EVALUATION OF ACCELERATED TEST PARAMETERS FOR MIGRATION TESTING OF

EVALUATION OF ACCELERATED TEST PARAMETERS FOR MIGRATION

TESTING OF FOOD PACKAGING

By

SHIN BAE KIM

A thesis submitted to the

Graduate School-New Brunswick

Rutgers, The State University of New Jersey

in partial fulfillment of the requirements

for the degree of

Master of Science

Graduate Program in

Food Science

written under the direction of

Dr. Thomas G. Hartman

and approved by

________________________

________________________

________________________

New Brunswick, New Jersey

January, 2011

ii

ABSTRACT OF THE THESIS

EVALUATION OF ACCELERATED TEST PARAMETERS FOR MIGRATION

TESTING OF FOOD PACKAGING

By SHIN BAE KIM

Thesis Director:

Dr. Thomas G. Hartman

This thesis focused on determining or evaluating accelerated analytical protocol

for detecting potential migrants from food contact surface of conventional ink printed

and/or UV/EB cured food packaging to food. Due to “offset transfer” effect of food

packaging system, the need of fast and precise migration testing protocols emerged,

which are in compliance with FDA recommendation and FDA guideline.

In this study, variations of migration levels by change of testing parameters such

as agitation, temperature, time, simulated solvent, and solvent volume/surface area ratio

were investigated. Furthermore, the comparison studies of migration level between water

soluble and insoluble compounds were performed. Single-side cell extraction and gas

chromatography-mass spectrometry (GC-MS) were used to detect migrant compounds.

Through the conclusion, 24-hour accelerated migration testing protocols are

suggested and evaluated, which are regarded to be equivalent to the FDA recommended

testing protocols.

iii

ACKNOWLEDGEMENTS

I would like to extend my sincere appreciation to my advisor, Dr. Thomas G.

Hartman for his guidance, encouragement, support, and direction which aided in the

completion of my study at Rutgers, the State University of New Jersey.

I would like to specially thank my committee members of master thesis review,

Dr. Chi-Tang Ho and Dr. Henryk Daun for their support and guidance throughout this

study.

My special thanks to Dr. Bin-Kong Khoo, Dr. Wudeneh Letchamo, Dr. Samia

Mezouari and Joseph Lech for their assistance and friendship during my study at Mass

Spec Lab, CAFT. I would also like to give special thanks to Dr. Sam Shefer and Dr. Adi

Shefer in Salvona LLC. for offering great internship opportunity and their endless

support.

My sincere appreciation goes to my parents and parents-in-law as well as my

family for their continued encouragement and endless love throughout my graduate work.

Last but certainly not least my biggest thanks goes to my wife, Mi-Na Lim for

being there by my side at all times. Her remarkable support and encouragement have

made this study possible.

iv

TABLE OF CONTENTS

TITLE ............................................................................................................................. i

ABSTRACT OF THESIS ............................................................................................... ii

ACKNOWLEDGEMENTS ............................................................................................. iii

TABLE OF CONTENTS ................................................................................................ iv

LIST OF TABLES .......................................................................................................... vi

LIST OF FIGURES ........................................................................................................ vii

I. INTRODUCTION ....................................................................................................... 1

II. LITERATURE REVIEW ............................................................................................ 3

A. General Information ......................................................................................... 3

1. Conventional ink printed packaging ........................................................... 3

2. UV/EB cured carton packaging .................................................................. 6

B. FDA Regulations Regarding Coating and Inks on Food Packaging ................ 9

C. Guidance for Industry: Preparation of Premarket Submissions for Food

Contact Substances: Chemistry Recommendations (December 2007) .......... 11

III. RESEARCH HYPOTHESIS .................................................................................... 13

IV. EXPERIMENTAL .................................................................................................... 14

A. MATERIALS ................................................................................................ 14

B. METHODS ..................................................................................................... 17

1. Sample preparation with 10% ethanol, 3% acetic acid in water, or water

simulant ................................................................................................... 18

2. Sample preparation with 95% ethanol simulant ....................................... 18

v

3. Gas Chromatograph-Flame Ionization detection (GC-FID) analysis ....... 19

4. Factors affecting extraction efficiency ...................................................... 20

4.1. Conventional Ink base carton paperboard preparation .................... 20

4.2. EB/UV cured paperboard preparation ............................................. 20

4.3. Experimental design for identifying factors affecting extraction

efficiency ..................................................................................... 21

V. RESULTS AND DISCUSSION ............................................................................... 23

A. Data Analysis of Migrants from Conventional Ink Packaging ...................... 23

1. Total migrants of “CONVENTIONAL INK” packaging

system by conditions ............................................................................... 25

2. Comparision of Soluble and Insoluble Extractables

from Conventional Ink Packaging ......................................................... 31

B. Data Analysis of Migrants from UV/EB Curable Packaging ........................ 38

3. Total migrants of “EB/UV CURABLE” packaging system

by conditions ........................................................................................ 40

4. Comparision of Soluble and Insoluble Extractables from

UV/EB Cured Packaging ..................................................................... 46

VI. CONCLUSION ......................................................................................................... 53

VII. REFERENCES ........................................................................................................ 55

vi

LIST OF TABLES

1. General conventional sheetfed ink composition ........................................................... 4

2. Comparison between conventional and UV/EB curable ink and coating ..................... 4

3. Commonly encountered UV/EB curable monomers used on food packaging prints ... 7

4. Recommended Food Simulants by US-FDA .............................................................. 12

5. Simulant volume to surface area ratio ........................................................................ 15

6. Percent recovery of the DCM and standard curves for the selected acrylate

monomers in 10% and 95% aqueous ethanol simulant ...................................... 17

7. Design matrix for selected five factors with FDA level and range of our

investigation ........................................................................................................ 21

8. Fractional factorial design matrix ............................................................................... 22

9. Detected representative extractables of conventional ink packaging ......................... 23

10. Solubilities of migrants of CONVENTIONAL INK printing packaging ................. 32

11. Detected representative extractables of EB/UV curable packaging ......................... 38

12. Solubilities of migrants of UV/EB Curable packaging ............................................. 47

13. Conditions for the 24-hour accelerated testing equivalent to FDA recommendation 54

vii

LIST OF FIGURES

1. Cross section of Typical Conventional Ink Printed Carton Board Packaging .............. 5

2. Cross section of Typical UV/EB Cured Carton Board Packaging ............................... 8

3. Diagram of single-side extraction cell for migration testing ...................................... 16

4. Chromatograph of Conventional Ink packaging extraction ........................................ 24

5. Total migrant level of Conventional ink packaging by Agitation variable ................ 25

6. Total migrant level of Conventional ink packaging by Simulated Solvent variable .. 26

7. Total migrant level of Conventional ink packaging by Time variable ....................... 27

8. Total migrant level of Conventional ink packaging by Temperature variable ........... 28

9. Total migrant level of Conventional ink packaging by Solvent volume/

Surface area Ratio (mL/Inch²) variable (ppb w/v unit) ....................................... 29

10. Total migrant level of Conventional ink packaging by Solvent volume/

Surface area Ratio (mL/Inch²) variable (ng/cm² unit) ........................................ 30

11. Migrant levels of soluble and insoluble compounds of ink-borne

by Agitiation variable ......................................................................................... 33

