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Agency Response Letter GRAS Notice No. GRN 000167

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See also Generally Recognized as Safe (GRAS) and about the GRAS Notice Inventory

CFSAN/Office of Food Additive Safety

September 29, 2005

Mark L. Itzkoff
Olsson, Frank and Weeda, P.C.
Suite 400
1400 Sixteenth Street, N.W.
Washington, D.C. 20036

Re: GRAS Notice No. GRN 000167

Dear Mr. Itzkoff:

The Food and Drug Administration (FDA) has received the notice, dated April 1, 2005, that you submitted on behalf of Tyson Foods, Inc. (Tyson) in accordance with the agency's proposed regulation, proposed 21 CFR 170.36 (62 FR 18938; April 17, 1997; Substances Generally Recognized as Safe (GRAS)). FDA received this notice on April 4, 2005, filed it on April 5, 2005, and designated it as GRN No. 000167.

The subject of the notice is carbon monoxide (CO). The notice informs FDA of the view of Tyson that CO is GRAS, through scientific procedures, for use as a component of a modified atmosphere packaging (MAP) system for case-ready fresh beef and pork. The level of CO in this MAP system is 2.2 milligrams (mg) CO per pound (lb) of meat. The other components of the MAP system are carbon dioxide and nitrogen.

Carbon monoxide was also the subject of GRN 000083 submitted by Pactiv Corporation and GRN 000143 submitted by Precept Foods, LLC. These submissions informed FDA that CO is GRAS, through scientific procedures, for use as a component of a gas mixture in a MAP system. The level of CO in Pactiv's and Precept's MAP system is 0.4 percent; other components of this MAP system are carbon dioxide and nitrogen. This packaging system is used for packaging fresh cuts of muscle meat and ground meat to maintain wholesomeness, provide flexibility in distribution, and reduce shrinkage of the meat.

As compared to Pactiv's and Precept's packaging system, Tyson's packaging system is a reduced head space system, and therefore to achieve the same ratio of CO to meat, they use a higher concentration of CO per unit volume. To achieve this end, Tyson states that they will use the concentration of CO necessary to achieve the same ratio of CO to meat (2.2 mg CO per lb of meat) as is used in the Precept and Pactiv systems. For example, a 620 cubic centimeter (cc) package containing 1 lb of ground beef would require a 0.89 percent concentration of CO to achieve the required concentration of CO; a 3000 cc package containing 5 lbs of meat would require 1.19 percent concentration of CO to achieve the required concentration of CO.

As part of GRN 000167, Tyson incorporates GRN 000083 and GRN 000143 by reference, and states that the detailed information establishing the GRAS status of CO in MAP systems is contained in GRN 000083.

GRN 000167 describes publicly available information pertaining to the identity and characteristic properties of CO. Carbon monoxide (Chemical Abstracts Service Registry Number 630-08-0) is a colorless, odorless, gas. The notice includes a list of properties of CO. Tyson uses the specifications in the previous GRAS notices; CO is a minimum purity of 98 percent and the remaining 2 percent are components found in the atmosphere (nitrogen, oxygen, carbon dioxide, argon, water, hydrogen and/or methane). Tyson considers CO of this purity to be "food grade."

Meat is placed on a tray within a chamber, the chamber is then filled with the desired atmosphere, and finally, a barrier film is affixed to the package. The packages are then labeled with a validated open date code at a central location and will be subject to no further processing or manipulation at retail. The open date code established for products packed in the MAP system will not exceed 35 days following the date of packaging for intact muscle cuts and 28 days for ground beef.

Tyson states that the CO is included in the modified atmosphere to help maintain the characteristic color of fresh meat. Tyson states that the CO is not intended to affect microbial growth and will not extend the shelf life of the product.

Tyson estimates that the exposure to CO would be 0.054 mg CO per meal of cooked meat. Tyson first assumes a scenario where the meat absorbs 30 percent of the CO in the package and 100 percent of the CO present in the meat is absorbed by the consumer. A dietary intake of 0.36 mg of CO per meal would occur when 8.8 ounces (250 grams) of meat is consumed. Tyson considers that this estimated intake of CO from its use in packaging meat is small compared to the amount that is presently accepted as a safe exposure limit by the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA).(1) Tyson then accounts for the fact that meat packaged with CO will be cooked prior to consumption and assumes an 85 percent reduction in CO exposure due to cooking of the meat. This 85 percent reduction decreases the maximum exposure from 0.36 mg to 0.054 mg CO per meal. If 100 percent of the CO in the package is absorbed, and 100 percent of the CO is consumed, an 8.8 ounce serving would expose the consumer to 1.2 mg of CO.

Based on the information that you provide on behalf of Tyson, as well as other information available to FDA, the agency has no questions at this time regarding Tyson's conclusion that CO is GRAS under the intended conditions of use. The agency has not, however, made its own determination regarding the GRAS status of the subject use of CO. As always, it is the continuing responsibility of Tyson to ensure that food ingredients that the firm markets are safe, and are otherwise in compliance with all applicable legal and regulatory requirements.

During its evaluation of GRN 000167, OFAS consulted with the Labeling and Consumer Protection Staff of FSIS regarding the use of CO in meat products. Based on the information submitted by Tyson, FSIS has concluded that the MAP system as described in Tyson's notice, and used under the conditions stated in Tyson's notice, would be acceptable for packaging red meat cuts and ground meat. If you or Tyson have any additional questions, you should direct your inquiry to Dr. Robert Post, Director, Labeling and Consumer Protection Staff, Office of Policy, Program and Employee Development, Food Safety and Inspection Service, 1400 Independence Ave, S.W., Suite 602, Annex, Washington, DC 20250-3700. The telephone number of his office is (202) 205-0279 and the FAX number is (202)205-3625.

In accordance with proposed 21 CFR 170.36(f), a copy of the text of this letter, as well as a copy of the information in your notice that conforms to the information in proposed 21 CFR 170.36(c)(1), is available for public review and copying on the homepage of the Office of Food Additive Safety (on the Internet at


Laura M. Tarantino, Ph.D.
Office of Food Additive Safety
Center for Food Safety and Applied Nutrition

cc: Dr. Robert Post, Director
Labeling and Consumer Protection Staff
Office of Policy, Program, and Employee Development
Food Safety and Inspection Service
1400 Independence Ave., SW, Suite 602, Annex
Washington, DC 20250-3700

(1)EPA's National Ambient Air Quality Standards is 9 ppm CO in air, resulting in the inhalation of 52 mg CO in 8 hours. The OSHA Permissible Exposure Limit is 50 ppm in air, resulting in the inhalation of 290 mg CO in 8 hours.

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