Document DDgxDRNmdpnvOrK8MygLeGw44

August 13, 1951 Mr. C. L. Risso-Gill The Associated Ethyl Company Ltd. Artillery House, Artillery Row London, S .. 1, England Dear Charlie : Thanks very much for your letter of July 20 with the interesting information sent along from Australia from Jack Batchelor. I have gone over this with considerable interest. My essential reaction to it is that investigations of this kind provide ample justifica tion for our activity, in that it is shown that we have not at any time worked on the ragged edge of safety, but with a rather large safety factor on our side. With reference to this whole problem of the life of canisters, I have written my opinions in a fairly extensive manner to Doctor Boyd in a recent letter which answered, or tended to answer, some of his questions. Inasmuch as the ground is covered reasonably well, and is an expression of my viewpoint, I am sending you a copy of the letter* As you will see from my letter, there is no question in my mind that the time of use of the canisters of our masks could be very considerably increased without risk. On the other hand, you will 3ee Why I have wanted to have a very considerable safety factor in the thing. You may have been fortunate, or the circumstances may have been somewhat different in the area in which you worked, but: we have had a series of accidental spills of gasoline mixed with fluid in high concentration, in which,all of the facilities available at mixing plants had to be used for tile protection of people who had to clean up the spills and decontaminate the area. There have been several instances in which the masks have been used in a fairly high concentration Of tetraethyl lead vapors. Under these circumstances I have recommended the same procedure that we have used at our manufacturing plant, namely, that when the canister has to be used in a high concentration of vapor, it is well to lean over backwards and change the canisters frequently, rather than to run the slightest risk of a tragic accidentabased on incomplete filtration of the air. It is difficulty, 'though probably not impossible, to simulate,in tests of these canisters, all of the conditions that may exist in the field. Consequently I have wanted our regulations to set up a standard of performance which would almost be certain to be safe 'under the worst possible conditions of the use of our equipment. Unquestionably there is some inconvenience and some additional expense associated with unnecessary frequency in changing the masks. Our people, generally, in this country, and by that I mean the safety and management people at refineries, have felt, as we do, that this is a small matter of inconvenience and expense, in view of the poten tialities on the other side* Mr. C. L. Risso-Gill - (2) - August 1J, 1951 All of these discussions need not indicate to you any reluctance on my part to relax the standards that we apply at. the present time on the basis of a realistic consideration of our experience of the past and the facts as we know them, with reference to the order of magnitude of exposure. All I want is a fairly.large factor of safety. ' John Phair has reported on you to me on his return from his trip abroad. I am certainly grateful to you.as he was. for your many courtesies. It was good to hear about you, and I hope that things will continue to go well and to your satisfaction. With kindest personal regards, Sincerely yours, RAK ef Enc. Robert A. Kehoe, M. D. HE 0000475