12. Migrant levels of soluble and insoluble compound of ink-borne

by Simulant variable ........................................................................................... 34


by Time variable ................................................................................................. 35


by Temperature variable ..................................................................................... 36


by Solvent volume/Surface area Ratio (mL/Inch²) variable (ng/cm² unit) .......... 37

viii

16. Chromatograph of EB/UV curable packaging extraction ......................................... 39

17. Total migrant level of EB/UV curable packaging extraction by Agitation variable . 40

18. Total migrant level of EB/UV curable packaging extraction by Simulant variable . 41

19. Total migrant level of EB/UV curable packaging extraction by Time variable ....... 42

20. Total migrant level of EB/UV curable packaging extraction by Temperature

variable ................................................................................................................. 43

21. Total migrant level of EB/UV curable packaging extraction by Solvent

Volume/Surface Area Ratio (mL/Inch²) variable (ppb w/v unit) ....................... 44

22. Total migrant level of EB/UV curable packaging extraction by Solvent

Volume/Surface Area Ratio (mL/Inch²) variable (ng/cm²) ................................. 45

23. Migrant levels of soluble and insoluble compounds of UV/EB curable packaging

by Agitiation variable .......................................................................................... 48


by Simulated Solvent variable ............................................................................ 49


by Time variable ................................................................................................. 50


by Temperature variable ..................................................................................... 51


by Solvent Volume/Surface Area Ratio (mL/Inch²) variable (ng/cm²) ............... 52

1

I. INTRODUCTION

Printed paperboard carton packaging is one of the most broadly used packaging

materials for foods such as dairy products, fruit juices and frozen foods. The outer, non-

food contact surface of the packaging is typically heavily printed with inks and then a

clear overprint varnish (OPV) is applied to convey abrasion resistance. Printing inks

broadly fall into one or two categories, conventional or energy curable. Conventional inks

and coatings are water or solvent based systems that are applied to the surface and then

dried or cured. Energy curable systems are solventless and use ultra-violet (UV) or

electron beam (EB) irradiation to cure the inks and coatings. Both conventional and

energy curable inks and OPV are composed of a plethora of chemicals including solvents,

pigments, resins, plasticizers, surfactants, antioxidants, UV-photoinitiators and many

other compounds, none of which are generally recognized as safe (GRAS) food additives

by the US Food and Drug Administration (FDA) (Yoo, Pace, Khoo, Lech and Hartman,

2004). According to FDA regulations, the food packaging must be a functional barrier to

the non-GRAS chemicals used in inks and coatings. Printed food packaging flatstock

and/or rollstock is stored before use with the printed/coated side of the packaging in

direct physical contact with the unprinted food contact surface. In this orientation, ample

opportunity for the transfer of printing/coating chemicals to the food contact surface

exists. The phenomenon whereby ink or OPV chemicals migrate from the print side to

the food contact side is called “offset transfer”. FDA limits migration via this mechanism

to 50 parts per billion (ppb) for each non-GRAS substance and requires extraction testing

with food simulating solvents for regulatory compliance (FDA, 2007). Typical FDA

2

extraction studies take up to 10 days or more to complete. This time constraint is

problematic for industry in that quick decisions must often be made on suitability of

packaging.

3

II. LITERATURE REVIEW

A. General Information

1. Conventional ink printed packaging

Conventional ink printing is a solvent based system. In order to obtain a “quick

set” effect, generally low viscosity, low aromatic mineral oils are applied. However,

when inks are printed on non-absorbent substrates such as plastics, it is hard to expect

“quick set” effect. The general conventional sheetfed ink composition is shown on Table

1. Due to solvent based system, conventional ink printing and coating take relatively over

time for drying and coating. Moreover, conventional ink printing process requires high

temperature environment for effective drying process during absorbing or evaporating

excessive ink and solvent or water, or a combination of both. The penetration of the low

viscosity oils into the substrate also induces a physical drying (setting). The rollers for

conventional inks are typically Nitrile Butadiene rubber (NBR) which is compatible with

more apolar materials such as hydrocarbons, whereas rubber rollers for UV inks are

based on EPDM (ethylene propylene diene Monomer (M-class) rubber, a type of

synthetic rubber), (Gevaert, 2010). The general comparison between conventional and

UV/EB curable ink and coating is shown on Table 2. In addition, the cross sections of

typical conventional ink printed carton board packaging are shown on Figure 1. The

Figure 1. shows general two types of conventional printings, surface printing and reverse

printing. Because the paperboard with surface print is more prone to offset transfer,

reverse printing paperboard is used for our research.

4

Table 1. General conventional sheetfed ink composition (Gevaert, 2010)

Conventional Sheetfed Ink

Mineral Oil (280-320°C) 0-30%

(semi) Drying vegetable oil and esters thereof

15-30%

Drying alkyd 10-20%

Hard resin (rosin mod) 20-35%

Pigment 14-24%

Fillers 0-5%

Wax 3-5%

Driers 2%

Anti-oxidants 0-2%

Table 2. Comparison between conventional and UV/EB curable ink and coating

Printing Ink Conventional Energy(Radiation) Curable

System Water or Solvent Solventless

Speed Slow Drying and Coating Fast Curing

Operation Temp.

High (for drying) Room Temp.

Cost High Low

VOC’s Emitting*

High Few

Quality Less Higher

*VOC: volatile organic compounds

5

Figure 1. C

ross section of Typical C

onventional Ink Printed C

arton Board P

ackaging (A. S

urface Printed ; B. R

everse Printed)

6

2. UV/EB cured carton packaging

Ultraviolet (UV) and/or Electron beam (EB) cured packaging system has been

popular since its commercialization in late 1960’s. Because of its prominent advantages

such as fast cure speed, room temperature operation, high quality end products and

economic cost, UV/EB cured packaging has been used in broad area for food packaging

industry. As known cool and solventless process, UV/EB curing system fulfils the US

Environmental Protection Agency (US-EPA) recommendation by decreasing the use of

volatile organic compounds (VOS’s), incinerators and/or solvent recovery units (Yoo,

2004).

Curing is the toughening or hardening of a polymer material by cross-linking of

polymer chains (Wikipedia, 2008) and the chemical reaction that a material goes through

to get from the wet to the dry stage (Utschig, 2004). Thus, in UV/EB curing to produce

polymers, generally acrylate monomers and oligomers are used for food packaging. The

most mainly used acrylate monomers are shown on Table 3. For UV curing,

photoinitiators (PIs) which induce photopolymeization or photocross-link of the acrylate

resins are applied. Fouassier explained the two-step process of photoinitiation in his book;

PIs absorb the UV energy to convert to free radicals and then free radicals attack and

break the acrylic double bonds to initiate polymerization (Fouassier, 1995). On the other

hand, for EB curing, the acrylic double bonds are attacked by the high energy of

accelerated electrons, which directly initiate polymerization of the ink or coating (Leach,

1998 and Rechel, 2001). Furthermore, application of propoxylation and ethoxylation has

7

been broadly accepted in the ink and coating industry. Both propoxylation and

ethoxylation are to induce cross-linking between oligomer molecules and other

monomers and to increase complexity of the structure of polymers.

