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Table 3. List of several common plastic additives

Antioxidants Octaethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

t-Bu

Phosphorous acid, tris(2,4-di-tert-butylphenyl)ester

t-Bu

Plasticiser Di-n-octylphthalate

UV absorbers 2-(2u-Hydroxy-5u-methylphenyl)benzotriazole

2-Hydroxy-4-n-octyloxybenzophenone

Acidity regulator Stearoyl-2-lactylic acid, calcium salt

C(H

Lubricants/

Antistatics

Glycerol 1-monostearate

C(H

N,N-Bis(2-hydroxyethyl)lauramide

C(H

Behenamide

C(H

Antifogging agent Sorbitan, esters with acids, aliph., monocarbonic acids (more than

C5) (R)

HO OH

Slip agent (Z)-13-Docosenamide (Erucamide)

(CH

)

C(H

768 MIGRATION FROM FOOD CONTACT MATERIALS

Usually the following procedures are used for detection

and quantiﬁcation of migrants: Foils and boards are ﬁxed

into a migration cell (see Figure 2(a)), covered with the

food or adequate food simulant and stored at speciﬁc time

and temperature conditions, which are laid down in

speciﬁc directives (see the section on ‘‘Regulation’’). As

food itself is too intricate to analyze, certain food simu-

lants are allowed to be used instead: simulant A (distilled

water) for aqueous foods, simulant B (acetic acid 3%) for

acidic foods (pHr4.5), simulant C (ethanol 10%) for alco-

holic foods, 50% ethanol for milky products, simulant D

(olive oil) for fatty foods, and the synthetic polymer Tenax

for dry foods. As olive oil presents analytical problems,

there are two alternative food simulants for fatty food-

stuffs, ethanol 95% and isooctane.

The migration solution is analyzed by means of gas or

liquid chromatograph coupled with certain spectrometers

and/or detectors. Another option is the complete immer-

sion of the package into the liquid (see Figure 2(b)).

Quantiﬁcation is derived from using internal standards

(semiquantitative procedure) or by using calibration solu-

tions (quantitative procedure), and evaluation is done

depending on existing legislation requirements.

Sometimes it is more convenient to start not with

analytical determination of migration but with calcula-

tion. When the initial concentration of the migrant in the

polymer (c

P,0

) is known, it is common and legal practice in

veriﬁcation of compliance with migration limits to assume

complete mass transfer of the migrant from the packaging

material into the food or food simulant. If the result is

below the speciﬁc migration limit, no more analytical

measurements are necessary regarding this speciﬁc

migrant.

As shown in the second section, mass transfer from

monolayer materials into food is a predictable physical

process, which can be quantiﬁed with appropriate math-

ematical algorithms. After European authorities com-

pleted the project ‘‘Evaluation of Migration Models to be

used under Directive 90/128/EEC’’ (10) in 2002, migration

modeling could now be used as an alternative method for

evaluation purposes and the use of migration modeling

was legalized in the ‘‘plastic directive’’ 2002/72/EC (Article

8, Section 4) (11). Details on which types of plastic

materials and foods are covered by this paragraph as

well as the basic mathematical algorithms that can be

used for the migration estimation are summarized in the

‘‘Practical Guide’’ and ‘‘Note for Guidance’’ (12, 13) for

‘‘Estimation of migration by generally recognized diffusion

models.’’ This document states a series of conditions that

should be considered when someone intends to use model-

ing to determine compliance of a certain packaging mate-

rial. Several software programmes have been developed

(e.g., (14) to aid in migration estimations.

It is stated above that many different types of materials

are used in multilayer packages and it is assumed that

there is no interaction between packaging and food

simulants.

However, migration processes are more complicated

and sometimes it is difﬁcult to choose the correct simulant

that does not swell the material. For this reason, the use of

numerical models and algorithms are necessary to get

reliable migration results and/or a consistent interpreta-

tion of experimental data, and to get a deeper insight and

understanding on migration processes. Software pro-

grames like MIGRATEST

EXP (15–17) have been devel-

oped and adapted to deal with the increasing complexity of

multilayer food contact materials. Because of the huge

amount of different (food) contact materials and because

multilayer systems pose analytical problems, the use of

existing sophisticated migration modeling software

programs and their continued development will be

indispensable.

REGULATION IN THE EU AND USA

Conservation of the high quality of foodstuff is the most

important function of food packaging materials. As out-

lined in the previous sections, potentially harmful mi-

grants may diffuse out of the packaging into the foodstuff

and be consumed. Therefore, diffusion processes out of

packaging materials and the total amounts of migrants

in the food should be minimized and are regulated by

national and international authorities.

Food simulant

Lid

Sample

Beaker

Metal clamp

Metal plate

Screw cap

Food simulant

Sample

Metal clamp

Lid

Beaker

Screw cap

(a)

(b)

Figure 2.

MIGRATION FROM FOOD CONTACT MATERIALS 769

In the European Union, the European Food Safety

Authority (EFSA) is the keystone of EU risk assessment

regarding food and feed safety. EFSA produces scientiﬁc

opinions and advice providing basic information to the

European Commission, European Parliament, and EU

Member States as well as allowing them to make (legisla-

tive) decisions. Due to the lack of regulations in the food

packaging sector and as not all packaging materials are

yet covered by European legislation, national legislation

(and national recommendations, e.g., recommendations of

the German Bundesinstitut fu

r Risikobewertung (BfR))

have to be taken into account.

