finish. Per this section, a Class I Interior Floor Finish will have a minimum critical radiant flux of 0.45 watts per square centimeter or greater. The life safety require-ment of 0.45 watts per square centimeter is also recognized by the Depart-ment of Health, Education, and Welfare standard on flammability of floor coverings (Chapter 8-40, Attachment,l) paragraph 8-40-40, "Standard for Flammability". Part A states that "Floor coverings used in corridors and means of egress in health care facilities shall have a minimum critical radiant flux of 0.45 watts per square centimeter as determined by the .
Floor Radiant Panel Test".
Since the Radiant Panel Test does not include a smoke value, the ASTM E-662 Smoke Density Chamber (NFPA 258) Test has been used to regulate carpets to a maximum optical density. Using this test, the Department of Health, Education, and Welfare set a standard of 450 or less in paragraph 8-40-50, "Standard for Smoke Developed". Per attachment 2, NBS Technical Note,757, "The Smoke Density Chamber Method for Evaluating the Potential Smoke Generation of Building Materials", vinyl asbestos tile has a flaming smoke development of 325.
As stated in Attachment 3, the carpet that is proposed to be used in the control room at WNP-2 meets or exceeds the critical radiant flux rating of 0.45 watts per square centimeter per the ASTM E-648 Test. Per the manufacturer, the carpet has a critical radiant flux of 1.01 watts per square centimeter. The carpet also has a smoke value of less than 250 per the ASTM E-662 Test. Both of these values are well within the re-quirements set by the Department of Health, Education, and Welfare for health care facilities and the smoke value of the carpet is less than that for vinyl asbestos tile which the NRC has already accepted as non-combustible and'acceptable for use in the WNP-2 control room. It is the Supply System position that the proposed carpet meets and exceeds the NRC requirements. Additionally, a review in accordance with 10 CFR 50.59 has been completed and the Supply System considers that no significant hazards or unreviewed safety questions will.result from the change.
The WNP-2 Plant Staff's schedule for implementation of this improvement is quite restricted. Your cooperation with expeditious review and concurrence in this matter is appreciated. If you have any further questions concerning this matter, please contact Mr. P. L. Powell, Manager, WNP-2 Licensing.
Very truly yours, G. C. S rensen, Manager Regulatory Programs
'SIS/tmh Attachments (3) cc: R Auluck - NRC WS Chin - BPA D Kubicki - NRC AD Toth - NRC Site
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CHAPTrn 8-40 Safety Standard for Flammability of Floor Coverings 8-40-00 Purpose 10 Pol i cy 20 App 1 i cabi 1 i ty 30 Effective Date 40 Standards for Flammability 50 Standard for Smoke Developed 60 Standard for Static Build-up 70 Standard for General Safety 80 Standard for Vse by Handicapped 90 Previous Standards for Departmental Facilities 100 Previous Standards for'Program Facilities 110 Exceptions 8-40-00 ~Pur ose To establish a Department of Health, Education, and Welfare safety standard on the flammability of floor coverings.
t 8-40-10 ~P0'l1c It is the policy of the Department of Health, Education, and Helfare to assure a safe and healthful environment insofar as practicable, for its employees in the performance of their assigned responsibilities and to those members of the public whose environments may be affected by activities or programs of the Department, through the establishment of appropriate Departmental safety and health standards, criteria, policy and guidance for untfom,and consistent use on a Depart-,.=nt-wide basis.
8-40-20 ~ll 'll t lilt This standard is applicable to all types of floor coverings and surfacings used in all facilities owned or operated by. the Department of Health, Education, and Welfare and to all program areas of the Department including Federally aided and grant programs, 8-40-30 Effective Date This standard is,effective on January 1, 1977; floor coverings installed prior to the effective date of this standar d may be continued in use. In those cases where a purchase contract or simi lar commitment to install floor coverings was entered into prior to January 1, 1977, but for 'installation to commence after that date, the policy standards in this chapter should be adhered to if it is feasible to renegotiate the contract or
fety Standard for Flammabili Floor coverings Page 2 8-40-30 (continued) simil ar commi tment.
