[Federal Register: December 23, 2004 (Volume 69, Number 246)]
[Rules and Regulations]               
[Page 76844-76847]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Food and Drug Administration

21 CFR Part 179

[Docket No. 2003F-0088]

Irradiation in the Production, Processing and Handling of Food

AGENCY: Food and Drug Administration, HHS.

ACTION: Final rule.


SUMMARY: The Food and Drug Administration (FDA) is amending the food 
additive regulations by establishing a new maximum permitted energy 
level of x rays for treating food of 7.5 million electron volts (MeV) 
provided that the x rays are generated from machine sources that use 
tantalum or gold as the target material, with no change in the maximum 
permitted dose levels or uses currently permitted by FDA's food 
additive regulations. This action is in response to a petition filed by 
Ion Beam Applications.

DATES: This rule is effective December 23, 2004. Submit written 
objections and request for a hearing by January 24, 2005. See Section 
VII of this document for information on the filing of objections.

ADDRESSES: You may submit written objections and requests for a 
hearing, identified by Docket No. 2003F-0088, by any of the following 
     Federal eRulemaking Portal: http://frwebgate.access.gpo.gov/cgi-bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.regulations.gov. 

Follow the instructions for submitting comments.
     Agency Web site: http://frwebgate.access.gpo.gov/cgi-bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.fda.gov/dockets/ecomments. 

Follow the instructions for submitting comments on the agency Web site.
     E-mail: fdadockets@oc.fda.gov. Include Docket No. 2003F-
0088 in the subject line of your e-mail message.
     FAX: 301-827-6870.
     Mail/Hand delivery/Courier [For paper, disk, or CD-ROM 
submissions]: Division of Dockets Management (HFA-305), Food and Drug 
Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852.
    Instructions: All submissions received must include the agency name 
and docket number for this rulemaking. All objections received will be 
posted without change to http://frwebgate.access.gpo.gov/cgi-bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.fda.gov/ohrms/dockets/default.htm, 

including any personal information provided. For detailed instructions 
on submitting objections, see the ``Objections'' heading of the 
SUPPLEMENTARY INFORMATION section of this document.
    Docket: For access to the docket to read background documents or 
comments received, go to http://frwebgate.access.gpo.gov/cgi-bin/leaving.cgi?from=leavingFR.html&log=linklog&to=http://www.fda.gov/ohrms/dockets/default.htm 

and insert the docket number, found in brackets in the heading of this 
document, into the ``Search'' box and follow the prompts and/or go to 
the Division of Dockets Management, 5630 Fishers Lane, rm. 1061, 
Rockville, MD 20852.

FOR FURTHER INFORMATION CONTACT: Celeste Johnston, Center for Food 
Safety and Applied Nutrition (HFS-265), Food and Drug Administration, 
5100 Paint Branch Pkwy., College Park, MD 20740-3835, 301-436-1282.


I. Introduction

    In a notice published in the Federal Register of March 13, 2003 (68 
FR 12087), FDA announced that a food additive petition (FAP 3M4745) had 
been filed by Ion Beam Applications (IBA), 6000 Poplar Ave., suite 426, 
Memphis, TN. Since the publication of this notice, IBA has been sold to 
PPM Ventures, which subsequently changed its name to Sterigenics 
International, Inc., 2015 Spring Rd., suite 650, Oak Brook, IL 60523. 
As a result, the rights to FAP 3M4745 have been transferred from IBA to 
Sterigenics International, Inc. The petition proposed that the food 
additive regulations in Sec.  179.26 Ionizing radiation for the 
treatment of food (21 CFR 179.26) be amended by increasing the maximum 
permitted energy level of x rays for treating food to 7.5 MeV from the 
currently permitted maximum level of 5 MeV. Higher x ray energy will 
result in an increased concentration of x rays in the forward direction 
and increased penetration of these x rays in materials. This increased 
emission efficiency (i.e., concentration of x rays produced in the 
forward direction) will result in reduced treatment time for food, and 
therefore, higher production rates and lower treatment costs. The 
increased penetration of 7.5 MeV versus 5 MeV x rays will allow for the 
irradiation of larger packages.

