CAS no. 12202-17-4 Pb4O3(SO4)H2O MW is: 990.83 g/mol TBLS has excellent stabilizing properties in PVC. The special surface coating increases the effectiveness of lower concentration permitting manufacturing PVC compounds and products of lower stabilizer usage and hence low cost. It improves initial and long term thermal stability of compounds containing chlorinated parrafin. It gives better light stability and improved electrical results. It is not a lubricant stabilizer so is generally used with Lead stearate and Di basic lead stearate..