8-40-40 Standard for Fl ammabili t Floor coverings used in corridors and means of egress in h..alth care facilities shall have a minimum critical radiant. flux of 0,45 watts per square centimeter as determined by th'e Flooring Radiant Panel Test (FRPT).
See Exhibit K-25.
Floor coverings used in cor ridors and means of egress in facilities other than health care shall have a minimum critical radiant flux of 0.22 watts per square centimeter as determined by the Flooring Radiant Panel Test (FRPT). See Exhibit X-25.
C. Carpets and rugs used in spaces other than corridors and means of egress of all facilities (including health care) are required by Federal L,aw to meet "Standard for the surface Flaranability of Carpets and Rugs" DOC FF 70 (Pill Test).
See Federal Register, April 10, 1970. Only those floor coverings installed after April 10, 1970 are required to meet DOC FF-1-70.. Floor coverings of other materials used in spaces other than corridors and means of egress of all facilities m~a be required to meet the interior finish requirements of the "Life Safety Code," 1973 edition as published by the National Fire Protection Association as determined by the authority having jurisdiction.
- 0. When floor coverings are composed of multi-layered materials, such as a carpet over a separate pad, the minimum criteria above shall apply to the entire assembly.
E. When an additive or process has been applied to either the basic material or to the final floor covering material which significantly decreases the flammabil-ity of the floor covering and enables it to meet the acceptance criterion of this standard, the test method calls for a washing or other determination that such treatment or process is not easily removed by normal maintenance procedures.
F. Special treatments, such as carpet shampoo which may render a floor covering less flammable, shall not be used to comply with above criteria. The use of such treatments requires judgment on the part of the enforc-ing nfficial as to the acceptability of such treatments for previously installed floor coverings.
,;age 3 Saf Standard for Flammab$ 1$ ty of' or Coverings 8-40-50 Standard for Smoke Oevelo ed coverings, installed throughout any facility, after I'loor the effect1ve date of this standard shall possess a "smoke developed" rating of 450 or less as determ1ned by the stand-ard "Smoke Generated by Solid Materials".
(Note: Thfs standard fs currently National Fire Protection Association's No. 258T and was developed as Natfonal Bureau of Standards Technical Note No. 708. The smoke developed rating is intended to permit hardwood floors and most re-silient (vinyl, asbestos, etc.) floor coverings).
8-40-60 Standard for Static Build-u Floor coverings, unless in conflict with another safety or med1cal standard, installed after the effective date of this standard, shall not build-up a static level exceeding 3.5 kY when tested by the AATCC Test Method 134-1969. In locations where flammable liquids, vapors, gases, and highly combust1ble solids are present, there should be no measurable bu11d-up of static electricity charges.
8-40-70 Standard for General Safet Floor cover1ngs, installed throughout any facflfty after the ef-fective date of this standard, shall be of types which do not present an unusual slipping or tripping hazard to those persons traveling over them.
8-40-80 Standard for Use b Handica ed All carpeting in areas subject to use by handicapped indfvfduals shall, fn addftion to meeting other requirements of these stand-ards, be specfff d as h1gh density, low uncut pile, and non-absorbent. Underlayments are permissible provided they are specified as firm or hard and do not exceed 3/8 inches in depth.
Carpets,and underlayments if used, shall be 1nstalled stretched taut and securely anchored at all edges to the floor. Edg1ng strips shall not project h1gher than 3/8 1nches above the floor line.
8-40-90 Previous Standards for De artmental Facilities Floor coverings fn use in Department owned or operated health care facilities prior to the effective date of this standard and installed after May 17, 1973 are required to have a flame spread rating of 75 or less as determined by ASTH E-84 test method (Steiner Tunnel).
.(Note: This ASTM E-84 standard will no longer apply to floor cover1ngs installed after the effective date of this : standard.
Sar Standard for Ftammabt'Ifty ofOoor Coverings Page 4 8-40-1 00 Previous Standards for Pro ram Facilities Floor coverings i n use i n facilities under a Department funded or grant pr ogram were required to meet vari ous standards according to the parti cul ar program . These floor coverings may be conti nued i n use , provided they met the applicable .standards of the specific program
{ Hi 1 1 -Burton , Medicare , Medicaid , etc . ) at the time of installation .