II. Evaluation of Safety

    A source of radiation used to treat food meets the definition of a 
food additive under section 201(s) of the Federal Food, Drug, and 
Cosmetic Act (the act) (21 U.S.C. 321(s)). Under section 409(c)(3)(A) 
of the act (21 U.S.C. 348(c)(3)(A)), a food additive cannot be approved 
for a particular use unless a fair evaluation of the data available to 
FDA establishes that the additive is safe for that use. FDA's food 
additive regulations in 21 CFR 170.3(i) define safe as ``a reasonable 
certainty in the minds of competent scientists that the substance is 
not harmful under the intended conditions of use.''

III. Evaluation of the Safety of the Petitioned Use of 7.5 MeV X Rays

A. Safety Concerns of Higher Energy X rays

    The maximum energy limit of an x-ray machine is the maximum energy 
of the individual x-ray photons produced by that machine. When 
individual photons of x rays are absorbed by food, the absorbed energy 
causes atoms to be ionized until all the energy is converted into heat 
or chemical change. The amount of change in the food will depend on the 
total energy absorbed (i.e., dose). Because this petition seeks only to 
raise the maximum energy limit for x rays used for treating food, with 
no change in the maximum doses currently permitted by Sec.  179.26, FDA 
concludes that the petition presents no new chemical issue, and that 
the only safety issue to be addressed is the potential for inducing 
radioactivity in the food.
    Food, as well as other natural materials, displays low levels of 
naturally occurring radioactivity, such as that due to the presence of 
potassium-40 or carbon-14. To assess the safety of increasing the 
maximum energy of x rays to 7.5 MeV, the petitioner evaluated the 
potential for 7.5 MeV x rays to induce additional radioactivity in 
food. X rays with energies above an atom's threshold energy are capable 
of ejecting neutrons or protons from the nuclei of some atoms that have 
absorbed the x-ray energy. The threshold energy needed to cause the 
emission of a proton is higher than 7.5 MeV; therefore, the primary 
mechanism for inducing radioactivity in food by 7.5 MeV x rays will be 
from the loss of a neutron. This may in some cases result in the 
formation of radioactive nuclei. Radioactive nuclei are unstable and 
decay to a more stable form, spontaneously emitting particles and 
electromagnetic radiation in the form of gamma rays (i.e., high-energy 
photons). Often, this transition can occur very rapidly, such that an 
isotope produced in food from x rays will decay to a stable, 
nonradioactive state before leaving the irradiation facility. However, 
some radioactive isotopes could be sufficiently stable to be present in 

[[Page 76845]]

when ingested. Radioactive atoms decay at a rate specific to their 
identity and, if taken into the body, could emit ionizing energy that 
would be absorbed in tissues in the body. Whether any emitted energy 
would increase the risk of harm to health depends on the amount and 
type of radiation absorbed by the body and the site of absorption.
    Two reports in the petition provide the petitioner's primary basis 
that the petitioned use of 7.5 MeV x-ray radiation is safe. One report, 
from the International Atomic Energy Agency (IAEA), addresses natural 
and induced radioactivity in food treated with radiation, including 
high energy x rays (Ref. 1). The second report, by Gregoire et al., 
assesses the induced activities in fresh meat and in meat ash 
irradiated with high-energy x rays using evidence provided by 
theoretical calculations and experimental measurement (Ref. 2). As part 
of its review, FDA contracted with the Department of Energy, Oak Ridge 
National Laboratory (ORNL), for an independent evaluation of data in 
the petition (Ref. 3).

