INCH-POUND

MIL-DTL-32235B

30 March 2021

SUPERSEDING

MIL-DTL-32235A

15 September 2010

DETAIL SPECIFICATION

UNITIZED GROUP RATION – EXPRESS (UGR-E) HEATER MODULE, 

GENERAL SPECIFICATION FOR

This specification is approved for use by all Departments and Agencies of the Department of 

Defense.

1. SCOPE

1.1 Scope. This specification describes the performance and design of self-contained

heater modules consisting of polymeric food trays, Institutional Size Pouches (ISP) or BoilIn-Bag (BIB) modules, flameless heaters, activation fluid, heating trays, an activation 

mechanism and other components, as applicable. The heater module is used by the 

Department of Defense as a component of the Unitized Group Ration-Express (UGR-E) 

operational group ration to provide hot meals to eighteen individuals.

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3, 4 or 5 of 

this specification. This section does not include documents cited in other sections of this 

specification or recommended for additional information or as examples. While every effort 

has been made to ensure the completeness of this list, document users are cautioned that they 

must meet all specified requirements of documents cited in sections 3, 4 or 5 of this 

specification, whether or not they are listed.

AMSC N/A FSC 8970

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

Comments, suggestions or questions on this document should be addressed to the 

Combat Capabilities Development Command (DEVCOM) Soldier Center, FCDD-SCDSCR, 10 General Greene Avenue, Natick, MA 01760-5000 or emailed to 

elizabeth.r.painter2.civ@mail.mil. Since contact information can change, you may want 

to verify the currency of this address information using the ASSIST Online database at 

https://assist.dla.mil/.
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2.2 Government documents.

2.2.1 Specifications, standards, and handbooks. The following specifications, 

standards, and handbooks form a part of this document to the extent specified herein. Unless 

otherwise specified, the issues of these documents are those cited in the solicitation or 

contract.

DEPARTMENT OF DEFENSE SPECIFICATIONS

MIL-PRF-44073 - Packaging of Food in Flexible Pouches

MIL-PRF-32004 - Packaging of Food in Polymeric Trays

MIL-DTL-32235/3 - Unitized Group Ration – Express (UGR-E)

Heater Module: Boil-In-Bag (BIB) Module

MIL-DTL-32235/4 - Unitized Group Ration – Express (UGR-E)

Heater Module: Assembled

(Copies of these documents are available online at https://quicksearch.dla.mil.)

2.2.2 Other Government documents, drawings and publications. The following other 

Government documents, drawings, and publications form a part of this document to the 

extent specified herein. Unless otherwise specified, the issues of these documents are those 

cited in the solicitation or contract.

COMBAT CAPABILITIES DEVELOPMENT COMMAND (DEVCOM)

SOLDIER CENTER

PCR-E-017 - Egg Mix, Reduced Cholesterol, Pasteurized, Uncooked, Dehydrated, 

Packaged in a Boil-In-Bag (BIB)

(Copies of this document are available from the Combat Capabilities Development 

Command (DEVCOM) Soldier Center, FCDD-SCD-SCR, 10 General Greene Avenue, 

Natick, MA 01760-5000)

U.S. ARMY 

 Army Regulation 40-5 - Preventive Medicine

 Army Regulation 70-1 - Army Acquisition Policy

 Army Regulation 70-1 - Army Acquisition Procedures
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(Copies of this document are available online at http://ww.apd.army.mil or from U.S. Army 

Publishing Directorate)

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Federal Food, Drug, and Cosmetic Act and regulations promulgated thereunder 

(21 CFR Parts 170-189)

(Copies of this document are available from online at http://www.govinfo.gov or 

Superintendent of Documents, ATTN: New Orders, P.O. Box 371954, Pittsburgh, PA 15250-

7954.)

U.S. DEPARTMENT OF LABOR

Occupational Safety and Health Administration (29 CFR Part 1910, Subpart H)

(Copies of this document are available online at http://www.osha.gov or U.S. Department of 

Labor Occupational Safety & Health Administration, 200 Constitution Avenue, N.W., Room 

Number N3626, Washington, D.C. 20210.

U.S. DEPARTMENT OF TRANSPORTATION

Research and Special Programs Administration (49 CFR Parts 171-180)

(Copies of this document are available online at https://www.fmcsa.dot.gov or 

Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402-

0001.)

