Innocent bystander
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What are the Allowable Limits of CO2 EXPOSURE
Carbon dioxide exposure limits PEL and TLV set by OSHA and NIOSH
Carbon dioxide is regulated for diverse purposes but not as a toxic substance.
bullet The U.S. EPA CO2 exposure limits: The U.S. EPA recommends a maximum concentration of Carbon dioxide CO2 of 1000 ppm (0.1%) for continuous exposure. bullet ASHRAE standard 62-1989 recommends an indoor air ventilation standard of 20 cfm per person of outdoor air or a CO2 level which is below 1000ppm. bullet NIOSH CO2 exposure limits: NIOSH recommends a maximum concentration of carbon dioxide of 10,000 ppm or 1% (for the workplace, for a 10-hr work shift with a ceiling of 3.0% or 30,000 ppm for any 10-minute period). These are the highest threshold limit value (TLV) and permissible exposure limit (PEL) assigned to any material. NIOSH's recommended CO2 exposure limit for 15 minutes is 3.0% or 30,000 ppm . A CO2 level of 4% (40,000 ppm) is designated by NIOSH as immediately dangerous to life or health. bullet OSHA CO2 exposure limits: The U.S. Department of Labor Occupational Safety & Health Administration, OSHA, has set Permissible Exposure Limits for Carbon Dioxide in workplace atmospheres at... bullet 10,000 ppm of CO2 measured as a Time Weighted Average (TWA) level of exposure bullet OSHA has set 30,000 ppm of CO2 as a Short-Term Exposure Limit (STEL). bullet OSHA has also set a Transitional Limit of 5,000 ppm CO2 exposure TWA. bullet [OSHA's former limit for carbon dioxide was 5000 ppm as an 8-hour TWA.] bullet OSHA recommends a lowest oxygen concentration of 19.5% in the work place for a full work-shift exposure. As we calculated above, for the indoor workplace oxygen level to reach 19.5% (down from its normal 20.9% oxygen level in outdoor air) by displacement of oxygen by CO2, that is, to reduce the oxygen level by about 6%, the CO2 or carbon dioxide level would have to increase to about 1.4% 14,000 ppm. In summary, OSHA, NIOSH, and ACGIH occupational exposure standards are 0.5% CO2 (5,000 ppm) averaged over a 40 hour week, 3% (3,000 ppm) average for a short-term (15 minute) exposure [we discuss and define "short term exposure limits" STEL below], and 4% (40,000 ppm) as the maximum instantaneous limit considered immediately dangerous to life and health.
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