UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF 

PREVENTION, PESTICIDES AND 

TOXIC SUBSTANCES 

April 1, 2004 

Memorandum

Subject: Lower Risk Pesticide Chemical Focus Group’s Assessment for Carbon 

Dioxide Tolerance Reassessment

From: Mark Perry 

Product Reregistration Branch 

Special Review and Reregistration Division (7508C) 

Through: Linda Propst, Branch Chief 

Product Reregistration Branch 

Special Review and Reregistration Division (7508C) 

To: Lower Risk Pesticide Chemical Focus Group 

Kathryn Boyle, Co-Chair 

Kerry Leifer, Co-Chair 

Registration Division (7505C) 

The following is the Lower Risk Pesticide Chemical Focus Group’s science assessment 

for carbon dioxide (PC Codes 016601, 800029). The purpose of this review is a reassessment of 

the exemption from the requirement of a tolerance under 40CFR 180.1049. This assessment 

summarizes available information on carbon dioxide. In performing this assessment, EPA has 

relied on a peer-reviewed evaluation performed by the Food and Drug Administration (FDA). 

Carbon Dioxide (CO2) is an odorless, colorless, noncombustible gas. Under ordinary 

conditions of temperature and pressure, the gas is one and one half times as dense as air, and is 

moderately soluble in water, dissolving at about a 1:1 ratio by volume. At 0.03%, it is the fourth 

most abundant gas in the Earth’s atmosphere and is an essential component of plant and animal 

respiration. Animals exhale carbon dioxide as a metabolic byproduct, and plants use carbon 

dioxide by converting it to sugars and other forms of energy through photosynthesis. In the 

human body, carbon dioxide is involved in several vital functions, including the regulation of 

Page 1 of 3 
respiration, the maintenance of acid-base balance, the liberation of oxygen to tissue and is an 

end-product of carbohydrate and fat metabolism. The average adult produces more than 500 

grams of carbon dioxide per day, under resting conditions. 

Carbon dioxide has many commercial uses. Its most well known use is in the production 

of carbonated beverages. It is also used in water softening, manufacturing of aspirin, as a 

propellant in aerosol cans and in the coffee packaging process. Solid carbon dioxide, or dry ice, 

is used as a refrigerant. Carbon dioxide is obtained for commercial use from chemical 

fermentation, from the burning of limestone or carbonaceous fuels, and from natural springs and 

wells. As a pesticide active ingredient, carbon dioxide is used indoors as a fumigant to control 

insects in stored food and feed by displacing oxygen in the container’s atmosphere. It does not 

accumulate in treated raw agricultural commodities, but rather diffuses into the atmosphere 

following application. Currently there are four registered end-use products containing carbon 

dioxide as the active ingredient, as well as one experimental-use and one Special Local Needs 

registration. As a pesticide inert ingredient carbon dioxide is used as an aerosol propellant. 

The Office of Pesticide Programs published its Carbon and Carbon Dioxide 

Reregistration Eligibility Decision (RED) Document in September of 1991. The RED considers 

the many vital functions which carbon dioxide performs in the human body as well as the 

available acute, sub-chronic and chronic studies performed on carbon dioxide. That document 

acknowledged that exposure to relatively high levels of carbon dioxide may result in serious 

health effects and even death through asphyxiation. 

The Food and Drug Administration (FDA) has classified carbon dioxide as Generally 

Recognized As Safe (21CFR 184.1240) as a direct food additive. The 1979 FDA evaluation of 

carbon dioxide, entitled “Evaluation of the Health Aspects of Carbon Dioxide as a Food 

Ingredient,” also considers the essential role of carbon dioxide in the human body and the 

available toxicity data. This evaluation found that although data relating directly to carbon 

dioxide safety as a food ingredient were not available, “there is substantial evidence that the 

amount of carbon dioxide ingested with foods is negligible compared with that produced 

normally by the body.” The Evaluation also states that “[c]arbon dioxide also has been 

administered experimentally without ill effects in amounts orders of magnitude greater than from 

possible food sources.” The FDA evaluation goes on to conclude that “there is no evidence in 

the available information on carbon dioxide that demonstrates, or suggests reasonable grounds to 

suspect, a hazard to the public when it is used at levels that are now current or that might 

reasonably be expected in the future.” 

Based on the available information on carbon dioxide, its expected use pattern, its safe 

history of use as a food additive, and its essential role in human metabolism and respiration, there 

is a reasonable certainty of no harm from exposure to carbon dioxide through its use in 

pesticides. Furthermore, there is no concern for potential sensitivity to infants and children. As 

with all chemicals, carbon dioxide must be used safely according to good manufacturing or good 

agricultural practices. The Agency believes that exposure to levels of concern of carbon dioxide 

are unlikely as a result of its use in pesticide products, and would be most appropriately 

addressed through the use of protective equipment, adequate ventilation, and labeling, not 

through the establishment of tolerance exemptions. 

Page 2 of 3 
References: 

U.S. Environmental Protection Agency (EPA), 1991. Reregistration Eligibility Document 

(RED), Carbon and Carbon Dioxide. 

U.S. Food and Drug Administration (FDA), 1979. Evaluation of the Health Aspects of Carbon 

Dioxide as a Food Ingredient. Prepared by Life Sciences Research Office, Federation of 

American Societies for Experimental Biology. 

Page 3 of 3