Document bOLDZ1gZ8qgQp6ZkOJypaa9Nk

From /*-- August 21, 195 S / INTERNSrCORRESPONDENCE LESTER V. CRALLEY PITTSBURGH j 1 1 T R. S. Adams F. B. Colby E. N. Goas W. E. Goza F.P. Haluska N. A. Hayes G. W. Hutton B. D. Kent J. F. LaClair J. H. Long A. B. Masters R. H. Moore J. J. Moroney W. L. Mowe C. G. Orr R. E. Paine R. L. Parsons A. W. Petrey J. T. Quirk J.W. Schachtele R. E. Schenck H. A. Semken D. F. Shantz C. S. Short C. L. Teubert E. M. Trimble R. E. Whitson W.V.M. Williams E. B. Youngblut f _ Olean ^ - Garwood - Crcssona - Pt. Comfort - Cleveland - Badin - Wenatchee - Davenport - Lancaster - E.St.Louis Lafayette - Rosiclare - Massena - Mobile mm Alcoa Fab. - Vernon - Warrick - Vancouver - Bridgeport - Chillicothe - Detroit - Rockdale - Richmond - N.K. - Chicago - Bauxite M. mm Bauxite Al. - Alcoa Sm. rnm Edgewater Re: INDUSTRIAL HYGIENE Attached are hygienic guides for the following substances: Asbestos 2-4 Dinitrophcnol Ethylene Dibronide Lead and its Inorganic Methyl Bromide Silica Sodium Chlorate Uranium (Natural) Compounds LVC: DB cci A.L.Alexander - Alcoa Sm, C.T.Bardo -Massena r --C.G.Bell - Cleveland R.H.Brown - Mobile J.E.Burns - Warrick Frank Cox - Alcoa Fab. B. H. Droz- Wenatchee A. L. Gantt - Badin 0. L. Goelct - Detroit G. L. Hunting- Vancouver BPV.r'M. T4VMOIMMUM . A W. G. Martin - Rockdale L. V. Cralley APC 001277 A. B. Masters - Lafayette John Miner - Buffalo E. J. Mulligan - Pt. Comfort F. H. Regehr - Vernon A. W. Westfall - E. St. Louis G. D. Wheeler - Pt. Comfort L. L. White - Bauxite Al. T. B. Bonney & J, M. Plunkett - N.K. ^C. L. Bradshaw St W. R. Gilliland - Pgh. : -JINTERNAL CORRESPONDENCF'-WSvember 1, 19^/ From LESTER V. CRALLEY PITTSBURGH Re: INDUSTRIAL HYGIENE To--R. S. Adams Olean lo v .'-0 .-Dell \ * F. B. Colby Cleveland Garwood *7 \ E. N. Goas Cressona V^W, E. Goza Pt. Comfort ^ N. A. Hay.es Badin " G. W. Hutton Wenatchee ^B. D. Kent Davenport A. J. Kukla Buff alo <- J. F. LaClair Lancaster ^ J. |H. Long E. St. Louis v R. iH. Moore Rosiclare y J.IJ. Moroney Massena * W. :L. Mowe Mobile C. G. Orr Alcoa Fab. ^ R. E. Paine Vernon r'- R. L. Parsons Warrick - A. Vf. Petrey Vancouver f J. T. Quirk Bridgeport . J.W.Schachtele Chillicothe 1 R. E. Schenck Detroit . H. A. Semken Rockdale v D. F. Shantz Richmond C. S. Short N.K. * C. L. Teubert Chicago - E. M. Trimble Bauxite M. >' R. E. Whitson Bauxite Al. W.^r.M.Williams Alcoa Sm. w R. G. Wood Laf ayette v E. B. Youngblut Bdgewater Attached are the following enclosures for your information: 1. Threshold Limit Values for 1957 - Note that values for benzene, butyl cellosolve and sulfur, dioxide have been lowered; lead increased; and nitric acid is new. 2. Hygienic Guides - Dimethylf ormamide Hydrogen Peroxide Pentachlorophenol and Sodium Pentachlorophenate Silica (Free Silica, Silicon Dioxide) Sulfuric Acid 3. A comprehensive study of Waterless Hand Cleaners by Donald J. Birmingham. This is an excellent coverage of the subject, 4. National Safety Council Data Sheet D-443. Note that the threshold limit for lead has been increased from 0.15 to 0.2 mg./cubic meter (ACGIH Threshold Limit). 5. Reprint of the Noise Control article by JacksonBonney and Bittner. APC 001278 2 6. Information pertinent to a portable sampling device. LVCsDB Ends. Lester V. Cralley s: w A. L. Alexander - Alcoa Sm. ^C. T. Bardo - Massena H. brown r< `"J. B. Burns - Mobile - Warrick . Prank Cox - Alcoa Fab. >- B . H. Dr oz *- A. L. Gantt - Wenatchee - Badin r 0. L. Goelet - Detroit / G. L. Hunting * W. G. Martin - Vancouver - Rockdale - A. B. Masters - Laf ayette John Miner - Buf f alo E. J. Mulligan - Pt. Comfort F. H. Regehr - Vernon A. W. Westfall - E. St. Loui G. D. Wheeler ` L. L. White - Pt. Comfort - Bauxite Al. T. B. Bonney and ,John M. Plun! *"C. L. Bradshaw and W. R. Gill ARL N.K. Pgh APC 001279 Threshold Limit Values for 1957 Adopted at the 19th Annual Meeting of the American Conference of Governmental Industrial Hygienists St. Louis, April 20-23, 1957 Values are given in the following tabulation for the maximum average atmos pheric concentration of contaminants to which workers may be exposed for an eight-hour working day without injury to health. These values are based on the best available information from industrial ex perience, from experimental studies, and, when possible, from a combination of the two. They are not fixed values but are reviewed annually by the Committee on Threshold Limits for changes, revisions, or additions as further information liecomes available. Threshold limits should be used as guides in the control of health hazards and should not be regarded as fine lines between safe and dangerous concentrations. They represent only conditions under which it is felt that workers may be repeatedly exposed, dav after flay, without adverse, effect on their health. The figures listed refer to weighted average concent rat inns of an eight-hour work ing shift rathef than a maximum which is not to be exceeded even momentarily. The amount by which these figures may he exceeded for short periods during the workday depends upon a number of factors, such as the nature of the contaminant, whether very high concentrations even for short ]>eriods produce acute poisoning, whether the results are cumulative, the frequency with which high values occur anti for what periods of time. All must be taken into consideration in arriving at a decision as to whether a hazardous situation is deemed to exist. These values are not intended for use, or for modification for use, in the evaluation or control of community air pollution or air-pollution nuisances. The Committee welcomes the suggestion of substances to be added to the list and also comments, references, or reports of experience with these1 materials. Received for publication May 23, 1957. RECOMMENDED VALUES Gases and Vapors Approx. M(i- SOMSTANCK ITM* |er Cu. M.t Aceisddchyde .................. .. . 200 360 Acetic acid...................... .. . 10 25 Acetic anhydride .......... 5 20 Acetone .......................... ...1,000 2,400 Acrolein .......................... 0.5 1.2 AUvl alcohol ................. 12 (x)Allyl chloride ................ 5 IS Allyl propyl disulfide .. ... 2 12 Ammonia ........................ ... 100 70 Amyl acetate.................. .. . 200 1,050 Amyl alcohol (isoamyl alcohol) ... ... 100 360 Aniline ........................... ... 5 19 Arsine ............................. ... 0.05 0.2 Approx. M. SUHSTANCh I'l'M* |r I'n. 1 Benzene ( Ik-iizoI) .... .... 25 80 Benzyl chloride .......... 1 5 Bromine ........................ 1 7 Butadiene 11,3-lmtadienc) ........ . .. .1,000 2,200 Bulanonc (methyl elliyl ketone) ............ .... 250 740 Butyl acetate (-hutyl acetate) ... .... >00 S0 lluiyl alcohol (n-butanol) ............... .... 100 300 Hutylamine .................. .... S 15 Butyl cellosotve (2-butoxyethanol) .. .... 50 240 APC 001280 A. M. A. AKCHll liS Ol INDUSTRIAL HEALTH Approx. Mg. SiI'ANCK PPM* per Cu. M.t Carlxm dioxide ................ .5,000 0,000 Carlton disulfide ................ . 20 60 Carlton monoxide ............ . 100 no Carlton tetrachloride ........ . 25 160 Cellnsolve (2-cllmxycthannl) ........ . 200 740 I'ellosolvc acetate (2-cllioxyetlivl arrtnlc) . 100 Chlorine ............................. 1 540 .1 Chlorine trifluoridc .......... Chlorobenzene 0.1 0.4 (inonorlilorobenzcnc) .. . 75 Chloroform .150 (trichloromethnne) ___ . 100 1-Chloro-l-iiilropropane .. . 20 490 100 < x K'bloropicrin ...................... 1 7 Cltloroprene (2-chloro1,3-hutadirne) ................ . Crcsol (all iwaners) ........ . 25 5 90 22 Cvrlohcxaite ...................... . 400 1,400 Cvelohexanol ...................... . 100 Cyclohexanone .................. . 100 410 400 Cyclohcxenc ...................... . 400 1,350 Cyclopropane .................... . 400 690 < x) Decaborane .......... .......... 0.05 0.3 Dincctonc alcohol (4-liy(iroxv-4-melliyl2-pentanonc) ................. . Diborane ............................ 50 0.1 240 0.1 o-Dicldorolteniene ............ . 50 1 hrhlorodiJinnrnmethaiic .. .1,000 1,1-Dichlorocthanc ............ . 10ft 1,2-1 Jichlornct hane 500 4.950 (ethylene dichloride) .. . 1.2-Dirhloroethylcnc ........ . Dii-ldoroelhyl ether ........ 1 >ichloromi>noHioro- 100 200 15 400 7`Xl 90 methane .......................... .1,00(1 1.1-Dichloro-l- 4.20(1 niirocthunc ...................... 10 Dichlorotcl ratluoroethanc .1,000 60 7,000 1 )ieliiylntnine ...................... . 1)i fluorod ihromomcthane . Diisohutyl ketone .............. . 1 Jimelbylanilinc 25 100 50 75 860 2*Xl ( Af-dimcthylanilinc) ... 1 hmcthylsulfale ................ 5 i 25 5 Dioxanc (diethylenc dioxide) ......................... . 100 .too Ktliyl acetate...................... . 400 1.400 (x) Kthyl acrylate .................. . 25 Kthyl alcoltol (ethanol) . .1,000 100 1.900 Kthylamine......................... . 25 Kthyllicnzene ...................... . 200 Elltyl hrocnidc.................... . 200 Ethyl chloride.................... .1,000 45 870 800 2,600 Kthyl ether ........................ . 400 1.200 262 Approx. Mg. SutlSTANCt: TPM* per Cu. M. Ethyl formate.................. .. 100 300 Ethyl silicate .................. .. 100 850 Ethylene chlorohydrin .. Ethylenediamine .............. 5 10 16 30 Ethylene dibrtxnidc (1,2-dibromoethanc) .. .. 25 190 Ethylene inline ................ 5 9 Ethylene oxide ................ .. 50 90 Fluorine ............................ 0.1 0.2 FluorotricMommelhnnc . ..1,000 5,600 Formaldehytle .................. 5 6 (x)Furfural ............................ 5 Gasoline ............................ .. 500 Heptane (w-heptane) ... .. 500 Hexane (*i-hexane) ___ .. 500 Hexanone (methyl butyl ketone) .............. .. 100 Hexone (methyl isobutyl ketone) .......... .. 100 Hydrazine.......................... 1 Hydrogen bromide.......... 5 Hydrogen chloride ........ 5 Hvdrogen cyanide .......... 10 Hvdrogen fluoride .......... 3 Hydrogen peroxide. 'W/< 1 Hydrogen sclenitle ........ 0.05 Hydrogen snlfiilc .......... .. 20 Iodine ............................... 0.1 rsophoronc ........................ .. 25 (sopropyUunine -.............. 5 Mesityl oxide .................. .. 50 Methyl aceftif* .............. . . 280 Methyl acetylene ............ .1.000 20 2,000 2,(XXI 1,800 410 410 1.3 17 7 ii > 1.4 0.2 30 1 140 12 200 610 1.650 I x) Methyl acrylate ............ . . 10 Methyl alcohol (methanol) .................. .. 200 Methyl bromide .............. .. 20 Methyl cellosolve (2-methoxyethanol) ... .. 25 Methyl rellosolve art-talc (ethylene glycol monomethyl ether acetate) . .. 25 Methyl chloride .............. .. 100 Mcthylal (dimethovNmethane) ...................... . . 1,1X10 Methyl chloroform (1,1,1-trichloroel hane) . . 500 Melhylryclohexanc ........ .. 500 Methyleycloliexanol ........ .. 100 Methylcyclohexamme . .. .. 100 Methyl formate .............. .. 100 Methyl isobntvl carhinol (methyl antyl alcolitjl) .. 25 Methylene chloride (dichloronieihanc) .... .. 500 Naphtha (coal tar) . ... .. 200 Naphtha (petroleum) .. 500 35 80 m 120 210 5.100 2,71X1 2,(XXI 470 460 250 100 1,750 800 2.000 APC 001281 riiHiisnoLD limit r.tu i-.s Approx. Mg. Siins r.xNCK Nickel carbonyl .. PPM* per Cn. M.t o.ooi 0.007 *\>Niirir acid...................... 5 25 ? NitnKiniline .................. i 6 Niirolietuenc.................... i 5 N'itroctham* ...................... too .no Xilmgeti dioxide ............ 5 6 \ilr014lyrerit1 .................. 0.5 5 Xiinimciliiine .................. . 100 2-Niiropropam* ................ .. 50 250 180 Nitrotnluene .................... 5 30 < Static............................... .. 500 2.350 (Ir.onc ............................... 0.1 0.2 1 `entane ............................ .1,000 2*150 I'rulanixte (inelliyl pr>|>yl ketone) ............ .. 200 700 1 Vrchlorethylene t lelrachloroethylcnc \ .. 200 1.350 Phenol............................... 5 11 Phenylhvdrazine .............. 5 22 Phosgene (carlKMiy! ciiloride) ........................ 1 4 Phosphine......................... 0.05 0.07 Phosidiorus trichloride . . 0.5 3 Prupvl acetate ................ .. 200 840 I'ropyl alcoliol f isoproryl alcohol) Propyi ether . . 400 980 (isopropyl ether) .... . . 500 2.100 A|>lrtx. Ml: SUBSTANCh IT,VI* per Cn. M Propylene dichloride 11,2-dichloropropam'> . Prtpvlcitr inline ............ 75 25 350 60 Pvridine ................. . . 10 30 *2uiiHnc............................. Stibinc ............................. Stoddard Mtlvcttl ............ .. Styrene monomer 0.1 0.1 500 0.4 1.5 2."0t (plienyletliylcnc) ........ .. ino 420 Sulfur dioxide ................ 5 13 Sulfur hexafluoride .... . .1,000 6,000 Sulfur nmuochloridc ... 1 6 Sulfur pentafluoridc ___ 0.02,5 0.2: /*-Tert iaryhillyItolucne 1,1,2.2-Tetrachlornet bane 10 5 Ml 35 t x iTetraliydrofuran ............ .. 200 5bU Telranitrometlianc .......... 1 K Toluene (toluol) .......... .. 200 750 *-Toluidine ...................... 22 Trirliloroelhvlenc ............ . . 200 T ritl uorotnonobrotuo- 13)50 methane.......................... . .1.000 11,100 Tiir)ienliiie ........................ .. 100 560 Vinyl chloride t chloroethvlenc 1 . . 500 t,J00 Xvlenc fxvlol) . . 200 870 ' I'arU of va|r or j*cr million parts of sir by volume, i Approximate milligrams per cubic meter of air. < O TWrsc value* api*r*re*l on the tentative list for 1956. Toxic Dusts, Fumes, and Mists St'MviANtt Mg. per Cn. M4 Aldrin (I,2,3,4,10,10-licx;chloro- 1,4,4a,5,8,8a-hexahydro-1,4,5,ft- dimethanonaphthalene) ..................... 0.25 Animate ( ammonium sulfamate) .... 15 Antimony ................................................ 0.5 (x)ANTU (alpha-naphthyl-thicnirea) ... 0.3 A rsenir....................................................... 0.5 Itariuni (soluble cmnpmmds) ............ 0.5 Oulmiuin oxide fume ......................... 0.1 ( x Kalcinm arsenate..................................... 0.1 Odt rdane (1,2,4,5,6,7,R,R- nctachloro-3a,4,7,7a-ielralndro- 4,7-methanoindane) ........................... 2 (x )Chlorinatcd campheue. 60% .............. 0.5 Chlorinated diphenyl oxide .................. 0.5 Chlorodipbenyl (42% chlorine) .......... 1 (x) Cblorodiphenyl (54% chlorine) .......... 0.5 Chromic acid an<l chromates (as CrO) Crag herbicide (sodium 2-|2,4- dichtorophenoxy) ethanol hydrogen 0.1 sulfate) ................................................. 15 Mg. lnrr Suhst.anlk Cn. M.T Cyanide (as CN) ..................................... 214-D(2,4-ilit*lilorophci)xyat*ciit* 5 acid) .......................................................... 10 i \ ) ODT (2,2-bisi^-chloropIu*iiyl1-l,l,l- trichloroelhane) .................^................. 1 Jieldrin (),2,3.4,10,10-lie.\achioro- 6,7-epoxy-l,4,4a,5,6,7f8,8a-octahydn > 1 1,4,5,8-tlinicihano-nnphthalrue) ......... 0.25 i x) Dinitrobenzene............................... ........ 1 Dinitmioiuenc ............................................ 15 Dinitro-o-cresol ......................................... 0.2 KPN (O-Uhyl O-^-niirojdicnyl ihiouobcnzenephosphonatc) ............... (\)Ferbam (ferric tlimcthyi 0.5 dithiocarbamalc) ................................. 15 Ferwvaiwdlnm dual ................................. \ Flnoriilb ........................................................ 2.5 l x) HF.TIr (hexaethyl irtraplinspliau*) .. 0.1 Hydroqttinonc ............................................ 2 Iron oxide fume ....................................... 15 I.cad .............................................................. 0.2 263 APC 001282 ,4. M. A. ARCHIVES OE INDUSTRIAL HEALTH Mg. per St' I1STa n>. Cu. M.J (x)Lcad arsenate ....................................... 0.1S l.imlanc (hexachlororyclohexane, gamma isomer) ................................. O.S Magnesium oxide fume........................ IS Malalhion (O.O-dimelliyi dithiophos- pliatc of diethyl mcrcaptosuccinatc) . 15 Manganese ............................................... 6 Mercury ................................................... 0.1 Mercury (organic compounds) .......... 0.01 Mclhoxycldor (2,2-di-^-mcthoxyphenyl- 1,1,1-tricliloroctlinnc) .......................... 15 Mtdylxlcmmt (soluhle compounds) .......................... 5 (insoluble compounds) ...................... 15 ( x) Nicotine..................................................... 0.5 l'anubion (O.O-dicthyl O-/1- nitroplicnyl tliiopliosplialc) .............. 0.1 Pcntachloronnplitlinlene ........................ 0.5 Pcntnclilorophenol ................................... 0.5 Phosphorus (yellow) ............................ 0.1 Phosphorus pcntachloridc ..................... 1 Phosphorus pcntasulfidc ........................ 1 Picric acid ............................................. 0.1 < x) I'yrclhrnm ............"................................. 2 t x) Koienixic ................................................... 5 Selenium compounds (as Sc) .............. 0.1 Soilium hydroxide................................... 2 (x)Sodiuin fluoroacetatc (10X0) .............. 0.1 (x)Slryclniinc ............................................... 0.15 Sulfuric arid ........................................... 1 Mg. per Substance Cu. M.t TEDP (tetraethyl dithionopyrophosphate) ...................... 0.2 TEPP (tetraethyl pyrophosphate) .. 0.05 Tellurium ................................................. 0.1 Tetryl (2,4,6-trinitroplienylmethylnitramiiie) ................................. (x)Tliirain (tetramethyl thiuram disulfide) ............................................... (x)Thallium (soluble compounds) .......... Titanium dioxide..................................... Trichloronaphthalcnc .............................. Trinitrotoluene ......................................... Uranium (soluhle compounds) .......................... (insoluble compounds) ...................... Vanadium (V/). dust) ....................................... 1.5 5 0.1 15 5 1.5 0.05 0.25 0.5 (V0* fume) ....................................... (x)VVarfarin (3-fir acctonyllienzyl J-4- hydroxycoumarin) ............................. Zinc oxide fumes ............................... 0.1 0.5 15 Zirconium compounds (as Zr) ............ 5 Radioactivity: For permissible concentrations of radio* isotopes in air, see '`Maximum Permissible Amounts of Radioisotopes in tlie Human Doily and Maximum Per missible Concentrations in Air and Water/' Handbook 52. I*. S. Deioirtment of Commerce, National Bureau of Standards, March, 195.1. In addition, ace "Permissible Dose from External Sources of Ionising Radiation/' Hamllwolc 59, U. S. Department of Commerce, National Bureau of Standards, Sept. 24, 1954. Revision of the two publications mentioned almvc i in progress. t Milligrams of dust, fume, or mist per cubic meter of air. (x) These values appeared on the tentative Hat for 1956. Mineral Dusts Substance MPPCFS Aluminum oxide ................................. .......... 50 Asbestos ............................................... .......... 5 Dust (nuisance, no free silica) .... .......... 50 Mica Oxdow 5% free silica) .......... .......... 20 1'tirthuxl cement ................................. .......... 50 ___ 20 | Millions of particles per cubic foot of air. Silica high (above 50% free SiO.) .. medium (5 to 50% free SiO.) .. low (below 5% free SiO.) .... Silicon carbide ............................... Soapstone (below 5% free SiO.) MPPl'I-S ... 5 ... 20 ... 50 ... 50 20 TENTATIVE VALUES Approx. Mg. Substance PPM|| per. Cu. M.lf Acetylene tctrabromidc .......... 1 14 Allyl glycidyl ether (AGE) .. 10 45 beryllium ................................... 2y/m* Huron trifluoridc .................... 1 3 n-Hntyl glycidyl ether (BGE) ........................ 50 270 (x)Hulyl mercaptan ...................... 10 35 Cldoroaceuldehyde .................. 1 3 Appnrx. M^r Substance PPM# per. Cn. M.1) (x ) Chlorobromomelhanc (ClBrCH.) ............................ 400 2,100 Diglycidyl ether (DGE) ___ 10 Dimethyl formamide .............. 20 55 60 Dipropylencglycolmcthylclher . 100 600 (x)Ethyl mercaptan ...................... 250 640 (x)Furfuryl alcoltol ...................... 50 200 Glycidol....................................... 50 150 264 APc 001283 TIIKIiSIIOf.n LIMIT r.u.uns Approx. Mg. Sl'HXTANO I'PMII I>cr. Ol. M.| Kopropyl glyri<l)l cllicr ll(;K) ........................... .. . 50 240 Lithium hydride ................ 25y/m* lOMrlhyl mcrmpiati .......... .... SO 100 i Miilivl sivrcnc .............. .... 100 Mouomcthyl aniline.......... 7 480 0 1 ;ir;idicluorobcnzcnc ................ 7a 450 1 x ) I'crrlilnrumclhyl mercaptan .. 0.1 0.8 I'lmiyl glyridyl cllicr il'OF.) ........................... .... 50 310 Approx. Mg. Substanit: ITM|| per. fu. M. Fropvleue oxide .............. .... 100 240 ___ 100 500 (x ) Tolylcne-2,4-d:isoryanaic .... 0.1 0 7 Tricthvl amiiH* .................. 25 UK) Vinyl toluene ................... .... 100 4K0 Yttrium ami inorganic compounds ..................... 5 Xvlidinc ............................. 25 () Teflon decomposition products ......................... .... 0 ft (*) Pctilaborane (11.11.) ........ 00 r. ParU of va|wr or >sa. |**r million part* of air by volume. Z Approximate mtllturatnx per cubic meter of air. (k) Tliexe val(M! n|prareil on the tentative l**t fur 1956. ` Until more (Lila nrc fortlicoming, it it important that almo*pt*eric concentrations of tliene material* tn wIih-Ii wrkei arc ex|i*C'l mutt lie kr|H n* near 0 at poMiMc. W'ii.liam L. Rai.i. I.. T. I'AIKHAIX II. E. StokingTM Kai.ph S. Smttw W. H. KkINIIAKT S. D. SlI.VKH W. Clakk Cooi-kk AUXAN L. Cot.KMAN, Chairman 26i APC 001284 Waterless Hand Cleaners DONALD J. BIRMINGHAM, M.D., Medical Director, Ckiel Dermatologist VERNON B. PERONE, Industrial Hygienist, (Dermatology) Occupational Health Program, Public Health Service U.S. Department of Health, Education and Welfare Cincinnati, Ohio \ \T/~ATERLESS cleaners are designed for rapidly \Y/ removing tenacious soils from the skin ' * without using water. This property makeB them desirable for use in many industrial operations, particularly where water is difficult to obtain. The waterless cleaner is not a recent de velopment. Over 25 years ago, auto mechanics and painters used crude preparations of paste or liq uid products which contained petroleum solvents and/or ammonia in irritant amounts. The vigor ous cleaning effect and the accompanying after feel and odor on the skin apparently were toler ated by some mechanics and painters, but such waterless cleaners were not accepted generally. The Public Health Service dermatologists studying occupational skin diseases became in terested in waterless cleaners about 1946, when numerous inquiries regarding the irritant and/or allergenic properties of specific cleaners were re ceived from practicing dermatologists and in dustrial physicians. Little more was heard of them until 1952, when an outbreak of dermatitis, totaling 56 cases in one plant, was found to be caused by a waterless cleaner containing petro leum solvent and ammonia. Because of this dermatitis-producing potential, many plant Medi cal Departments were reluctant to accept them 48 cleansing agents. Nevertheless, the obvious convenience and soil-removing ability of water Auguat, 1957 less cleaners has made them increasingly popular for industrial, home, and office use. In 1966, the Aero-Medical Laboratory of the U. S. Air Force became interested in these prod ucts and contracted with the Public Health Serv ice to study the efficiency, utility, and safety of waterless cleaners. The results of a laboratory and field evaluation of 15 waterless hand cleaners conducted with human subjects form the basis of this publication.* Laboratory Studies Classification : The 16 waterless hand cleaners in the form of pastes, creams, liquids, or gels were classed in three broad groups based on the principal cleansing ingredient contained in them, as suggested by Lesser.* A detailed classification was impracticable because of the frequent changes in formulation and inadequate informa tion provided by the manufacturers on the com position of the cleaners. Group I -- Solvent Type -- cleanses primarily through the petroleum slovent content. A manu facturer's typical formula contains deodorized kerosene, lanolin, lecithin, oleic soap base, and The report to the U. 8. Air Fores *u published by thst tfney as document WADC Technical Report Kl~4<?, This paper ! based on date, collected for that report, and is published with the permission of the U. 8. Air Force. __ _ APC 001285 361 synthetic detergent. Cleaners 1, 4, 5, 6, 7, 8, 9, and 13 were placed in this group. A wide variety of petroleum-based solvents are used in group I products. Group II -- Alkali Type -- cleanses primarily through the soap or alkali action. A manufac turer's typical formula contains fatty acid, heavy organic amine, lanolin, water, perfume, and humectant. Cleaners S, 10, and 14 were placed in this group. (These cleaners also contained ap preciable amounts of petroleum solvent.) Group III -- Wetting Agent Type -- cleanses primarily through wetting agents. One manu facturer's formula contains neutral alkyl-aryl sul fonate emulsifier, stearic acid, sodium hexametaphosphgte, glycerine, mineral oil, nonionic syn thetic detergent, lanolin, water, and perfume. Cleaners 2, 11, 12, and 15 were placed in this group. Free Alkalinity and Acidity 'J'he skin does not tolerate excessive alkaline insult, and since some of the products in group II cleanse primarily because of their alkali con tent, it was considered essential to make these determinations. Acidity was determined because of the high fatty acid content of many cleaners. The total alkalinity of soap solutions depends upon the amount of free alkali, the alkali liber ated upon hydrolysis, and alkali derived from builders.1 The testing methods employed to de termine free alkalinity and acidity are conven tional ones in use for several years.