Document ppErQkgXedryKq6vb9wVbLYbX

E. P. Wheeler - St. Louis September 11, 1968 Arcelor 125** Kimberly Clark f\aj. ja^ K. A. Wells 0. R. Hansen Mr. Lee Judy Chicago It Is difficult to give specific numbers In answer to Ulsterly Clark's questions about elevated temperatures and sufficient ventilation. Somewhat arbitrarily we have selg in the past that if Aroclor 125*1 Is heated above 150 f then mechanical exhaust ventilation ahoulddbe provided to remove vapera. Thla - may or nay not be conservative depending on the concentration of Aroclor In a formulation, the surface area exposed, the duration of the Sevated tempersture and the amount of genera 1 room ventilation provided. "Sufficient ventilation" la that amount needed to reduce vapor concantratlons of. Aroclor 125*1 to the Threshold Limit value (TLV) of -0.5 milligrams per cubic mater of air. The TOY Is that amount which worker* can Inhale t) hours a day, 5 days a wask for a working lifetime without danger of Injury. This obviously will lead to the question of Kimberly Clark of how the concentration in a workman is determined. Aroclor vapors cannot be measured with simple Instruments that can be used for such common work place contaminants such as carbon monoxide, hydrogen sulfate, many chlorinated hydrocarbon solvents, ate. The measurement of Aroclor vapora requires sampling equipment and tacholquaa that Involve wet chemistry analysis In a suitable laboratory. "Sufficient ventilation1' can also be defined as the amount of air moving over the source of a contaminant (In thla case Aroclor) and Into appropriately defined ventilating systems to carry the vapors outside the working area, impending on the type and nature of the source the design of the ventilating system can be simple or complex. In either case a common household situation serves to Illustrate the point, For txasple, one would not try to capture and remove the odor of frying fish or cooking cabbage la the ares of the kitchen range by placing a window fan in on upstairs window or attic. Common sense says to put a hood over the range where it Is more economical to move smeller quantities of air end yet capture the offending materials. Secondly, It obviously Is preferable not to draw the odors through the rest of the house. MOMS 0979Q0 \ Mr. 1m Judy -2- StptMMr 11, 1968 Thia eeeae ao obvloue that no ona would expect to rind dealgna of ventilating ayateaa In lnduatry that would draw Aroolor vapora aeroaa a work rocn expoelng uanoeaaaaMly a largo nuabor of poopio and aoeondly acrying many nora cubic faat of air to control the expoaure than If the ventilation waa applied directly over the aouree. Uexnhfaourtautnvaetenlytilaptlaionnt englneera arelarepthe#atedly nlaa^popvleyl.ng If Kimberly Clark doean't have qualified, trwxn-- . to do air aaapling and analyela and experienced ventll*txn dealgn englneere, there are many conaultanta available that could help then. EPWicJa Bluer ?. Wieeler HONS 097901