U.S. ENVIRONMENTAL PROTECTION AGENCY

Resource Conservation and Recovery Act (40 CFR, Parts 239-282)

(Copies of this document are available online at http://www.epa.gov or from the 

Superintendent of Documents, ATTN: New Orders, P.O. Box 371954, Pittsburgh, PA 15250-

7954.)

2.3 Non-Government publications. The following documents, drawings, and 

publications form a part of this document to the extent specified herein. Unless otherwise 

specified, the issues of these documents are those cited in the solicitation or contract.
MIL-DTL-32235B

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AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

D1974/D1974M - Standard Practice for Methods of Closing, Sealing, and 

Reinforcing Fiberboard Boxes

D5118/D5118M - Standard Practice for Fabrication of Fiberboard 

Shipping Boxes

(Copies of these documents are available at www.astm.org or from ASTM International, 100 

Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959)

2.4 Order of precedence. Unless otherwise noted herein or in the contract, in the 

event of a conflict between the text of this document and the references cited herein (except 

for related specification sheets) the text of this document takes precedence. Nothing in this 

document, however, supersedes applicable laws and regulations unless a specific exemption 

has been obtained.

3. REQUIREMENTS

3.1 Specification sheets. The individual item requirements shall be as specified 

herein and in accordance with the applicable specification sheet. In the event of any conflict 

between the requirements of this specification and the specification sheet, the latter shall 

govern.

3.2 First article. When specified (see 6.2), a sample shall be subjected to first article 

inspection in accordance with 4.2.

3.3 Materials. Note that the terms bag and pouch are used interchangeably.

3.3.1 Components and ingredients. The contractor shall select materials capable of 

meeting the interface, interoperability, environmental, operating and support requirements. 

The active ingredients, additives and activation fluids shall be uniform chemicals and 

compounds and shall meet all requirements of this document. The materials cited are 

recommended.

3.3.1.1 Recycled, recovered, or environmentally preferable materials. Recycled, 

recovered, or environmentally preferable materials should be used to the maximum extent 

possible, provided that the material meets or exceeds the operational and maintenance 

requirements, and promotes economically advantageous life cycle costs.
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3.4 Interface and interoperability requirements.

3.4.1 Heater. The heater, its materials and design, shall be evaluated and designated 

by the criteria of the Environmental Protection Agency (EPA) Resource Conservation and 

Recovery Act (RCRA). The individual unused heater shall meet the criteria to be unregulated 

according to RCRA regulations. The assembled heater module shall meet the criteria to be 

unregulated according to RCRA regulations. It is preferable that multiple unused heaters 

(such as a bulk container of heaters or pallet of packed heaters) also meet the criteria to be 

unregulated according to RCRA regulations.

3.4.1.1 Heater elements. The active ingredients and additives shall be uniformly 

blended and distributed in a matrix that, when the heater is triggered by the activation fluid, 

shall allow for safe and uniform heating of the polymeric trays or pouches of food. (See 3.1)

3.4.1.2 Heater design. The heater elements shall be contained in a gas and water 

permeable material which, upon the introduction of the activation fluid, shall initiate and 

propagate the heating process. (See 3.1)

3.4.1.3 Protection of the heater. The heater(s) shall be packaged or sealed in barrier 

material to avoid premature chemical reaction or degradation of the heater. (See 3.1)

3.4.2 Activation fluid. The activation fluid shall be of a chemical constitution and 

adequate volume which, when combined with the heater, shall safely initiate and propagate 

an exothermic reaction. (See 3.1)

3.4.2.1 Protection of the activation fluid unit. Activation fluid shall be packaged in a 

barrier material to avoid premature release or degradation of the fluid. (See 3.1)

3.4.3 Polymeric food tray. The polymeric food trays shall be in accordance with 

MIL-PRF-32004.

3.4.4 Institutional size pouch (ISP). The ISP shall be in accordance with MIL-PRF44073.

3.4.5 Boil-In-Bag (BIB) module. The BIB module shall be in accordance with MILDTL-32235B/3A.

3.4.6 Boil-In-Bag (BIB). The BIB shall be in accordance with the applicable food 

document. Note that the eggs in a BIB are cited in PCR-E-017.

3.4.7 Construction of heater module. All components shall be constructed into a 

heater module that facilitates ease of use, optimum performance and allows venting of gases. 

