xvEPA
United States
Environmental Protection
Agency
Pesticides And
Toxic Substances
(7508W)
738-F-91-101
September 1991
R.E.D. FACTS
Pesticide
Reregistration
Carbon Dioxide
All pesticides sold or used in the United States must be registered by
EPA, based on scientific studies showing that they can be used without
posing unreasonable risks to people or the environment. Because of
advances in scientific knowledge, the law requires that pesticides which
were first registered years ago be reregistered to ensure that they meet
today's more stringent standards.
In evaluating pesticides for reregistration, EPA obtains and reviews a
complete set of studies from pesticide producers, showing the human health
and environmental effects of each pesticide. The Agency imposes any
regulatory controls that are needed to effectively manage each pesticide's
risks. EPA then reregisters pesticides that can be used without posing
undue hazards to human health or the environment.
When a pesticide is eligible for reregistration, EPA announces this and
explains why in a Reregistration Eligibility Document, or RED. This fact
sheet summarizes the information about carbon dioxide presented in the
RED for carbon and carbon dioxide.
Use Profile
Regulatory
History
Carbon dioxide is the active ingredient in four pressurized liquid and
gas fumigant products used to control insects in enclosed indoor areas where
grain or other food and feed crops are stored.
A ubiquitous, naturally-occurring gas found in the atmosphere and a
product of animal metabolism, carbon dioxide is necessary for plant and
animal life as it is essential for respiration. Carbon dioxide's best known
use is for the carbonation of beverages. It also has many other non-
pesticidal uses.
Carbon dioxide was first registered by EPA in 1981, in an aerosol
spray insecticide product. However, the registrant of these products has
recently notified EPA of its intent not to support the reregistration of carbon
dioxide for this use. Therefore, the aerosol spray insecticide use has not
been considered in this RED.
In 1982, carbon dioxide was registered for use as a fumigant to
control insects and mites in stored grain. EPA exempted carbon dioxide
from tolerance requirements on all agricultural commodities in
1980 (see 40 CFR 180.1049), and established a food additive tolerance for
post-harvest use of carbon dioxide on all processed agricultural commodities
in 1981 (see 40 CFR 185.650).
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Human Health Toxicity
AsS6SSm6nt All toxicology data requirements for the pesticide fumigant use of
carbon dioxide have been satisfied, and no further studies are required for
reregistration.
Acute inhalation toxicity studies show that exposure of test animals to
atmospheres containing increasing concentrations of carbon dioxide causes
increasingly severe effects on the heart, brain and nervous system,
ultimately resulting in death.
Subchronic toxicity studies show reversible weight loss in test animals.
A chronic toxicity study on brewery workers suggests that there are no
significant physiological effects from chronic intermittent exposures to
relatively low level carbon dioxide concentrations. Other chronic studies
using test animals resulted in birth defects and adverse effects on sperm
production.
Dietary Exposure
Carbon dioxide has been consumed in naturally carbonated "mineral"
water for centuries, and in manufactured carbonated beverages for many
years, without any indications of toxic effects. It is listed as a substance
Generally Recognized as Safe, or GRAS, for use in food (please see 21
CFR 184.1240).
Carbon dioxide is used on fruits and vegetables after they are
harvested to control insects during storage; this use is exempt from the
requirement of a tolerance (please see 40 CFR 180.1049). Carbon dioxide
also may be used on all processed agricultural commodities as a food
additive for stored product insect control (please see 40 CFR 185.650).
Applicator Exposure
The indoor use of carbon dioxide products to fumigate stored raw and
processed foods poses potential exposure risks for workers, especially when
they must reenter confined, enclosed spaces. Carbon dioxide gas may
collect in poorly ventilated depressions in grain bins, shafts, etc., and in
sites where recirculation of air is minimal. Product labels will require air
monitoring while treated areas are being ventilated to reduce ambient levels
of carbon dioxide. Reentry of more than 15 minutes into treated areas will
not be allowed until carbon dioxide levels fall below 10,000 ppm.
Human Risk Assessment
Many of the studies usually required for pesticide registration are not
necessary for EPA to regulate carbon dioxide as a pesticide. People are
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naturally exposed to carbon dioxide during normal respiratory and metabolic
processes. We normally consume carbon dioxide in foods and beverages
daily. The human body can rapidly compensate for moderate atmospheric
increases of carbon dioxide.
Serious birth defects can result from acute exposure to atmospheres
containing more than 10 percent carbon dioxide. However, applicators are
not likely to encounter these levels if they use the fumigant products in
accordance with approved labeling.
The only risk of concern associated with the pesticide fumigant use is
the risk to workers who enter treated areas which have not been sufficiently
ventilated. However, EPA believes that this risk is low if products are
applied correctly and treated areas are ventilated properly, consistent with
labeling.
EPA is not requiring any environmental fate or ecological effects data
AsSGSSITIGnt on carbon dioxide. All the usual data requirements have been waived.
Environmental Fate
Carbon dioxide is a naturally occurring substance whose physical and
chemical properties are well understood. Since it is used indoors to
fumigate insects, EPA believes its use will not adversely effect the
environment. Therefore, all environmental fate data requirements have
been waived.
Additional Data
Ecological Effects
Since carbon dioxide is used indoors to control insects in stored food
and feed, exposure to nontarget organisms is not expected. Therefore, no
ecological effects data are required for reregistration.
The generic data base supporting reregistration of carbon dioxide is
determined to be complete for reregistration. However, product- specific
acute toxicity, efficacy and product chemistry data are being required.
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Product Labeling
Changes Required
Regulatory
Conclusion
For More
Information
End-use fumigant products containing carbon dioxide must bear
several new, detailed label statements. Please see the RED for the exact
language required. Briefly, new label statements are required in these
areas:
• Human hazard precautionary statements;
• Spill and leak procedure statement;
• Placarding requirements;
• Storage and handling requirements.
• All registered pesticide products containing carbon dioxide can
be used without causing unreasonable adverse effects in people
or the environment. Therefore, they are eligible for
reregistration.
• The four end-use grain fumigant products containing carbon
dioxide will be reregistered once product specific data and
revised labeling are received and accepted by EPA.
EPA is requesting public comments on the Reregistration Eligibility
Document for carbon and carbon dioxide during a 60-day time period, as
announced in a Notice of Availability published in the Federal Register. To
obtain a copy of the RED or to submit written comments, please contact the
Public Response and Program Resources Branch, Field Operations Division
(7506C), Office of Pesticide Programs (OPP), US EPA, Washington, DC
20460, telephone 703-557-2805.
In the future, the RED will be available from the National Technical
Information Service (NTIS), 5285 Port Royal Road, Springfield, VA
22161, telephone 703-487-4650.
For more information about carbon dioxide, or about EPA's pesticide
reregistration program, please contact the Special Review and Reregistration
Division (7508W), OPP, US EPA, Washington, D.C. 20460, telephone
703-308-8000. For information about the reregistration of individual
carbon dioxide products, please contact the Registration Division (7505C),
OPP, US EPA, Washington, DC 20460, telephone 703-557-5447.
For information about the health effects of pesticides, or for assistance
in recognizing and managing pesticide poisoning symptoms, please contact
the National Pesticides Telecommunications Network (NPTN). Call toll-
free 1-800-858-7378, 24 hours a day, seven days a week, or Fax your
inquiry to 806-743-3094.
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