WASHINGTON (CN) – The Environmental Protection Agency has released a report on the effects that short-term exposure to carbon dioxide may have on car passengers and drivers, indicating that a ceiling of 40,000 parts per million is the limit for human safety.
The report, by Eastern Research Group, Inc. was commissioned by the EPA as part of its investigation into the proposed use of carbon dioxide as a replacement refrigerant for the hydrofluorocarbon CFC-12 in motor vehicle air conditioning systems. The report contains data from a range of studies that show that exposure to carbon dioxide in concentrations as low as 30,000 parts per million may cause headaches and dizziness which could impair a driver’s ability to concentrate.
Although carbon dioxide is a greenhouse gas, its global warming potential is 1,400 times lower than CFC-12’s, and in its liquid form, as a refrigerant, it is said to have no ozone depletion potential. Use of carbon dioxide in vehicle air conditioning systems would require the use of parts capable of dealing with the high pressure at which carbon dioxide circulates.