Document epD4Q9Ma7kmvYGwRRJ2oRqJE

sWi .Alois' GLxVSB ^02VJI>AXV " riM*<r in ou^"M" . MamU^^CT^IMK H ON CtAH M I'uOOVCTN GRMntAU Opjicrs T0U21)0 ` Februa^ 12, 1943 Dr. L. V. Gardner, Saranac Laboratories, Saranac Lake, New York. Dear Sirs You will recall an extensive investigation which you conducted lor this company several years ago as to tho air hygiene as pacts of fiberglus. T7e have now in the pilot plant stage a new material regarding which we need sons guidance as to v;h&t is indicated as necessary from that cone standpoint. The material is A hydrous calcium silicate. . . Silica of 200 mech per inch and finer is incorporated with calciten hydroxido in a water suspension. Alter sufficient preliminary' reaction tb" convert a portion of the reactants to a gelatinous form of such consistency as to suspend the remainder of the reactantc and avoid settling, the material is poured into molds which arc'then placed* in a steam cylindor similar to those cossonly used in the manufacture of sand lime brick and subjcctod to 125 lbs* per square inch prossure of steam and its resultant temperature for appro^.rately ten hours. During this time a crystallisation occurs although the naterial is still wet when removed from the cylinder. It is then'dried and yields a porous mass which eon be sawed like l\csber. It is intended to use this material for certain interior structure uses, also as an industrial thermal insulating material for pipe, etc. The material contains no free *calcixm hydroxide but does contain a very slight ceount of unreacted silica; presumably the larger pertic3cc of cilica which have persisted while the available calcium hydroxide has been consumed in the formation of the hydrous calcium silicate. The following points merit consideration: . 1. - Does the hydrous calcium silicato of itself constitute any air hasard from an air hygiene standpoint? 2. - Arc the few residual particles of silica of such sise and fre quency as to constitute a hasard7 3. - It should be considered from the standpoint of employees v.-orhing in the plant where tho. material is made or where it cay be suv.od to desired dimensions, and also considored from the standpoint cf applicators or erectors at the point of use.. Dr. L. U. Gordnor, * Saranac Lake, Now York. February 12 , 19 43 T7e aro forwarding to you by nail two sanples - ono which* will reprysont the material which collects in our clast-collecting systen, end the other represents material, presumably finor, which has settled iron tho atmospharo in a finishing room whoro cutting of the material is done. *7e would like to have your opinion tentatively as to the situation for our present needs and your suggestion as to a suitably comprehensive program to permit a final determination of its status. . *% The writer recalls very pleasantly having lunch with you and Ur. realtors at Baltimore a few years ago during a meeting of the .American Ceramic Society. 1 .` ' U. E. Bowes j cc - lir. A. C. Hirth Ur. U. K. Olender Ur. H. H. Renn Ur. David Innes - Berlin Director of Research I' * --j A O Owkns-Illinois Glass Company VIMMT IN Kl.AHH M.vn i: k.\:t:kk h ir I>ukh ['xiintrcTH Gkxkhal omixs Tolkdo "ebruary 12 , \Z *'r. L. V. lardr.er. -srar.ac Laboratories, 2-i.rar.ac Lake, New fork. 2ear Sir: Vcu v/ill recall an extensive investigation which you conducted for this company several years ago as to the air hygiene aspects cf fiberglas. Te have now in the pilot plant stage a r.ew material regarding which v.-e r.eed some guidance as to what is indicated as necessary frcn that sane standpoint. The material is a hydrous calcium silicate. Silica of 200 mesh per inch and finer is incorporated with calciun hydroxide in a water suspension. After sufficient preliminary reaction to convert a portion of the reactants to a gelatinous form of such consistency as to suspend the remainder of the reactants and avoid settling, the material is poured into molds which are then placed in a steam cylinder similar to those comonly used in the manufacture of sand lime brick and subjected to 125 lbs. per square inch pressure of steam and its resultant temperature fcr approximately ten hours. During this time a crystallization occurs although the material is still wet when removed from the cylinder. It is then dried and yields a porous mass which can he sawed like lumber. It is intended to use this material for certain interior structural uses, also as an industrial thermal insulating material for pipe, etc. The material contains no free calcium hydroxide but does contain a very slight mount of unreacted silica, presumably the larger particlee of silica which have persisted while the available calcium hydro3d.de has been consumed in the formation of the hydrous calcium silicate. The following points merit consideration: 1. - Does the hydrous calciun silicate of itself constitute any air hazard iron an air hygiene standpoint? 2. - Are the few residual particles of silica of such size and fre quency as to constitute a hazard? isac 3. - It should be considered from the standpoint of employees working in the plant where the material is aade or where it may be sawed to desired dimensions, and also considered from the standpoint cf applicators or erectors at the point of use. ' OOP32C1Asbestos Litig. Saranac Lake 1989 Depos. Exhibit p.16 >mit4 i4* 3r. I_. V. ^Krdr.er, 3arar.ac Lak*, :.ev/ York. rebruary 12, U no ' fe are forwarding to you by mail two samples - one which will repre sent the TAterial which collects in our dust-collecting system, and the other represents material, presumably finer, which has settled from the atmosphere ir. a finishing room where cutting of idle material is dene. \ ;'e would like to have your opinion, tentatively as to the situation . for our present needs and your suggestion as to a suitably comprehensive % program to permit a final determination of its status. The writer recalls very pleasantly having lunch with you and Hr. 'Valters at Baltimore a few years ago during a meeting of the American Ceramic Society. Very truly yours, U. S. Bowes j 1 cc Hr. A. C. Hirth Hr. it. V.. 0lander Hr. !!. IT. Renn Hr. DavidInnes - Berlin Director of Researob % 00PT2 Asbestos Litig Saranac Lake 1989 Depos. Exhibit p.17