Instructions shall be included with each heater module. The design shall promote and ensure 
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operator safety. The components shall be compatible. The heater module, when used 

according to instructions, shall heat the food properly. (See 3.1)

3.4.7.1 UGR-E Heater module. The UGR-E heater module (see 3.1) shall consist of:

(1) One or more heaters

(2) One or more activation fluid units

(3) One or more activation mechanisms, as applicable

(4) One or more polymeric food trays or ISPs, as applicable. The preferred stacking 

orientation is main entrée, starch, vegetable, and dessert (or least dense food tray or ISP), 

from bottom to top. When used, the BIB module shall be on top. 

(5) Three or four heating trays, as applicable

(6) BIB module, when applicable

(7) Additional components, as applicable

3.4.7.2 BIB heater module. The BIB heater module (see 3.1) shall consist of:

(1) One BIB heater

(2) One activation fluid unit

(3) One BIB of food

(4) One rehydration pouch

(5) One serving tray in a polyethylene bag

(6) Additional components, as applicable

3.4.7.3 Activation of heater module. The activation, either manually or mechanically 

as applicable, shall initiate the heating of the food.

3.4.7.4 Design and dimensions of heater module box. The heater module box shall 

accommodate the components. The heater module box shall fit in the UGR-E box. The BIB 

module, when used, shall fit in the heater module box. (See 3.1)

3.4.7.5 Activated heater module. The by-products of the activated heater module 

shall be non-toxic and safe. Disposal of the activated heater module shall be unrestricted. 

Activated heaters shall be safe for disposal as unregulated consumer waste.

3.5 Environmental requirements.

3.5.1 Shelf life. The shelf life of all heater module components (except polymeric 

food trays, ISPs or BIBs) shall be not less than 24 months at 80°F.

3.5.2 Temperature range of operation. The heater module shall be capable of 

withstanding extreme temperatures in storage and transport ranging from -20°F to 160°F. At 

the time of use, the module shall be capable of operating at temperatures ranging from 10°F 
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to 160°F. At ambient temperatures ranging from 35°F to 120°F, the heater module shall 

perform as intended and raise the temperature of the food in the polymeric food trays, ISPs or 

BIBs by no less than 160°F. The heater module components shall exhibit no failures, major 

deformities or degradation as a result of the heating process.

3.6 Operating requirements.

3.6.1 Chemical and physical properties. The heater module shall be capable of 

heating one, three or four polymeric food trays, ISPs or BIBs, as applicable; each containing 

approximately 6 pounds of food. The heater module shall be self-contained and shall be 

activated without requiring additional materials.

3.6.2 Heater module use. The heater module shall require no specific training to use.

Instructions located on the top of the heater module, shall provide guidance and the sequence 

of actions. The heater module shall be easily activated and opened, and shall allow food to be 

easily served from the polymeric food trays, ISPs, BIBs or serving trays, as applicable. (See 

3.1)

3.6.3 Food safety. The materials used in the heater module and their by-products 

shall be safe for use with food in accordance with 21 CFR, Parts 170-189, applicable material 

safety data sheets, or other recognized health standards and regulations.

3.6.4 Heating performance for the UGR-E heater module. The activated UGR-E 

heater module shall be capable of providing a 100°F minimum temperature rise in the bottom 

three water filled polymeric food heating trays in 45 minutes or less and a 75°F minimum 

temperature rise in the top water filled polymeric food heating tray in 45 minutes or less.

3.6.5 Heating performance for BIB heater module. The activated BIB heater module 

shall be capable of heating a BIB of food from 40°F to 170°F in 30 minutes. 

3.7 Support requirements.

3.7.1 Heater by-products. The heater module shall operate without emission of any 

objectionable odors such as burning plastic or metal or sulfurous odors. After the polymeric 

food trays, ISPs or BIBs are removed, there shall be no evidence of precipitate or residue, 

except on the bottom of polymeric food trays, ISPs or BIBs that have been in direct contact 

with the heater. There shall be no more than 10 ml of fluid remaining in each heating tray or 

module after the heating reaction. The heater module shall be designed to allow escape of 

gases generated by the heating reaction. The heater by-products shall be of an amount and 

nature that incidental contact with food shall not render food unsafe.

