Document rBe6MDYmed3KKdNZk3K1a1060

FILE NAME: US Gypsum (USG) DATE: February 12, 1937 DOC#: USG061 DOCUMENT DESCRIPTION: 1937 Letter to FG Johnson from AC Hirth regarding response to letter of January 29. 75 February 12, 1937. Hr. Fred a. Johnson, Usnager, Insulating Wool Sales, U. S . Gypsum Co., 300 TT. Adams St., Chisago, 111. Dear Hr. Johnson The delay in answering your letter of January 29 has been oooasioned by ay absenoe from the oity. t TTe hare Tory oare fully oonsidered the ad visability of permitting Dr. Gardner>s report to be furnished to salesmen generally, and passed from hand to hand. It is our feeling that suoh prooedure would be unwise, end that the possibility of the report being twisted and misused by others orershadows the advantage gained. . * s In individual eases we have found it neoessary to disouss the report with the oustoner. TTe believe, however, that its use should be confined to this sphere. Very early in the manufacture of glass wool we oonsidered the possibility of its having deleterious effects upon those working with it or using it. An investigation was made and it soon developed that there was a soaroity of pertinent experimental work published in the literature. It therefore appeared wise to oonduot our own experiments, which procedure had the advantage that the results would apply specif ically to our own commeroial grades of glass wool made from our own batch. - 1- ..'i'.-S GP02 i 0999 1U - 2- Several group# of experiments were undertaken . .. to determine what, if any, untoward physiological effeot . gin** wool might haw# whoa it oom## in oontaot with the human body. The reasoning behind this work, which diotated the hoioe of experiments, was briefly as follow It was assumed that glass wool might enter the body by three route, by inhalation, by swallowing, and by penetration of the skin. If glass wool dust is breathed, assuming the partiole* are small enough to enter the small air spaoes of the lung#, answers to these questions were sought* Will inhaled glass wool dust oause a reaotion in the lung tissue similar to that produoed by silloa dust in sillooslst Will the * reaction be at all harmful? If not, what will become of the glass wool dust? If glass wool fibers are swallowed will they produoe any serious or permanent injury to the digestive tract? If glass wool fibers penetrate the skin - will the glass aot as a tissue poison? What will become of particles of glass wool that might be injected in the skin? Dr. Leroy W. Gardner of Saranao Laboratory, Saranao ** u"d***took two groups of animal experiments, and Lr. Philip Drinker of the Harvard School of Public Health, together with Dr. Albert C. Titus, undertook a third group of experiments. Animal Injection Bxoerlments In determining whether inhaled glass wool dust would act in any way comparable to free silioa dust, it is essential that the exposure be prolonged over a period of many years in order to show up ohronlo offeots. Ho group of workmen in this country have used glass wool long enough to show positively whether or not chronio injury to the lungs might result. X-ray and olinioal examinations on our workmen with the longest periods of service, however, revealed no unhealthy lung oondition * t1* ^ e effeots of inhaled dust can be aooelerated n e oase of animal axporiaoat, and it waa for this reason . to oheok our inconclusive X-ray findings - that Dr. Gardner's help was solicited. t * . G'*02l loco - 3- r. Animal experiments to determine the effeet of inhaled dust osa he performed in two mays* First, the animals sen b e p l a o e d la dustladen atmospheres and made to breathe dusty air for long periods of time. Second, the dust ia question oan be injected into the animals* bodies, and it is generally reoogaized that the type of inflammation or reaction that results indicates to a trained pathologist whether the harmful effeots are at all comparable to those produoed by free silica dust Because the "dusting" method requires two or more years to get results, the injection or sooond type of experiment was selected. Animals were injected with glass- wool dust, both *P^*^* and "oiled",_ (Oil is applied to some oommeroial grades of glass wool to reduce fracturing of the fibers and to pre-rent dust being given off during handling). Animals were examined at intervals of several days or weeks for a total period of 285 days. Dr, Gardner states t "Experience in this laboratory and else - where has shown that these methods are adequate to demonstrate the capacity of a mineral duet to produce fibrosis. Injection of