Document YkNEoODnwdx5L0kKnwDwydjK

January 7, 1941 Mr. Hu9811 Schell Ethyl Gasoline Corporation Chrysler Building New York, New York Dear Husa: The point brought up in your letter of November is theoretically of considerable interest to us. If vie assume that there is aero ventilation in a tank and that the tank is then thoroughly cleaned, but as a. consequence cf the absence of this ventila tion, the air is in equilibrium and saturated with hydrocarbon and lead vapors as determined by the temperatures and concentrations of each in the sludge, we sre forced to recognise that the tank in practically just as hazardous as though it had not been entered and cleaned at all, T.n view of the fact that repair men may in instances enter tanks immediately after the cleaning operation has been completed, it might be possible for accidents to occur to them in spite of the precautions taken. From the practical point of view, however, we do not believe that this hazard is a groat one. In the first place the safety engineer is on bend to establish that the tank is free from dust or odors of lead compounds before repairmen enter it and secondly, since both hydrooarbon and lead vapors will have their origin from the residues in the tank, it v/ould follow that the tank would have to ba of necessity ventilated to a sufficient degree to eliminate the hydrocarbon vapors and the lead vapors would be taken out at the same time* It la our experience that load vapors will volatilize from sludge at least as rapidly as will hydrocarbon vapors and accordingly in instances where ventilation is minimal we would not bo likely to encounter a situation in which the hydrooarbon vapors would all have come off and been removed while Mr. Russell 3chell - (2) - January 7, 1940 lead vapors were still being involved. In other words, we believe that it is safe to assume that the presence of hydrocarbon vapor will prevent men entering tanka without respirators after cleaning procedures have been completed until suoh ventilation {as is operating) has reduoed the concentration of both hydrocarbon and lead vapors to safe levels* I think it would be advantageous to get information on certain aspects of this problem and I would like to see you and Oscar or both of you when I am in New York on January 16 or 17 $ith best wishes, I am Cordially, willard Machle, U. D. K 0022546