3.7.2 Health hazard assessment. The item shall not present a health hazard when used 

as intended. Department of the Army Regulation (AR) 40-5, Preventive Medicine, AR 70-1, 
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Acquisition Policy, and Department of the Army Pamphlet 70-3, Acquisition Procedures 

require that all new chemicals and materials being added to the Army supply system have a 

Toxicity Clearance. A Toxicity Clearance involves a toxicological evaluation of materials 

prior to introduction into the Army supply system. The Army Program Manager is 

responsible for identifying materials and requesting a Toxicity Clearance for use of that 

material within their program. All chemicals (including proprietary materials) shall be 

identified and accompanied by the appropriate Material Safety Data Sheet (MSDS). If 

requested, the contractor shall furnish the formulation of the heater and the activation fluid to 

the Army Public Health Center ATTN: MCHB-TS-O, 8252 Blackhawk Road, Aberdeen 

Proving Ground, MD 21010-5403. The formulation shall detail the exact percentages of the 

chemicals and compounds used in the heater and the activation fluid, including the chemical 

composition of trade name ingredients.

3.7.3 Workmanship. The end item shall be free of defects that could adversely affect 

performance or durability and shall have a good general appearance. The end item shall 

conform to the quality established by this document.

3.8 Labeling requirements.

3.8.1 Heater. Each heater (heater elements in a matrix) shall be correctly and legibly 

labeled. The label shall contain the following information:

(1) Name and type of heater

(2) Contractor's name and address

(3) “Do Not Eat” pictogram. The pictogram shall be printed in three colors; a black 

figure of a person on a white background with a red circle and a bar (prohibition 

sign). The minimum outside diameter of the pictogram circle shall be 7/8 inch. (See 

Figure 1)

3.8.2 Packaged heater. The heater(s) in a barrier package or material shall be 

correctly and legibly labeled. The label shall contain the following information:

(1) Name

(2) Quantity and contents

(3) Active ingredients with proper chemical names in accordance with Occupational 

Safety and Health Administration (OSHA), U.S. Environmental Protection Agency 

(USEPA) and U.S. Department of Transportation (USDOT)

(4) Net weight

(5) Date of pack 1/

(6) Contractor's name and address and emergency phone number, as required by 

OHSA, USEPA and USDOT
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1/ Each packaged heater(s) shall have the date of pack noted by using a four digit code 

beginning with the final digit of the current year followed by the three digit Julian day code. 

For example, 14 February 2030 would be coded as 0045. The Julian day code shall represent 

the day the heater(s) was packaged.

3.8.3 Activation fluid unit. Each activation fluid unit shall be correctly and legibly 

labeled. The label shall contain the following information:

(1) Name

(2) Active ingredients with proper chemical names in accordance with 

Occupational Safety and Health Administration (OSHA), U.S. Environmental 

Protection Agency (USEPA) and U.S. Department of Transportation (USDOT)

(3) Net volume

(4) Date of pack 1/

(5) Contractor’s name and address and emergency phone number, as required by 

OHSA, USEPA and USDOT

1/ Each activation fluid unit shall have the date of pack noted by using a four digit code 

beginning with the final digit of the current year followed by the three digit Julian day code. 

For example, 14 February 2030 would be coded as 0045. The Julian day code shall represent 

the day the activation fluid was packaged.

3.8.4 Heater module box. One side of the heater module box shall be correctly and 

legibly printed or labeled. The label shall contain the following information:

(1) Name, type and style, as applicable (see 3.1)

(2) Contents

(3) UGR-E menu number, if applicable

(4) Date of pack 1/

(5) Instructions for use and caution statements shall be on top of module (See 3.1)

1/ Each heater module shall have the date of pack noted by using a four digit code beginning 

with the final digit of the current year followed by the three digit Julian day code. For 

example, 14 February 2030 would be coded as 0045. The Julian day code shall represent the 

day the heater module was assembled.

4. VERIFICATION

4.1 Classification of inspections. The inspection requirements specified herein are 

classified as follows:

a. First article inspection (see 4.2).
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b. Conformance inspection (see 4.3).