*'4 Of the 15 waterless cleaners studied, only one, a type II product (14), contained free alkali, which amounted to 0.86% expressed as sodium hydrox ide. All the other cleaners contained varying amounts of free acid, ranging from a low of 0.35% to a high of 12.60% expressed as oleic acid. From these determinations it was concluded that 14 of the waterless cleaners studied could be used without causing excessive alkaline in sult to the skin; however, these 14 contained free acid in excess of the 0.1% allowed by gov ernment standards for soaps. Cleaner Stability at Various Temperatures leaners used or stored in temperate, tropical, or arctic temperatures should possess a high degree of stability, because workers will not use cleaners after they have frozen or liquified be cause of temperature extremes. We felt that ex posure to temperatures of 20F, 70-85F, and 106*F for prolonged periods was a more practical measure of stability than the usual procedure,4 in which they are subjected to a high tempera ture (140F) for 16 hours and a low temperature (--31*F) for 16 hours, brought to room tempera ture, and their separation effects observed. Samples of all waterless cleaners were exposed to room temperature (70*-85*F), elevated tem perature (105* 1*F), and freezing tempera ture (20* 1*F). Daily observations were made until the physical state of the cleaners had changed. Thereafter, weekly observations were made for a total of 10 weeks at each temperature. The cleaners were then removed from the oven or refrigerator, uncovered, brought to room tem perature and further changes in their physical states observed. The cleaners stored at room temperature were likewise uncovered at the end of 10 weeks, and remained uncovered for an additional week. Since a workman uses approximately eight ounces of cleaner per 20 work days, a cleaner that withstands temperature ranges from 20* to 105*F for 30 days would be fairly stable, provided it is completely used in that time. Naturally, for periods longer than 30 days these tests are not adequate. Under all temperature variants in the testing procedure, none of the waterless cleaners was able to withstand the environmental tests for a 30-day period. Only one cleaner, 10 (alkali type II), showed any change at room temperature. Relative Cleaning Efficiency 'JO test cleaning efficiency, the 15 waterless cleaners and six conventional cleaners were challenged by floor varnish, glue, axle grease, India ink, mimeograph ink, used crankcase oil, 1% solution of gentian violet, flat wall paint, roofing tar, and household adhesive cement. The test method consisted of applying a thin layer of soil to a 25 square cm area of the skin and allowing the soil to "set." The area was then scrubbed with the waterless cleaner applied to a pledget of cotton. The time interval of scrubbing to remove the soil was recorded with a limit of 120 seconds arbitrarily selected as the maximum time permitted. If a cleaner failed to remove a soil in this allotted time, it was con sidered to be ineffective for that particular soil. Evidence of soil removal or nonremoval was made by gross observation. New skin test sites were used for each cleaner tested. No preliminary preparations of skin test sites were made; how ever, subjects were requested to avoid the use of hand creams or lotions prior to cleansing tests. Since some laboratories test the efficiency of a skin cleaner on polyethylene, glass, or a simi lar smooth surface, a polyethylene surface was included in these tests for comparison. Without doubt, the more realistic approach to cleaning efficiency is to use the skin itself. In several in stances, cleaners removed soils (dyes, roofing tar) from the polyethylene surface, but failed to do so from the skin. None of the cleaners, waterless or conventional, removed household adhesive cement either from the skin or the polyethylene surface. On the 36* Industrial Medicine and Surgery APC 001286 basis of the testing procedure, one type III wa aromatic and other unsaturated hydrocarbons. terless cleaner was the most efficient in its clean Results of the physical analysis of the solvents ing ability against the remaining nine soils. are shown in Table I. The index of refraction of Thirteen waterless and two conventional cleaners solvents identified as deodorized kerosene and were rated from average to slow in removing light petroleum oils is about 1.4290 to 1.4296 soils. One waterless cleaner (2, wetting agent (4, 5, 6, and 9). The refractive index of those type) and four conventional products (three Identified as aliphatic hydrocarbons, or purified powdered and one common bar soap) were con hydrocarbons is 1.4194 and 1.4182 (8 and 13). sidered ineffective for special soil removal. Those containing aromatics (1, 3, 10, and 14)' have higher refractive indices and specific gravi Solvent Content ties. giNCE some manufacturers did not supply ade Waterless hand cleaner 15 (wetting agent type quate information on the solvent used in their III) was the only cleaner that did not contain products, it was necessary to identify them any water-immiscible solvent. Cleaners 2, 11, and through physical analysis. There was additional 12 (wetting agent type III) contained relatively need for undertaking these analyses, since several small amounts, 4.2%, 4.3%, and 18.6% respec cleaners containing kerosene showed contrasting tively, compared to the remainder of the cleaners behavior on the skin. which contained solvents in amounts ranging Steam distillation of all cleaners was per from 31.9 to 56.7%.* formed, using 50-gram portions to which six to It is significant that cleaners 1, 3, 10, and 14, eight grams of sodium chloride were added to which were considered unsatisfactory in over-all minimize emulsification. This process vfas re performance in the laboratory and field studies peated on additional portions of each cleaner, if prior to the solvent analyses, all contained aro necessary, until sufficient quantities of the water- matic hydrocarbons. This finding would suggest immiscible solvents had been separated for frac that the aromatic hydrocarbon fraction was the tionation and further tests. After determining cause of their adverse reactions on the Bkin. This the specific gravity of the solvent mixtures, frac cannot be stated categorically until further stud tional distillations were conducted at 10-12 mm ies of the action of aromatic and aliphatic sol pressure. The individual fractions were- analyzed vents on the skin are made, because cleaners 3, by infrared spectrophotometry and the refractive 10, and 14 also contained alkali, which can be a index of each fraction determined. skin irritant. The infrared spectrograms of most of the sol vent fractions were similar to those of aliphatic Residual Effects on Metals hydrocarbons. Solvent fractions from two of the l^THEN dealing with precision instruments or cleaners (1 and 3), however, yielded a pair of delicately tooled components of mechanisms strong infrared absorption bands characteristic such as jet engines, corrosion from any source of aromatic groups. These same bands were pres is a highly important consideration. Since all of ent in the spectrograms of two additional cleaners the waterless cleaners left a residue on the hands, (10 and 14), although their intensities were markedly lower. The presence of aromatics in certain solvents explained in part some of the dif We with to Acknowledge the assistance of M*. Rotbut G. Kbinan of thia laboratory for devising the steam distillation procedure and for the interpretation of the Infrared examination of the solvent fractions. ficulty in correlating our derma tologic laboratory and field data with the solvents as reported by the manufacturer. For example, some cleaners reported to contain Cleaner* Table I. Physical Analysis Data Gm % Water Immiseible Solvent Manufacturers' Solvent Irtenti- fleation Aromatics Present Specific Refractive Gravity Index deodorized kerosene had been found superior to others contain ing plain kerosene or related sol vents. Upon examination of the 1 6 12 b 18 42.6 61.8 18.6 43.0 68.0 Hydrocarbon Deodorised kerosene Mineral oil Light petroleum oil Purified hydrocarbon Yea No No No No 0.746 0.703 0.680 0.744 0.707 1.4467 1.4206 1.4104 1.4206 1.4182 spectra of the latter solvents, aro matics were noted in all but one (7), where a plain kerosene type 11 2 14 8 4.2 None No -- 1.4610 4.8 Fatty alcohol No -- 1.4480 48.4 None Yea 0.762 1.4818 81.0 Aliphatic hydro* No 0.708 1.4104 had been indicated as the solvent. On the other hand, aromatics .were absent in all cleaners con 10 3 47.1 6C.7 carbon Odorless oil base Mid^ontinent petroleum Yea Yea 0.760 0.766 1.4322 1.4317 taining deodorized kerosene. This is reasonable, since the deodoriz ing treatment of kerosene with fuming sulfuric acid removes 16 4 6 7 0 Sulfonated vegetable No *-- -- oil 48.6 Light technical oil No 0.718 1.4200 68.0 Deodorized keroaene No _ 0.746 1.4200 87.3 Kerosene -- 0.761 1.4471 APC 001287 August, 1957 363 the corrosive effect of these residues on metals skin surface sebaceous material was similar to was tested by having 18 of the laboratory per that of Cruickshank,0 essentially the immersion sonnel use the waterless cleaners three times of the hand and forearm into a cylinder of ace daily and handle chips of aluminum, brass, cop tone for three minutes. In this investigation, per, iron, and lead after each use of the cleaner. both hands were immersed to the wrists sepa After six weeks of this procedure, no corrosive rately. Ethyl ether was used, since other in- effects were demonstrated on the metals studied. vestigators7-'10-10-11 have shown that this solvent causes only temporary superficial irritation to Pkysiologic Observations on Humans the skin surface and is superior to other solvents in extracting skin fat. The analysis of the ether- Mildness tests: Although leaving a closed soluble substances was similar to that of Herr patch containing cleaners in contact with mann and Prose,7 in which the ether washing the skin for even a short period of time producewsas filtered, transferred to a weighed container, a greater insult to the skin than normal use of evaporated, and the residue weighed on an ana the cleaners, this test does demonstrate the rela lytical balance. The difference in weights repre tive mildness of various preparations. By patch sented the quantity of ether-soluble lipid ma test, we found that the wetting agent type clean terial. ers could be classed as nonirritant, those con Twenty volunteers, divided into two groups of taining solvents as mild or severe irritants, and 10, participated in the lipid studies. In group A, those containing large amounts of alkali and sol each of seven subjects used a separate waterless vents as severe irritants. cleaner and each of the remaining three was as Severe patch test reactions to waterless clean signed a conventional cleaner. In group B, eight ers do not always mean that similar reactions waterless cleaners and two conventional cleaners will occur in actual use, for a solvent or alkali were assigned. The subjects were instructed to or a combination of the two applied to the skin use the assigned cleaner three times daily for and then covered will most likely produce a re two months, avoiding other cleaners and solvents action. However, it is probable that those cleaners during working hours and at home. Lipid extrac which do not produce any reactions, or, at the tion tests were performed weekly to develop com most, mild irritation under the 24-hour patch parative lipid values. The subjects did not wash test, will have less tendency