Document ymgxKbJMxL6jE63DeXngbENNE

`-eptembor S3, 1927 Hr. 33. W. Webb, c/o Ethyl Gasoline G orp., 25 Broadway, Hew York City. . Tty dear Hr. Webb; Replying to your letter of September 4 concerning item TJo. 11 of our rules and regulations. You will probably realise that the wording of this paragraph is obscure only because It is not possible, under the varying conditions of mixing in different parts of the country, to make a-standard rule in this matter. experiments show that these eannlsters containing activated char coal are adequate for approximately seventy-two hours of continuous use in the saturated vapor of tetraethyl l e a d . Under the conditions of use' in Canada it would take many months to use up the eannlsters except for possible deterioration of the charcoal as a result of being exposed to other organic vapors around refineries, these eannlsters would undoubtedly last for a year, because of the possibility of such contamination, however, it is advisable that the canalster be changed at regular and shorter intervals. I-would suggest that the charcoal be changed quarterly, as a matter of fact, I made this verbal recom mendation to some one of their responsible men at the time of their first installation. There is really no adequate method of testing the camiister for its adequacy in picking up tetraethyl lead, except by passing tetra ethyl lead through it and testing the emerging air. Tills is not practicable, for obvious reasons, so that the only thing that they can do is to protect their masks as much as possible against organic vapors, and to allow a time interval sufficiently short to be well within the limits of safety, ill customary procedure is to put a date on the cannister at the time it is refilled, and to require changing it at the end of the proper time interval, which in their case would be as indicated above. 1 have not answered hr. Ikying*s letter myself, and, unless you . wish me to, I shall not do so. It seems just as well that you should transmit to him such portion of the above information as you consider advisable* . .. Yours very truly, ]:.J