parts per million
Trace amount unit
Parts per million is a unit expressing very small concentrations—the number of units of one substance per million units of another.
Abbreviated ppm.
Most commonly used for pollutants in air or water, or trace elements in soil: The EPA limit for lead in drinking water is 15 parts per million.
One ppm equals 0.0001 percent.
- traceMinute remnant or pursue
- air quality indexScale measuring atmospheric pollution levels
- air pollutionToxic atmospheric contamination
- carbon dioxideRespiration byproduct, photosynthesis fuel
- stoichiometryQuantitative chemical reaction analysis
trace amounts · molarity · measure · dilute · concentration gradient · dissolve · density · drinking water · safe levels · heavy metals · vapor · ppb · grain · speck · filter · sample · droplet · whiff
- Carbon Cyclecarbon cycle, carbon dioxide, CO2, photosynthesis, respiration
- ratiosratio, proportion, fraction, percent, percentage
- solutionssolution, answer, fix, remedy, cure
- toxicity levelstoxic, nontoxic, lethal, safe, hazardous
- spectroscopyspectrum, spectrometer, spectroscope, spectrograph, spectrogram
- compound unitskilowatt hour, watt hour, kilometers per hour, miles per hour, feet per second
parts per millionpercentage
Proportion out of hundred
percent · one hundred percent · whole · majority · totality
parts per millionrough estimate
Imprecise preliminary calculation
ballpark figure · approximation · order of magnitude · guesstimate
parts per millionnegligible
Too small to consider
bulk · majority · predominant · unmeasured · approximate
part, parts, parted, parting, partial, partially, partiality, partition, partake