to harm the skin. their hands nor have them contact any water for Patch tests performed to determine irritant in four hours prior to the tests. It is possible, when dices only, do not exclude the possibility of sen using a restricted area of the skin for the re sitization to the products tested. moval of surface lipid, to protect completely the test site and thus avoid environmental contami Skin Surface Lipid Removal nants.7 In this study, using both hands as test 'J'HE normal skin surface has a lipid film con areas made protection impracticable. sisting of fatty acids, cholesterol, and liquid The results showed that three waterless clean waxes derived from the sebaceous glands and ers, 2, 11, and 15 (wetting agent type III), and keratinizing epidermis.5 This constitutes, at least two conventional hand cleaners (a common bar in part, a natural barrier against water-Boluble soap and a powdered type) had little, if any, irritants. Soaps, detergents, solvents, and alkalis demonstrable effect on defatting the skin sur are capable of removing the lipid film; however, face. Following the use of cleaners 6 and 9 (sol the physiologic restoration of- surface fat ordi vent type I), 12 (wetting agent type III), and narily maintains an equilibrium unless it is se one conventional hand cleaner (powdered type), verely disturbed or intrinsically deficient. the amount of surface skin lipids recovered was .The lipid tests were undertaken to determine slightly less than that recovered prior to their if waterless hand cleaners, when used daily for a use. The use of cleaners 1, 5, 7, 8, and 13 (solvent relatively long period (two months), would cause type I) and 10 (alkali type II) caused a con a decrease in the amount of surface lipid nor siderably lessened amount of recoverable lipid. mally present on the skin. Baseline values were The greatest decrease in the amount of recovered established for the subjects' recoverable surface skin lipids occurred after the use of cleaners 4 lipids before testing the waterless hand cleaners. (solvent type I) and 3 and 14 (alkali type II). We then determined the amount of recoverable In the two subjects using conventional cleaners lipid in the same subjects, some of whom used and a hand lotion, the amount of recoverable waterless cleaners. These results were compared surface lipids was considerably greater than that with those from selected control subjects who prior to using hand lotion. Undoubtedly, the .in used conventional soap and water cleansing tech crease was due to the emollients in the lotion, niques. Ether extraction procedures were em rather than to a surge of sebaceous flow. ployed each week to develop comparative lipid The influence of weather upon the condition values. of the skin is important when considering the The technique employed for the removal of amount of lipids present on the surface of the 36i Industrial Medicine and Surgery APC 001288 normal akin, particularly during a two-month period. Usually, the amount recoverable is greater in the summer when heat permits a smooth flow of sebum.11 The subjects in group A used the cleaners during the winter; those in group B during the summer. Waterless cleaner 14 (alkali type II) used in the winter showed a much greater capacity to decrease the amount of re coverable surface lipids than waterless cleaner 15 (wetting agent type III) used during the same period. During the summer, two waterless cleaners, 1 (solvent type I) and S (alkali type II), were associated with marked decreases in the amounts of recoverable skin lipids as com pared to the six other waterless cleaners, 2 and 11 (wetting agent type III) and 1, 6, 7, and 9 (solvent type I). These tests corroborate the results of the microscopic skin grades obtained in field trials of the cleaners, and also of the solvent content study of waterless cleaners. In general, cleaners con taining no solvent, or relatively small amounts, were associated with the least amount of surface skin lipid removal, whereas those containing aro matic hydrocarbon solvents and/or alkali were associated with the greatest amount. Skin pH Change and Recovery Time ^ORMALLY, the surface pH of the skin, often referred to as the "acid mantle layer," ranges from 4.0 to 6.5. The importance of maintaining the pH of the outer layer within this range has been emphasized by various investigators.11-14-18'1* Among the factors which alter the skin pH are alkalis, soaps, detergents, and solvents. The nor mal skin, when exposed within reasonable limits to these agents, has the ability to neutralize their action. Physiologic mechanisms believed to bring about the neutralization are the influence of sweat,17-18 the buffering effect of the amino acids of keratin and sebum,1*-20 and changes in the keratin layer which give rise to C02 diffusion.11 Prolonged exposure to strong cleansing agents can produce a contact type dermatitis believed to occur in part through the removal of the "acid mantle layer." This has been demonstrated by Burckhardt10 in his studies of eczematous pa tients who lacked the ability to neutralize alkali. He concluded that decreased resistance of the skin to alkali rather than allergic hypersensi tivity was an important cause in this form of dermatitis. Laboratory studies on skin pH were therefore undertaken to determine the degree of skin surface alkalinity brought about by wash ing with waterless cleaners compared to con ventional cleaners and the time required for the skin pH to return to normal. Thirty human subjects (11 females and 19 males) comprised the study group. The subjects were instructed not to wash their hands for at least two hours prior to the tests, and to avoid the use of hand creams or lotionB after washing. The procedure for determining skin pH was that of Blank,21-11 using a Beckman pH Meter with external skin electrodes. Baseline pH determinations on the palmar and dorsal surfaces of each hand were obtained. A waterless cleaner was then applied to the palm of one hand and an equal amount of a conven tional control cleaner to the other. The areas were scrubbed for 30 seconds with a pledget of cotton, pH determinations being made at this point and at regular intervals after removal of cleaners until the pH returned to normal. The experiment was then repeated using the dorsal surfaces of each hand. The waterless cleaners were removed from the skin with a paper towel, and the conventional cleaners were first rinsed off with water, followed by drying of the hand with a paper towel. Table II. pH and Averace Restitution Times op Individual Cleaners Cleaner Type pH of Undiluted Sample 9I 8.03 11 III 8.14 12 III 8.69 1G III 7.26 16* Sulf. oil 6.69 2 III 8.16 17' Syndet -- 1I 9.63 41 8.12 7I 8.07 <I 7.42 IS* Powder -- 8I 8.17 GI 8.87 IS I 8.09 3 II 8.16 14 II 9.06 10 II 8-92 'Control conventional cleaner*. pH of b% Aquwui Solution 6.87 7.40 6.76 7.62 6.72 8.39 10.32 9.61 8.37 9.20 8.00 9.10 8.92 8.81 8.12 8.46 9.87 9.12 Av. pH of Skin Before Cleaner Application 6.97 6.24 6.61 6.93 6.67 6.02 6.88 6.76 6.24 6.71 6.36 6.86 6.24 6.49 6.78 6.91 6.66 6.87 Av. pH Unit Riee Following Skin Application 1.28 0.14 0.32 0.97 0.66 0.66 2.31 1.81 1.27 1.23 1.22 2.40 1.68 2.19 1.76 1.66 2.40 2.06 Av. pH Unit Drop Follow ing Cleaner Removal 0.67 0.12 0.19 0.38 0.31 0.17 1.18 0.78 0.68 0.48 0.41 1.14 0.66 0.8ft 0.37 0.28 0.44 O.ft? Av. Time Required for Reatitution of Skin pH (in Minutea) 10 10 1ft 16 13 20 29 33 38 38 4ft 61 60 80 90 90 106 166 APC 001289 August, 1957 365 The three conventional cleaners selected as controls included a sulfonated oil, a heavy duty powdered soap, and a powdered synthetic de tergent. It was demonstrated by Klauder and Gross,14 in their studies on the effects of soaps on the pH of the skin, that higher pH values of the skin following the use of soaps and detergents re quired longer restitution time. Our results agree with these findings for con ventional cleaners. However, when conventional and waterless cleaners are compared, the syn thetic detergent and the heavy duty powdered cleaner produced considerably higher unit rise in pH than the majority of the waterless cleaners, but were markedly lowered following rinsing. For example, the synthetic detergent and the heavy duty cleanser produced rises in pH of 2.31 units and 2.40 units respectively, which decreased 1.18 and 1.14 units following rinsing of the hand. The corresponding restitution times were 29 and 51 minutes. A waterless cleaner of solvent type (5) and one of alkali type (14) produced pH rises of 2.19 units and 2.40 units respectively while in contact with the skin, and decreased 0.85 and 0.44 units following removal of cleaner, with corresponding restitution times of 80 min utes and 105 minutes. In a few instances, there was little difference in skin pH after use of waterless or conventional cleaners following rinsing and/or removal. In other instances, the skin pH following removal of the waterless cleaners was lower than that of conventional cleaners after removal from the hands, yet the pH restitution times were much slower with these waterless cleaners. For exam ple, each of two waterless cleaners caused skin pH rises of 1.2 units following removal of the cleaner. A restitution time of 38 minutes was recorded. The synthetic detergent caused a skin pH rise of 2.3 units following removal of cleaner. The restitution time was 29 minutes. An explanation for this observation is prob ably the incomplete removal of the waterless cleaners from the skin. Possibly the oily residue deposited by some waterless cleaners may impede the exit of those substances which act to restore the skin pH to normal within 45 minutes. The rinsing, drying, and more complete removal of the conventional cleaners from the hands are undoubtedly advantageous in aiding the skin to overcome the relatively large pH increase produced. All of the waterless cleaners produced a higher pH in an aqueous solution than when undiluted. This is probably due to hydrolysis of the alkali components of the cleaners. In no instance did the pH of the skin rise above the pH of the undiluted waterless cleaner or the aqueous solution of the conventional cleaner. see ! Field Trials Objective results: Field trials were con ducted on 16 waterless hand cleaners and four conventior al industrial hand cleaners among 500 subjects divided into five groups each con sisting of 100 men, including machinists, welders, sheet metal workers, painters, mechanics, car penters, photographers, linotype operators, and office workers. By distributing a cleaner to 26 subjects, three waterless cleaners could be tested against one conventional cleaner in every group studied. Weekly observations on each group were made for a period of three months. Prior to the actual use of the cleaner, the hands of each par ticipant in the study were examined with a binocular dissecting microscope to determine their initial condition with regard to erythema, scaling, and Assuring, or, in rare instances, eczematized skin. The following basis was used for grading the hands: Grade Microscopic Skin Grading of Hands 10 -- Smooth, with no evidence of scaling (best grade possible). 9 -- Very slight evidence of scaling. 8 -- Slight evidence of scaling. 7 -- Moderate scaling and slight redness. 8 -- Moderate scaling and redness. 6 -- Marked scaling, redness, and dryness. 4 -- Marked scaling, redness, extreme dryness, moderate cracking. 3 -- Extreme redness, dryness, and cracking. 2 -- Extreme redness, dryness, and cracking, with deep fissures. 1 -- Raw and bleeding. 