Document 91BMdpev9q3oB9Jm2M963DKKV

COMMERCIAL PRODUCTS HIGHWAY SIGNS ARCHITECTURAL PRODUCTS ADVERTISING IDENTIFICATION SIGNS CALIFORNIA METAL ENAMELING COMPANY 6904 EAST SIAUSON AVENUE LOS ANGELES 22, CALIFORNIA RAYMOND 3-6351 January 25, 1963 Dr. Robert A. Kehoe University of Cincinnati The Kettering Laboratory College of Medicine - Eden Avenue Cincinnati 19, Ohio Dear Dr. Kehoe: V/e wish to thank you for your letter of January 23, 1963, regarding the ceramic glazets to be used in aluminum cookware. Your thoughts on the matter are very much appreciated, as well as your carefully explained reasons for your answers to our questions. We are enclosing a copy of the California Test Method, which will explain their system for testing. We have checked the various colors proposed to be used in this program and find them to have a lead solubility of between two (2) and four (4) parts per million when tested with boiling acetic acid. Basically, the reason for the finish on the interior of the aluminum bowls is one of esthetics and saleability of the product. It is not in there for any engineering purpose per se. There are other porcelain finishes for aluminum which are lead free. It is our understanding, however, that the frits are generally composed of other types of heavy metals such as cadmium, and that these other metals might generally be as toxic as the lead used in the formulation proposed for the units in question. We have generally found that their resistance to acetic acid and citric acid are not as high as the lead bearing glazes proposed. We received a report from a Dr. Rutherford P, Johnstone, written by Mr. Edgar Littlefield. In this report, Mr. Littlefield suggested a test of 48 hours of lemon jiice and vinegar. In running this test the parts were carefully scrutinized to check the surface for any roughening or pitting, or any other change in texture or color. No such change was noted on a close examination of the parts. Mr. Littlefield stated that "If these full strength food acids do not affect the glaze, you can, in my opinion, consider the glaze to be safe.". Actually, these parts, being proposed, would not be used as a daily thing. This is a gift ware item, which would be used more for entertaining, generally speaking. K 0008345 N9689 / Or. Robert A. Kehoe University of Cincinnati Page 2 January 25, 1963 We recognize the need for control of lead in products such as these, and do not wish to produce any article which would tend to be unsafe in use. These particular products, however, cannot achieve acceptance without the porcelain finish applied to the interior and if our glaze does not constitute a hazard, we would then propose to manufacture these parts under careful production controls. We would most certainly appreciate your comments relative to the above additional information. Very truly Vfours HVP:hb Enc H. V. Penton President 0008346 sew ,<> ' Scape; TENTATIVE xssSOQ OF TES? FOR SOLUBILITY OF LEAD P&OH GLAZE 5CHFACE5 r ec eiv e d JAN 1 7 19o! SAFETY DEPARTMENT This aethori of teat covers tiie procedure for determining the lead extrac tion from glass surfaces on exposure to organic acids, or specifically acetic acid. Sigfi 1. f jcarce o.f_ Tost: Tliia ia a siisple procedure for plant control use. Thv test may give coo high values far "lead" because other ratals, such as copper, biav-ch, cadmium, tin, nrasaic* &nfcjjx',ony, ox- mercury which aiey also he present, are precipitated ]/ Ta o "citiiy,oa" !2thoii" raav bo used ?,? a a?ore & pacific lest for lead. The present test though,. deaigifcd to sitmlavS conditiotts in service, should of um.: for plant ceacrol and deTroiopaer.l work. "er:.-! f iptci"ir?5;:;! : Van o u r f ti shapes may be used, *.&.. fruit d.i.ehes, bcvl*, cups, etc. For Eor critic,'.! ccmiparison a similar siiap* should be tused so r-hnt the total BurfeoC' contacted by the re&gonn during the. test is aearly fha naaa. A sca.ndar-a size cup is recossaeoded,, Standard d-clvzi q u o ; The standard solutions shryji be r--i by a.hii*.y tno correct tesouni.-r. of ck*&iii;.\.y *-n * lead uiIrate to; a 11 .t : '. : eolutio-ki/ t In asnv d5>iHCwe, it will b*r found to be aim-* sca*rniont to use white dini v-.uw*sf<&y uiich con tains about 1:1 acetic acid. Where this is- none tUu di <?i tilled vinegar ssimil ce used else in prepsriag tho standard uolutioaw.. Standards hu-J. \ fn p.rnpd>ro-i which contain 1/2, 1- 2; ^, u.l 8 parts of lead per esilliou puria of resTo prepare the standardsv dissolve C.Glfb of u, l-b a .-' TV.,,., is 5C0 cc o f reagatii; end dilute to exac* ly 1 Ilti-n. '. .'r solution \'cortr.xn ii ; .y'--. of Pu, %Xf cc of this shall r.u, x` ;-.e a -- rd:yy aduties of thin concentretion. The r<\- Maihir.:; .S-bO cc aoiuvton ah ill J be diluted to 1 liter which produces a concenV.ro;ion of '. par. cf lend. The dilution process shall be continued 1?' tne standard solutions containing 2, 1, ami 1/2 ppst Ft in scJ utiou. tb...-' 'V* lV g 0008347 ^9689-04 2- - The standard solutions shall be subjected to the H^S precipitation as described under procedure. The color of the precipitated standards fade in light so it is necessary to prepare freshly precipitated standards daily before each series of tests. The stability of these samples can be improved by the addition of 1/4% gelatin to the standard solutions. If the reagent after the test contains higher amounts of lead, aliquot portions shall be used in the colorimetric comparisons. Higher concentra tions of lead make comparison difficult or impossible. Procedure: A. 150 cc of the boiling reagent (5% acetic acid solution or white, distilled vinegar) shall be poured into the standard cup or ether shape specimen and allowed to cool for 1/2 hours. The reagent shall then be placed in a Kessler tube. A brisk evolution of hydrogen sulfide gas shall be passed through the reagent for 3 minutes. Tns coloration of the reagent shall then be compared with the standard solution in Kessler tubes which have been subjected to the same hydrogen sulfide treatment. A suitable colorimetric or turbidi meter will greatly aici in making comparisons. The colorimetric comparisons shall be made as soon as possible after the precipitation of the test reagent and standard solutions. B. An alternate procedure involves the exposure of the test specimen to the test reagent introduced and maintained at room temperatxire for a period of 24 hours. Reports: The report shall state the lead in ppm contained in the test reagent. It shall further indicate the specific reagent^ used, the specimen shape, and which of the test conditions (A) or (B) was employed. 1/ Scott's Standard Methods of Chemical Analysis, N. H. Furman, Editor 3th Edition, Voi. I. p 521, d. Van Hostrand Co., Inc. 1939 2/ 5% acetic acid solution or white, distilled vinegar. It may also be desirable in some cases to use other organic acids, e.g., citric acid. The concentration of the organic acid used shall be stated. K 0008348