Table 3. Commonly encountered UV/EB curable monomers used on food packaging

prints

Common Name Chemical Name

TPGDA Tripropylene glycol diacrylate

TMPTA Trimethylol propane triacrylate

HDDA 1,6 hexane diol diacrylate

DPGDA Dipropylene glycol diacrylate

PETA Pentaerythritol tri-, tetraacrylate

NVP N-vinylpyrrolidone

ODA Octyl decyl acrylate

OH-Butyl acrylate Butanediol monoacrylate

EO-TMPTA Ethoxylated trimethylol propane triacrylate

EO-HDDA Ethoxylated 1,6 hexane diol diacrylate

GPTA Glyceryl propoxylated triacrylate

PO-NPGDA Propoxylated neopentyl glycol diacrylate

di-TMPTA Di-Trimethylol propane tetraacrylate

8

Figure 2. C

ross section of Typical U

V/E

B C

ured Carton B

oard Packaging

9

B. FDA Regulations Regarding Coating and Inks on Food Packaging

FDA permits the use of conventional & energy curable inks and coating as

components of food packaging under certain conditions in compliance with certain

regulations. Actually, conventional inks are able to be utilized onto direct food contact

side with approved functional barrier or FDA acceptable coating such as resinous coating,

protective film, transparent cover, etc. by FDA (Gettis, 1997). The FDA states that if

printed material is separated by approved functional barrier, the printing ink ingredients

would not need to be approved for that use (Gettis, 1997). However, the UV/EB inks and

coatings are not approved for direct food contact due to their safety concern. Whatever

the ink or coating substances are approved to be applied onto direct or indirect food

contact side of food packaging or not, migration of the chemical substances from food

packaging to food is strictly restricted by FDA regulation.

According to No-Migration exemption, clarified by the United States Court of

Appeals for the D.C. circuit in Monsanto v. Kennedy decision (D.C.Cir.1979), the term

“food additive” has been clearly defined as :

“Food additives includes all substances not exempted by section 201(s) of the

Federal Food, Drug, and Cosmetic Act, the intended use of which results or may

reasonably be expected to result, directly or indirectly, either in their becoming a

component of food or otherwise affecting the characteristics of food. A material

used in the production of containers and packages is subject to the definition if it

may reasonably be expected to become a component, or to affect the

10

characteristics, directly or indirectly, of food packed in the container. "Affecting

the characteristics of food" does not include such physical effects, as protecting

contents of packages, preserving shape, and preventing moisture loss. If there is

no migration of a packaging component from the package to the food, it does not

become a component of the food and thus is not a food additive. A substance that

does not become a component of food, but that is used, for example, in preparing

an ingredient of the food to give a different flavor, texture, or other characteristic

in the food, may be a food additive.”(21 Code of Federal Regulations (CFR)

170.3(e) Food Additives, Definitions)

In addition, a substance, detected at below 50 part per billion (ppb) with an appropriately

conducted migration study, is considered to be not a food additive. The migration study

should be conducted in accurately simulated conditions of actual use. There is also a

proper guideline for migration study according to the FDA, entitled “Guidance for

Industry: Preparation of Premarket Submissions for Food Contact Substances: Chemistry

Recommendations (December 2007).”

At Code of Federal Regulations, Title 21, parts 170, 39, “Threshold of regulation

for substances used in food-contact articles” of FDA stipulates the proposition for the

substances which can be considered as safe on the basis of low dietary exposure. The

substance at extremely low levels, 0.5 PPB or below in the diet may be considered as

GRAS.

11

C. Guidance for Industry: Preparation of Premarket Submissions for Food Contact

Substances: Chemistry Recommendations (December 2007)

The Federal Food, Drug, and Cosmetic Act (the Act) at sec409 (h) (6) defines the

food-contact substance (FCS) as “any substance that is intended for use as a component

of materials used in manufacturing, packing, packaging, transporting, or holding food if

the use is not intended to have any technical effect in the food” (FDA, 2007). As well, the

section 409 of the Act includes the requirements for food contact notification (FCN) or

food additive petition (FAP), which involve “sufficient scientific information to

demonstrate that the substance that is the subject of the submission is safe under the

intended conditions of use” (FDA, 2007).

This guidance for industry (FDA, 2007) contains “FDA's recommendations

pertaining to chemistry information that should be submitted in a food contact

notification (FCN) or food additive petition (FAP) for a food-contact substance (FCS)”

(FDA, 2007). Especially, in ‘section II. Chemistry information for FCNs and FAPs’, the

document describes migration testing and analytical methods in detail such as design of

migration experiment (II D 1 A-E), characterization of test solutions & data reporting (II

D 2), analytical methods (II D 3 A-E), migration database (II D 4), and migration

modeling (II D 5).

The specifications of migration cell, test sample, food stimulants, temperature,

and time of test are well explained in the section of design of migration experiment. For

example, the document shows food simulant samples for test, as shown at Table 4. The

12

guidance also recommends 10 mL/Inch² for the acceptable ratio of specimen volume/

surface area when it is not able to be similar to the ratio of actual food packaging. For

temperature and time of testing, a test temperature of 40 ºC (104 ºF) for room temperature

application and 20 ºC (68 ºF) for refrigerated or frozen food applications were acceptable

for 10 days each instead of the recommendation of FDA, the most severe conditions of

temperature and time anticipated for the proposed use (FDA, 2007).

Table 4. Recommended Food Simulants by US-FDA

Food-Type as defined in 21 CFR 176.170(c) Table 1 Recommended Simulant

Aqueous & Acidic Foods (Food Types I, II, IVB, VIB,

and VIIB) 10% Ethanol

Low- and High-alcoholic Foods (Food Types VIA, VIC) 10 or 50% Ethanol*

Fatty Foods (Food Types III, IVA, V, VIIA, IX) Food oil (e.g., corn oil), HB307,

Miglyol 812, or others**

* Actual ethanol concentration may be substituted

** HB307 is a mixture of synthetic triglycerides, primarily C10, C12, and C14. Miglyol 812 is derived from coconut oil

13

III. RESEARCH HYPOTHESES

Accelerated analytical methods can be evaluated to assess the migration potential

of ink-borne from conventional ink printed packaging and/or UV/EB curable components,

which migrates from food contact surface of printed food packaging to foods. The

evaluation can prove that accelerated analytical methods can be equivalent to FDA

recommended protocols and satisfying FDA recommendations. Accelerated parameters

such as agitation, increased temperature, and intensified ratio of simulant volume to

surface area of sample, and various simulated solvents can hasten the migration speed of

ink-bornes or UV/EB curable ink components. Thus, extraction testing can be shortened

in 24 hours rather than 10 days.

Also, comparison of water soluble and insoluble compounds among the migrants

of can confirm that accelerated analytical methods are valid to both water soluble and

insoluble compounds. We anticipate that changing and/or accelerating the affecting

factors may cause similar effects to both water soluble and insoluble compounds for both

conventional ink printed packaging experiments and UV/EB cured packaging

experiments.

Thus, based on the evaluation, optimized and accelerated analytical methods will

be suggested through the experiments. Then, we expect that the results of optimized and

accelerated (24 hours) migration testing will be equivalent to those of the FDA migration

testing.