0 -- Eczematous lesions (worst grade possi ble). i t The technique was suggested by Johnson,'Kile, Kooyman, et al2i and has been used many times in evaluating the effects of soaps and synthetic detergents on the hands of housewives. In addition to the microscopic hand examina tions, a history of skin diseases was recorded prior to beginning the field trials. Each individual was then provided with a container of cleaner, a supply of paper towels, a list of printed instruc tions, and finally the proper use of the cleaner was demonstrated to the participants. In evaluating the action of these agents on the hands microscopically, two of the cleaners, both of wetting agent type, produced lessened scaling and increased smoothness of the hands of their users, machinists who come into contact with oils and solvents. In contrast, the hands of those using one of the most irritating of the cleaners showed a marked increase in scaliness. It is significant that the improvement in scalihess and smoothness shown with the two cleaners of wetting agent type occurred in the winter-spring season, when scaling is more prevalent, while the group which showed the most adverse effects Industrial Medicine and Surgery APC 001290 was observed in the summer, when scaling is less prevalent Waterless cleaners of the wetting agent type were associated with higher skin grades than seen with cleaners of the solvent type. The lowest grades were seen among those using the alkali type waterless cleaner containing solvent. Subjective Results |N the clinical trials, several subjective observa tions were made regarding the use of all 16 cleaners. (a) After-feel and residual odor: The unpleasant after-feel and the residual odor imparted to the hands have more importance than just a "feeling of unpleasantness." Actually, cer tain occupations did not lend themselves to the use of these cleaners; for example among pho tographers, the cleaners often left a deposit on the film, prints, and sometimes the lenses. Among linotype operators, greasy cleaners made the fingers too slippery to punch the keyboard prop erly. Typists experienced the same effect as linotype operators, and, in addition, complained of finger marking and smudging papers because of the dust and dirt collected and adherent to the oily film on the fingers. Laboratory workers whose duties required the handling of glassware, pipettes, and precision instruments complained of the greasy residual as a contaminant. An in teresting complaint registered occasionally but not correlated with any particular preparation was that the waterless cleaner made the hands too soft. At times calluses were lost, causing the hands of workmen to become too tender. (b) Cuticle and nail toil: All of the waterless cleaners have a peculiar capacity for depositing the loosened soil around the cuticles and under the nails. The extra effort required to remove this Boil and the fact that the soil frequently was not present in these areas prior to cleansing constituted a legitimate com plaint. (c) Preferred cleaner: The largest percentage of the field trial sub jects preferred the use of conventional cleaners to waterless cleaners, although those who used four of the waterless cleaners preferred them to conventional ones. objective of this study was to establish, if pos sible, a group of standards which could be utilized by the manufacturers of waterless clean ers in the development and testing of their own products. Further, it was hoped that some of these standards would form the basis for water less hand cleaner specifications. Fifteen waterless hand cleaners representative of three basic types were evaluated in the labo ratory and in field usage trials to obtain in formation regarding their behavior on the skin compared to five conventional industrial hand cleaners and one synthetic .detergent. Selected standards known to be practical in the study of potential cutaneous irritant effects and physical characteristics of soaps, detergents, and solvents were utilized to determine: A. In the laboratory: 1. Free alkalinity and acidity. 2. Cleaner stability at various tempera tures. 3..Relative cleaning efficiency. 4. Solvent content. 6. Residual effects on metals. 6. Patch tests for relative mildness. 7. Skin Burface lipid removal. 8. Skin pH change and recovery time. B. In the field trials: 1. Skin grades. 2. After-feel and residual odor. 3. Cuticle and nail soil. 4. Preferred cleaner. When the laboratory and field data were as sembled and analyzed, it was plainly evident that differences in performance existed among the waterless cleaners and the controls which had been tested. The results of this study, however, should in no way be misinterpreted to imply that the only acceptable waterless cleaners are those which were evaluated or that the only inferior ones are those which performed poorly in the study. Both during the course of and after the laboratory and field trials it was recognized that there were a number of waterless cleaners com parable to those evaluated. Howeyer, to have in cluded in this study all cleaners sent to us or about which we had heard would have eventuated in a project requiring several years to complete. Summary IT is accepted that the most essential require ment of a good industrial cleaner is that it will not harm the skin. When industrial hand cleaners cause excessive lipid removal, unduly dehydrate the skin, or markedly alter Bkin pH for prolonged periods, they should be considered as harmful and undesirable. It is also important that the cleaner be able to remove soil and at the same time be pleasant to use. Thus, a basic Conclusions as a result of a study with selected testing I techniques, 11 of the 15 waterless cleaners studied were classed as satisfactory, while four of the cleaners were definitely inferior in per formance. 2. Those cleaners classed as wetting agent type were found to be preferable to those classed as solvent type. 3. Cleaners which contained alkali or combina tions of alkali and solvent were associated with APC 001291 August, 1957 367 more irritant action on the akin than waa seen with the other types. 4. Aromatic hydrocarbons should not be in corporated into the cleaner solvent. 6. Waterless hand cleaners have a practical ap plication for usage under a variety of conditions: (a) Where workmen encounter tar, paint, heavy greases, dyes, and inks, among other tenacious soils. (b) In areas where workmen must walk long distances to obtain washing fa cilities. (c) On aircraft, submarines, and surface vessels where water storage may con stitute a problem. (dj In tropical and polar installations, provided the specific cleaner can meet temperature requirements. (e) In those operations where.machinists, mechanics, field crews, road gangs, and maintenance men are in contact with variable degrees of tenacious Soilage. The waterless cleaners tested represented fair to high grade products except for the few con sidered inferior. As a group, they can replace effectively raw solvents for hand-cleaning pur poses. Some are definitely superior to most con ventional hand cleaners for rapidly removing certain tenacious soils. By no means are water less cleaners exclusive substitutes for conven tional products, but they are more convenient and efficient for selective usage. References 1. Lsaan, M. A.: Waterless Hand Cleanan. Drug and Cos metic industry, 72:326 (March) 1663. 2. riSHBBiN. M. (Editor) : Medical Um of Soap. J. B. Lipptneott Company. Philadelphia, 1646. 8. Fed. Spec. P-S-636b (4 Jan.) 1961 -- Soapa and Soap* Product* (Including Synthetic Detergent*); Sampling and Testing. 4. P-H-31 (Navy Ships) (4 Feb.) 1962 -- Interim Fed. Spec. Hand Cleaners, for Use Without Water. 6. Rothman, S.: Physiology and Biochemistry of ths Skin. The Univenlty of Chicago Press. Chicago, 1964. I. CxuicxaHANK, C. N. D.: Evaluation of Skin Cleansers and Protective Creams for Workmen Expoeed to Mineral OIL Brit. J. indust. Med., 6:204. 1946. 7. HegxNANN, F.. and Pxosb, P. H.: Studies on the Ether- Soluble Suhstancsa on the Human Skin. J. Invest. DermeL, 16:217, 1961. 8. Kvoshino, 8. A.: Investigations Into Pharmacology of Skin Fata and Ointment#; Collection and Quantitative Deter mination of Lipids on Skin. Acta pKarmaeoL st lesioot, 6:648, 1946, 9. JoNga. K. K., SrgNCBX. M. C,, and Samcum, S. A,; The Estimation of the Rate of Secretion of Sebum In Man. J. invest. Dermet., 171 til, 1961. 10. Pxitchabo, J. EowAton, L. D,, and Chbmtian, J. E.: The Study of Surface Lipids of Skin. J. Am. Bkarm. A., 86:646, 1949. 11. Emanuil. 8. V.: Quantitative Determinations of the Sebaceous Glands' Function, with Particular Mention of the Method Employed. Acta Dermal.-VenereaL, 17:444, 1966. If. Gaul, L. B., and Umpopwooo, Q, B.: Relation of Dow Point and Barometric Pressure to Chapping of Normal Skin. J. invest. Dermat^ 19:9, 1966. 18. Blank. L H.: Action of Soap on the Skin. Areh. Dermat. A Syph., 89:611, I960. 14. KLAUPia, J. V,, and Gaoaa, B. A.: Actual Causes of Certain Occupational Dermatoses. 111. A Further 8tody with Special Raferenee to Effect of Alkali on the Skin, Effect of Soaps on pH of Bkin, Modern Cutaneous Detergents. Areh. Dermal, dt Syph^ 68:1, 1961. 16. Gnoaa. p,, Blade, M. 0,, Chestse, B. J., and Sloan* M. B. i Denaatltla of Housewives as Variant of Nummular Beamns, A Study of pH of the Skin and Alkali Neutralisation by the Burckhanlt Technique; Further Advances In Therapy and Prophylaxis. Areh. Dermal. A Syph,, 70:94. >1964. 16. Bubckuabot, W.: Beitrmge tur Ekiemfragt; DU Bollo dca Alkali in der Pathogeneee das Ekearns spesieU das Gewebaeksema. Areh. $. Dermat. a Syph., 173:166, 1936. 17. Rosxrr, P., and Jaddou, J.: Untarsuchungan fiber den Elnflus* der Schweiasekretion auf die AlkaUneutralisatlons- fihigkeit der Haut. Dermatologiea, 86:72, 1942. 18. Veembex, D. J. H.: Method for Determination of Neu tralisation of Alkali by Skin. NederL Titdschr. v. gsnsssk., 94:3649 (December 9) 1960. 19. Yexmxza, D. J. H.. de Jono, J. C.. and Lbnbtea. J. B.: Significance of Amino-Acids for Neutralisation by Skin. Der- matelopica, 103:1, 1961. 20. Jacobi. O.: Uber die RcaktionaffihigkeU und das NeutraUsationsvcrmogen der lebenden menschlichea Haut. Dsrmot. Hchniehr., 116:738. 1942. 21. Pitch, H. G.: Das Neutraliaationavermfigen der Haut gegenttber Laugen und seine Besiebung sur Kohlensfiureabgabe. Arch. /. Dermat. u. Syph., 133:691, 1943. 22. Blank, I. H.: Measurement of pH of the Skin Surface. I. Technique. J. invest. Dermat., 2:67, 1939. 23. Blank, 1. H.: Measurement of pH of the Skin Surface. II. pH of the Expoeed Surfaces of Adults with No Apparent Skin Lesions. J. Invest. Dermat., 2:76, 1989. 24. Johnson, S. A. M., Kilx, R. L-. Kooyman. D. 6., Wmntuouftg. H. S., and Baoo, J. S.: Comparison of Effects of Soaps and Synthetic Detergents on Hands of Housewives. Arch. Dermat. A Syph., 68:648, 1963. Objectives am a frequent visitor to our Medical Center at Pisgah Forest. I never look at this I adequate, but Bimply constructed, building without a feeling of pride because of the minor role I played in bringing this facility into being. I likewise look with pride as I enter the building and read the dedication plaque which is located in the small entrance foyer where all may see it. I have a feeling of pride because here again I had a minor role in stating these objectives. As I read them today, I feel that they just as adequately state what we now hope to accomplish as they did when the Medical Center was dedicated in 1952. The plaque reads: "The professional staff and facilities of this Medical Center are pledged to the task of achieving a healthier and happier life span for our workers through sound medical practices in order that, by useful and gainful activity in their work, homes and communities, they may become even better examples and stronger defenders of the principles and way of life which make us a nation of free people." --From "An Industrialist Looks At Occupational Health/' by N. H. Columoh, Exaeutlvs Vico President, OUn Mathlsaon Chemical Corporation, presented at the Governor's Conference on Occupa tional Health. Raleigh, North Carolina, January 64, 1967. APC 001292 388 Industrial Medicine and Surgery Noise Control in New Plant Design J. W. JACKSON, JR., Construction Engineering Division THOMAS B. BONNEY. Industrial Hygiene Department S. E. BITTNER. JR., Construction Engineering Division Aluminum Company of America Pittsburgh, Pennsylvania IN 1953, Aluminum Company of America 202,000 sq ft. A two-story office building, planned an expansion of its fastener and 46 ft by 300 ft is attached to the front or foil production facilities, both of which were north face of the main one-story plant struc housed in their Edgewater (New Jersey) ture and a 60 ft by 80 ft boiler house ad Works. It was decided to place the entire joins the southwest rear corner. Fastener and Screw Machine Products Di In general, 60-ft roof trusses, supported vision, in a new plant. The usual considera on steel columns at 20-ft centers, with 16 ft tions, including the available labor market, of clearance to the bottom chords and about transportation facilities, utilities, and hous 23 ft to the ceiling, comprise the framing ing, were thoroughly studied and eventually in the manufacturing area. Exterior walls' a site on the outskirts of Lancaster, Penn are 8-inch concrete block faced on the out sylvania, was selected. Alcoa, conscious