Parts per million

{
  "id": "MLC-T-ENV-020328",
  "term": "Parts per million",
  "field": "Environment",
  "term_source": "Parts Per Million",
  "definition": "1. One ppm is comparable to one drop of gasoline in a tankful of gas (full-size car).\n\n2. Parts per million parts, a measurement of concentration on a weight or volume basis. This term is equivalent to Milligrams per Liter (mg/L) which is the preferred term.\n\n3. Units commonly used to express contamination ratios, as in establishing the maximum permissible amount of a contaminant in water, land, or air.\n\n4. A unit of measurement that can be used to describe the concentration of a particular substance within air, water, soil, or some other medium. For example, the concentration of carbon dioxide in the Earth's atmosphere is almost 400 parts per million, which means 1 million liters of air would contain about 400 liters of carbon dioxide.\n\n5. 1 ppm = 10⁻⁶ or .0001%, and 1% = 10,000 ppm.\n\n6. Number of parts of a chemical found in one million parts of a particular gas, liquid, or solid. See concentration.",
  "abbreviation": "ppm",
  "subject": "General environmental",
  "references": [
    "Environmental Issues Terms & Acronyms; Pesticides Glossary",
    "Drinking Water Technical & Legal Terms",
    "Terms of Environment",
    "Student's Guide to Global Climate Change",
    "Indoor Air Quality Glossary",
    "Greenhouse Gas Emissions"
  ],
  "url": "https://mlchart.com/terminology/environment/parts-per-million/"
}