( Note : These program standards will no longer apply to floor coverings i nstal 1 e'd after the effective date of thi s standard .)
8-80-110 ~Eti llhen deviations from the basic intent of this standard are required to meet specific conditions or problems, justifi-cations supporting such determinations may be submitted to the official possessing waiver authority for the specific pro-gram or facility involved. In the case of Departmental owned or operated facilities justifications shall be submitted via appropriate organizational channels to the Director, Office of Safety Management, in accordance with 8-00-40 of the Safety Management Manual, OHEW.
ATTACHMENT 3 BIG FI OW SANFORD ~ INC ~
P. 0. BOX 3089 GREENV ILI.F., S. C. 29602 PHONE (803) 299-2630 pRODUCT IDENTIFICATION: CV01963 Revision 1 Remake DA E June 5 1984 Flooring Radiant Panel: This is to certify that a carpet sample identified as above was tested for critical radiant flux in accordance with ASTM Test Method ASTM F;648, NVLAP Code 03/F04, Bigelow-Sanford Test T-232.
TEST ASSEMBLY: Specimens were mounted as part of:
Meets or exceeds:
Average Critical Radiant Flux, Watts/sq. cm.
A direct Glue Down System using NuBroadlok Adhesive. .45 A Carpet Flooring System using Standard 50 oz. rubberized jute/hair cushion.
A Carpet Module Loose Lay System without any adhesive.
A Carpet Module Release System using 3M Blue Glue.
This laboratory is accredited by NVLAP of the U. S, Department of Commerce as having the competence to perform above tests in accordance with prescribed test method and accreditation criteria.
NBS Smoke: This is to certify that a carpet sample identified as above was tested for "Specific Optical Density of Smoke generated by "~nli'd 'materials" in accordance with Nl'PA 258, ASTM E-662, 79, Bigelow-Sanford Test T-219.
'P The Maximum Average Specific Optical density i>>:
Non-Flaming 250 or less than 250 Flaming 250 or less than 250.
Approved by:
Bigelow-Sanford, Inc.
Reference:
Report Number 23800 Report Date 5/29/84
BIGELOW-SANFORD, INC.
P.O. BOX 3089 GREEQfILLE, S.C. 29602 PHONE (803) 299-2646 REPORT NO. 28800 SUBJECT Electrostatic Propensity of Carpets HA.'iUFACTURER Bigelow-Sanford,lnc.
PRODUCT IDENTIFICATION: CV 01963 Revision 1 Remake This is to certify that a carpet sample identified as above was tested for electrostatic propensity in accordance with AATCC-134 Test Hethod.
TEST ASSENBLY; Test specimen was mounted as part of carpet flooring system comprised of a rubberized jute/hair cushion.
The maximum static voltage generated at 20K RH and 70'F was less than 2000 volts.
Approved By:
BIGELOW-SANFORD,INC Ref erence: Repo'rt Number Date Electrostatic propensity of Carpets AATCC 134/CRI 102, NVLAP Code 03/EOl, Bigelow-Sanford Test T-213.
This laboratory is accredited by NVLAP of the U.S. Department of Commerce as having the competence to perform specified tests in accordance with pre-pcribed test method and accreditation criteria.
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ATTACHMENT 2 A UNITEO STATES OEPARTMENT OF COMMERCE PUBUCATION SSS Yxe~WL >OT< 5
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)EPARTMENT OF COMMERCE National Bureau of Standards
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'I The Smoke l9ensity Chamber Method For Evaluating the Potential Smoke Generation of Buillding Materials
'i'. C. I.<<t C<<ttt<<r I'or lluiltlittgT<<ehnoio<<y ltt.'titttto I'or Appli<<tl To<<ltuology t >atit>nal llureau t>f Statttlartls
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> IIIS Technical >t>>tcs are >Ieeigne>l to ~upplen>ent the Itureau'a regular publication>> program. They provhle a n>ean>> for n>al'ing available>>cientilie >tata tlu>t are of tran.ient ur lin>ite>I intere>>t. Teel>nieal >tote>> >nay bc tb le>l ur referre>l to in tl>e>>pen liter>lure.
