450 ppb to ppm

450 ppb = 0.45 ppm

ppbppm
435 ppb0.435
440 ppb0.44
445 ppb0.445
4500.45
455 ppb0.455
460 ppb0.46
465 ppb0.465

450 ppb = 0.45 ppm

Formula

1 ppm = 1 mg/L (aqueous, density ≈ 1 kg/L) · 1 ppb = 0.001 mg/L · 1% = 10,000 ppm