In the framework regulation 1935/2004/EC of the Eur-

opean Parliament and of the council (18) on materials and

articles intended to come into contact with food, common

and superior guidelines regarding demands on food packa-

ging are laid down. Also a list of groups of materials and

articles (e.g., adhesives, ceramics, rubbers, plastics, paper

and board, inks, cellulose, etc.) is stipulated, which may be

covered by speciﬁc measures. Until now only speciﬁc

regulations exist for plastics (directive 2002/72/EC and

its ﬁve amendments) (11), ceramics (84/500/EEC and its

amendment) (19), and regenerated cellulose (2007/42/EC)

(20). Most important is the ‘‘plastic directive’’ where

several alternatives for veriﬁcation of compliance of the

food packaging materials are given. Therein measuring of

the migration is possible by an adequate experimentation

(see directives 82/711/EEC, 85/572/EEC, 93/8/EEC, and

97/48/EEC) (21–24) and by application of generally recog-

nized mathematical diffusion models based on scientiﬁc

evidence. Furthermore, a positive list of authorized mono-

mers and additives with restrictions for certain sub-

stances (e.g., ‘‘speciﬁc migration limits’’ SMLs) was built

up at the community level. The SML values are generally

calculated based on ADI (acceptable daily intake) and TDI

(tolerable daily intake) values, laid down by the Scientiﬁc

Committee for Food (SCF). ADI and TDI values are

derived from toxicological studies.

Hence, for a positive evaluation of a certain packaging,

the migration results should meet the following limits:

. Global migration is less than 10-mg/dm

and 60-mg/

kg food, respectively.

. The amount of each detected additive (listed in the

positive list) is under its SML or the global migration

limit.

. The amount of each detected additive, which is not

listed in the positive list, is under 10 mg/kg food)

(2007/19/EC) (25) when no toxicological data exist.

In addition, the packaging shall be manufactured in

compliance with good manufacturing practice (GMP) and

the additional general requirements laid down under

article 3 of the directive 1935/2004/EC.

For evaluation and addition of a new substance to

national or European positive lists, a petition has to be

transmitted to the adequate authority, including identity

and proposed use of the new substance, migration, and

toxicological documents. As a general principle, the higher

the exposure through migration, the more toxicological

information is required (see Table 4).

Whereas EU authorities look at the identity and quan-

tity of chemical substances detected in the food or food

simulants, and list all substances, which are toxicologi-

cally evaluated and allowed to be used in all kinds of

packaging material, the U.S. Food and Drug Administra-

tion (FDA) established a food contact notiﬁcation process,

whereby food additives are deemed to be safe for their

intended use. That means that in comparison with the EU,

substances evaluated by the FDA are only allowed to be

used in special applications and concentrations, which are

mentioned in their authorization processes (food contact

notiﬁcation, FCN). For using these substances in other

applications, a new FCN has to be submitted to the FDA.

The law governing food packaging in the United States is

the Federal Food, Drug and Cosmetic Act of 1958 as

amended and the Fair Packaging and Labeling Act. Regu-

lated food contact substances can be found in title 21 of the

Code of Federal Regulations (CFR) (26). This title is

subdivided into parts covering speciﬁc regulatory areas

(e.g., indirect food additives: polymers; indirect food ad-

ditives: adjuvants, production aids and sanitizers, etc.).

Sometimes there are substances ‘‘generally recognized as

safe’’ (GRAS; e.g., ascorbic acid). Such substances are

allowed to be used in packaging materials, if a consensus

is reached by scientists that the substance is GRAS, and if

Table 4. Required toxicological information for evaluation by EFSA

Migration of substance Tests

o0.05 mg/kg food 3 mutagenicity tests . induction of gene mutations in bacteria

. induction of gene mutation in mammalian cells

in vitro

. induction of chromosomal aberrations in

mammalian cells in vitro

0.05–5 mg/kg food . 3 mutagenicity tests

. 90-day oral toxicity study

. data to demonstrate the absence of potential for

accumulation in human being

W5 mg/kg food . above mentioned tests

. further studies (e.g. on reproduction,

absorption, distribution)

770 MIGRATION FROM FOOD CONTACT MATERIALS

there are experimental data and published studies that

support this opinion.

In addition, if the estimated daily intake (EDI) from the

proposed use of the substance is less than or equal to

0.5 mg per kg food and 1.5 mg per person and day, respec-

tively (‘‘threshold of regulation’’ TOR), and if the sub-

stance has not been shown to be a carcinogen in humans

or animals and presents no other health or safety con-

cerns, an exemption from the notiﬁcation process can be

granted by the FDA. If not, the petitioner has to send

roughly the same toxicological and migration data to the

FDA as to the EFSA. Whereas the European SMLs are

calculated from toxicological values that are compared

with migration data, the FDA calculates from migration

data the EDI, which is compared with the corresponding

ADI and TDI values. The EDI is calculated as the product

of the migrant concentration o M W in the total daily diet,

based on consumption factors (CF) and food type distribu-

tion factors (f

), and the factor 3, assuming that one

person consumes 3 kg of food (liquid and solid) per day:

EDI ¼ 3 kg food=person=day  M

 CF ð8Þ

¼ f

aqueous and acidic

ðM

10% Ethanol

Þþf

alcohol

ðM

50% Ethanol

þ f

fatty

ðM

fatty

CF describes the fraction of the daily diet expected to

contact speciﬁc packaging materials. It represents the

ratio of the weight of all food contacting a speciﬁc packa-

ging material to the weight of all food packed. These

values were derived using information on the types of

food consumed or the types of food contacting each packa-

ging surface. The factor f

considers the nature of food that

will likely contact the food contact material containing the

migrant. Both factors, CF and f

, are published in certain

guidances (e.g., (27)).