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+rav ot U.S. DEPARTMENT OF COMMERCE, Peter G. Peterson, Secretary NATIONAL BUREAU OF STANDARDS, Lawrence M. Kushner, Acting Director, Issued January 1973
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THE SMOKE DENSITY CHAMBER METHOD FOR EVALUATING THE POTENTIAL SMOKE GENERATION. OF BUILDING MATERIALS T. G. Lee The paper reviews the Smoke Density Chamber Test Method and illustrates its use and application to assess smoke generation of building materials in fire situations. It shows how test results may ai8 the Fire Services and code authorities in evaluating and reducing the potential light-obscuration hazard of smoke in buildings. An example is given for calculating visibility in a simplified fire situation involving material of known smoke generation. The smoke generation of some common interior finish and construction materials are given.
Key words: Building Codes; building materials; fire; Fire Services; smoke; smoke density chamber; smoke generatipn; test method; visibility.
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The Smoke Density Chamber, Method for'Fvaluating The Potential Smoke Generation of Building Materials
- 1. Introduction There is a well known adage, "where there's smoke, there's fire." Fire is one of the foremost causes of accidental injury and we suffer the consequences of its by-product, smoke.
Statistics show that "smoke inhalation" and "asphyxiation" rather than burn injury cause a majority of the fire fatalities in this country. It is not accurately known how many people are trapped by decreased visi-bility due to dense smoke and who eventually succumb to the direct effects of fire and smoke in the immediate vicinity of the fire. Smoke can also cause apprehension, panic, or even death to occupants in other parts of a building because of smoke movement induced by natural convection or by mechanical ventilating systems. Furthermore, property losses are greatly increased because smoke also impedes fire fighting efforts. A smoke logged building often requires venting, in order to clear out smoke and hot gases. This generally increases the fire severity, but allows the E
fire fighting to be accomplished more effectively. The extent of these difficulties depends 'on the amount and rate of smoke generation in a given fire.
The increased use of plastics in coatings insulations, furnishings, and t
other) materials of construction has changed the type and volume of
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smoke
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generated and thereby broadened the fire problem. Chemical treatments or retardants added to reduce flammability of material may also increase the smoke generated in a fire.
4 One way to reduce problems associated with smoke is to provide reliable and meaningful information on the smoke generation of common materials.
Such data may then be used by building designers, owners, or code officials in selecting materials of construction and furnishings at various levels of risk. For example in certain locations where smoke is critical such as in shafts, heating plant rooms and enclosures, exitways, duct linings and filters in air conditioning systems, material of low smoke potential may be selected.
We have come to understand the concept and the application of fire loadl in the design of fire resistive walls, columns, and floors. We should now begin thinking in terms of a smoke load so that a rational building design will allow control of smoke by automatic venting, dilution, and/or shaft (i.e. stair and elevator shaft) pressurization in high rise buildings.
1 Fire load: the total heat which could be liberated by the complete burnout of combustible materials in a prescribed area. Commonly expressed in terms .of weight of combustibles per 'square foot of floor area in a compartment on the basis of a calorific value of 8000 Btu/lb.
Smoke load: the total smoke which could be liberated by the com-bustion of furnishings and finish materials in a compartment under prescribed exposure conditions. It may be based on the summation of the product of specific optical densities and the area of smoke producing materials associated with a given volume. The specific optical densities are determined by measurements of sample specimens in the standardized Smoke Density Chamber.
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0 I At the present time very little meaningful data on quantitative smoke production are available to those who wish to design low-risk facilities such as nursing homes.
- 2. Requirements of a Meaningful Test Method To date, smoke requirements have been used only sparingly; this is due partly to a lack of knowledge on how to apply smoke limitations, and partly to a lack of a meaningful test method. The need for a quantitative means for smoke measurement, based on flaming and nonflaming modes of exposure was clearly apparent to fire research workers, in both govern-ment and private organizations.