over 20 different types of dust has indicated that if no reaotion oeours in organs other than the lungs, none will occur in the respiratory tract, and that conversely, dusts like silioa and asbestos that are known to produoe fibrosis of the lungs, also cause fibrosis in other tissues when injeeted in sufficient quantities," Dr. Gardner summarises this series of experiments ss follows* * "neither plain nor oiled glass wools have oauaed fibrosis or any ohronio progressive reaotion by injection, and therefore, it is a reasonable assumption that their inhalation would likewise fail to produoe such effects," GI'O ?1 1001 - 4- Eating Glass TTool i. X considerable number of reference* exist in the literature to eases There oiroue perfermsri and individuals vith ulterior motives, have either eaten glass or oaused others to eat it. Usually in these reports' the glass vas in the shape of chunks or pieces large Enough to see with the naked eye. In no instance thai has ooae to our attention did the reports shew that any serious injury was done to the individual by the glass, 1 There remained the possibility, however, that long-continued swallowing of small amounts of extremely fine partioles of glass might produce some ehronio damage to the body. Dr* Gardner therefore undertook?, the second series of experiments in whioh fasting guinea', pigs were injeoted with finely ground glass wool by stonaoh tube. Hone showed any ill effeots even after the injections were repeated, \ Guinea pigs were then fed glass wool d#t, mixed with a portion of grain, before they reoeived their morning rations. After these meals were administered daily for period* varying up to a total of 119 days, examination failed to disclose evidenoe of the glass fragments or any injury inflisted by them," \ Dr. Gardner oonoludesi \ . . "One may therefore eonelude that th# ingestion of as muoh as 81 grams of finely powdered glass wool, administered in divided doses, will not oause injury in 4 months* " time. In the absence of any reaction at ' all, it would hardly seem essential to con tinue the investigation further.* His concluding statement we think is oxtremely pertinent. It is as follows t "Trusting these findings may alia svantioiaa aa t0 * theoretioal hasard from the handling of glass wool, I am Very truly youre, Leroy U. Gardner, H.D. Direotor* G21 100^ >/, i1,.f',. ' * - 5- lability of Gift Wool jo Inform ation * ^ ^ 4 ^ 0 ! how s o l u b l e g la of gl* *n boJJ flUd#lt*t?N> essential in answering it in body fluid *f * lae, *fter it antert the tht qutttion, *WHat beoornea or gra.. body?" . W . T i t ther.f.r., D rin ker, ohomioal wool in blood aornm. By ft the solubility of ****** ' VSSSSt V T SS^ i o f ^ ..SUJB. 5 * i ^ t h o d he alto obtained " ille*) in blood terua. f*nnd to ba axtroaaly r i ^ a r ^ i V o a9rta during a two-montha pariod. la th . . . . . . * B ; S S ` . S * J in T .n ^ r S r .^ d u r i n g t h . . . = . p.riud. - c o n c lu s io n . Inferring to ft8^ ^ f t f t i l a ^ w o o ^ d i i t / i f ^ b ^ ^ t h e d , that D r. Gardner ahornad ftj* f1 tbe lung tiaaua oomparable will produoa ^ J u . t / A . a matter of in any way to that < a oonoluaiona. w. 7 assume fact. in view of D r . * * * * * * ' ^ there is no, harmful aff or a 7 . a *>,+; criaaa wool dust whioh antera Xt i 8 i d #he*ram oTad b y t h e n orm al *o t i a 4o f _ f t * the lungs would f t h , l y n t h a t i o system , and in r ie w o f 0H r!a r r rin h .r ` . - r k . t h a t t h . p a r t i l e , w i l l e v e n t u a l l y pass o f f i n s o l u t i o n . lh. . n i . . r . . i . d j, sir " supplemanted by Or. h. 4i(, , s tiT e tr.ut ii slaaa p e ^ a n .n t 1` " 5V 1\ _ r n l CE la r g e d o .. or in . n a i l " o o l 1 . . l l o r a d , i 'ther IIn J S l * lo 4 of M a . . " h l l . do.e. takan rag a y n ieoe. o -laei nould out tha it 1. U h . l y t h a t ^ . r e . reported lathe digestir. trao thi* injury heal, oonpletely in d. .!^aid predi... pr.eti.eliy "= d i . . * * . 0 0 1 IZOciO V -y> * - 6- , Prom. Dr. Gardner work, it 1 evident that th* aotual prooaa of going into solution, that is, the prooo of solid glass being earrisd off by liquid, doss not giro rise to any tissue poison This indicates that glass in the body will bo dissolved and eliminated slowly and continuously without any injurious or poisonous offsets on the individual. 7 J Te trust that this information will assist you in overooming whatever sales resistance you may meet on this sooro. * Tours very truly, OTTENS-ILLINOIS, GLASS COUPANT A. dU Hirth,' ob I*ogai Patent 'Department. - V if" - - G^oai