Document e76Obr0b9Z0mX9RND09D3rVoM

Jsbruaiy 17, 1971 it. w. Xordu, Jr* iuperviser, Applied Research 1-salngton Arms Ccapany, Xno* Bridgeport, Conneotlout 06602 rpxxczrr or zst rnasr ass rax paaorcnka --___nugimi^MKBSHdi tcrui latter 'of January 19, 1971 to Or. John AJ Sapp, Jr., vaa given to aa for remnant. I.aad. 1 t Based upon tha mnalysia given in your lattar, the amount of i.aad in ona ri^fire priaar will be 5.2 milligrams. vhaa aulti- ]>liad by tha number of rounds estimated to bo coneased in om activity period, which ia 2SO, wa find that a total af, 1300 nilllgrau will ba aonsuned* Hast of this will antpx tha air of tha apaea within which tha firing ia dona. Z assume from tee prior discussion that tha firing ia axpactad to ba dona within confinad quarters, such as a basement ranga. tha amount of air thaoratieally nacassary to dilute tha 1300 milligrams of :.aad to tha Threshold fclalt Valua of 0.2 milligrams pax cubic tieterof air will ba 240,000 cubic faat. A safa atmospheric concentration can ba if tha spaaa in which- tha firing :.s dona ia supplied with air at a rate of approximately 25,000 <ruble faat par ainnte, if tha firing is dona in 10 minutaa or n correspondingly lasses rata whan tha firing ia prolongad over an axtondad period of time. For exaaple, if tha firing is all done within ona hour, tha rata drops to about 4,000 eubio faat per minute. Asbestos in tha Projectile. S the weight of tha projectile is not given in your latter, on the basis of 26 per east by weight of asbestos in the pro;|eotil# we estimate (assuming projectile weight of one gram) 'diet 250 rounds; would probably contain 50 to 100 grams of usbastos as a minimum, Tha projaatile is dssoribed.as "friable*. He judge from this description that the asbestos oould be iredueed by friability to discrete fibers and disperse at laast \yo a partial extent In tee air of the enclosure In which tee i!iring is done* I DUP 0972732 M. N. Kordas, Jr, February 17, 1971 Pig* 2 Asbestos in the Projectile (confd). % The danger of Inhaling aabaatoa fibers has received a lot J cf attention in recant years, the Amrioan Conference of governmental Industrial Hygienists now reecnends a Threshold limit Value of 5 fibers per 111111tar of air (fibers greater than S aierons in length counted by a phase contrast netted following collection by a n--brans filter technique). ibis low level of concentration reflects the concern that is felt ior the health effects of Inhaling asbestos fibers. In addi tion to the fibrotio disease called aabestoaia, which has long lean ^aeogfilted, it is now known that persons who acquire the disease asbestosis are aora likely to develop lung cancer than rates for the general population would predict. It would be well to seek a suitable substitute for asbestos in the friable projectile. - In the building construction industry, where asbestoscontaining insulation has been sprayed on steel structural neobers, it ha* been nacessary to seek substitutes for (Lsbeatos. Various eoepositlons containing fibers froa steel riill slag have ben used In the Insulating of steel uaberi of iauildings, This sight be e starting point in e search for an adequate substitute for asbestos in the friable projectiles. .mc^bjd ^aaioiNAL siaMeo : 3AMS3 a Morgan Janes f, Morgan 7 \ 5up 0972733