Document zdj1EZbK8ba5dDv8VELMR6bvg

L. Y. CBALLXT mALDt UEBEUHKSINEGETSQEHAECH LABOHATORIKS HR. C. G. BELL CLEYSLABD WORKS PLAINTIFF'S EXHIBIT BSS..ATK JICJSSS AL2401 I have examined the testa reported on May 18 and June 8, 1949. There are a few results which may need further study. Samples 1101 and 1103 (Station LI and L3) showed 7.4 and 16.9 MPPCF dust respectively. The maximum allowable concentration for daily 8-hour exposures for dust having high free silica content, of which this is an example, is 5.0 KPPCF according to the Ohio State Department of Health and even lower according to the Industrial Commission. When the averages weighted dust count values of the workers on the above jobs are calculated for the entire day, the averages will probably be quite low. This should be done in order to obtain a picture of the overall dust exposure where oases exist of high dast counts but of intermittent or short duration. I also think it suggests souroes of dust which should receive attention for oontrol when future ohanges in equipment are wade in these areas. Past tests at L-l have not been as a rule that high. If the highest count was not due to some other factor as the unloading of sand, it might be well to make additional observations here to determine the. cause. Tests at Station L-3 have generally been high, but a respirator program should offer adequate protection since the 916279 0617 job is intermittent. In the report sheet, the 5th item is referred to as Min. Cone. I would suggest that this be changed to Daily Max. Avg. Cone. The June 8 report mentions Stations H117 and E120 as fair-exhaust hood not working. Does this mean that the ventilation equipment was not in working order, or that it was not in use, and if the latter, was it supposed to be in use but just not turned on? LVC/enw L. V. CRALLEY 916279 0618