1 milligram per gram (mg/g)= 1'000 parts per million (ppm)1 fluid ounce, US per 1 gallon (1 fl. oz./1 gal US)= 7'490 parts per million (ppm)1 fluid ounce, US per 100 gallons (1 fl. oz./100 gal US)= 75 parts per million (ppm)