Document J35aGmvV6Ey5GL5gLBgOan4Nr

INTEB OFFICE COR LOUISIANA DIVISION BATON I O t C I i LA. November 2, 1951 TO: Dr. Howard Hansen, Medical Department SUBJECT: Analysis of Air Samples for Asbestos Insulating Cement Dust - No. 2 Storehous On the morning of November 1, 1951 I collected air samples during the unloading of 150 fifty pound bags of No. 450 asbestos insulating cement at No. 2 Storehouse. The material was contained in paper bags. Weather conditions of this date were cool, rainy and with a wind from the north. The railroad car containing the shipment of asbestos was spotted on the north side of No. 2 Storehouse and unloading was performed through the adjacent Storehouse door. Five colored laborers were used in the unloading operation. A fork lift truck pallet was stacked with 20 bags and then conveyed into the storehouse where the pallet was stacked without removing the bags. Two dust samples were collected using the midget impinger apparatus. The collecting medium was a solution of 15% ethyl alcohol and 25% water: Sample No. Location Dust Concentration (mppcf)* 1 Pallet loading operation Floor of Storehouse Less than 1.0 2 Inside railroad car during unloading 2.9 * Million particles per cubic foot of air. Results of these counts indicate no concentrations of dust, including asbestos, which could be considered excessive. The accepted maximum allowable concentration of asbestos dust is 5 million particles per cubic foot of air. The next shipment of asbestos cement due to arrive within 1 to 2 weeks, will be that of #302 rubberoid, packed in 100# burlap bags. It is expected that dust concentrations will be greater for this unloading operation than for the #450 cement. Also, weather conditions may be more favorable for dust dispension. I have ordered a standard counting cell to replace the haemaeytometer cell which was used for the above counts. The haemaeytometer has the distinct disadvantage of having a small sample aliquot volume. Very truly yours, FSVsheb Fred S. Tenable, Industrial Hygienist E HO 03161