The Smoke Density Chamber meets all the following essential requirements of a good laboratory test method for measuring smoke generation of materials:
- l. It must give relevant and useful results. Exposure conditions in the test should simulate important and typical parameters experienced in a real fire. For example, the amount and rate of smoke generation for most materials depends on whether the specimen is exposed to flame or just radiant heating.
- 2. The method must provide reliable and quantitative results. The degree of reproducibility (among laboratories) and repeatability (within a laboratory)
1 of the test results, determined by interlaboratory t
evaluations of the test method, must be acceptable.
- 3. The method must provide a continuous scale of measure and have sufficient resolution to cover the common materials. It should be capable of measu ing the total smoke generated as well as the amount released over a specified time period.
- 4. The result must be understandable to various user groups (Fire Service, code official, architect, engineer, etc.) and fit the concept of performance criteria in building code enfoxcement. A building designer should be able to use the data to design for the possible smoke load. He should, for example, be able to select a material with moderate potential smoke generation to cover small parts of a room (or its furnishings), and a material of very low potential smoke in the rest of the room; so that the total smoke generation does not exceed some agreed upon limit.
- 3. The Test Method, Reliability, and Limitation 3.1 The Test Method The .test method, using the Smoke Density Chamber, was developed in 1966 by the Fire Research Section at the National Bureau of Standards (NBS) for the measurement of smoke potential of solid materials. 1 [1] Several 1
The original work was supported by the Federal Housing Administration as part of a technical study of test methods and performance criteria for I' wall systems.
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TABLE 1 Smoke Generation of Selected Specimens Thickness Density . Smoke (Dm)
S ecimens inch lb/ft oz/ d Non-Flam. Flamen Wall & Ceilin Material Asbestos Cement Board 0.187 125 0 0 Gypsum Board (unfinish, paper) 0.375 51 35 10 Plywood 0.17 32 305 45 Fiber Board 0.5 16 230 75 PVC Veneer on Gypsum 0.5 51 109 110 (Veneer) (0.01)
~F1oorfn Red Oak Flooring 0.75 39 505 300 Vinyl Asbestos Tile 0.062 93 24b 325 Polyamide (aromati'c) carpet 0.22 49 175 105 Nylon (foam backing) carpet 0.39 86 310 270 Acrylic carpet 0.375 82 470 220 Pol er Sheet Polyvinyl Chloride 0.01 87 100 Polyvinyl Chloride 0.015 87 210 Polyvinyl Chloride 0.03 87 120 430 Acrylonitrile-Butadiene-Styrene .022 66 188 Acrylonitrile-Butadiene-Styrene .032 66 220 450 GlasWReinforced Polyester .110 48 420 720 Wood Elm 0.05 . 40 150 35 Elm 0.125 40 270 Elm 0.185 40, 390 65 Elm 0.24 , 40 510 Insulatidà Glass Fiber Insulation 1.0 3.5 25 25 Polystyrene Foam (Rigid) 1.0 1.8 25 390
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of the early applications of the Smoke Density Chamber were the measure-ment of smoke produced by aircraft interior finish materials [1] and the effect of ventilation on the smoke produced by wood and plastic materials
[2]. References [3] and [4] give the complete theory, construction details and the test method procedures of tl 'moke Density Chamber. The Chamber is an 18 ft3 closed cabinet in which a specimen three inches square is supported vertically in a holder and is exposed to heat under one of two conditions, designated as "flaming" or "nonflaming" (smoldering).
The thickness and mounting of the test specimens should match the end use (installation) thickness and mounting. For each specimen, the combustion generated smoke accumulates within the chamber and the reduction of light transmission during the test is reported in terms of optical density of the smoke. The principle of smoke measurement in the chamber is based on application of the law of light absorption through solid or liquid aerosols commonly referred to as the Beer-Lambert Law [3].
Optical density is the single measurement most characteristic of a "quantity of smoke." The data from the chamber gives both the maximum optical density and the rate of increase in optical density during the test. To simplify use of the test results, however, only the maximum optical density, D , may be used to estimate the potential smoke generation of materials in building fires. The range of the instrument is bebwea'n 0 and 800 units which adequately covers the D levels for most building finish materials.