B. Neutron-Induced Radioactivity in Food

    The IAEA report provides a compilation of available data on natural 
and induced radioactivity in food and investigates to what extent 
increases in absorbed dose in food or increased energy levels of 
radiation sources used to irradiate food could induce radioactivity in 
the food. One of the scenarios considered in the report was the 
potential for inducing radioactivity in food after being irradiated 
with 7.5 MeV x rays (using an x-ray target of tantalum or gold) to a 
dose of 30 kiloGray (kGy).\1\ The report compared possible radiation 
exposure in humans from induced radioactivity in food to that from 
natural radioactivity in food. A reference food model was used for this 
analysis with an elemental composition similar to that of meat.\2\ The 
report concluded that consuming 40 kilograms (kg) (88 pounds) per year 
of reference food with an absorbed dose of 30 kGy (a dose more than six 
times the maximum permitted dose level of 4.5 kGy permitted by FDA for 
refrigerated meat and meat products), would result in an estimated 
human radiation exposure of 1.3 x 10-3 millisieverts/year 
(yr) (mSv/yr) (a dose 300 times less than the yearly dose due to 
natural radioactivity from food) (Ref. 1). The calculation assumed that 
the food would be eaten immediately after being irradiated. However, 
the radioisotopes with the greatest probability of being produced decay 
quite rapidly. Therefore, because of radioactive decay, any 
radioactivity in the treated food, which would normally be consumed 
more than 24 hours after treatment, would actually be significantly 
less at the time of consumption.

    \1\Thirty kGy is close to a sterilizing dose. Foods, generally, 
would not be irradiated at such a high dose.
    \2\The concentrations of elements in the reference food were 
chosen to be reasonably close to those of meat because, compared to 
other foods, meat is likely to be the food that receives the highest 
doses and that is consumed in the largest quantities. Although the 
concentrations of trace elements in foods can vary significantly, 
the difference in the radiation exposure to humans from consumption 
of one irradiated food and another food due to these variances would 
be insignificant.

    The report by Gregoire et al. provided theoretical estimates and 
experimental results of the radiological implications of irradiating 
meat with higher energy x rays. Induced activities in meat irradiated 
at 15 kGy with 7.5 MeV x rays and a resultant human exposure to 
radiation were calculated. Based on the most abundant isotopes produced 
in meat by neutron capture reactions at thresholds below 7.5 MeV, and 
assuming a person consumes 40 kg of meat per year and a 24-hour delay 
between irradiation and consumption, the corresponding dose to humans 
was calculated to be 0.2 x 10-3 mSv/yr.
    Theoretical estimates of induced activity can be more reliable than 
direct measurements, especially for low levels of activity. However, to 
check the validity of the theoretical estimates, Gregoire et al. 
compared their predictions with experimental data. Experimental results 
from a 1991 study by Wakeford and Blackburn were discussed. This study 
investigated the irradiation of codfish, rice, and a macerated meat 
product with x rays produced by an electron linear accelerator that 
generated electrons at energies up to 12 MeV and predominately at 8 MeV 
(Ref. 4). These foods received radiation doses ranging from 8.8 to 14 
kGy. Induced activities in the foods were reported to be approximately 
the same as natural background levels, and dropped quickly. The report 
also summarized the results from another study in which induced 
activities in fresh meat and in meat ash were measured after being 
irradiated with x rays generated at 7.3 MeV and 8.1 MeV at doses of 15 
kGy and 8.6 kGy, respectively. Based on the measured activity from the 
two experiments and assuming a consumption of 40 kg/y of irradiated 
meat and a 24-hour delay time between irradiation and consumption, the 
total annual dose from meat due to treatment with higher energy x rays 
was determined to be 0.24 to 0.29 x 10-3 mSv/yr, a dose 
about 1,500 times lower than the 0.39 mSv received per year from 
consumption of food due to naturally occurring radionuclides (Ref. 3). 
Because most meat would be consumed more than 24 hours after treatment, 
the annual dose from the irradiated meat would be far less than the 
dose indicated from these experiments.
    ORNL evaluated the information in the IAEA report. ORNL estimated 
induced activities in beef irradiated to 15 kGy with 7.5 MeV x rays and 
the resultant dose from consumption of the treated food (Ref. 3). ORNL 
used the elemental composition of beef for their analysis because its 
composition is similar both to that of the reference food used in the 
IAEA report and to food in general. From this information, ORNL 
determined induced radioactivity in beef and used this to estimate a 
potential radiation dose to humans from consumption of the food. The 
annual effective dose based on consumption of 40 kg/yr of beef was 
calculated to be 0.4 x 10-3 mSv, which is approximately 
1,000 times less than the annual effective dose from consumption of 
foods due to naturally occurring radioactivity, and is consistent with 
the results from both the IAEA report and the Gregoire et al. report. 
In addition to beef, ORNL also calculated the effective annual dose 
from consumption of pork, poultry, and eggs treated with 7.5 MeV x rays 
and an absorbed dose of 15 kGy, ORNL determined that based on the 
average quantity of beef, pork, poultry, and eggs consumed in a year, 
the total effective annual human exposure from consumption of these 
irradiated foods would be 1.0 x 10-3 mSv/yr, which is about 
400 times less than the 0.39 mSv/yr that people receive due to natural 
radioactivity in food. It is also important to note that this estimated 
exposure is highly conservative because it assumes the following: (1) 
That all of the beef, pork, poultry, and eggs that a person consumes in 
a year has been irradiated, (2) that these foods are consumed within 24 
hours after irradiation, and, (3) that such foods would be treated with 
an average dose of 15 kGy, which is significantly higher than both the 
currently maximum permitted dose for these foods as well as doses that 
would be practical to apply to foods in commerce.
    The results discussed previously considered potential radiation 
exposure for humans from consumption of various foods irradiated with 
high energy x rays. Although foods other than those that were studied 
may be irradiated with 7.5 MeV x rays, the