FUTURE TRENDS IN PACKAGING AND EVALUATION

The majority of the just off-the-shelf produced materials

and articles intended to come into contact with foodstuff

are passive materials mainly made out of plastics, (re-

cycled) paper, and metal. In the future there will be a shift

to the development and increased usage of active and

intelligent packaging materials. These active and intelli-

gent materials can, for example, indicate the edibility of

the food and prolong the freshness and the shelf life of

food. Also nanotechnology will be used in the food packa-

ging sector to increase the functionality of materials (e.g.,

protection and indication of freshness). The development

of more sustainable and environmentally friendly packa-

ging is an ongoing trend, and new sustainable and biode-

gradable packaging materials will be developed and used.

However, legislative authorities will still have to eval-

uate the impact of food safety of these new materials on

the health of the consumer. Authorities also still have to

evaluate the safety of ‘‘nonplastic’’-layers (e.g., coatings,

adhesives, etc.) in multilayer materials that have not been

taken into account yet.

As mentioned, the experimental measurement of mi-

gration is closely linked to certain directives, e.g., 85/572/

EEC (22). But some problems arose in this system as

implemented with the use of food simulants and not food-

stuffs to measure migration in a simple and reproducible

way. Therefore, the European Union and (industry) part-

ners have launched the project ‘‘Food Migrosure’’ to over-

come these weaknesses. The EU foresees that in order to

show compliance, the migration into foodstuffs and not

into food simulants is crucial and the exposure evaluation

has to be based on migration values in food. Migration

values are obtained by experiments and by modeling. In

addition, other (proposed) projects like FACET (‘‘ﬂavours,

additives and food contact material exposure task’’) are

aimed at collecting deeper knowledge about both consumer

exposure by packaging components and the physical

properties of each layer of the multilayer packaging

materials.

BIBLIOGRAPHY

1. H. C. Langowski, ‘‘Permeation of Gases and Condensable

Substances Through Monolayer and Mulilayer Structures’’

in A. Baner, O. Piringer, eds., Plastic Packaging – Interactions

with Food and Pharmaceuticals, Wiley-VCH Verlag, Wein-

heim, 2008, pp. 297–348.

2. J. Brandrup, E. H. Immergut, and E. A. Grulke, eds., Polymer

Handbook, Wiley Interscience, New York, 1999.

3. H. S. Carslaw and J. C. Jaeger, Conduction of Heat in Solids,

Oxford University Press, Oxford, UK, 1959.

4. J. Crank, Mathematics of Diffusion, Oxford University Press,

Oxford, UK, 1975.

5. A. L. Baner and O.-G. Piringer, Plastic Packaging Materials

for Food, Wiley-VCH Verlag, Weinheim, 2000.

6. O. Piringer, Evaluation of Plastics for Food Packaging, Food

Add. Contam. 11, 221–230 (1994).

7. J. Brandsch, P. Mercea, and O. Piringer, ‘‘Modeling of Additive

Diffusion Coefﬁcients in Polyoleﬁnes,’’ in S. J. Risch, ed., Food

Packaging—Test Methods and Applications, ACS Symposiun

Series 753, American Society, Washington, DC, 2000, pp. 27–

36.

8. W. Limm and H. C. Holliﬁeld, Modeling of Additive Diffusion

in Polyoleﬁnes, Food Add. Contam. 13(8), 949–967 (1996).

9. A. Baner and O. Piringer, ‘‘Partition Coefﬁcients’’ in A. Baner

and O. Piringer, eds., Plastic Packaging – Interactions with

Food and Pharmaceuticals, Wiley-VCH Verlag, Weinheim,

2008, pp. 89–121.

10. T. Begley, L. Castle, A. Feigenbaum, R. Franz, K. Hinrichs, T.

Lickly, P. Mercea, M. Milana, A. O’Brien, S. Rebre, R. Rijk,

and O. Piringer, Evaluation of Migration Models that Might

Be Used in Support of Regulations for Food-Contact Plastics,

Food Add. Contam. 22(1), 73–90 (2005).

11. Commission Directive 2002/72/EC relating to plastic materi-

als and articles intended to come into contact with foodstuffs

(6 August 2002).

12. European Commission, Practical Guide–A Practical Guide for

Users of European Directives, (updated on 15 April 2003).

13. European Food Safety Authority, Note for Guidance for Peti-

tioners Presenting an Application for the Assessment of a

Substance to be used in Food Contact Materials prior to its

Authorisation, (updated on June 2006).

MIGRATION FROM FOOD CONTACT MATERIALS 771

14. MIGRATEST Lite 2004, A software to estimate the migration

from polymeric packaging into foodstuffs and food simulants,

FABES Forschungs-GmbH, Schragenhofstrasse 35, D-80992

Munich, Germany.

15. SMEWISE, MULTITEMP, MULTIWISE, INRA-CPCB,

Moulinde de la Housse, B.P. 1039, F-51687 Reims Cedex 2,

France.

16. Prediction of Speciﬁc Migration from Packaging Material into

Food, Swiss Federal Ofﬁce of Public Health, Division of Food

Science, Bern, Switzerland.

17. MIGRATEST

EXP 2008, FABES Forschungs-GmbH, Mu-

nich, Germany.

18. Regulation (EC) No 1935/2004 of the European Parliament

and of the Council on materials and articles intended to come

into contact with food and repealing Directives 80/590/EEC

and 89/109/EEC (27 October 2004).

19. Council Directive 84/500/EEC on the approximation of the

laws of the Member States relating to ceramic articles

intended to come into contact with foodstuffs (15 October

1984).

20. Commission Directive 2007/42/EC relating to materials and

articles made of regenerated cellulose ﬁlm intended to come

into contact with foodstuffs (29 June 2007).

