Question: is ppb the same as ng/ml?
Answer: 1 ng/mL = 1 ppb. 1 x 1 ppb = 1 Parts Per Billion. Definition: In relation to the base unit of [density] => (kilograms per cubic meter), 1 Nanograms Per Milliliter (ng/mL) is equal to 1.0E-6 kilograms-per-cubic-meter, while 1 Parts Per Billion (ppb) = 1.0E-6 kilograms-per-cubic-meter.