Carbon Dioxide
Health Hazard Information Sheet
10,000 ppm (1.0%) Typically no effects, possible drowsiness
15,000 ppm (1.5%) Mild respiratory stimulation for some people
30,000 ppm (3.0%) Moderate respiratory stimulation, increased heart rate and blood
pressure, ACGIH TLV-Short Term
40,000 ppm (4.0%) Immediately Dangerous to Life or Health (IDLH)
50,000 ppm (5.0%) Strong respiratory stimulation, dizziness, confusion, headache, shortness
of breath
80,000 ppm (8.0%) Dimmed sight, sweating, tremor, unconsciousness, and possible death
The response to CO2 inhalation various greatly even in healthy individuals. The seriousnessof
the symptoms is dependent on the concentration of CO2 and the length of time a person is
exposed. Since CO2 is odorless and does not cause irritation, it is considered to have poor
warning properties. Fortunately, conditions from low to moderate exposures are generally
reversible when a person is removed from a high CO2 environment.
Another health hazard caused by CO2 is frostbite by contact with solid CO2 (dry ice) andvapors
off-gassing from dry ice. Precautions should be taken to prevent direct skin and eye contactwith
dry ice or with vessels/bins containing dry ice. Similar effects may occur from compressed CO2
gas as it is being released from a cylinder if it comes in contact with the skin or eyes. CO2 gas
at room temperature will not injure the skin or eyes.
What OSHA standards and exposure guidelines apply?
OSHA has established a Permissible Exposure Limit (PEL) for CO2 of 5,000 parts per million
(ppm) (0.5% CO2 in air) averaged over an 8-hour work day (time-weighted average orTWA.)
The American Conference of Governmental Industrial Hygienists (ACGIH) recommends an 8-
hour TWA Threshold Limit Value (TLV) of 5,000 ppm and a Ceiling exposure limit (not to be
exceeded) of 30,000 ppm for a 10-minute period. A value of 40,000 is considered immediately
dangerous to life and health (IDLH value).
The TLVs are intended to minimize the potential for asphyxiation and undue metabolic stress.
The ACGIH TLV supporting document states that: “Based on the long-term exposure studies,
even though the majority of references are concerned with studies on physically fit males in
confined spaces, a TLV-TWA of 5,000 ppm, is recommended. This value provides a good
margin of safety from asphyxiation and from undue metabolic stress provided normal amounts
of oxygen are present in the inhaled air.” The TLV-STEL is based on short-term studies which
showed that “concentrations of 27,600 to 39,500 ppm produced increased pulmonaryventilation
rates. Therefore, a TLV-STEL of 30,000 ppm is considered appropriate.”
How are occupational exposures monitored or measured?
CO2 concentrations in air can be measured using detector tubes (for immediate short term
samples) and passive indicator tubes or dosimeters (for longer TWA full or partial shift
sampling). The primary OSHA method for the sampling and analysis of CO2 involves using a
ESHG-Health-02.00 FSIS Environmental, Safety and Health Group