4.2 First article inspection. The first article shall be inspected in accordance with the 

provisions of this document and evaluated for overall performance. Any failure to conform to 

the requirements shall be cause for rejection of the lot. Defense Logistics Agency (DLA)

Troop Support - Subsistence shall select sample units during production of contracts and 

submit them to the following address for evaluation:

COMBAT CAPABILITIES DEVELOPMENT COMMAND (DEVCOM)

SOLDIER CENTER

FCDD-SCD-SCR

10 GENERAL GREENE AVENUE

NATICK, MA 01760-5000

Three (3) sample units (heater modules) produced shall be randomly selected from that one 

production lot. The three (3) sample units shall be shipped to Natick within five (5) working 

days from the end of the production month and upon completion of all inspection 

requirements. The sample units shall be evaluated for materials, interface, interoperability, 

environmental, operating, support and labeling requirements.

4.3 Conformance inspection. Conformance inspection shall include the tests 

specified in Table I and the examination of 4.4.
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TABLE I. Verification methods

Title Requirement Verification

Interface and interoperability 3.4 4.5.2

 Heater 3.4.1 4.4

 Heater elements 3.4.1.1 4.5.4.1, 4.5.4.3, 4.5.4.4

 Heater design 3.4.1.2 4.4, 4.5.4.1, 4.5.4.3, 4.5.4.4

 Protection of the heater 3.4.1.3 4.4

 Activation fluid 3.4.2 4.5.4.3, 4.5.4.4

 Protection of the activation fluid unit 3.4.2.1 4.4, 4.5.4.1, 4.5.4.3, 4.5.4.4

 Polymeric food tray 3.4.3 4.5.2.1

 Institutional size pouch (ISP) 3.4.4 4.5.2.2

 Boil-In-Bag (BIB) module 3.4.5 4.5.2.3

 Boil-In-Bag (BIB) 3.4.6 4.5.2.4

 Construction of heater module 3.4.7 4.4

 UGR-E Heater module 3.4.7.1 4.5.4.3

 BIB heater module 3.4.7.2 4.5.4.4

 Activation of heater module 3.4.7.3 4.4

 Design and dimensions of heater module box 3.4.7.4 4.4

 Activated heater module 3.4.7.5 4.5.2.5

Environmental 3.5 4.5.3

 Shelf life 3.5.1 4.5.3.1

 Temperature range of operation 3.5.2 4.5.3.2

Operating 3.6 4.5.4

 Chemical and physical properties 3.6.1 4.5.4.3, 4.5.4.4

 Heater module use 3.6.2 4.5.4.1, 4.5.4.3, 4.5.4.4

 Food safety 3.6.3 4.5.4.2

 Heating performance for UGR-E heater module 3.6.4 4.5.4.3

 Heating performance for BIB heater module 3.6.5 4.5.4.4

Support 3.7 4.5.5

 Heater by-products 3.7.1 4.4

 Health hazard assessment 3.7.2 4.5.5.1

 Workmanship 3.7.3 4.4

Labeling 3.8

 Heater 3.8.1 4.4

 Packaged heater 3.8.2 4.4

 Activation fluid unit 3.8.3 4.4

 Heater module 3.8.4 4.4

4.4 Heater module examination. Each heater module shall be examined for 

conformance to the requirements specified in 3.3 through 3.8. Defects and defect 

classifications are listed in Table II.
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TABLE II. Heater module defects 1/ 2/ 3/ 4/

Category Defect

Critical Major Minor

1 Missing polymeric tray or ISP or BIB or BIB module.

2 Polymeric tray or ISP or BIB damaged to expose food.

3 Missing or severely damaged heater.

101 Incomplete heater or slightly damaged heater.

201 Heater elements not uniformly blended and distributed in a matrix.

202 Heater elements not contained in a gas and water permeable 

material.

203 Heater(s) not packaged or sealed in barrier material.

4 Activation fluid missing or leaking.

102 Activation fluid not of adequate volume.

103 Activation fluid unit not properly installed or damaged.

204 Activation fluid not packaged or sealed in barrier material.

104 Heater module design does not facilitate ease of use.

205 Heater module does not allow venting of gases.

206 Heater module design does not promote and ensure operator 

safety.

105 Activation does not initiate heating of food. 5/

106 Heater module box or component not clean.

107 Heater module box not as specified or damaged.

108 Heater module not constructed properly.

207 Heater module not self-contained.
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TABLE II. Heater module defects 1/ 2/ 3/ 4/ - Continued

Category Defect

Critical Major Minor

109 Any other component missing or damaged.

110 Components do not fit in module or are incompatible.

208 Precipitate or residue remaining after heating reaction.

209 More than 10 ml of fluid remaining in heater tray or module box 

after heating reaction.

