Document mmKOy7RbN2rq74YqpMy4Jp02d

July 8-11, 1969 ETHYL CORPORATION PASADENA, TEXAS Dust Counts Obtained On Samples of Air Collected By Use of Midget Impinger During Indoor Sandblasting Operations at Sodium Plant. Location of S ampler Sampler located ap proximately 15 ft. from operator, (#1) during sandblast ing Observer in same area not wearing (#2) respirator Outside air near en closed sandblasting area HB-Z Millions of Particles Per.Cubic Foot of Air mppcf 18 20 1.2 Calculated* TLV __ seegf__ 2.8 Calculated from the formula: mppcf 250 %si2 + 5" and is based upon a per cent silica of 85% (average of two samples analyzed). ETH 002242 July 8-11, 1969 ETHYL CORPORATION PASADENA, TEXAS ANALYSIS OF SAND COLLECTED FROM SANDBLASTING AREA FOR FREE SILICA Sample Identification Sample taken from previ ously unopened bag as received from supplier - Per Cent Free Crystalline Silica in Sample Quartz Cristobalite Tridymite 89 absent absent Sample collected from settled dust inside sandblast room in HBZ area 81 absent absent ETH 002243