Document 4jQ9yM4Xxr6ro1YoM2dMkndV

March 13,. 1962 Mr. Byron R. Hubbard Snior Industrial Hygiene Engineer State of California Department of Public Health 2151 Berkeley Way Berkeley 4, California Dear Mr. Hubbard; I can well believe that the problem of lead-containing glazes on table ware is a matter of interest and concern to yourself and your associates. It was quite a shock to me to find that the hazard associated with such glazes was as significant as it turned out to be in the case of the particular product of the Laurel Pottery. This matter has been taken very seriously by a representativegroup of potters, especially those in West Virginia and by officials of the American Potters Association. A Committee was formed to explore this matter with us, including one representative of the U.S. Bureau of Standards, and another of the Lead Industries Association. A program of investigation was laid out by the Committee and ourselves, jointly, and we have been following it. This program had two primary objectives: (a) to develop a test, or a battery of tests, whereby the extractability of the lead from the glaze could be determined satisfactorily; and (b) to establish a permissible limit of extractability. Both of these objectives can be achieved, we believe, and through proper action on the part of the industry (regardless of any other action, governmental or otherwise) the safety of the public can be assured. The industry, as represented by its officials is prepared to accept the responsibility for establishing safe craftsmanship in this regard. We shall be prepared shortly, I believe, to recommend both a method of testing and a hygienic standard. I suspect at this time that the latter will turn out to be not very far from 1 part of lead (Pb++) per liter of an extraction agent. The most satisfactory test appears to be the use, for a certain period of time, of a solution of 5 per cent acetic acid (alternatively a well-standardized vinegar) at a certain temperature. Our experimental procedure at present is directed toward the determination of the influence of both time and temperature and the establishment of optimum conditions with respect to both of these variables. Another important point under examination is the matter of the adequacy or inadequacy of any one test agent. If it is necessary to employ a battery of extraction agents,in order to cover the potentialities represented in various glazes, the problem of Mr. Byron R. Hubbard 2 March 13, 196;>2 testing will be a bit more complex. On the question of a safe level, we shall be prepared to make a recommendation, on the basis of voluminous data concerning the quantities of lead which now (and for the past twenty-odd years) are represented in the daily diet of citizens of the U.S.A., and a realistic estimate of the contribution which has been made by table ware to these quantities. This sounds like a very complex matter, but it is not quite so complex as it seems. 1 consider it only wise, however, to withhold any estimate of this level until we can sit down and explore all of the pertinent facts in a completely objective manner. One last word might be said. It might appear to those who have responsibility for the public health that the best way to deal with this matter is to outlaw the use of lead-containing glazes. I do not believe that this is either necessary or wise. I shall not go into the reasons for this view at present, but they are not based on a willingness to compromise in relation to a little danger. At the proper time we shall express an opinion on this matter in a comprehensive manner. Sincerely yours, Robert A. Kehoe, M.D 0006015 / MALCOLM H. MERRILL. M.D. D IRECTO R O F P U B L IC HEALTH STATE OF CALIFORNIA DEPARTMENT OF PUBLIC HEALTH 2101 BER K ELEY WAY BERKELEY 4. CALIFORNIA Karen 9, 1962 EDMUND G. BROWN GOVERNOR S. A. Kehoe, H.D., Director Kettering Laboratory University ox Cincinnati College of Medicine Cincinnati 19 Chio Dear Doctor Kehoe: The so3.ubility of lead glaze on dishes is still a matter of considerable interest here. In addition, problems generated by the possible disposal of the last of the laurel rettery Stock have made ns mud; aware of the need for a standard method for determining the solubility of glazes. This morning, Dr. Sinert mentioned that you ana Dr. Choisk have been working on this problem and suggested that I write to you tc learn if you may have progressed to the point where you might be able to give us your ideas. Although I realize that your work may not be complete, if you have arrived at a point where you can give us any advice either on the matter of a standard procedure or on a limiting value, your help will be most appreciated. Very truly yours, Howard W, Mitchell, M.D., Chief Bureau of Occupational Health BRH:amt ByronR. Hubbard Senior Industrial Hygiene Engineer QQC6 3 16