This standard specifies a method of determining the lead content of water and wastewater, using an air-acetylene flame and direct flame atomic absorption.The method is applicable to the determination of lead in the concentration range 0,1 mg/L to 5 mg/L, but the detection limit can be reduced to less than 0,05 mg/L by concentration of the sample through evaporation.When the sample has a high dissolved solid content, background correction may be required to eliminate non-specific or continuous absorption.