Table 1 shows the maximum specific optical density of some common materials under flaming and nonflaming exposure conditions. In general, 7
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TABLE 2 Combined Results of Interlaboratory Evaluation of Smoke Density Chamber (AMINCO) Test Reproducibility Repeatability Specimen Thickness Mean Standard Coefficient of Standard Coefficient of in. D m
(corr.) Deviation Variation Deviation Variation eg ey Non-flamin Ex osure Linoleum 0.125 725 49 6.7 46 6.4 Polypropylene Rug 0.22 621 52 8.4 28 4.5 Red Oak 0.25 552 40 7.2 18 3.2 ABS/.022 a-Cellulose 0.022 0.03 188 20 4.7 ll 12 6.4 162 2.9 4.2 2.6 PVC-Gypsum 0.5 109 6.6 6.0 3.5 3.2 Polystyrene Foam 1.0 23 6.3 g7 6.7 29 Flamin Ex osure GRP 0.062 719 49 6.8 36 5.0 ABS/.032 0.032 451 17 3.8 20 4.5 Polystyrene Foam 1.0 391 52 13 32 8.0 Polypropylene Rug 0.22 292 24 8.3 20 6.9 PVC-Gypsum Acoustic Tile 0.5 0.75 109 23 29 2.7 27 12 12 3.4 ll 16
specimens from wood products gave higher smoke values under the non-I flaming than under the flaming exposure condition while for solid plastic materials, the reverse was true.
Although not a part of the smoke density measurement and not discussed in this paper, the Smoke Density Chamber can also be used for the simultaneous measurement of the concentration of potentially toxic gases and vapors.
3.2 Reliability The reproducibility of the test result from one laboratory to another
,compares favorably with other fire test methods. Several interested laboratories constructed their own chambers based on the published drawings and used the method to measure the smoke produced by a variety of materials [5,6]. This led, in 1970, to the production of a commercial version of the chamber. incorporating a number of refinements by the American Instrument Company (AMINCO).
Twenty-two laboratories (18 with identical AHINCO chambers, four with "home-made" chambers) have participated in an inter-laboratory evaluation of the method involving eight common building materials under the pre-screed flaming and nonflaming exposure conditions [4]. Several recommendations for procedural changes by the participants were accepted and are included in the latest test method standard; see Appendix II, NBS Technical Note 708 [4]. Table 2 shows a summary of these results
including supplemental flaming tests by twelve laboratories. The median reproducibility (among laboratories) for a variety of materials under the two exposure conditions was on the order of 8%.
Two standard reference materials to check the performance of the chamber are available from the Office of Standard Reference Materials, National Bureau of Standards.
3.3 Limitations This test, in common with some other fire tests, does not measure an inherent property or "smoke characteristic" of a material; what the test does measure is the light obscuration'haracteristic of smoke generated by a particular material or assembly (of prescribed density, thickness, moisture content, etc.) under two stipulated'onditions of fire exposure.
At the present time, it is not possible to predict smoke production from a specimen without testing. For a solid uniform material, the smoke generated increases proportionally with thickness up to a certain thickness depending on its density and thermal properties. Specimens submitted for testing should be identical in all respects including thickness to that to be used in the field. The test specimen holder can handle specimens up to one inch thick.,
- 4. How to Use the Data to Estimate Relative Smoke Hazard In practical situations where no information is available on the dispo-sition of interior finish material in the building, D m
may be used to 10
J estimate the comparative light-obscuration hazard of smoke from burning different specimens. A simple specification, for example, could require that the surface finish materials of a room or other space not exceed a value of D based on the average of flaming and nonflaming exposure conditions, or alternately based on the higher value. However, to be accurate, information on the volume of the room or building, and the size, and type of the material should be used by designers to calculate the potential smoke load. Consideration should also be given to the effect of air dilution in the room or building as a basis of estimating possible smoke levels in the event of fire.
