Document 7MpEavVXBro0GObDGDb06nn9B

John C.McCool 0. S. Kurtz SUBJCCT Log g57 F'ELO POINT OP OSPT. & IlOO. NO. Akron, C/0020, B/5-H PJ8LO POINT OP OBPT, & BLOG. NO. Brecksville R 6 D Center, D/8506 T YOUA LETTBP OAT* Twia letter March 10, 1976 There were two blanks submitted with this set of personal monitors. We measured 3-17 yg VCM in one tube and were unable to detect any in the other. This sizable difference raises several questions. Is there diffusion through the plastic cap? Is there migration around an improperly fitting or defective cap? Could those instances where we have a relatively large amount in the back section be due to one of the above rather than breakthrough"! ?:'! In the light of these questions we have chosen not to subtract any amount as a blank from these measurements. The measurements we are reporting are maximum values and still show .5 ppm or. less. We have also chosen not to use the > designation when the back section contained 20% or more tharr the front section because we have no assurance that this represents break through. cc: P. M. Zakriski R & D Files THE B. F. SO. r.iArf 2 9 1S76 mmu vmaI 22287001 7 ?< iiro tu ) BFG20001