of side with open-ribbed or "fluted" aluminum the increasing attention being given to in panels. Interior walls of concrete block, dustrial noise, was anxious to include noise poured-in-place gypsum roof deck, and con control in the design of this plant. crete floor slabs with brick in the trucking The new plant is situated on an 83 acre aisles, make up the typical construction. plot and so oriented that substantial ex The heating and ventilating system is an pansion is possible on any of three sides, as unusual one; there are few wall openings, shown in Fig. 1. Except for minor aux no cross-ventilation or natural ventilation iliary structures, the plant is under one and no air-conditioning. Oil mist haze, roof, 420. ft by 480 ft, covering some which usually accompanies screw machine Fig. I. LencAstor -- Artist'* rendering of Aluminum Company of Americe's Leneester Plent for manufacturing Aluminum screw meekine products, rivets end noils. ARC 001293 Industrial Hygiene Quarterly 119 Fig. 3. Edgawatar -- Lin* of >m*ll rivet haadan. Net* th* congaitad condition *nd th* larga window *r**. operations, is practically eliminated "by this system. The design and performance of this heating and ventilating installation are discussed in detail in a paper entitled, "Heat, Mist.and Noise," presented by Al coa's staff engineer, B. R. Small, at the Nineteenth annual Industrial Hygiene Foun dation meeting in Pittsburgh, November, 1954. As most of the fastener manufacturing equipment in the Edgewater installation was to be moved to the new location and many similar machines were to be added, it was considered wise to make a noise survey at Edgewater. Thus, during the time when several suitable plant sites were being re viewed and initial layouts and designs were in progress, the survey was conducted cov ering equipment operators' exposures and area noise levels, both inside and outside the building. Such information was to serve as a guide toward engineering noise con trol into the design of the new plant as far as possible, within the limits of good construction practices and reasonable econ omy. A brief description of the situation at the Edgewater Works seems advisable (Figs. 2 and 3). The rivet and screw ma chine departments were housed on the fourth and sixth floors, respectively, of a 10-story reinforced concrete building, lo cated adjacent, to a residential area. The floor, ceiling and walls, being of concrete, were highly noise reflective surfaces. The Fig. 3. Edgawaiar -- A lin* of hand tcr*w machinal. Net* th* ceng*it*d conditioni and th* noil* raflactiv* concrat* fleon, w*IU, calling and columns. window area in the 17-ft high walls was con siderable, which proved a double problem. Since there was little transmission loss through the windows (especially in the summer when most or all were open) there existed the threat of community complaints. Also, since glass is acoustically very reflec tive, the large window area helped to main tain the high noise levels within the plant. Both departments experienced consider able growth over the years. New machines had been added continually until it was im possible, because of space limitations, to add any more. These many-varied pieces of equipment, when placed in relatively small areas, insured an extremely high back ground noise level. The wide variety of ma chines also meant that it was quite unlikely that any single noise reduction technique applied to each machine would be successful. Any reduction at the source is usually a big step in the solution of noise control problems. Even a cursory investigation of the general conditions revealed that more information regarding specific types of ma chines would be needed if any reduction "at the source" was to be accomplished. Sev eral means of reducing source noise were suggested: (1) modification of the mecha nism; (2) enclosure; (3) isolation to pre vent machine vibrations from reaching base plates and floor; (4) reduction of air pres sure used in the operation; and (6) good maintenance. APC 001294 220 September, 1957 With these ideas as a start, it became necessary to investigate the various ma chines to determine which method might produce practical and significant reductions. Therefore, octave-band analyses of noises produced by several different machine types were recorded and studied. The first investigation was of the rivet headers. Most of the noise from these ma chines radiated from the gear case and machine housing, indicating that changes in machine design would likely be very re warding relative to noise reduction. From Alcoa's viewpoint, this was impractical, but it does present a real challenge to machine designers and manufacturers. Total enclosure also was impractical be cause both internal and external portions of the machines must be accessible for effi cient operation and maintenance. In addi tion, oil spray used in the operation would penetrate the absorptive lining of the en closure, creating a fire'hazard and affect ing the acoustic properties of the lining. Others have tried enclosures and discarded them for these same reasons. Partial en closures have not proved satisfactory be cause the large openings required for access render the enclosures acoustically ineffec tive; also, operators consider them as being "just in the way" and usually treat them accordingly. Modification of machine mountings gave as many different results as there were ma chines. Some pieces of equipment were at tached to heavy cast-iron bases; some were mounted on wood or cork pads; others were anchored to the floor slab to prevent creep ing. The variety of machine mountings was the result of many trials and years of ex perience, not to mention whims and fancies. In general, modifications of mountings pro duced no appreciable noise reduction and, oddly, the best reductions occurred in the quieter machines. Therefore, changes in mountings were thought to be impractical and unimportant in reducing these source noises. One thing that was important, how ever, was to make certain the hammering noises were not carried through the new building by the floor slabs and columns as was the case at Edgewater where that building fairly "danced," radiating noise from all surfaces. Reduction of the compressed air noises did prove feasible. A certain amount of compressed air is necessary to blow the light aluminum rivet away from the die before the hammer returns on its next cycle. Most of the men worked under the assumption that if a little air pressure does a good job a lot will do a better job. As a result, often times a wide open valve of 90 psi of air was used to clear the rivets from the die. Some of these air lines were %-inch in diameter. It was found that a 'A-inch diameter line at a much reduced pressure was sufficient and considerably quieter. In some cases only 12 to 15 psi was required. By proper directioning of the jet so that there was a minimum interruption of the air stream by moving machine parts, fur ther noise reduction could be obtained. During the investigation of the rivet headers, it was discovered that many pulley and belt guards were loose and vibrating. These vibrations added considerably to the machine noise level. Secure fastening de vices placed on these guards and all other vibrating panels resulted in less rattles and additional noise reduction. An investigation of the screw machines showed that the main noise sources were the gear train, machine parts and guide tubes against which the stock material would rattle. Good maintenance of the ma chine parts usually reduces the over-all noise level but modifications in machine de sign are probably more rewarding. Again, the machines that were on hand had to be used and machine design was not a practical approach. Mast rewarding was the substitu tion of fiber-lined "silent" tubes for stock guides. This resulted in a reduction of noise from the stock tubes to a level below that from the machine parts. With the results of this investigation and studies of the Edgewater conditions, Alcoa was convinced that efforts should be con centrated on the noise of the rivet and screw machine departments at the new location. Thus, the problem at the Lancaster plant was to provide appropriate noise controls to relieve the employees in these two de partments, and also to prevent noise from these departments adding to the ambient levels of adjacent areas both within and without the building. As noise control takes many forms, it is important to apply the proper type of control and materials to suit APC 001295 i Industrial Hygiene Quarterly Ml the particular problem. The attack at the Lancaster plant followed the generally ac cepted fundamental principles as outlined below. I. Control of noise at its source. A. Vibration isolation. B. Machine modification. C. Orientation. D. Enclosure. II. Absorption -- reduction of reflected noise. III. Personal protection. Some conditions may be satisfied by a single type of treatment and aome may require a combination of several or all methods. Controlling the Noise at Its Source A vibration isolation: From the Edgewater studies, it was found that little benefit could be gained by revision of the machine mountings. Therefore, existing equipment and similar new machines were mounted as tests and experience had dic tated. To isolate the machinery vibrations in the floor slabs, thus preventing building columns, walls and ceilings from becoming transmitting media and radiating surfaces, as was so pronounced at Edgewater, several rather simple things were done (Fig. 4). The entire floor slabs of the rivet and screw machine departments were poured on a sand cushion of six-inch minimum thickness. This was done to prevent much of the vibra tion getting ito the underlying rock and transferring to adjacent floor slabs. Around the perimeter of these rooms, about 18 inches from the walls, a one-inch thick fiber- glas perimeter insulation strip was inserted in the floor slab. Also, insulation strips were placed around all column pedestals and other independent concrete foundations that pro jected into the slabs. B. machine modification: Considerable improvement was accomplished by regu- - JtiMMHM Cornu Wtrf*A*OOFWStf ANOdflAkVl <3 Concomr* T /' fkdf Ft09**LA.I AO+*V Aocx bY+iu, -- Acoosrtc Panels i ,9i *- NiQP+tHM Oft MfM MtA e- i 4covyric Plastrr ilm I' Cm Roof t 0LQKK Wah O > 3 -2 thick FiDcaolas PF-414 ? "SA^ah PtAATte Covkr6 OH. VAPOR AJtKA /* <c *^ "f o I! :: I - APlCuRmFiOnRuAmTt5DMCCoKMr^TviOA'ftD TCoMCAtTt Slock *Vau' -!2`Co*c*$tz Ilock tiAU " ^*. [ * ' t V . * * ** J Viall Foorma ----fj '.j * * * '----*--- ------ * / fThick Fibkholaj Sound AaotiiK.1^ , Sand cushion - mihiihuhi THIcknsss 6" - Detail at Interior Wall ^Asick 7ftvCKif*Q AlSLi ^ CoMc*grc fieot u. * C- I rJiw' /- fF,ioo* Sla& . I... SHDAT* MiHtMUM SaHO CuOHtOH UMorm KLOOtC JLAS *.1 tfhtck FtmeOOLAJ At9t"tTK* ST*tP SiCTon thru Typical E^tcrior, Wall 1M ACOVATlCAttY TftB AT CD Aft tAS ' `' >7^ TYPtCAL S&ct/qm Thru Fig. 4. APC 001296 222 September, 1957 Fig. S. LincuUr --- Operators landing a group of mall lingU-ttroki rivaf haadart. lating the air pressure and carefully sizing and directing the ejection nozzles on the rivet headers. Good maintenance of the ma chines, which included tightening and stif fening loose, rattling guards, was*helpful. The installation of Corlett-Tumer "silent" stock tubes on the automatic screw machines was of great significance. 