The maximum optical density D m
is a property of the particular specimen, its thickness and type of backing. Tf the identical material were to be similar exposed in a room, visibility, through the smoke generated in that room neglecting eye irritation, may be estimated from data based on the laboratory tests. To do this, we take into account the three geometrical factors affecting smoke density:
the exposed area of material producing smoke, (A)
Greater area, more smoke; the volume of the room in which tbe smoke is accumulating (V)
Greater volume, lower density (concentration);
the ~leo th of visite path (L)
Greater length, reduced visibility.
~ t The estimated density of smoke (D/L) in a room can be calculated from the (D )
m value in the test chamber by the following equation:
D/L ~ D m
x A/V Equation (1)
The relation between visual distance and smoke density is determined experimentally. Figure 1 is based on data from Jin (7] for smoke of various types. It represents the visual threshold response for several observers situated outside the room viewing through a window either a back-lighted sign or a side illuminated placard. These results show that for a given smoke density, the visual distance is affected primarily by the brightness of the sign and only slightly by the color of the smoke, burning conditions and type of material used. How-ever, other studies have indicated variability in the relationship between visual distance and smoke density as summarized in the review by McGuire et al f8]. All of this work has ignored the irritant and lachrymatic effect that the smoke may have on an occupant located within the room.
The following example shows how data from the Smoke Density Chamber r
may ge used to estimate the visibility in a hypothetical situation.
It is desired to estimate the visibility in a 3200 ft3 room where a 32 ft2 area of material is exposed to fire over its entire surface and is the only material producing smoke. A test specimen of thickness identical to that of the panel is tested in the Smoke Density Chamber and.the measured maximum specific optical density (D )
m is 100.
12
I.O 0.8 0.6 Backlighted (0.05-0.2 lambert) Sign 80 Lux illumination 0.2 CI O
Illuminated Placard 40 Lux illumination C3 O. I I-0.08 LIJ 0.06 hJ O
0.04 0.02 0.01 3 4 6 8 IO 15 20 30 40 60 VISUAL DISTANCE, ft.
Fig. 1. Smoke Density and Visual Threshold of Signs Based on Data Ref. [7].
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Substituting these numbers in equation (1), the smoke concentration (optical density per unit length) in the room will be:
D/L = 100 x 32/3200 = 1.0 per foot Though experimental data on visibility in the 1.0 optical density per W
foot range was not given by Jin, extrapolation of the curves in Figure 1, (for illustration purposes) may be used to estimate visibility. D/L = 1.0 corresponds to a visual distance of only 3.5 ft for a back lighted (exit) sign under a typical light level of 80 lux+ (without smoke) and 1.3 ft for a side illuminated placard under a light level of 40 lux.
However if the smoke were diluted from the room by natural convection due to stack effect or by a forced air ventilating system into the whole building with a volume of 45,000 ft3 , the smoke concentration'assuming no losses will be:
D/L = 100 x 32/45,000 .071 per foot From Figure 1, D/L ~ .071 corresponds to a threshold visual distance of about 50 ft for the back lighted (exit) sign and about 18 ft for the side illuminated placard under the same lighting conditions.
- 5. How the Smoke Density Chamber Can Aid the Fire Services and Buildirig Code Officials The I'4 Fire Services in various jurisdictions nature of the problem of
- NFPA No. 101-1970 smoke have realized the standard for exit sign calls for a minimum of 5 foot-candle or approximately 54 lux on the illuminated surface.
critical in high density public occupancy buildings
such as nursing homes, apartment buildings, and hotels. Some juris-dictions have enacted ordinances for its control. The Smoke Density Chamber is offered as a tool to evaluate the potential smoke generation which may occur in a room, a corridor, or a building caused by either surface finishes or by contents.
A test method based on the use of the Smoke Density Chamber has been submitted to AS&i for consideration and possible promulgation as a voluntary standard. At the present time over 70 chambers of the com-mercial type are being used by industrial, research and testing laboratories in this country and abroad. The following commercial testing laboratories have reported that they can provide the test service for the public:
American Instrument Company Silver Spring, Maryland 20910 Underwriters'aboratories, Inc.