14

IV. EXPERIMENTAL

A. MATERIALS

Single side extraction cells were used for migration testing. To extract

conventional ink elements and/or EB/UV curable components from the one-side surface

of food packaging prints, single side extraction cells were designed according to FDA

specifications for food contact polymer migration testing and developed by Dr. Thomas

G. Hartman (Center for Advanced Food Technology, Rutgers University, NJ, USA).

Single side extraction cells consist of two stainless steel plates which sandwich a Teflon

gasket (Teflon spacer) assembly and screws as shown Figure 3. The Teflon gasket

isolates 51 cm² (7.9 inch²) surface area of only the food contact surface or direct

printed/coated surface for extraction. Also, the Teflon gaskets (spacers) can hold 30mL,

62.5mL or 125mL of food simulant volumes accordingly their sizes. The ratios of

stimulant volumes to surface area of a substrate are 3.8, 7.9 or 15.8, respectively. Due to

FDA recommendation of testing, the ratio of 10, 125mL Teflon gasket is selected with

79mL of simulant.

A specimen, of which the food contact surface is facing up, was put on the top of

bottom plate. A Teflon spacer which has cavity for food simulant was placed on the

specimen’s food contact surface. Then, the top plate was put on the Teflon spacer. All

together was tightened up by 12 screws. Through the hole of the top plate, the food

simulant was injected into the assembled extraction cell.

As internal standards, approximately 100 ppb level of anthracene d-10 and/or n-

docosane were matrix-spiked into the extracts. Then, the extracts were concentrated

15

Table 5. Simulant volume to surface area ratio

Simulant Volume (mL) Surface area of a

specimen (in²)

Simulant volume / surface

area Ratio (mL/in²)

7.9 7.9 1

23.7 7.9 3

39.5 7.9 5

79 7.9 10*

* The ratio, the FDA recommended, of simulant volume to surface area of a specimen.

16

Figu

re 3. Diagram

of single-sid

e extraction cell for m

igration testin

g (design

ed b

y Dr. T

hom

as G. H

artman

, Cen

ter for

Ad

vanced

Food

Tech

nology (C

AF

T), R

utgers U

niversity, N

J)

17

B. METHODS

The methods used for my experiment were validated by Yoo, S.J. in his

dissertation in 2005. According to Yoo’s dissertation, the method accuracy (percent

recovery) of selected acrylate monomers such as TPGDA, TMPTA, HDDA, EO-HDDA,

EO-TMPTA, and GPTA in DCM were within FDA’s acceptable ranges as shown in

Table 6. (Yoo., 2005).

Table 6. Percent recovery of the dichloromethane (DCM) and standard curves for the

selected acrylate monomers in 10% and 95% aqueous ethanol simulant (Yoo., 2005).

* The analysis was performed in triplicate and % was mean of triplicates. Relative standard deviation (RSD %) of each acrylate monomers was below 11%.

** Validation of analytical methods (II. D.3. e.), In Guidance for Industry: “Preparation of food contact Notification and Food Additives Petitions for Food Contact Substances”: Chemistry Recommendations, Final Guidance, April (2002).

Acrylate monomer

Recovery percentage*

In 10% aqueous ethanol

In 95% ethanol FDA acceptable

levels**

TPGDA 97.9% 98.5%

80-110% At below 100ppb Levels in foods

TMPTA 99.0% 97.8%

HDDA 98.1% 99.7%

EO-HDDA 87.8% 95.5%

EO-TMPTA 90.5% 94.6%

GPTA 85.4% 81.9%

18

1. Sample preparation with 10% ethanol, 3% acitic acid in water, or water

simulant

8mL, 24mL, 40mL or 80mL of solvent simulants such as 10% aquous ethanol, 3%

acitic acid in water, or water were incubated in single-side extraction cell in controlled

circumstances. After incubation, those simulants were transferred from extraction cells

into 50mL or 100mL size test tubes which have Teflon-lined cover. 100 ppb internal-

standards were matrix-spiked into each sample simulant. Anthracene-d10 in

dichloromethane (DCM) and n-C22 Docosane in DCM were chosen as internal standards

(approximately 1.0 mg acrylate/10 mL DCM). The reason why two internal standards

were used was to avoid the confliction between internal standard and extracted-

compound such as TMPTA. For example, each of 0.8µL of internal standards was spiked

into 8mL stimulants and 2.4µL of internal standards into 24mL simulants. Then, 5mL of

DCM was added into the sumulants to vigorously back-extracted. The simulants were

vigorously hand-shaken for 10 minutes and centrifuged at 3000 rpm for 30 minutes. The

extracts at bottom layer were taken and concentrated to approximately 0.1mL using

gentle stream of nitrogen at room temperature. The concentrated extracts were analyzed

by Gas Chromatography-Flame Ionization Detector (GC-FID).

2. Sample preparation with 95% ethanol simulant

24mL of 95% ethanol simulant was incubated in single-side extraction cell in

controlled circumstances. After incubation, the simulant was transferred from extraction

cells into 50mL size test tubes which have Teflon-lined cover. 100 ppb internal-standards

19

were matrix-spiked into sample simulant (2.4µL of internal standards). Anthracene-d10

in DCM and n-Docosane(C-22) in DCM were chosen as internal standards

(approximately 1.0 mg/10 mL DCM). Then, the simulant was vortexed. 5mL of simulant

was taken and transferred into another 50mL size test tube. 42.5mL of water was added

into the test tube in order to make 10% aqueous ethanol solution by dilution. After

voltexing it, 5mL of DCM was added into the sumulant to back-extract compounds. The

simulant was vigorously hand-shaken for 10 minutes and centrifuged at 3000 rpm for 30

minutes. The extracts at bottom layer were taken and concentrated to approximately

0.1mL using gentle stream of nitrogen at room temperature. The concentrated extracts

were analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID).

3. Gas Chromatograph-Flame Ionization detection (GC-FID) analysis

GC-FID analyses were performed on a Varian 3400 gas chromatograph with

flame ionization detector (GC-FID). The data were acquired and processed with Peak-

Simple™. The temperature of injector was 280ºC with splitless injection. After 30

seconds, 100:1 split was programmed with septum purge. The 1µL injection of the

analyte in DCM (methylene chloride) was made on MDN-5S (Supelco, Serial# M895-

01B), Fused Silica Capillay Column, 30m x 0.32mm ID x 0.25µm. Helium was the

carrier gas at 10 psi pressure. The GC oven temperature was defined from 50ºC, held for

3 minutes, and then increased up to 320ºC at a rate 10ºC/min, then held at 320ºC for 10

minutes.

20

4. Factors affecting extraction efficiency

4.1. Conventional Ink Base carton paperboard preparation

Conventional ink based carton paperboard samples were prepared at Carton

Services Packaging Insights in Shelby Ohio. The substrate is F230H grade Waynsville

coated board stock. The samples were made for “Will’s Fresh Foods” products. Samples

were printed with the reverse printing method. Sections of each carton sample measuring

10cm x 15cm were cut and placed into a custom stainless steel (SS) extraction cell

(single-side extraction cell), as described above.

4.2. EB/UV cured paperboard preparation

EB/UV cured (printed/coated) Minute Maid Fruit Punch Carton paperboards

were prepared at Blue Ridge Paper Products Division, Evergreen Packaging at

Waynesville, NC. Sections of each carton sample measuring 10cm x 15cm were cut and

placed into a custom stainless steel (SS) extraction cell (single-side extraction cell), as

described above.