210 Instructions missing or incorrect or illegible.

211 Labels missing or incorrect or illegible.

212 Pictogram on heater missing or incorrect or illegible.

1/ Presence of any foreign materials such as, but not limited to dirt, insect parts, hair, glass, 

wood or metal, or any foreign odors such as, but not limited to burnt, scorched, rancid, sour, 

stale, musty, or moldy shall be cause for rejection of the lot.

2/ Any evidence of rodent or insect infestation shall be cause for rejection of the lot.

3/ Individual heater designation as unregulated by OSHA, EPA RCRA, and USDOT shall be 

verified by Certificate of Conformance (CoC). Any hazard markings required for OSHA, 

USEPA and USDOT compliance are to be labeled on the heater, activation fluid unit, and all 

boxes, as appropriate.

4/ By-products of the activated heater module shall be non-toxic, safe and unregulated waste,

and shall be verified by CoC.

5/ BIB Eggs must be cooked to an internal temperature of 145 ̊F (63 ̊C) for fifteen seconds.

Polymeric food trays must be reheated to an internal temperature of at least 135 ̊F (57 ̊C).

4.5 Verification methods. The types of methods included in this section are visual 

inspection and measurement, sample tests, full-scale demonstration, engineering evaluation, 

component properties analysis and similarity to previously approved designs.

4.5.1 Verification alternatives. The manufacturer may propose alternative test 

methods, techniques or equipment, including application of statistical process control, tool 

control or cost effective sampling procedures to verify performance.
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4.5.2 Interface and interoperability verification.

4.5.2.1 Polymeric food tray. The polymeric food trays shall demonstrate 

conformance to 3.4.3, when examined in accordance with MIL-PRF-32004.

4.5.2.2 Institutional size pouch (ISP). The ISPs shall demonstrate conformance to 

3.4.4, when examined in accordance with MIL-PRF-44073.

4.5.2.3 Boil-In-Bag (BIB) module. The BIB module shall demonstrate conformance 

to 3.4.5, when examined in accordance with MIL-DTL-32235B/3A.

4.5.2.4 Boil-In-Bag (BIB). The BIB shall demonstrate conformance to 3.4.6, when 

examined in accordance with the applicable food document.

4.5.2.5 Activated heater module. The activated heater module shall demonstrate 

conformance to 3.4.7.5, when all applicable disposal standards are verified.

4.5.3 Environmental verification.

4.5.3.1 Shelf life. All heater module components (except polymeric food trays, ISPs 

or BIBs) shall demonstrate conformance to 3.5.1, when tested in a storage study.

4.5.3.2 Temperature range of operation. The heater module shall demonstrate 

conformance to 3.5.2, when heater module is exposed to temperature extremes.

4.5.4 Operating verification.

4.5.4.1 Heater module use. The heater module shall demonstrate conformance to 

3.6.2 when tested. The heater module shall be activated by following the instructions. Any 

unclear instructions, failure for heater module to perform, or any unsafe conditions shall be a 

failure.

4.5.4.2 Food safety. The heater module shall demonstrate conformance to 3.6.3, 

when all applicable health standards are verified.

4.5.4.3 Heating performance for UGR-E heater module. The activated UGR-E heater 

module shall be capable of providing a 100°F minimum temperature rise in the bottom three 

water filled polymeric food heating trays in 45 minutes or less and a 75°F minimum 

temperature rise in the top water filled polymeric food heating tray or ISP in 45 minutes or 

less. Thermocoupled polymeric trays (filled and sealed in accordance with MIL-PRF-32004) 

containing 96 ounces (2720 grams) of water shall be used. The UGR-E heater module, 

conforming to 3.4.7 (water trays in lieu of food trays), shall be assembled and conditioned at 

35°F to 40°F for a minimum of 24 hours prior to testing. The test shall be conducted at an 
MIL-DTL-32235B

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ambient temperature of 72°F + 2°F in an explosion-proof exhaust fume hood or sufficiently 

ventilated environment, away from open flame or potential ignition sources. The 

thermocouples shall be connected to a data recorder or computer and the initial temperatures 

of the trays recorded prior to activating the heater module. The UGR-E heater module shall 

be activated by following the instructions on the UGR-E heater module. The temperature rise 

at minimum time intervals of 1 minute shall be recorded and observation continued through 

45 minutes.