Northbrook, Illinois 60062 Southwest Research Institute San Antonio, Texas 78228 U. S. Testing Company Hoboken, New Jersey 07030
- 6. Summary and Conclusion The Smoke Density Chamber is a method for the measurement of the smoke
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generation of materials based on common fire exposure situations. A large number of industrial and government research laboratories have used the method to develop information on the smoke generation of a wide variety of materials. Tests are also being performed by several 15
commercial testing laboratories. Reduction of visibility by smoke without consideration of its irritant effect may be calculated based on the results of laboratory tests. The precision of the method has been determined by inter-laboratory evaluation using typical materials.
Standard reference materials are available for the test calibration.
The concept of the Smoke Density Chamber method is proposed as a suitable first step in evaluating the production of smoke and as a basis for future code requirements. Limitation on the use of materials on the basis of smoke production or smoke load in building may vary, however, depending on fire experience, type of occupancy, level of risk, and type of built-in protection used. These factors should be considered in any requirement to be established.
16
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- 7. References
[1] Gross, Loftus, Lee, and Gray, "Smoke and Gases Produced by Burning Aircraft Interior Materials," NBS Building Science Series BSS 18, 1969.
[2] Gaskill, "Smoke Development in Polymers 5uring Pyrolysis of Combustion," Journal of Fire and Flammability, 1, pp. 183-216, 1970.
[3] Gross, Loftus, and Robertson, "A Method for Measuring Smoke from Burning Materials," ASTM Special Technical Publication STP 422, 1967.
[4] Lee, T. G., "Interlaboratory Evaluation of Smoke Density Chamber,"
NBS Technical Note 708, December 1971.
[5] Brenden, J. J., "Usefulness of a New Method for Measuring Smoke Yield from Wood Species and Panel Products," Forest Product Journal 21, pp. 23-28, 1971.
[6] Gaskill and Veith, "Smoke Opacity from Certain Woods and Plastics,"
Fire Technology, 4, pp. 185-'95, 1968.
[7] Jin, T., "VisibilityThrough Fire Smoke," Report of Fire Research Institute of Japan 31 33 (1971).
[8] McGuire, Tamura, and Wilson, "Factors in Controlling Smoke in High Buildings," ASHRAE Symposium: Fire Hazards in Building, pp. 8-13, January 1970.
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FORM K85 114A tt rtt U.S. OKPT. OF COMM.
BIBLIOGRAPHIC DATA
~ PUBLICATION OR REPORT NO.. Gov t hccesston Recipient's Accession No NBS TN-757 SHEET
- 4. TITLE AND SUBTITLE S. Publication Date i
January 1973 The Smoke Density Chamber Method for Evaluating the 6. Performing Organization Code Potential Smoke Generation of Building Material's
- 7. AUTkIOR(S) 8. Performing Organir" tion T. G. Lee
- 0. Project Tas Work Unit No.
9o PERFORhllNG ORGANIZATION NAihIE AND ADDRESS NATIONAL BUREAU OF STANDARDS 11. Contract/Grant No.
DEP ARThIENT OF CohL~IERCE WASHINGTON, D.C. 20234
- 12. Sponsoring Organization Name and Address 12. Type of Rcport gt Period Covered Same as 9 14, Sponsoring Agency, Code S. SUP PLESIENTARY NOTES ABSTRACT (A 200-amrd or less factual summary of most significant information. If document includes a significant bibliography or literature survey, mention tt herc.)
The paper reviews the Smoke Density Chamber Test Hctltod and illustrates its use and application to asse.,s moke generation of building materials in fi-e ituations. It shows now test results may aid the 1'ire Services and code authorities in evalual.ing ;.nd reducing the potential light obscuration hazard of smol.e in buildings. An example is given for calculating visibility in a simplified fire situation involving material of known s...nke generation. The smoke generation of
~some common interior finish and construction materials are given.
Iy. KEY WORDS (Alphabetical ordet, separated by semicolons)
B uxlding materials', fire', fire services; smoke; smoke density, chamber; smoke potential; test method;
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