3. orientation of EQUIPMENT: Near the machine, an operator will experience a de cided variation in the intensity of the direct noise striking his ear, depending upon hie distance from the noise source. In general, the intensity drops off from three to six decibels for each doubling of the distance from the source varying with the type of noise and the characteristics of the room. With the understanding that doubling the intensity of noise amounts to an increase of three decibels in the noise level, and a corresponding increase in loudness of about 20%, the spacing of machines becomes an important factor. Therefore, to accomplish any appreciable reduction the distance be tween machines was increased at Lancaster. Arrangement of equipment was carefully planned to meet production requirements and to provide aisles so that operators were not surrounded and bombarded with direct machine noises from all sides as had been the case at Edgewater. Such a layout re quired areas of 155 ft by 210 ft (34,000 sq ft) for the rivet department, and 90 ft by 210 ft (19,000 sq ft) for the Bcrew ma chines, which is approximately three times the respective areas occupied by these de partments at Edgewater (Figs. 5 and 6). D. enclosure: From Alcoa's experience, as well as that of others, it has been found Fig. *. Lincittir -- Opanton landing a group of Singla Spindla automatic straw machinal. Nota tha itaggarad arrangamant of machinal and tha acouitically treated walls. impractical to use total or partial enclosures on rivet headers or screw machines. Such devices for isolation interfered with efficient operation, maintenance and possessed other disadvantages as well. From a larger point of view, prevention of sound transmission from one room to another or to the outside is a common noise control' problem; and a> large factor in this case; Pn general! the transmission loss is governed- by the mass or weight of the di viding waif or partition. Transmission loss values usually increase three to six decibels for each doubling of the noise frequency and also increase four to five decibels as the weight of the wall is doubled. In someinstances, lighter weight double-wall con struction is effectively used, requiring strict inspection during construction to maintain the designed T.L. value. Fortunately, at Lancaster the direction of material flow and floor area requirements permitted the placement of the noisy rivet header and screw machine departments in areas which could be isolated rather easily (Fig. 7). Eight-inch concrete block walls, having an average T.L. value of 49 decibels were selected to enclose these departments. Although window openings were not es sential to the heating and ventilation re quirements, it was felt that most workers prefer being able to "see out." Thus, a few windows, amounting to about 5% or 6% of the exterior wall area were installed, re sulting in a T.L. reduction of about 12 decibels. Since approximately one-half the window area can be opened, the T.L. value APC 001297 Industrial Hygiene Quarterly 13 Floor plan. of the wall would be reduced by another 20 decibels with all windows fully opened. In some locations, such a condition would be very unsatisfactory, if houses or other buildings were close by these open win dows; but at Lancaster the distance to the property lines, neighboring buildings, houses and roads are such that plant noise is reduced to the point of being masked by the ambient area noise levels. In the event of future expansion, involving the erection of adjacent structures, these win dow openings could be walled up, thus re storing the full T.L. value of the 8-inch concrete block wall. Eight-inch interior concrete block walls provide sufficient at tenuation to safeguard all adjacent rooms. A satisfactory T.L. value of about 40 decibels is provided by the roof, which consists of gravel and waterproofing on a 2-inch, poured-in-place gypsum slab. Absorption of the Noise pACTORY noise is intensified when reflected noise is added to the direct noise from the source. Such a condition was decidedly evident at the Edgewater Works where noise fairly "bounced" off the hard-surfaced floors, walls, ceilings and sash, resulting in very high sound levels. Judging from this condition, it was easily under standable that acoustical treat ment would be a significant fea ture at Lancaster. Furthermore, as very little success was obtained through reduction of the noise at its source, it was realized that a considerable amount of acoustical treatment would be required to insure acceptable noise levels in both the rivet header and screw machine departments. Absorptive treatment is most effective when selected to suit a particular noise spectrum. This is because the coefficients of absorp tion vary with the frequency of sound, and the physical properties and method of application of the acoustical material used. There are a number of reliable working rules, based on research and ex perience, to guide in noise absorp tion treatment. Worthy of note is the fact that the doubling of the absorption units in a room reduces the noise level by about three decibels. Economics enters the picture as the point of diminish ing returns is reached in treatment costs. It became a simple matter to apply these factors to acoustical design of the rivet and screw machine departments of the Lan caster plant. The walls and ceilings of both rooms provided sufficient area so that with a covering of material having good ab sorption coefficients in the middle and high frequencies, substantial noise reductions could be expected. On the basis of the differ ences in room constants of the old and new plants, a reduction of 14 to 15 decibels in each room was predicted. Since there would be some quieting of machines because of modifications in them before placement in the new building and because of the greater dispersion of the machines, these factors would have some effect on the over-all noise level. Therefore, it appeared certain that the noise reduction actually accomplished would be greater than the predicted reduc tion based on absorption treatment only. The acoustical treatment consists of 2inch thick fiberglas insulation boards fas tened to the side walls and covered with perforated, corrugated aluminum sheets. Owens-Coming Fiberglas PF614 was se- APC 001298 224 September, 1957 s~~F*ct or ConeKira lock Wail t /////// ///Z/Zr/////. - lit t'lYoLMAHIZID WoooJtkip -mail to masdhky wall 1/2'Woimahihd Wocd-Stkip- hail to /*S arnia "4" ////tu/S-IZ/'-L- CtMeitr P'OaAOLAS 70 HAILIK Hi OIL YAPO* MIA 3'mDa JtnM tap* applho at jourra of "jAKAn'pLAmc com SHOWING APPLICATION OF ACOUSTICAL T*tATMtHT lected because of the efficient absorption coefficients in the particular frequencies in volved (Noise Reduction Coefficient .85) and the ease of handling in construction. The very slight absorption advantage in the 3-inch thickness did not warrant the 50% increase in material cost. The concrete block walls are 12 inches thick for a height of four feet above the floor, and eight inches thick from there up to the ceiling. The acoustical treatment was started at the 4-inch setback four feet above the floor, thus keeping the treatment beyond the range of possible damage during ma terial handling and other operations. By furring the fiberglas about % inch from the wall, the absorption in the low fre quencies was slightly improved. Wood fur ring strips were fastened to the wall to space and support the 2 ft x 4 ft fiberglas "bats" and to serve as nailers for the .024inch thick perforated corrugated aluminum sheeting. The perforations in the aluminum sheeting are Vs-inch diameter holes spaced on 5/16-inch centers, giving an open area of 13%. As long as the open area in the covering is over 10%, the acoustical ab sorption is not appreciably affected. The aluminum sheeting was erected so that the corrugations run horizontally, presenting an attractive, easy to clean wall surface and permitting wider spacing of furring strips and economy in construction. This treat ment covered about 10,000 sq ft in each room. In the room housing the automatic screw machine department, a covering of Saran plastic, in sheets 36 inches wide and .002 inch thick, was applied between the fiber glas insulation and the aluminum sheeting to prevent oil vapors from penetrating the acoustical blanket and creating a fire haz ard. The plastic covering was sealed around the edges and at the joints with strips of 3-inch wide Mylar adhesive tape. The cover ing was free to act with drum action on the surface of the fiberglas and thus did not harm the absorption effectiveness. On wall surfaces in the vicinity of roof trusses and bracing, where it was difficult APC 001299 Industrial Hygiene Quarterly i25 to erect the acoustical pan eling, a sprayed-on coating of acoustical plaster was applied to carry the treat ment to the ceiling. One-inch thick flberglas acoustical form board was used on the ceilings to serve Table I. Noise Reductions Accomplished at the Lancaster Works Reductions, in decibels, are based on comparisons of noise levels at similar locations in the Lancaster and Edgewater Works Fnqumey -- Cycles per Second Location Rivet Department Over* Below 75 150 300 COO 1200 2400 Above ail 70 150 BOO BOO 1200 2400 4800 4800 two purposes. It served as Operator's Exposure 10 10 15 13 13 17 IB 21 28 a form for the poured-in- Among Machines. #1 It 12 15 15 17 10 17 10 14 ph.ee gypsum roof slab and Among Machines* #2 20 IB 17 14 15 10 20 23 Amonr Machines* #3 10 30 gave a high noise absorp Screw Machine Dept. tion value to the ceiling Operator's Exposure 24 14 IB 0 21 22 10 21 17 areas, the noise reduction coefficient being .75. Since a poured-in-place gypsum roof was to be put on the entire plant, it was desira,ble to use the same form board throughout, thereby Among Machines, #1 Among Machines, #2 Outside the Plant* 20 20 O' DiitaBC. -- Eut*1 2 0 573 5 1 --3 -5 200* Distance --* East** 2 -3 1C 3 -1 --4 --7 0<K Distance -- South 7 11 13 11 11 7 2 --4 * Outside measurements at Lancaster compared to quietest outside measure* meats of Edgewater. * Opposite Air Intakes. obtaining very effective noise reductions in all plant areas. In the oil ment of the Lancaster Plant, below those mist area, Saran covering on the form board of comparable areas at Edgewater, have was not too practical, as it would prevent proved most successful. Levels at Lancaster the gypsum roof slab drying from the under are at comfortable levels compared to the side and it presented application difficulties. din formerly present at Edgewater. A thin neoprene coating was sprayed on the Four factors contribute to the noise re exposed surface of the form board ceiling duction : in the screw machine department. (1) Installation of acoustical materia] on It may be of interest to note that the walls and ceilings. This treatment has tre acoustical treatment on the walls cost about mendously reduced the amount of reflected $1.07 per sq ft, which included the Saran noise in the Screw Machine Department. plastic covering at 34 per sq ft and the At Edgewater, the noises reflected from neoprene spray at 2Wi per sq ft. To insure room surfaces added to noises coming di the best results for the investment in this rectly from the machines, resulting in high acoustical treatment, elaborate details were sound levels. At Lancaster, on the other shown on construction drawings and the hand, we do not have a room "filled with specifications spelled out the exact materials noise." and methods of application (Fig. 8). (2) Installation of lined stock feeding Personal Protection tubes on the automatic Bcrew machines. The "Silent Tubes" have silenced many large gECAUSE of the noise reductions accom noise-radiating surfaces that contributed plished, no personal protection was re considerably to the noise levels in the Edge- quired. water Plant (especially high frequency noises). Evaluation of Noise Control Methods (3) Sand cushion under floor slabe and installation of perimeter isolation strips. A y^FTER the new plant had been in operation check with a vibration pick-up showed prac for several months a noise control evalu tically no transfer of floor slab vibrations ation survey was conducted. Table I shows across the joints into adjacent slabs, col a brief r6sum6 of the results of this survey. umns and walls. Screw Machine Department (4) Better spacing of the machines was a large factor in the reductions in TN general, steps taken to reduce noise noise exposure experienced by individual levels within the Screw Machine Depart operators. APC 001300 S6 September, 1957 Rivet Department 'T'he favorable comments concerning the Screw Machine Department also apply to the Rivet Department The substantial noise reduction can be attributed to: (1) Installation of acoustical material on walls and ceiling as explained for the Screw Machine Department. (2) Attention to the air ejectors used to clear the rivets from the header dies. (3) Sand cushion under the floor slabs and installation of perimeter isolation strips. (4) Greater spacing between machines. Other Manufacturing Areas TN all other plant areas, such as the misx cellaneous fastener and finishing depart ments, maintenance and tool room, receiving and shipping areas and storeroom, the noise levels are at comfortable levels. This is due to the reduction and confinement of rivet header and screw machine noises in their respective areas and the use of acoustical form board in the ceiling