4.5.4.4 Heating performance for BIB heater module. The activated BIB heater 

module shall be capable of heating a BIB of food (or dummy load of paraffin wax and water) 

from 40°F to 170°F in 30 minutes. A BIB module or a re-usable apparatus that mimics the 

module may be used. A thermocoupled BIB of food or a thermocoupled BIB containing 56

ounces (1580 grams) of paraffin wax and 17.6 ounces (500 grams) of water may be used. The 

filled BIB shall be equilibrated to 40°F. The test shall be conducted at an ambient 

temperature of 72°F + 2°F in an explosion-proof exhaust fume hood or sufficiently ventilated 

environment, away from open flame or potential ignition sources. After initiation of the 

exothermic reaction, the filled BIB shall attain a temperature of 170°F in 30 minutes. The 

temperature of 170°F shall be maintained for a minimum of 15 minutes. Cooling of the 

product (a drop from the maximum temperature attained) shall be evident 60 minutes after 

initiation of the exothermic reaction.

4.5.5 Support verification.

4.5.5.1 Health hazard assessment. Health hazard assessment shall demonstrate 

conformance to 3.7.2, when all applicable hazardous material standards are verified.

5. PACKAGING

5.1 Packaging. For acquisition purposes, the packaging requirements shall be as 

specified in the contract or order (see 6.2). When packaging of materiel is to be performed by 

DoD or in-house contractor personnel, these personnel need to contact the responsible 

packaging activity to ascertain packaging requirements. Packaging requirements are 

maintained by the Inventory Control Point’s packaging activities within the Military Service 

or Defense Agency, or within the military services’ system commands. Packaging data 

retrieval is available from the managing Military Department or Defense Agency’s 

automated packaging files or by contacting the responsible packaging activity.

6. NOTES

(This section contains information of a general or explanatory nature that may be 

helpful, but is not mandatory.)
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6.1 Intended use. The heater modules covered by this specification are intended for 

use as a component in the UGR-E operational group ration. The UGR-E heater module is

used for direct heating of polymeric trays, ISPs of food, and, when applicable, as a container 

for the BIB module. The BIB heater module is used for the cooking of food in BIBs. The 

heater modules are military unique since they must withstand high temperatures when 

heated, be capable of heating food to an acceptable temperature in an austere environment 

and be easily operated by the user.

6.2 Acquisition requirements. Acquisition documents should specify:

a. Title, number and date of this specification.

b. Type and style of heater module, as applicable.

c. When first article is required (see 3.2).

d. Packaging requirements (see 5.1).

6.3 Shelf-life. This specification covers items where the assignment of a Federal 

shelf-life code is a consideration. Specific shelf-life requirements should be specified in the 

contract or purchase order, and should include, as a minimum, shelf-life code, shelf life 

package markings in accordance with MIL-STD-129 or FED-STD-123, preparation of a 

materiel quality storage standard for type II (extendible) shelf-life items, and a minimum of 

85 percent shelf-life remaining at time of receipt by the Government. These and other 

requirements, if necessary, are in DoD 4140.27-M, Shelf-life Management Manual. The

shelf-life codes are in the Federal Logistics Information System Total Item Record. Additive 

information for shelf-life management may be obtained from DoD 4140.27-M, or the 

designated shelf-life Points of Contact (POC). The POC should be contacted in the following 

order: (1) the Inventory Control Points that manage the item and (2) the DoD Service and 

Agency administrators for the DoD Shelf-Life Program. Appropriate POCs for the DoD 

Shelf-Life Program can be contacted through the DoD Shelf-Life Management website:

https://www.dla.mil/HQ/InformationOperations/DLMS/elibrary/manuals/regulations/.

6.4 Subject term (key word) listing.

Ration

Self-heating

6.5 Changes from previous issue. Marginal notations are not used in this revision to 

identify changes with respect to the previous issue due to the extent of the changes.
MIL-DTL-32235B

17

FIGURE 1. “DO NOT EAT” Pictogram
MIL-DTL-32235B

18

Custodians: Preparing activity:

Army – GL Army – GL

Navy – SA (Project 8970-2021-001)

Air Force – 35

Review activities:

Army – MD, QM

Navy – MC

DLA – SS

NOTE: The activities listed above were interested in this document as of the date of this 

document. Since organizations and responsibilities can change, you should verify the 

currency of the information above using ASSIST Online database at https://assist.dla.mil.