21

4.3. Experimental design for identifying factors affecting extraction

efficiency

Five factors – temperature, time, surface area to simulant volume ratios,

agitation and solvent strength- were considered and selected as potentially affecting

extraction efficiency, according to the FDA recommended testing conditions. In order to

identify and clarify of the affectability of each parameter, fractional factorial design was

set up as on Table 8. The testing was triplicated and the results were analyzed. The levels

of the conditions also were based on FDA recommended testing conditions. FDA

recommended testing conditions had to be minimum levels to investigate our accelerated

optimum conditions. FDA recommended testing conditions are shown on Table 7.

Table 7. Design matrix for selected five factors with FDA level and range of our

investigation

*FDA recommended conditions for aqueous & acidic foods for room temperature application.

** Agitation was performed by voltexing incubator (New Brunswick Scientific Products.)

Agitation**Temperature

(°C)

Solvent

Volume to

Surface Ratio

(mL/Inch²)

Solvent

Strength Time

FDA* No Room

Temp. 10 10% EtOH 10 days

Range of

our

investigation

No or FullRoom tm.

40, 60, or 801,3,5, or 10

10%, 95% EtOH,

3% aqueous Acetic Acid, or

Water

1, 4, or 10

days

22

Table 8. Fractional factorial design matrix.

* Sample 1 is for Conventional Ink packaging test produced by Carton Service, Packaging Insights

** Sample 2 is for EB/UV cured packaging test produced by Evergreen Packaging EB printed Carton LLN5045

EXP. No.

Sample Temp. AgitationSolvent

Volume/Surface Area Ratio (mL/In²)

Time Simulated Solvents

1 1* 40°C O 3 24 Hrs. 10% EtOH

2 1 40°C X 3 24 Hrs. 10% EtOH 3 2** 40°C O 3 24 Hrs. 10% EtOH 4 2 40°C X 3 24 Hrs. 10% EtOH

5 1 40°C O 3 24 Hrs. 10% EtOH 6 1 40°C O 3 24 Hrs. 95% EtOH

7 1 40°C O 3 24 Hrs. 3% Acetic in H2O

8 1 40°C O 3 24 Hrs. H2O 9 2 40°C O 3 24 Hrs. 10% EtOH

10 2 40°C O 3 24 Hrs. 95% EtOH 11 2 40°C O 3 24 Hrs. 3% Acetic in H2O

12 2 40°C O 3 24 Hrs. H2O

13 1 40°C O 3 24 Hrs. 10% EtOH 14 1 40°C O 3 4 Days 10% EtOH

15 1 40°C O 3 10 Days 10% EtOH 16 2 40°C O 3 24 Hrs. 10% EtOH 17 2 40°C O 3 4 Days 10% EtOH

18 2 40°C O 3 10 Days 10% EtOH

19 1 Rm. O 3 24 Hrs. 10% EtOH

20 1 40°C O 3 24 Hrs. 10% EtOH 21 1 60°C O 3 24 Hrs. 10% EtOH 22 1 80°C O 3 24 Hrs. 10% EtOH

23 2 Rm. O 3 24 Hrs. 10% EtOH 24 2 40°C O 3 24 Hrs. 10% EtOH 25 2 60°C O 3 24 Hrs. 10% EtOH

26 2 80°C O 3 24 Hrs. 10% EtOH

27 1 40°C O 1 24 Hrs. 10% EtOH



34 2 40°C O 10 24 Hrs. 10% EtOH

23

V. RESULTS AND DISCUSSION

A. Data Analysis of Migrants from Conventional Ink Packaging

Through the single side extraction cell experiment of conventional ink packaging,

which followed FDA recommended testing conditions, tens of elements were migrated

and detected. Representative detected extractables of conventional ink packaging are

listed on Table 9. Our food contact side extraction of the conventional ink printed

packaging carton showed relatively high levels of ink-borne migrants. Significant counts

of compounds were non-GRAS. Some of them exceeded the FDA threshold of 50 ppb

w/v such as cyclohexanone, 2-ethylhexyl alcohol, acetophenone, 2-ethylhexyl acetate,

diethylene glycol, monobutyl ether, Surfynol 104, Kodaflex TXIB type ester alcohol

plasticizer, and dipropylene glycol, monobenzoate isomer.

Table 9. Detected representative extractables of conventional ink packaging

1 cyclohexanone

2 2-ethylhexyl alcohol

3 acetophenone

4 2-ethylhexyl acetate

5 diethylene glycol, monobutyl ether

6 diethylene glycol, monobutyl ether acetate

7 2,4,7,9-tetramethyl-5-decyn-4,7-diol (Surfynol 104)

8 propylene glycol, monobenzoate

9 2,2,4-Trimethyl-1,3-Pentanediol Diisobutyrate (Kodaflex TXIB type ester alcohol plasticizer)

10, 13 Ethoxylated tetramethyldecynediol (Surfynol 440 oligomer: Surfynol 104 polyethoxylate oligomer)

11, 12 dipropylene glycol, monobenzoate isomer

14 dipropylene glycol, dibenzoate

15 D-10 anthracene (internal standard)

16 n-c22Docosane (internal standard)

24

Figure 4. C

hromatograph of C

onventional Ink packaging extraction

* Num

bered compounds on the chrom

atograph are listed on Table 9.

** Chrom

atograph of experiment num

ber 21-1 on Table 8. ; W

ith agitation, 1 day, 10% E

TO

H, 60 ºC

, 3mL

/in² (agitation, extraction duration, food sim

ulant, temperature, and solvent/surface ratio, respectively)

25

1. Total migrants(ppb) of “CONVENTIONAL INK” packaging system by

conditions

1.1. Agitation variable

Holding other factors constant - 1 day, 10% ETOH, 40 ºC , 3mL/in² (extraction

duration, food simulant, temperature, and solvent/surface ratio respectively) -, the total

migrant levels are 1165.72 ppb with agitation and 1142.77 ppb without agitation,

respectively, as shown on Figure 5. The level difference of total migrants of conventional

ink packaging is insignificant.

Figure 5. Total migrant level of Conventional ink packaging by Agitation variable

* Concentrations of total migrants are mean of three experiments.

1165.72 1142.77

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00

with Agit. without Agit.

ppbTotal Migrants (ppb)

26

1.2. Simulated Solvent variable

As shown Figure 6., holding other factors constant - 1 day, with agitation, 40 ºC ,

3mL/in² (extraction duration, agitation, temperature, and solvent/surface ratio

respectively) -, the total migrant levels were 1177.42 ppb with 10% EtOH, 7012.24 ppb

with 95% EtOH, 860.87 ppb with 3% Acetic Acid in Water, and 1049.92 ppb with Water,

respectively. The solvent strength had a significant effect on extraction. The other

solvents affected similarly in conventional ink extraction.

Figure 6. Total migrant level of Conventional ink packaging by Simulated Solvent

variable


1177.42

7012.24

860.87 1049.92

0.00

1000.00

2000.00

3000.00

4000.00

5000.00

6000.00

7000.00

8000.00

10% ETOH 95% ETOH 3% Acetic Acid in Water Water


27

1.3. Time variable

Through the experiments #13-15 on Table 8., time variable tests were performed.

With other factors constant - 10% ETOH, with agitation, 40 ºC , 3mL/in² (food simulant,

agitation, temperature, and solvent/surface ratio respectively) -, the total migrant levels

are 1016.91 ppb with 1 day extraction, 1383.22 ppb with 4 days, and 1814.11 ppb with

10 days, respectively. As incubation time increased, the level of total migrants rose. 10

days experiment had only about 1.8 times total migrant level than 1 day experiment. This

is insignificant difference. The migrant level of 10 days extraction is close to the

recommended level for FDA test.