21. Council Directive 82/711/EEC laying down the basic rules

necessary for testing migration of the constituents of plastic

materials and articles intended to come into contact with

foodstuffs (18 October 1982).

22. Council Directive 85/572/EEC laying down the list of simu-

lants to be used for testing migration of constituents of plastic

materials and articles intended to come into contact with

foodstuffs (19 December 1985).

23. Commission Directive 93/8/EEC (15 March 1993).

24. Commission Directive 97/48/EEC amending for the second

time Council Directive 82/711/EEC laying down the basic

rules necessary for testing migration of the constituents of

plastic materials and articles intended to come into contact

with foodstuffs (29 July 1997).

25. Commission Directive 2007/19/EC amending Directive

2002/72/EC relating to plastic materials and articles intended

to come into contact with food and Council Directive 85/572/

EEC laying down the list of simulants to be used for test-

ing migration of constituents of plastic materials and

articles intended to come into contact with foodstuffs (2 April

2007).

26. Ofﬁce of the Federal Register, National Archives and Records

Administration, Code of Federal Regulation: Foods and

Drugs, U.S. Government Printing Ofﬁce, Washington, DC,

2008.

27. U.S. Food and Drug Administration – Center for Food Safety

& Applied Nutrition, Guidance for Industry, Preparation

of Food Contact Notiﬁcation and Food Additive Petitions

for Food Contact Substances: Chemistry Recommendation,

2002.

General References

G. L. Robertson, Food Packaging – Principles and Practice, CRC

Press, Boca Raton, FL, 2006.

O. G. Piringer and A. L. Baner, eds., Plastic Packaging – Interac-

tions with Food and Pharmaceuticals, Wiley-VCH Verlag,

Weinheim, 2008.

K. A. Barnes, C. R. Sinclair, and D. H. Watson, eds., Chemical

Migration and Food Contact Materials, Woodhead Publishing

Limited and CRC Press LLC, Cambridge, UK, and Boca

Raton, FL, 2007.

H. Zweifel, ed., Plastics Additives Handbook, Carl Hanser Verlag,

Kempten, 2001.

EFSA, available at http://www.efsa.europa.eu/EFSA/efsa_locale-

1178620753812_home.htm.

BfR, available at http://www.bfr.bund.de/.

FDA, available at http://www.fda.gov/.

MILITARY FOOD PACKAGING

RAUNO LAMPI

Consultant,

Food Science, Engineering,

Food Service Systems,

Westborough,

Massachusetts

INTRODUCTION

The packaging requirements for military food service

range from: prevailing commercial practice for food pre-

pared and consumed on permanent state-wide stations,

stabilized foreign theater sites, and shipboard; to highly

durable concepts for mobile combat troop usage for both

groups and individuals. This review will emphasize those

packaging practices required for the initiation and con-

duct of a signiﬁcant combat campaign. For the United

States, historically and currently, these have been over-

seas and have represented a wide range of package

challenging environments and food usage conditions.

Since hostilities may occur anywhere in the world and

it is impractical to design speciﬁc packaging for large

volume use for any deﬁned geographic and/or climatic

region and it is propitious to pre-position selected rations

around the world for immediate local availability, military

food packaging must be basically selected and designed for

any and all climates or geographic regions. The packaging

must also provide long-term protection to make pre-

positioned war reserves feasible. Further general require-

ments include compatibility with the mode of use: feeding

in groups, singly, or during patrols. Specialized packets or

supplements are needed for emergency use or unusually

extreme climates. Organoleptic acceptability is essential,

and packaging plays the key role in assuring that this

desirable characteristic exists at time of food consumption.

Doctrinally, the practice is to use combat rations (as

individually packaged meals or packets) for an initial

period, say three weeks, followed by the introduction of

bulk shelf-stable foods (currently termed B rations) to be

prepared in company-sized mobile or temporary ﬁeld

kitchens. As utilities become available and as operations

in the theater become stabilized, the master menu for

group feeding will include perishables—vegetables, frozen

meats, eggs, and so on (the A-ration). Of course, this

means that climate controlled storage and freezer storage

772 MILITARY FOOD PACKAGING

have become available. The type of packaging is parti-

ally changed to be less protective. For example, solid

ﬁberboard becomes replaced with weather-resistant

corrugated ﬁberboard and, for some items, standard com-

mercial packing. The rigors of transportation and hand-

ling have, accordingly, become less strenuous. Combat

rations for patrols and similar combat excursions and for

remote outposts remain an essential part of the subsis-

tence mix.

In actuality, based on informal yet direct feedback,

the doctrine is rarely followed. Combat rations are used

beyond the Surgeon General’s recommended time limit.

Standard mobile kitchens are underutilized. Much recent

operational theater food service has been contracted to

civilian concerns. So the packaging level, that is, the level

of protection prevalent, with the exception of combat

rations, varies.

THE REVOLUTIONARY WAR TO WORLD WAR II

Koehler (1) and Conference and Notes on Rations, QMS,

January 1949 (2) have presented comprehensive reviews

of military rations from the Revolutionary War era (1776)

to the World War II era (1945). Moody (3), also starting

with the Revolutionary War, has extended the review,

excellently, to status and development effort to the year

2000. Military packaging, up to 1936, was primarily

limited to common practices that deﬁned commercial

quantities and some protection from weather elements

and dirt. Food preservation, with the exception of some

canned items, was the result of curing, salting, and/or

dehydration. There was minimal reliance on packaging to

preserve edibility. The military diet was supplemented by

live animal slaughter and foraging where possible.

