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  2. Threshold limit value - Wikipedia

    en.wikipedia.org/wiki/Threshold_limit_value

    Threshold limit value - surface limit (TLV-SL): Supplements airborne TLVs by establishing a concentration on a surface that is not likely to cause an adverse effect due to direct or indirect contact. Threshold limit value − ceiling limit (TLV-C): An absolute exposure limit that should not be exceeded at any time.

  3. Limiting oxygen concentration - Wikipedia

    en.wikipedia.org/wiki/Limiting_oxygen_concentration

    The limiting oxygen concentration is shown in the lower right of the diagram. The limiting oxygen concentration ( LOC ), [ 1 ] also known as the minimum oxygen concentration ( MOC ), [ 2 ] is defined as the limiting concentration of oxygen below which combustion is not possible, independent of the concentration of fuel.

  4. Permissible exposure limit - Wikipedia

    en.wikipedia.org/wiki/Permissible_exposure_limit

    A short-term exposure limit is one that addresses the average exposure over a 15-30 minute period of maximum exposure during a single work shift. A ceiling limit is one that may not be exceeded for any time, and is applied to irritants and other materials that have immediate effects.

  5. National Ambient Air Quality Standards - Wikipedia

    en.wikipedia.org/wiki/National_Ambient_Air...

    Annual fourth-highest daily maximum 8-hour concentration, averaged over 3 years 40 CFR 50.19: Nitrogen dioxide (NO 2) Primary and Secondary 0.053 ppm (100 μg/m 3) annual Annual mean 40 CFR 50.11: Primary 0.100 ppm (188 μg/m 3) 1-hour 98th percentile of 1-hour daily maximum, averaged over 3 years 40 CFR 50.11: Lead (Pb) Primary and Secondary 0 ...

  6. National Emissions Standards for Hazardous Air Pollutants

    en.wikipedia.org/wiki/National_Emissions...

    The National Emission Standards for Hazardous Air Pollutants (NESHAP) are air pollution standards issued by the United States Environmental Protection Agency (EPA). The standards, authorized by the Clean Air Act, are for pollutants not covered by the National Ambient Air Quality Standards (NAAQS) that may cause an increase in fatalities or in serious, irreversible, or incapacitating illness.

  7. Hydrogen sulfide - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_sulfide

    Hydrogen sulfide is a chemical compound with the formula H 2 S. It is a colorless chalcogen-hydride gas , and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs . [ 11 ]

  8. Maximum acceptable toxicant concentration - Wikipedia

    en.wikipedia.org/wiki/Maximum_Acceptable...

    The maximum acceptable toxicant concentration (MATC) is a value that is calculated through aquatic toxicity tests to help set water quality regulations for the protection of aquatic life. Using the results of a partial life-cycle chronic toxicity test, the MATC is reported as the geometric mean between the No Observed Effect Concentration ...

  9. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    As an example, a measured NO x concentration of 45 ppmv in a dry gas having 5 volume % O 2 is: 45 × ( 20.9 - 3 ) ÷ ( 20.9 - 5 ) = 50.7 ppmv of NO x. when corrected to a dry gas having a specified reference O 2 content of 3 volume %. Note: The measured gas concentration C m must first be corrected to a dry basis before using the above equation.