Figure 7. Total migrant level of Conventional ink packaging by Time variable


1016.91

1383.22

1814.11

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00

1600.00

1800.00

2000.00

24 Hours 4 Days 10 Days


28

1.4. Temperature variable

On temperature variable test, the total migrant levels are 350.41 ppb at 25 ºC,

1177.42 ppb at 40 ºC, 2159.38 ppb at 60 ºC, and 2891.43 ppb at 80 ºC, respectively,

while other factors were constant - 1 day, with agitation, 10% ETOH, 3mL/in² (extraction

duration, agitation, food simulant, and solvent/surface ratio respectively). The higher

temperature, the more migrant levels there are. The migration of conventional ink

components was significantly sensitive on temperature parameters.

Figure 8. Total migrant level of Conventional ink packaging by Temperature variable

* 40 ºC data is duplicated from the Simulated Solvent Variables experiment because of same parameter conditions.

** Concentrations of total migrants are mean of three experiments

350.41

1177.42

2159.38

2891.43

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

3500.00

25 ℃ 40 ℃ * 60 ℃ 80 ℃

ppb Total Migrants (ppb)

29

1.5. Solvent Volume/Surface Area Ratio (mL/INCH²) variable

The ratio of solvent volume per surface area (mL/In²) variable experiments

showed that total migrant level of conventional ink extractables decreased on ppb (w/v)

unit as the ratio increased, as shown on Figure 9. However, when the unit was normalized

onto ng/cm², total migrant level of extractables increased gradually as the increment of

the ratio, as shown on Figure 10.

Figure 9. Total migrant level of Conventional ink packaging by Solvent volume/Surface

area Ratio (mL/Inch²) variable (ppb w/v unit)

2349.62

1133.65

893.51

642.37

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

1 mL/Inch² 3 mL/Inch² 5 mL/Inch² 10 mL/Inch²

ppb Total Migrants (ppb)

30

Figure 10. Total migrant level of Conventional ink packaging by Solvent volume/Surface

area Ratio (mL/Inch²) variable (ng/cm² unit)

* This is the normalized analysis.

368.57

533.48

700.79

1007.64

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00


ng/cm2Total Migrants (ng/cm²)

31

2. Comparison of Soluble and Insoluble Extractables from Conventional Ink

Packaging

The comparisons between water soluble and insoluble compounds at

conventional ink extract experiment were performed in order to identify the differences

of extractability by parameters. The water solubility of each element is listed on Table 10.

As examples, diethylene glycol, monobutyl ether acetate (CAS# 124-17-4) and

dipropylene glycol, dibenzoate (CAS# 94-51-9) were chosen for representatives of water

soluble and insoluble compounds, respectively. The reason why diethylene glycol,

monobutyl ether acetate (CAS# 124-17-4) was selected is that diethylene glycol,

monobutyl ether acetate has the solubility of 65g/L, which is the biggest solubility among

the extractables. Also, diethylene glycol, monobutyl ether acetate (CAS# 124-17-4) was

extracted in significant amount at almost all of our experiments, which was over the FDA

regulation -50 ppb w/v- for non-GRAS compound. Monobutyl ether acetate was one of

most extracted element from conventional ink packaging cell-extraction as well as

obvious one of water insoluble extractables.

32

Table 10. Solubilities of migrants of CONVENTIONAL INK printing packaging

CAS Number Water Solubility Other Solubility

Cyclohexanone 108-94-1 9075-99-4

slightly soluble (5-10 g/100 mL) 150 g/L (10 ºC)

Miscible in ethanol and common organic solvents

2-ethylhexyl alcohol

104-76-7 111675-57-1 (FEMA No. 3151)

1 g/L (20 ºC)

Acetophenone 98-86-2 5.5 g/L at 25°C 12.2 g/L at 80°C

soluble in sulfuric acid and most organic solvents

2-ethylhexyl acetate 103-09-3 slightly soluble

diethylene glycol, monobutyl ether

112-34-5 soluble

diethylene glycol, monobutyl ether acetate

124-17-4 98100-70-0

65 g/L

Surfynol 104 126-86-3 8043-35-4

1.5 g/L (20 °C)

propylene glycol, monobenzoate

37086-84-3 14.57-38.2(g/L) at 25°C

Kodaflex TXIB type ester alcohol plasticizer (2,2,4-Trimethyl-1,3-Pentanediol Diisobutyrate)

6846-50-0 1.5mg/L

Surfynol 440 oligomer (Surfynol 104 polyethoxylate oligomer)

9014-85-1 Immiscible with water

dipropylene glycol, monobenzoate isomer

32686-95-6 N/A

dipropylene glycol, dibenzoate

94-51-9 27138-31-4

insoluble

33


Through the agitation variable test, as shown in Figure.. diethylene glycol,

monobutyl ether acetate was extracted about 50 % more with agitation than without

agitation. The extracted compound levels of diethylene glycol, monobutyl ether acetate

were 92.11 ppb with agitation and 59.54 without agitation, respectively. On the other

hand, dipropylene glycol, dibenzoate had similar level of migration in with and without

agitation extraction experiment. Other controlled parameters were 40°C, 1 day incubation,

10% EtOH simulant, and 3mL/Inch² ratio.

Figure 11. Migrant levels of soluble and insoluble compounds of ink-borne by Agitiation

variable

92.11

59.54

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00


ppb


351.20 350.42

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00


ppb


34


Figure 12. shows that both water soluble and insoluble migrants (diethylene

glycol, monobutyl ether acetate and dipropylene glycol, dibenzoate) are around three

times extractable with 95% EtOH simulant solvent than with other simulant solvents. As

known in the variation of the total migrant levels by simulant solvent from Figure 12.,

solvent strength was also significantly affecting factor for water soluble and insoluble

migrant extractions.

Figure 12. Migrant levels of soluble and insoluble compound of ink-borne by Simulant

variable

73.18

265.88

57.90 62.52

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

10% ETOH95% ETOH3% Acetic Acid in Water

Water

ppb


353.87

1406.89

223.71282.28

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00

1600.00

1800.00

10% ETOH

95% ETOH

3% Acetic Acid in Water

Water

ppb


35

2.3. Time variable

On the time variable experiments, the data showed that incubating duration had

slight affect for water soluble and insoluble extractatbles, as shown at Figure 13. The

figure indicated that the level of diethylene glycol, monobutyl ether acetate had decreased

slightly after 10 days incubation than 4 days experiments. There could be degradation or

change of diethylene glycol, monobutyl ether acetate to diethylene glycol, monobutyl

ether due to its stability. On the other hand, dipropylene glycol, dibenzoate increased

slightly by longer extraction.

Figure 13. Migrant levels of soluble and insoluble compounds of ink-borne by Time

variable

79.35

110.32

85.98

0.00

20.00

40.00

60.00

80.00

100.00

120.00


ppb


335.93

394.41418.27

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

500.00


ppb


36


Figure 14. shows that generally the higher temperature extracted the more

extractables on both water soluble and insoluble compounds except at 60°C diethylene

glycol, monobutyl ether, 117.90 ppb w/v which was higher than extracted level at 80°C.

Diethylene glycol, monobutyl ether was not found at 25°C extraction experiment.