In the early 1800s, Nicholas Appert established that

heating food in a hermetic container preserved the con-

tainer’s contents, an initial event where the package was

vital for high moisture food’s safe storage and retained

edibility. Canning was born; however, it was not evident in

military rations until the Civil War era (1860s on) when

some canned items were introduced, but with many

defects and complaints. The high level of spoilage of both

fresh and canned foods continued into the 1890s, accord-

ing to reports from the Spanish-American War.

Again following Koehler’s treatise, canned items ﬁnally

became standard ration components in World War I. At

this time, it was also recognized that rations needed to be

categorized according to their intended ﬁeld usage. This

resulted in design of a menu for group feeding and an

organization of components for individual’s to carry and

consume in the ﬁeld. These were (1):

1. Reserve ration: food allowance for one man for one

day consisting of

a. One 1-lb (usually cylindrical) can of meat

b. Two 8-oz cans of hard bread

c. 2.4 oz of sugar

d. 1.12 oz of ground coffee

e. 0.16 oz of salt

2. Trench ration: food for 25 men in the ﬁeld for one

day consisting of

a. Sufﬁcient canned meats (roast beef, corned beef,

salmon, and sardines) to feed, heated or cold, 25

men

b. Supplemental items that included salt, sugar,

soluble coffee, solidiﬁed alcohol, and cigarettes

All components were packed in large galvanized con-

tainers that protected the contents from poison gas.

3. Emergency ration: food to sustain a soldier when no

other sustenance was available consisting of

a. Three 3-oz cakes of a mixture of beef powder and

cooked wheat

b. Three 1-oz chocolate bars

4. Packaging consisted of an oval lacquered can to ﬁt

into a soldier’s pocket. Ration categorization evolved

so that in the late 1920s, the American Army listed

four types of rations:

a. Garrison

b. Travel

c. Reserve (replacing the emergency ration)

d. Field (in essence, the ﬁrst true emergency ration)

This categorization exercise surfaced the need and efﬁcacy

of designing rations to ﬁt the major modes of theater

of operations activities—personnel on attack, in garrison,

on patrols, and in unanticipated situations. These basic

deﬁnitions were the foundation of military food service

until the current categories of A, B, and combat rations

came into ofﬁcial use. Ensuing developments within

the categorization have been impacted by packaging

improvements integrated with innovative processes, reli-

able refrigeration, freeze-drying, irradiation, high-barrier

packaging materials, container ship and aircraft delivery,

an acceptance of ﬂexible packaging in lieu of rigid cans for

shelf stable foods.

WORLD WAR II AND KOREAN CONFLICT

Although the need for organized ration development,

including signiﬁcant packaging, packing, and unitization

improvements, was surfaced in World War I, no mean-

ingful action was taken until the advent of World War II

became obvious in the late 1930s. This peacetime lack of

urgency and support for military readiness is typical and

recurring. At this time, among the ﬁrst steps forward were

the establishment of the Quartermaster Subsistence Re-

search and Development Laboratory and, later, to facil-

itate technical assistance from the commercial food sector

(then centered in the mid-west) and to accommodate the

needs of all service elements, the establishment of the

Food and Container Institute for the Armed Forces on

Pershing Avenue in Chicago, IL. Moody (3) covers the

evolution of the integration of commercially available

technology and food industry support as mutual beneﬁts

surfaced. Frequently the military’s research and develop-

ment efforts provided industry with commercially viable

products.

MILITARY FOOD PACKAGING 773

As subsistence research and development intensiﬁed,

the Research and Development Associates (a technical

organization of industry and government technologists)

and various Technical Committees of the National Re-

search Council were used to recommend, to contribute,

and to analyze the military’s needs and technical perfor-

mance. Packaging and Packing interests were active

participants and contributors.

An initial output from this concerted ration develop-

ment was the D ration: three 4-ounce bars of chocolate,

sugar, dry milk, cacao fat, oat ﬂour, and ﬂavoring meant to

support a person for one day. Packaging, since there is no

speciﬁc discussion, was probably aluminum foil for indi-

vidual bars packed in Kraft board cartons for shipment

and handling. The D ration was convenient and termed

tenuously the ﬁrst modern emergency ration.

The D ration had a short yet voluminous procurement

span, 600,000 rations in 1941 and 170 million through its

ﬁnal procurement in 1944. Misuse as a combat food and its

non-provision of three full, familiar nutritionally balanced

meals per day found it being relegated to being a supple-

ment and an emergency ration.

The experience with the D ration, reinforced by the

evolving recognition of adequate nutrition and menu

variety in assuring ration acceptance and combatant

performance, resulted in the development and ﬁelding,

predominantly for World War II, of the K and C rations.

Both were used throughout World War II.

There is some disparity as to when the C ration

assumed an identity. Basically, the components of the C

ration, in 12-oz, three-piece heavily tinned metal cans,

evolved from World War I individual items. In 1939, the

Adjutant General of the Army announced adoption of ﬁeld

ration C to consist of three cans containing meat and

vegetable components and three cans, termed B units,

containing crackers, sugar, and soluble coffee. In early

1944, separate component speciﬁcations were consoli-

dated into a single document, ‘‘Ration, Type C, Assembly,

Packaging, and Packing’’ where three canned meat en-

trees and three B unit cans were supplemented with a

ﬂexibly packaged accessory packet of sundries that

included a small folding can opener, essential to open

the durable, thick-tinned, three-piece double-seamed

cans. Ration components were packed in Kraft board

cartons, which in turn were packed six to a solid ﬁber-

board shipping case.

The C ration easily met the shelf-life requirement of

three years at 801F, as evidenced by reports of rations

issued far beyond their procurement dates. Organoleptic

acceptability and variety were lacking.