[[Page 76846]]

compositions of the foods that were considered are representative of 
foods in general. Even at absorbed doses that are higher than those 
normally used in practice, the results clearly show that any 
radioactivity that may be induced in any food treated with 7.5 MeV x 
rays will be trivially low and that any potential human exposure due to 
consumption of irradiated food will be inconsequential compared to that 
from radionuclides that are present naturally in food.

C. The Need to Limit the X-Ray Target Material

    Neutrons emitted from the x-ray target in the x-ray generator can 
also enter food and induce radioactivity. Therefore, FDA considered 
whether there is a need to specify or limit the x-ray target material 
to minimize neutron production from this source. Materials with 
photoneutron threshold energies below 7.5 MeV can produce 
photoneutrons, which could also be captured in the foods being 
irradiated. The petitioner has proposed the use of tantalum and gold as 
x-ray target materials. The x-ray energy levels needed to eject a 
neutron from the two common isotopes of tantalum (Ta-180 and Ta-181) 
are 6.6 and 7.6 MeV, respectively, but the neutron production from 7.5 
MeV x rays is insignificant, and considerably less than from tungsten, 
a common x-ray target material (Refs. 1 and 3). Gold also does not 
produce significant numbers of neutrons when impinged with 7.5 MeV x 
rays (Ref. 1). Therefore, FDA concludes that tantalum and gold are 
acceptable x-ray target materials for the proposed use and is 
specifying these two x-ray target materials as a condition of safe use 
for machine sources of 7.5 MeV x rays.

IV. Conclusion of Safety

    FDA has evaluated the data submitted in the petition and other 
relevant material and concludes that any added radioactivity in food 
from the use of 7.5 MeV x rays will be trivial compared to that from 
radionuclides that are present naturally in food. Therefore, the agency 
concludes that the proposed use of 7.5 MeV x rays for treating food is 
safe and that the conditions listed in Sec.  179.26 should be amended 
as set forth in this document.
    In accordance with Sec.  171.1(h) (21 CFR 171.1(h)), the petition 
and the documents that FDA considered and relied upon in reaching the 
agency's decision to approve the petition are available for inspection 
at the Center for Food Safety and Applied Nutrition by appointment with 
the information contact person (see FOR FURTHER INFORMATION CONTACT). 
As provided in Sec.  171.1(h), the agency will delete from the 
documents any materials that are not available for public disclosure 
before making the documents available for inspection.