treatment. Outside Noise Levels TsJOiSE levels outside the plant were re corded for a comparison with those found at Edgewater. These measurements were taken on a perimeter line at a distance of approximately 60 feet from the plant buildings. The highest readings were found near the air intakes. However, this is low frequency noise to which the ear is rela tively insensitive. Also, the distance the noise travels before reaching the plant prop erty line results in a considerable noise reduction. It is interesting to note that a noise spectrum could not be obtained at the front entrance since, at that point, the plant noises were at such a level as to be masked by wind and traffic noises. Not only did the instrument readings in dicate that a remarkable improvement had been accomplished, but the favorable com ments of many of the personnel also testify to this fact. Persons who had worked at the Edgewater Plant for at least 10 years and now work at similar jobs at the Lancaster Plant are enthusiastic over the results. Scientific Exhibits Tie AMERICAN industrial hygiene association Scientific Exhibits Committee wishes to solicit aika members foT scientific exhibits to be shown at the Industrial Health Conference in Atlantic City in April, 1968. Anyone interested should write for further information or for space application: A. c. pabst, Socony Mobil Oil Company, Inc., 160 East 42nd Street, Room 1401, New York 17, New York. World Congress on Accident Prevention Brusbels, Belgium will be the scene of the Second World Congress on the Prevention of Occupational Accidents. The meeting is scheduled for May 19-24, 1968. The Association Nationale pour la Prevention des Accidents du Travail and the Association des Industriels de Belgique are the cosponsors. Advance registration is required. Applications and inquiries should be sent to the Secretariat General du Deuxieme Congres Modialc de Prevention des Accidents du Travail, 29, Avenue Andre Drouart, Brussels, Belgium. APC 001301 INDUSTRIAL HEALTH CONFERENCE 1957 "FREON POWERED PORTABLE AIR SAMPLING KIT" R. C. CHARSHA and A. L. LINCH E. I. duPONT de NEMOURS and COMPANY CHAMBERS WORKS, PENNS GROVE, NEW JERSEY APRIL 25th, 1957 THE JET AIR SAMPLER Mobile air pollution surveys require analysis of "grab samples" which must either be taken to a laboratory for processing, or estimated in the field after passage through a solid, or liquid reagent designed to preduce a distinct color change on contact with the expected contaminant In collecting samples for laboratory analysis, several well standardized techniques are available: I 1. The entire air sample is taken to the laboratory. 2. The contaminant is concentrated from a known volume of air by: a. Scrubbing through a liquid which either dissolves the soluble components, or acts as an arresting fluid for dust impingement. b. Adsorption on an activated, porous solid such as silica, or alumina gel. 3. Dust collection on a filter. 4. Precipitation of particulate matter by impingement, thermal deposition, or in an electrostatic field. Concentration of the contaminants by absorption, filtration, or pre cipitation, as well as direct colorimetric field estimation requires movement of a known volume of air through the collection assembly. APC 001302 2- - Electrically driven pumps adapted to some assemblies (2) cannot be employed where explosion hazards may be encountered, and the batteries, or long lengths of appliance cord needed for power add bulk and weight to portable equipment already burdened with collecting equipment. Availability of 110 volt a.c. current usually presents an obstacle as air sampling frequently is needed far from appliance outlets. Hand operated mechanical pumps of three general types have offered the only practical alternative: 1. Rotating vane (5).' 2. Piston (usually a large volume glass syringe). 3. Rubber, or Neoprene squeeze bulb such as commonly furnished with the solid granule supported indicator detectors for H S, SO , HCN, etc. (5). 22 These mechanical pumping devices reduce the analysts' efficiency by expenditure of non-productive time and effort, require constant atten tion, and most are not suited to movement of relatively large air volumes required for accurate trace determinations. None of the types lend themselves to the analysis of the atmosphere which a workman is actually inhaling while working on his routine assignments. Vacuum production by a high velocity gas, or liquid jet passing through a venturi is a well recognized engineering principle widely applied in laboratories, and chemical manufacture (4). Application to easily portable equipment could not be practical until self-contained supplies of gas, or liquid in light weight containers under sufficient pressure, and in quantities sufficient to draw a reasonable volume of air through APC 001303 -3- the sampling system were available. Efforts were made to utilize liquid carbon dioxide (3), and compressed air (1), but the container weight, and high pressure hazards presented obstacles difficult to resolve. A high efficiency "micro aspirator" which requires low primary gas flow rates to produce a usable vacuum became available during the past year (1). Although originally designed to operate on compressed air, the venturi performs effectively on a "Freon" gas stream. Since a liquified gas offers the greatest space economy in transportation, selection of a low pressure "Freon" propellant in a light weight dis posable container offered the most promising solution to the problems posed by a portable pressurized jet pump. "Freons" widely used in re frigeration equipment, and as a propellant for insecticides, and many other pressurized products are readily available in compact one-pound "throw away" containers. "F-12"is well suited to generation of com paratively large volumes of non-flammable, non-toxic vapor under pressure sufficient to activate the aspirator, but not of a magnitude that would present a rupture hazard under normal conditions. The need for heavy and bulky gas meters, rotometers and orifice meters which require constant attention, or calibrated impingers used for manual pumping rate control is eliminated by introducing a limiting orifice between the gas supply and the venturi. Since the "Freon" pressure is a function of temperature (Fig. 3), the orifice calibration in terms of time required to draw a cubic foot of air through the sampling system must be corrected for temperature (Fig. l). In the range 50 - 105 F. the calibrations for six to twelve mils (thousands APC 001304 -4- of an inch) orifices are linear (Fig. 1 and 2). Between 50 and 20 F. the higher pressure "F-22", also available in disposable containers, is recommended. Fig. 4 shows an exploded view of an assembly which has performed consistently well under field sampling conditions. The discharge side of the needle valve supplied with the disposable can for recharg ing refrigeration units was rethreaded for 1/8 inch pipe. A 1/4 inch x 1/8 inch brass pipe bushing required to connect the valve to the aspirator was faced flat in lathe to provide a seat to seal the polythene gasket against the orifice plate. Support for the orifice plate is provided by a spacer that holds the venturi nozzle in place against the flange inside of the aspirator body. The side tap on the venturi is fitted with a 1/8 inch pipe adapter for the rubber tubing connection to the midget impinger exhaust connection (Fig. 5). The seal between the needle valve port and the orifice plate must be gas tight as leakage at this point permits "Freon" loss without useful air aspiration. Leakage at the tubing adapter will permit by-passing of the collecting scrubber, and give low results. To operate, seat the valve snugly on the "Freon" container, assemble the aspirator assembled on the valve port, open the valve wide (one to two full turns) to deliver full pressure against the orifice, and check for leaks. Soapy water, to which a few drops of glycerine has been added, applied with a small brush is an effective leak detector. Since the "Freon" pressure is dependent on temperature, this variable should +o 4 be determined within - 1 F. to maintain volumetric error within - "2% when sampling is started. A stainless-steel stem dial-thermometer APC 001305 -5- strapped in contact with the metal can is recommended. Best results are obtained when the charge temperature in the can is within a few degrees of the ambient air where sampling is to be carried out. After connecting the sample collecting equipment to the vacuum (side port) outlet on the aspirator body with flexible tubing, or a filter adapter, the assembly is ready for use. Fig. 1 is a representative sample of a calibration chart employed to determine minutes required to draw one cubic foot of air through the midget impinger shown in 0 Q Fig. 4 at temperatures between 50 - 105 F. for each of four orifices. Fig. 2 is an isothermal plot of time versus volume pumped for the three larger orifices. Although a midget impinger has been used exclusively by our Industrial Hygiene Laboratory, the choice of gas, vapor, mist or dust collecting apparatus is optional. The "Freon" vented from the aspirator does not under ordinary conditions dilute an air sample sufficiently to intro duce significant error even when the impinger is closely coupled as in Fig. 4. However, in confined locations where there is no air circula tion, samples collected near the floor may be diluted 10 - 15%. After operating 18 inches from the floor in an unventilated room containing approximately 550 cubic feet (6' x 9' - 10' ceiling) for ten minutes, air entering the impinger inlet contained 18% oxygen compared with 21% present initially. Approximately 1.25 cubic foot of "F-22" gas was released through a 10 mil orifice at 26 C during this period. An adapter permits use f a "millipore" micro-filter (6) directly on the side port of the aspirator body in place of the tubing adapter. APC 001306 6- - Conversion to a Greenburg-Smith impinger, electro-static precipitator, or absorption on porous solids is a simple operation. The choice of i procedure for detecting the expected contaminant whether a direct l visual indicating color reaction for field analysis by comparison with a calibrated scale, or color standards, or collection for laboratory analysis must be selected by the analyst, as an evaluation of standard procedures is beyond the scope of the development of a portable, selfcontained collecting device. The volumetric efficiency is surprisingly good (Table I). In the temperature range 45 - 97 F., the volume of expanded "F-12" gas consumed in pumping one cubic foot of air lies in the range 0.375 to 0.425 cubic feet and',F-22" in the range 0.312 to 0.452 cubic feet. One pound of "F-12" will pump 7 to 9 cubic feet at one atmosphere. Since the entire assembly ready for operation is compact, and weighs less than two lbs., the unit can be carried on a workman's back on a shoulder strap, or belt loop. By means of a flexible hose taped to his collar, continuous samples of the atmosphere that the subject is actually inhaling can be collected without interfering in any way with his routine job assignments. In this manner the question of representa tive sampling can be answered. The "Jet Air Sampler" is available in kit form from the "Union Industrial Equipment Company", 175 Main Street, White Plains, New York. "Millipore" micro-filter adapters, midget impingers, calibrated orifices, and supplies of "F-12" are also available from Union Industrial. APC 001307 -7- Summarv A compact air sample collecting assembly weighing less than two pounds vaporization and expansion of non-toxic, non-flammable is powered by ''Freon" from a disposable container through a micro-aspirator. A limiting orifice in the Freon gas stream is employed in place of space I consuming metering devices to determine sample volume from a timetemperature relation calibration chart. One pound of "Freon" will "pump" 7 cubic feet of air through a midget impinger, or filter. Using the 6 mil orifice 1 lb; of "Freon 12" will last 4 hours and 20 minutes. TABLE I Pumping Efficiency Determined By Rate "Freon" Consumption and Vacuum Produced "T ' Parameter Measured Orifice Size mil = 0.001 inch 8 mil. 10 mil. 12 mil Efficiency - weight"F-12" per Cubic Foot Air Average (6 determinations) Rgraanmges (,Temp. 70o -36nC)x grams Vacuum - Static (open end manometer mm Hg. 10C 26 C 40C $2 -3 19 21 25 55 v 5+9 -3 -4 27 31 40 96 70 124 APC 001308