Document V3r8Z0d1ejDpa02Z8zeqObbyo

'vr~ -FROM ROBERT P. CARTER I PITTSBURGH OFFICE - 7 MR. D. R. PITTSBURGH OFFICE - 8 O.P. April 23, 1973 RE: SUBSTITUTES FOR ASBESTOS In his memorandum of April 9, 1973, "Re: Substitutes for Asbestos", Mr. T. B. Bonney points out the strong desirability of replacing the use of asbestos with other materials because of the very strict requirements of the asbestos standard. In the second paragraph of that memorandum, he also points out that some environmental control measures may be necessary with some of the proposed substitutes for asbestos that are presently under consideration or development. In our telephone conversation of last week, I recommended to you that where it is likely that there will be worker exposures to airborne dust related either to the original use of the substitute materials or to repair and maintenance work in connection with their use, we should obtain from the suppliers of these materials detailed information regarding their composition. If any of these materials contains free (not chemically combined) silica, it is important that we know whether this silica is crystalline or amorphous and in what proportion it is present. Only in the light of this information can a proper determination be made of the maximum safe levels to which a worker may be exposed. I believe that you agreed that it would be desirable to obtain this information in all applicable situations at an early point in our consideration of these materials to permit industrial hygiene, review of the composition and establishment of any required controls. We will be glad to be of any needed assistance in this matter. ROBERT P. CARTER. RPC/map cc: Messrs. Rv C. Hinkle, Badin Works P. V. Bonsignore, ATC R. E. Spear/R. G. LaBar, ATC G. H. Farrah/J. M. Plunkett, ATC L. D. Hart, East St. Louis M. J. Caprio, Pittsburgh - 19 R. J. Getty, Pittsburgh - 24 J. E. Hatch, Pittsburgh - 23 J. Z. Nelson, Pittsburgh - 7 O.P. V. W. Rleke, Pittsburgh - 2 G. R. Swany, Pittsburgh - 23 F. E. Mueller, Pittsburgh- 23 Q ALCOA 916286 0350 $MH> (V.