Figure 14. Migrant levels of soluble and insoluble compounds of ink-borne by

Temperature variable


0.00

73.18

117.90

94.66

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

25 ℃ 40 ℃ * 60 ℃ 80 ℃

ppbdiethylene glycol, monobutyl ether

acetate

144.67

353.87

516.43

680.69

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

25 ℃ 40 ℃ * 60 ℃ 80 ℃

ppbdipropylene glycol, dibenzoate

37

2.5. Solvent Volume/Surface Area Ratio (mL/Inch²) variable

As shown on Figure 15., migrant levels of soluble and insoluble compounds of

ink-borne by solvent volume/surface area ratio (mL/Inch²) had similar pattern. With the

normalized unit (ng/cm²), migrant levels increased gradually along with the increment of

solvent volume/surface area ratio (mL/Inch²). To soluble substrate, diethylene glycol,

monobutyl ether acetate, migrant level of 10 mL/Inch² was 48.85 ng/cm² which was less

than double of 1 mL/Inch², 27.06 ng/cm². To insoluble compounds, dipropylene glycol,

dibenzoate, migrant level of 10 mL/Inch² was 217.18 ng/cm² which was slightly more

than double of 1 mL/Inch², 94.05 ng/cm².

Figure 15. Migrant levels of soluble and insoluble compounds of ink-borne by Solvent

volume/Surface area Ratio (mL/Inch²) variable (ng/cm² unit)

27.06

38.10 37.56

48.85

0.00

10.00

20.00

30.00

40.00

50.00

60.00

1 mL/Inch²

3 mL/Inch²

5 mL/Inch²

10 mL/Inch²

ng/cm2diethylene glycol, monobutyl ether

acetate

94.05

169.01159.38

217.18

0.00

50.00

100.00

150.00

200.00

250.00

300.00

1 mL/Inch²

3 mL/Inch²

5 mL/Inch²

10 mL/Inch²

ng/cm2dipropylene glycol, dibenzoate

38

B. Data Analysis of Migrants from UV/EB Curable Packaging

The data of single side cell extraction of EB/UV cured carton board packaging are

shown on Table 11. and Figure 16. A number of EB-ink and coating-borne were

extracted by food contact side cell extraction. TMPTA and combined eo-TMPTA

oligomers exceeded the FDA threshold of 50 ppb w/v at almost all of our experiments.

There were couple of peaks confliction between TMPTA and d-10 anthracene at

experiment number in Table.. In these cases, internal standard, d-10 anthracene, was

substituted with c-22 docosane.

Table 11. Detected representative extractables of EB/UV curable packaging

1 Diethylene glycol monobutyl ether (Dowanol DB)

2 Hydroquinone methyl ether (MEHQ inhibitor)

3 Azepan-2-one (Caprolactam)

4 Ethoxylated TMPTA oligomer (EO-TMPTA)

5 2,6-di-t-butylphenol (antioxidant)

6 Hexanediol diacrylate (HDDA)


8 N-octylpyrrolidinone

9 Tripropylene glycol, diacrylate (TPGDA)

10 D-10 anthracene (internal standard)

11 Trimethylolpropanetriacrylate (TMPTA)

12 Benzyl, dimethyl ketal (BDK, UV-photoinitiator)


14 n-c22 Docosane(internal standard)

39

Figure 16. C

hromatograph of E

B/U

V curable packaging extraction

* N

umbered com

pounds on the chromatograph are listed on T

able 11.

** Chrom

atograph of experiment num

ber 3-1 on Table 8. ; W

ith agitation, 1 day, 10% E

TO

H, 40 ºC

, 3mL

/in² (agitation, extraction duration, food sim

ulant, temperature, and solvent/surface ratio, respectively

40

3. Total migrants (ppb) of “EB/UV CURABLE” packaging system by conditions


Through the agitation variable test, holding other factors constant 1 day, 10%

ETOH, 40 ºC , 3mL/in² (extraction duration, food simulant, temperature, and

solvent/surface ratio respectively), the total migrant levels were 662.86 ppb with agitation

and 558.94 ppb without agitation, respectively. As shown in Figure 17., the test with

agitation extracted slightly more total extractables than without agitation.

Figure 17. Total migrant level of EB/UV curable packaging extraction by agitation

variable

* 40 ºC data is duplicated from the Solvent Volume/Surface Area Ratio (mL/Inch²) variable experiment because of same parameter conditions.

662.86

558.94

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

with Agit.* without Agit.


41


Through the simulated solvent variable experiments for EB/UV curable

packaging, the total migrant levels were 626.90 ppb with 10% EtOH, 4892.96 ppb with

95% EtOH, 582.35 ppb with 3% Acetic Acid in Water, and 556.17 ppb with Water,

respectively. Those data showed that the solvent strength also had a significant effect on

EB/UV curable packaging extraction. The simulated solvent 95% EtOH extracted about 8

times of migrants than the other solvents, with holding other parameters constant, 1 day,

with agitation, 40 ºC , 3mL/in² (extraction duration, agitation, temperature, and

solvent/surface ratio respectively).

Figure 18. Total migrant level of EB/UV curable packaging extraction by simulant

variable

626.90

4892.96

582.35 556.17

0.00

1000.00

2000.00

3000.00

4000.00

5000.00

6000.00

10% ETOH 95% ETOH 3% Acetic Acid in Water

Water


42

3.3. Time variable

Through the time variable tests, holding other factors constant - 10% ETOH, with

agitation, 40 ºC , 3mL/in² (food simulant, agitation, temperature, and solvent/surface ratio

respectively) -, the total migrant levels are 626.90 ppb with 1 day extraction, 721.55 ppb

with 4 days, and 873.37 ppb with 10 days, respectively, as shown on Figure 19. As

incubation time increased, the level of total migrants rose. 10 days experiment had about

1.4 times total migrant level than 1 day experiment. This is a slight difference. The

migrant level of 10 days extraction is close to the recommended level for FDA test.

Figure 19. Total migrant level of EB/UV curable packaging extraction by time variable

* “24 hours” data is duplicated from the Simulated Solvent Variable experiment (10% EtOH) because of same parameter conditions.

626.90

721.55

873.37

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

800.00

900.00

1000.00

24 Hours* 4 Days 10 Days

ppb

Total Migrants (ppb)

43


As shown on Figure 20., levels of total migrants of EB/UV curable packaging

extraction increased progressively by temperature increment. With holding other

variables were constant - 1 day, with agitation, 10% ETOH, 3mL/in² (extraction duration,

agitation, food simulant, and solvent/surface ratio respectively)-, the total migrant levels

are 478.81 ppb at 25 ºC, 626.90 ppb at 40 ºC, 745.08 ppb at 60 ºC, and 1066.73 ppb at 80

ºC, respectively.

Figure 20. Total migrant level of EB/UV curable packaging extraction by Temperature

variable

* 40 ºC data is duplicated from the Simulated Solvent Variable experiment because of same parameter conditions.

478.81

626.90

745.08

1066.73

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

25 ℃ 40 ℃ * 60 ℃ 80 ℃


44

3.5. Solvent Volume/Surface Area Ratio (mL/Inch²) variable

As shown on Figure 21., The ratio of solvent volume per surface area (mL/Inch²)

variable experiments showed that total migrant levels of UV/EB cured printing

extractables decreased on ppb (w/v) unit as the ratio increased. However, when the unit

was normalized onto ng/cm², total migrant level of extractables increased gradually as the

increment of the ratio, as shown on Figure 22.