The K ration was developed to provide an individual,

easy-to-carry ration, initially requested by the U.S. Air

Force, and as its acceptance grew, it was, in 1942, adopted

for all service use, termed Field Ration, Type K. Per

Moody (3) it became the ration of choice in World War II

and for a while was quite popular. However, as noted by

Koehler (1), an improved C ration diminished the K’s

usefulness and popularity; it was declared obsolete in

1948.

The K ration went through seven revisions/improve-

ments, including packaging, before the ﬁnal speciﬁcations

were published. Menus were divided into breakfast,

dinner, and supper units. Aside from minor variations,

each meal menu consisted of a can of meat or cheese,

two biscuits, and what would best be called an accessory

bag (fruit or chocolate bar, beverage powder, confections,

chewing gum, spoon, and key can opener). For each

meal assembly, cans were held in a chipboard sleeve-

type box; the remaining cans were held in a laminated

cellophane bag. These two units were assembled and

sealed in a waxed carton that was, in turn, enclosed in a

non-waxed outer carton suitably labeled with the K-ration

design and color. Twelve complete rations were packed

in a ﬁberboard box that was overpacked in a nailed wood

box (1).

DEVELOPMENTS LEADING TO CURRENT RATIONS

Because of (a) both actual and perceived deﬁciencies with

the C ration and its clone-like successor, the Meal, Com-

bat, Individual (weight, variable acceptability), (b) issue of

many of these rations to troops after the ration’s intended

shelf life had expired, (c) need to explore the applicability

of newer technologies in both food processing and in

packaging materials and designs, and (d) accommodation

to the military’s highly mobile combat tactics, in the late

1950s the Army issued a request (Qualitative Materiel

Development Objective) to improve combat rations. The

Army’s needs were supported by the U.S. Marine Corps

and acceded to by all DOD elements under the jurisdiction

of the Joint Formulation Board of the DOD Food Research,

Development, and Engineering Program.

The signiﬁcance of a DOD-level program and funding

bears mention. It provides greater assurance that funding

support will not be siphoned off prior to its reaching the

working level and acknowledgment that all service per-

sonnel basically eat the same food. The implementation of

the program was assigned to the then-titled U.S. Army

Natick Research, Development, and Engineering Center,

Natick, Massachusetts (commonly referred to as Nlabs).

This progressive doctrinal and regulatory support was

steady and consistent as needed for aggressive, thorough,

and inevitably long-term (10–15 years) developments and

their implementation.

Among the desired improvements for combat rations

established

under the aegis

of the DOD Food Program and

further detailed in an Army Combat Development Objec-

tive Guide (CDOG) in 1956 were lighter weight, ease of

use and carrying by the individual, long shelf life, uni-

versal organoleptic acceptability, durability during trans-

port and use in any geographic area or climatic condition,

and adequate survivability on free-fall air drop.

During this time frame, mid-1950s to the late 1960s,

three food technological areas were identiﬁed that could

possibly be responsive to the military’s combat ration

needs. These were: freeze-dehydration, irradiation sterili-

zation, and substitution of ﬂexible packaging for rigid

containers for both the preceding preservation techniques

and its application to thermoprocessed foods. All three

areas were amenable to the consideration of ﬂexible

packaging in lieu of traditional rigid metal cans.

774 MILITARY FOOD PACKAGING

FREEZE-DRIED RATIONS

For the military, freeze-dried (lyophilized) foods had

obvious advantages: extremely light weight, excellent

retention of organoleptic characteristics, long shelf life

(if properly packaged to exclude oxygen), rapid rehydra-

tion, and suitability for ﬂexible packaging in conﬁgura-

tions that could be carried in the combatant’s gear or

clothing.

During the Vietnam conﬂict (1960s and early 1970s), a

Packet, Long-Range Patrol (aka LRP) was ﬁelded and

highly accepted by personnel, primarily during reconnais-

sance missions and combat excursions. Entrees were

‘‘ready-meals’’—a high-protein component, meat mostly,

combined integrally with starch and/or vegetables and a

sauce. Beef stew would represent such an item. Initially,

and for most of the Vietnam campaign, components were

individually freeze-dried and combined just prior to packa-

ging. It was established that pre-packaging combination

and cooking into partitionable servings improved accept-

ability, and later packets were so prepared and packaged.

During the active years of the Vietnam conﬂict, LRPs

remained popular and elicited much positive feedback on

quality and usage. Anecdotal comments, however, did

include (a) reluctance by combatants to use water that

they had to carry (canteen-full) in any way other than

direct consumption and (2) some reports that when, for

convenience, water was added to the packet at the start of

a patrol; that is, several hours before consumption, micro-

bial growth occurred and caused problems after entree

consumption.

As the Vietnam conﬂict neared its end, the use and

popularity of the LRP declined. High-quality entree com-

ponents became more difﬁcult to procure and costs rose.

The LRP remained in the system at a low interest level.

Then, in the 1990s, improvements were re-energized by

the U.S. Marine Corps’ need for a ration for extreme cold

environments, and the U.S. Army Special Operational

Forces’ need for a long shelf life restricted calorie ration

(back to the original LRP concept) for initial assault,

special operations, and long-range reconnaissance mis-

sions. This reborn ration is now termed the Meal, Cold

Weather/Food Packet, Long-Range Patrol (MCW/LRP),

expanded as a meal to include crackers, spreads, cookies,

sports bars, nuts, candy, and powdered beverages, and

packed in a white (MCW) or a beige (LRP) outer poly-

ethylene meal bag. There are 12 meal menus. Sixteen

ounces of water (preferably heated) is required for all

meals except those with eggs, which require 8 ounces.

Another 12–24 oz of water are required for beverages.

