Document Byp1x0wvrggvL4OML458RObY8

STO002516 MIDLAND, MICHIGAN March 6, 1970 R. G. Vaughn -Safety Department Louisiana Division Plaquemine Dear Bob* My apologies! I thought I had sent you the information that I generated during my last visit but apparently such is not the case. I am enclosing with this letter copies of the charts showing the noise levels measured in various locations in the Methocel Plant. I have penciled in the number of hours that are accept able for the noise represented by each chart, assuming that all other noise exposures for the men are below 90 db A. If such is not the case, then the penciled-in numbers should become the denominator of a fraction which has the actual number in the numerator. These fractions should then be all added together, accounting for the man's total day. If the result is less than one, the job is acceptable under Walsh-Healey Regulations. If it is more than one, then ear protection is required during the time the man is in the noisy area and we have to proceed forth with to investigate the feasibility of noise control. At levels of 90 db A, or below, all time in such an area can be entered as zero in the summing-up process described in the above. The two air samples which were taken for evaluation of the asbestos hazard in the cell manufacturing area were both less than .5 mppcf. These results are open to some question since the samples were not counted for a number of days after the sampling was actually done. The job should be evaluated by sampling on a number of different days with the samples being counted the same day that they are taken. This would require that we either find a microscope with suitable optics and a Whipple disc somewhere in the Louisiana Division, or else that this equipment be brought from Midland to Louisiana. I think that the results we have are reassuring in that there is very little likelihood that a real hazard due to asbestos would be found. On a previous trip we measured noise in the Polyethylene A Plant. You later had the people in the plant estimate the amount of time represented by each of the noise measurements we made. It is my understanding that time spent in the various J R. G. Vaughn -2- 3/6/70 work classifications which were not covered by measurement were in quiet areas that would not need to be considered in determining acceptability under the Walsh-Healey Act. Making this assumption, I have calculated the equivalent exposure ratios and have indicated on each job evaluation whether or not the noise was acceptable under Walsh-Healey. You will find these evaluations included along with this letter. B. R. Boyle Biochemical Research Laboratory 1701 Building . HRH.-reh Enc. ST00025I7 / A