V. Environmental Impact

    The agency has previously considered the environmental effects of 
this rule as announced in the notice of filing for FAP 3M4745 (68 FR 
12087). No new information or comments have been received that would 
affect the agency's previous determination that there is no significant 
impact on the human environment and that an environmental impact 
statement is not required.

VI. Paperwork Reduction Act of 1995

    This final rule contains no collection of information. Therefore, 
clearance by the Office of Management and Budget under the Paperwork 
Reduction Act of 1995 is not required.

VII. Objections

    Any person who will be adversely affected by this regulation may 
file with the Division of Dockets Management (see ADDRESSES) written or 
electronic objections by (see DATES). Each objection shall be 
separately numbered, and each numbered objection shall specify with 
particularity the provisions of the regulation to which objection is 
made and the grounds for the objection. Each numbered objection on 
which a hearing is requested shall specifically so state. Failure to 
request a hearing for any particular objection shall constitute a 
waiver of the right to a hearing on that objection. Each numbered 
objection for which a hearing is requested shall include a detailed 
description and analysis of the specific factual information intended 
to be presented in support of the objection in the event that a hearing 
is held. Failure to include such a description and analysis for any 
particular objection shall constitute a waiver of the right to a 
hearing on the objection. Three copies of all documents are to be 
submitted and are to be identified with the docket number found in 
brackets in the heading of this document. Any objections received in 
response to the regulation may be seen in the Division of Dockets 
Management between 9 a.m. and 4 p.m., Monday through Friday.

VIII. References

    The following references have been placed on display in the 
Division of Dockets Management (see ADDRESSES) and may be seen by 
interested persons between 9 a.m. and 4 p.m., Monday through Friday.
    1. International Atomic Energy Agency, ``Natural and Induced 
Radioactivity in Food,'' IAEA-TECDOC-1287, Food and Environmental 
Protection Section, IAEA, Vienna, 2002.
    2. Gregoire, O., Cleland, M. L., Wakeford, Mittendorfer, et al., 
``Radiological Safety of Food Irradiation With High Energy X-Rays: 
Theoretical Expectations and Experimental Evidence,'' 2002.
    3. Easterly, C. E., Eckerman, K. F., Ross, R. H., et al., 
``Assessment of Petition to Increase the Maximum X-Ray Energy to 7.5 
MeV from the Value of 5.0 MeV for the Treatment of Food by Ionizing 
Radiation,'' ORNL-2003-1, Oak Ridge National Laboratory, Life Sciences 
Division, 2003.
    4. Wakeford, C. A., Blackburn R., and Swallow, A. J., ``Induction 
and Detection of Radioactivity in Foodstuffs Irradiated With 10 MeV 
Electrons and X-Rays,'' Radiation Physics and Chemistry, vol. 38, No. 
1, pp. 29-38, 1991.

List of Subjects in 21 CFR Part 179

    Food additives, Food labeling, Food packaging, Radiation 
protection, Reporting and recordkeeping requirements, Signs and 

Therefore, under the Federal Food, Drug, and Cosmetic Act and under 
authority delegated to the Commissioner of Food and Drugs and 
redelegated to the Director, Center for Food Safety and Applied 
Nutrition, 21 CFR part 179 is amended as follows:


1. The authority citation for 21 CFR part 179 continues to read as 

    Authority: 21 U.S.C. 321, 342, 343, 348, 373, 374.
2. Section 179.26 is amended by revising paragraph (a)(3) and by adding 
paragraph (a)(4) to read as follows:

Sec.  179.26  Ionizing radiation for the treatment of food.

* * * * *
    (a) * * *
    (3) X rays generated from machine sources at energies not to exceed 
5 million electron volts (MeV), except as permitted by paragraph (a)(4) 
of this section.
    (4) X rays generated from machine sources using tantalum or gold as 
the target material and using energies not to exceed 7.5 (MeV).
* * * * *

[[Page 76847]]

    Dated: December 14, 2004.
Leslye M. Fraser,
Director, Office of Regulations and Policy, Center for Food Safety and 
Applied Nutrition.
[FR Doc. 04-28043 Filed 12-22-04; 8:45 am]