The package for the entree is brick-shaped (Figure 1)

when full and is designed for in-package rehydration and

food consumption. Beverages can be prepared in the

canteen cup; heat tablets are furnished.

Freeze-dried products require protection from water

vapor (products are strongly hygroscopic) and air (oxygen)

because of extensive exposed surface areas, and they also

require some protection of structural integrity (to some

degree, provided by immobilization in ﬂexible, vacuu-

mized packages). From the user’s aspect, the ration pack-

age must provide a shelf life of a minimum of three years

at 801F and 6 months at 1001F. It must retain its form to

serve as an easily opened rehydration and consumption

container.

Two ﬁlm structures are speciﬁed in Table 1.

Bonding of the sealant layer to the aluminum barrier

layer (ﬁlm 1) is to be by lamination or by extrusion

coating. The barrier is in turn bonded to an outer layer

of biaxially oriented nylon layer with 10 pound per ream

low-density polyethylene. For ﬁlm 2, the sealant ply is

laminated or extrusion-coated to a nylon ply, followed by

lamination to the foil that is bonded to an external

polyester (usually polyethylene terephthlate) ply. The

requirement for heat seals mentioned that the low-density

heat sealant layer shall be capable of forming a fusion seal

or shall be heat sealable and peelable. A peelable seal

would sufﬁce for the outer polyethylene meal bag, but the

seals of the component brick-shaped pouch are more

critical and should be fusion seals. As summarized by

Lampi et al. (4), nonfusion seals can meet tensile and

CLOSURE

SEAL

BOTTOM SEAL

FIN SEAL

AFTER CLOSURE SEAL

MINIMUM NOTCH

BEFORE CLOSURE SEAL

+/-

I.D

+/-

10 +/-

I.D

Figure 1. MCW/LRP packages for entre

MILITARY FOOD PACKAGING 775

burst test criteria at time of creation yet fail with time and

exposure to rough handling.

Pouch construction, ﬁlling, and ﬁnal sealing follow

standard practice. Some major requirements are:

1. Minimum heat seal width: 0.25 in.

2. Fusion seal tensile strength: 7 lb per linear inch

3. Vacuum level, at which ﬁlled pouches are sealed: 23

in. of mercury

Defects and acceptance standards and criteria are given in

detail in the ‘‘Packaging Requirements and Quality As-

surance Provisions for Dehydrated Product in a Brickpack

Pouch.’’

IRRADIATED FOODS

During the gestation period of freeze-dried food develop-

ment and early feasibility probes into ﬂexible packaging

for thermoprocessed foods, the preservation (i.e., to com-

mercial sterilization standards) of foods, including combat

ration entrees, by ionized radiation warranted explora-

tion. The anticipated advantages included very high

quality shelf-stable entrees with minimum destruction of

nutritive value, compatibility with a range of packaging

options from ﬂexible pouches to rigid metal containers (in

other words, from combat rations to B, and possibly A

ration usage), and commercial viability to provide a basis

for reasonable costs during procurements.

For military rations, irradiation treatments (X ray,

gamma, and electron beam) were applied at high enough

levels to provide commercial sterility—that is, doses up to

60 kGy, the universal criterion for long shelf-life storage.

To assure achieving this long-term stability, multiple-ply

foil containing materials were used—not radically

different in composition and structure from those for

freeze-dried or thermoprocessed foods. Irradiation was

performed with packaged items.

Packaging materials for irradiation have some singular

requirements, namely:

1. In ﬁnal ﬁlled package conﬁguration, retention of

integrity when frozen to temperatures as low as

501F and held at those temperatures during the

irradiation step.

2. Minimal chemical changes and/or creation of unde-

sirable extractives in the packaging materials as

the result of irradiation. These changes might be

cross-linking, which could beneﬁcially reduce migra-

tion; or, inversely, they might be degradation to

lower-molecular-weight elements (radiolysis pro-

ducts) with increased migration into the food.

3. Retention of package performance criteria—heat

seal integrity, absence of delamination, survivability

through the transportation and ﬁeld-handling trail,

and retention of these properties over the desired

shelf-life time span.

The effect of high-dose irradiation on food, candidate

packaging ﬁlms, and packaged irradiated foods (i.e., the

ﬁnal product) has been extensively investigated and the

ﬁndings periodically scientiﬁcally and conscientiously re-

viewed. The ﬁrst materials (5) approved for high-dose (up

to 60 kGy) packaging of irradiated foods in 1965 and 1967

were:

1. Vegetable parchments

2. Polyethylene ﬁlm

3. Polyethylene terephthlate (PET) ﬁlm

4. Nylon 6 ﬁlm

5. Vinyl acetate–vinyl acetate copolymer ﬁlm

Radiation-preserved packaged food items were technically

established as totally safe and nutritionally adequate, and

consumer-oriented taste testers found items acceptable.

However, the progression of high-dose irradiated foods

to either full-scale military or commercial usage is yet to

occur. Reasons implicated are: the existence (at least in

the United States) of an extensive established refrigerated

and frozen-food chain; the reluctance of investors to

establish costly manufacturing facilities without assur-

ance of a desirable, potentially ﬂourishing market (the old

paradoxical question, What comes ﬁrst, the chicken or the

egg?); signiﬁcant consumer reluctance to believe that the

process is safe, in spite of the massive data proving it safe;

and limitation of the process to meat items.

Although irradiated foods are suitable for inclusion in

military rations, none, with the exception of South Africa,

are currently included. No adequately sized production

capability for the volumes that would be required exists.

