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Basic Lead Sulfate I-A-c JOHN S. NORDYKE tfopermissible jeatf cogtempf resid#fl Consultant fpalnts to a maximumbTO^^. Pittsburgh, Pennsylvania Several basic lead sulfate compounds were used as paint pigments. These are called sublimed, or supersublimed white Pigment White 2 Colour Index Number 77633 Sublimed White Lead Basic Sulfate, White Lead Super Sublimed White Lead Barlet White Lead Lewis White Lead Chemical Formula (mixture) Normal Lead Sulfate PbS04 (MW 303.27) Monobasic Lead Sulfate PbS04 PbO (MW 526.48) lead (PbSC>4 PbO), and precipitated basic lead sulfate (PbS04 Pb(OH)2). Tetrabasic lead sulfate (PbS04 4Pb(OH)z) has had little if any use in paints or plastics. It does have a substantial and continuing use, however, in storage batter* ies used by telephone companies for emer gency power purposes. It is used in the positive plates only. Batteries in which te trabasic lead sulfate is used as the active positive material have a life expectancy of up to 30 years. Those using conventional lead oxide as the active positive material (.Public Law 91-695 enacted by the Congress have shorter life expectancy. Tribasic lead land signed by the President in January sulfate (3PbO PbS04 X(OH),,) is the most i 197J, effectively eliminated the use oflead widely used of all vinyl stabilizers, both in pigments in paints for residential structures the United States and abroad. These two in the United States. Subsequent legislation are the most widely used of the basic lead and regulations have progressively reduced sulfate pigments.