Document 9Jw891xM4LRLvg79xBM6Q2DGV

COMPAMY CONFIDENTIAL ANALYTICAL RESEARCH DEPARTMENT REPORT f- fit'roi - .'37/ 77?* SubJ act Teat for Lead In Lead Ft Paints_______________Q48-102 __ Manufacturer S-W Co. Cmtomer __ Department Analytical Research__ Requested bv H. E. Spit terDate Completed 9/3/71 ABSTRACT Recent governmental concern over the lead content of "lead-free" Interior paints prompted H. E. Spltzer to request that representative S-W "lead-free" paints be analyzed for total lead content. A method vaa developed and two samples each of Kem-Glo Enamel and Super Kentone were analyzed and found to have lead contents veil below the XX maximum now specified. CONFIDENTIAL Analyat 'T'/f P. (Ltt Thomas P. Carll/ac Richard W. Scott, Dlractor Analytical Raaaarch Department Sherwin-Williams Raaaarch Csntar 0007-SWP-O38169 COMPANT CONFIDENTIAL ADP-7726 PURPOSE Governmental concern regarding the lead content of "lead-free" Interior paints prompted Analytical Research, at the request of H. E. Spltzer, to develop a method for determining the lead content of total paint samples, and to use the method for the analysis of representative "lead-free" Interior paints. RESULTS 4 CONCLUSIONS The method used to determine the total lead content of two KemGlo Enamel paints, two Super Kea-Tone paints and one Kem-l-Coat exterior paint Involved the digestion of the dry paint sample with a 1:1 hydrochlorlcnltrlc acid mixture followed by oxidation of the digested sample with 3Z hydrogen peroxide. The treated sample was then filtered to remove thn undigested pigment and then concentrated by evaporation. The concentrated solution was then analyzed by atomic absorption analysis for lead concent. The results are aa follows: Sample X Pb on Total X Pb on tTVM tC3 G 33, Ken-Tone Hlghgete Green, C1941 K7 G 33, Kem-Glo Hlghgete Green, C1831 0.00074X 0.00688Z 0.0012X 0.0127X K3 W 97, Kem-Tone Dover White, C2231 K7 W 97, Kem-Glo Dover White 0.00096X 0.00576X 0.0016X 0.0105Z A3 W 16, Kem-l-Coat, C1981 0.1S286X 0.2153X The results Indicate that tha Kern-Tone and Kem-Glo samples contain laad lavals well below the current IX maximum level specified for interior paints. Tha sample of Kam-l-Coat was analyzed to teat tha efficiency of the method since lead nephthenate drier is present In the formula. Based on the formula, tha calculated percent lead on the total paint is 0.16973Z and on tha NVM is 0.239Z. Tha experimental reaulte of 0.15286X and 0.2153X, for the total paint and the NVM respectively, compare well with the calculated percentages. DISCUSSION Tha method for determining the total lead content of the samples Involved weighing a ten to twelve gram sample of the total paint into e 123-ml. Erlanmsver flank with a ground glees neck. Tha sample wee than dried at 105C. for twelve hours or until little, if any, solvent remained. The sample wee than allowed to cool to roam temperature and 23 ml. of concentrated HNO, and 23 ml. of concentrated HC1 were added. A water cooled condenser was then attached and the sample was refluxed until the initial digestion wee underway. At this point CONFIDENT 0007-SWP-038170 Q0Q7-SWP-000110351 COMPANY CONFIDENTIAL ADP-7726 2- - en additional 25 ml. of concentrated nitric acid was added and the reflux continued until the sample appeared to be completely digested. Three percent hydrogen peroxide (25 ml.) was then added and the solution refluxed until all of the peroxide was decomposed. The sample was then allowed to cool at room temperature and filtered into a 400-ml. beaker through highly retentive filter paper. The filtered solution waa then evaporated to a volume of approximately 20 ml. and re-filtered into a 50-ml. beaker quantitatively. The filtrate was then quanti tatively traneferred to a 50-ml. volumatrlc flask, and the atomic absorption analysis was completed on this solution. 0007--SWP-038171 T 0007-SWP-000110352