However, the U.S. Army Soldier Systems Command

(Natick, Massachusetts) has been furnishing (in lots of

200 or so) irradiated meat entrees (beef, poultry, pork, and

lamb) to NASA for space applications. Earlier regulatory

agency approvals listed above, because of the development

of newer materials and material analysis techniques, are

no longer valid. Loveridge and Milch (6) reﬂect the current

status of packaging for NASA programs. They evaluated

ﬁve commercially available ﬁlm structures, all without

current formal FDA approval for irradiated food entrees,

Table 1. Two Film Structures

Film 1 Film 2

Inner scalant layer 0.0035-in. linear low-density polyethylene 0.0035-in. linear low-density polyethylene

0.0006-in. biaxially oriented nylon

Barrier 0.00035-in. aluminum foil 0.00035-in. aluminum foil

Outer abrasion protection 0.006-in. biaxially oriented nylon 0.0005-in. polyester

776 MILITARY FOOD PACKAGING

but exempt for sole NASA usage and suitable for similar

food process applications. Of the ﬁve materials, the two

most readily commercially available were:

1. A new MRE pouch material (termed Quad since it

now had four plys) – fabricated from outer to inner

ply of polyester/nylon/aluminum foil/polypropylene.

2. The material used by South Africa – outer to inner

ply: nylon/aluminum foil/polyester/linear low den-

sity polyethylene.

Three other multi-ply ﬁlm constructions were also eval-

uated; these had some potential for use with irradiation –

sterilized foods.

NASA-speciﬁc entrees were put through the entire

process: ﬁlling, vacuum evacuation, sealing, cartoning,

dry ice freezing and shipping, irradiation at 44 kGy,

thawing, and return shipment.

Testing included seal strength, leak tests, drop and

vibration tests, frozen pouch abuse, and internal pressure

resistance. Criteria were those of the now massively

produced Meal, Ready-to-Eat, combat ration. If high-

dose irradiation of foods, already proven safe, becomes

prevalent and costs are reasonable, packaging materials

for military entrees would require re-approval and would

likely be constructed with aluminum foil and the polymers

or their successors listed above. Bonding of plies would be

by coextrusion. A possible variant would be the inclusion

of sealable polyethylene terephthlate (PET) as the inner

layer. In short, ﬂexible packaging for irradiated entrees

to enter the Meal, Ready-to-Eat matrix would in all like-

lihood be readily approved and available.

THERMOPROCESSED FOODS IN FLEXIBLE PACKAGES

While packaging (predominantly the use of multi-ply

ﬂexible ﬁlms) was being deﬁned for freeze-dried and

irradiated foods that were intended for combat use,

studies were initiated with the aim of replacing the

traditional cylindrical metal cans for standard thermo-

processed combat ration entrees with high barrier ﬂexible

polymeric ﬁlms. The ﬁrst probings to do this were prob-

ably in the late 1940s; however, the ﬁrst formal publica-

tion of experiments with thermoprocessing common foods

in ﬂexible ﬁlms was by Hu in 1953. The military, noting

potential functional advantages (per their CDOG) for

combat rations furthered these studies, initially reported

by Keller in 1959 (cited in reference 3). After initial

positive indications, these studies grew into a major

development project culminating in the procurement of a

new combat ration, the Meal, Ready-to-Eat, Individual

(MRE) initially procured in 1979 (3). It is now the basic

U.S. combat ration.

Some initial decisions and considerations that drove

the direction that the development effort would take were

as follows:

1. An aseptic processing and packaging approach

would have alleviated the burden of performance

on the ﬁlm and its formed package (speciﬁcally

resistance to process temperature as high as

2651F), but aseptic systems had no industry accep-

tance; and to undertake its technical development

(to include solids) and gain processor, regulator, and

consumer trust was felt to be prohibitive at that

time. The decision was to proceed with the tradi-

tional post-ﬁll-and-seal thermoprocessing.

2. Although conceivably prematurely at that stage of

the state of the art, the manufacturing system was

visualized as a blend plus modiﬁcation of equipment

already in use for forming, ﬁlling, and sealing for the

frozen food industry and thermoprocessing princi-

ples and equipment for ‘‘canned’’ foods; that is, the

need for radically new equipment was not antici-

pated. A need to tighten performance was accepted.

As a result, a new technology evolved.

3. The military could not replicate the technology

existing in the ﬂexible ﬁlm formulating and convert-

ing industries and would have to entice those

industries’ support by cooperatively revealing com-

mercial opportunities and/or providing monetary

support.

4. The package design would be a ﬂat four-seal pouch—

no gusset or vertical center seam (pillow pack) de-

sign—that is, avoidance of unnecessary loci for leak-

age. If a horizontally drawn form–ﬁll–seal package

concept were to evolve, it would be considered. It was

assumed that on-line pouch forming or the use of

preformed pouches would be suitable.

5. If successful, the replacement of the can with a

pouch (retort pouch) would offer signiﬁcant advan-

tages; this provided a strong mission-oriented in-

centive to proceed. Brieﬂy, these included:

a. lighter weight: 1.5 pounds per meal in the ship-

ping case

b. easy to open: side seam tear notch or two

c. improved palatability: ﬂat thin shape precludes

overcooking the periphery to assure sterility of

the geometric cold spot

d. easy to carry: ﬁts ﬁeld clothing pockets; ﬂat in the

rucksack

e. durable:

. during combat ﬁeld movement

. for air drop

. all forms of transport

all climates

storable: shelf life

suitable for war reserve mate-

riel usage

g. producible:

. materials

. form, ﬁll, seal process

h. heatability: in water in canteen cup ( Note:A

ﬂameless ration heater was later developed and

incorporated into each meal.)

From the earliest feasibility and ﬁeld performance

tests, the packaging ﬁlm producing and converting indus-

tries responded with proprietary ﬁlm developments and

MILITARY FOOD PACKAGING 777