Figure 21. Total migrant level of EB/UV curable packaging extraction by Solvent

Volume/Surface Area Ratio (mL/Inch²) variable (ppb w/v unit)

1205.02

662.86

437.25377.03

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

1400.00



45

Figure 22. Total migrant level of EB/UV curable packaging extraction by Solvent

Volume/Surface Area Ratio (mL/Inch²) variable (ng/cm²)

189.02

311.94342.94

591.43

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00


ng/cm2Total Migrants (ng/cm²)

46

4. Comparison of Soluble and Insoluble Extractables from UV/EB Cured

Packaging

The comparisons between water soluble and insoluble migrants of UV/EB cured

packaging extract experiment were performed in order to identify the differences of

extractability by parameters. The water solubility of each extractable from UV/EB cured

packaging is listed on Table 12. For the representatives of water soluble and insoluble

compounds, caprolactam (CAS# 105-60-2) and 2,6-di-t-butylphenol (antioxidant) (CAS#

128-39-2, 19126-15-9 or 118-82-1) were chosen, respectively. Caprolactam is one of the

highest water soluble compounds among the extractables. It has the water solubility of

820g/L at 20°C (Wikipedia, 2010). 2,6-di-t-butylphenol (antioxidant) (CAS# 128-39-2,

19126-15-9 or 118-82-1) is one of water insoluble extractables from UV/EB cured

packaging extraction, distinctly. Although, both of water soluble and insoluble

representatives - caprolactam and 2,6-di-t-butylphenol respectively - were extracted in

only infinitesimal amount, which were less than FDA regulation -50 ppb w/v- for Non-

GRAS compound to become food additives, at almost all of our experiments, those

migrants were still significant indicators for the extraction tests. It is because those

compounds are of integral substances for UV/EB curable ink.

47

Table 12. Solubilities of migrants of UV/EB Curable packaging

CAS Number Water Solubility

Other Solubility

diethylene glycol monobutyl ether (Dowanol DB)

112-34-5 Soluble, Miscible Ether, Alcohol, Aceton, Benzene

hydroquinone methyl ether (MEHQ inhibitor)

150-76-5 Soluble, 40g/L

(25℃)

caprolactam 105-60-2 Highly Soluble,

820g/L (20℃)

2,6-di-t-butylphenol (antioxidant)

128-39-2 19126-15-9 118-82-1 (ANTIOXIDANT SK-702)

Insoluble, NEGLIGIBLE

methanol, ether

hexanediol diacrylate (HDDA)

13048-33-4 88250-32-2 (SR 238)

<0.1 mg/mL @ 18°

N-octylpyrrolidinone 2687-94-7 1g/L (20℃) organic solvent

tripropylene glycol, diacrylate (TPGDA)

42978-66-5 0.036 g/100 mL

(25℃)

trimethylolpropanetriacrylate (TMPTA)

15625-89-5 15624-09-5 72269-91-1 (Saret 351)

Soluble

benzyl, dimethyl ketal (BDK, UV-photoinitiator)

24650-42-8 (PHOTOCURE 651)

74-91-8 (IR

651)

Insoluble

dibutyl phthalate

84-74-2 84-69-5 (Diisobutyl Phthalate) 784-74-2

Slightly soluble SOLVENT, 0.013 g/L Insoluble

ethoxylated TMPTA oligomer (EO-TMPTA)

28961-43-5 N/A

48


Through the agitation variable experiments, there were opposite results for water

soluble and insoluble migrants. As shown on Figure 23., water soluble extractable,

caprolactam, was extracted in level of 8.44 ppb with agitation, whereas 4.44 ppb without

agitation. With agitation, 1.9 times more caprolactam was detected than without agitation.

On the other hand, insoluble compound, 2,6-di-t-butylphenol, was extracted 1.48 ppb

with agitation, whereas 3.65 ppb without agitation which is 2.47 times more than with

agitation.

Figure 23. Migrant levels of soluble and insoluble compounds of UV/EB curable

packaging by Agitiation variable

8.44

4.44

0.00

2.00

4.00

6.00

8.00

10.00

12.00


ppbCaprolactam (ppb)

1.48

3.65

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50


ppb2,6‐di‐t‐butylphenol (ppb)

49


Figure 24. shows that simulant is a significant affecting factor to both soluble and

insoluble compounds of UV/EB curable packaging. With 95% EtOH, both caprolactam

and 2,6-di-t-butylphenol were extracted about 10-15 times more than other simulants

even though both soluble and insoluble compounds were detected in inconsiderable

amount to be treated as food additives. Both soluble and insoluble compounds had similar

patterns in simulated solvent variable experiments.


packaging by Simulated Solvent variable

2.96

39.46

3.15 2.12

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

10% ETOH95% ETOH 3% Acetic Acid in Water

Water


1.34

19.35

1.48 1.27

0.00

5.00

10.00

15.00

20.00

25.00

10% ETOH 95% ETOH 3% Acetic Acid in Water

Water


50

4.3. Time variable

As shown in Figure 25., levels of both water soluble and insoluble compounds,

caprolactam and 2.6-di-t-butylphenol respectively, increased by the increment of

incubating duration. Especially, caprolactam was significantly sensitive in extraction time,

which levels were 19.44 ppb with 10 days, 9.85 ppb with 4 days, and 2.96 ppb with 1 day

extraction, repectively. The migration level with 10 days, 19.44 ppb, was about 6.6 times

than that with 1 day. However, for water insoluble compound, the variation of migration

levels by time variable was slight.


packaging by Time variable

* “24 Hours” data is duplicated from the Simulated Solvent Variables experiment because of same parameter conditions.

2.96

9.85

19.44

0.00

5.00

10.00

15.00

20.00

25.00



1.341.57

3.28

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50



51


Through temperature variable experiments, as we expected, the higher

temperature extracted the more exractables. For both soluble and insoluble compounds of

UV/EB curable packaging, with 80°C, extractables were detected in significantly profuse

amount than others. However, with other temperatures, there was a gradual increment of

extracted level in soluble compound, whereas there was no significant difference in

insoluble compounds.


packaging by Temperature variable


0.282.96

11.14

40.20

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

25 ℃ 40 ℃ * 60 ℃ 80 ℃


1.59 1.34 1.58

10.21

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

25 ℃ 40 ℃ * 60 ℃ 80 ℃

ppb 2,6‐di‐t‐butylphenol (ppb)

52

4.5. Solvent Volume/Surface Area Ratio (mL/INCH2) variables.

After normalization within the range of the errors, we found that caprolactam and

2,6-di-t-butylphenol were extracted in the slight amount. For both soluble and insoluble

compounds, with 3mL/In² (ratio of solvent volume per surface area), extractables were

extracted the most than other ratios, as shown in Figure 27.


packaging by Solvent Volume/Surface Area Ratio (mL/Inch²) variable (ng/cm²)

4.16

6.23

2.73 2.77

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

1 mL/Inch²

3 mL/Inch²

5 mL/Inch²

10 mL/Inch²

ng/cm2

Caprolactam (ng/cm2)

0.75

2.25

0.91

1.26

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

1 mL/Inch²3 mL/Inch²5 mL/Inch² 10 mL/Inch²

ng/cm2

2,6‐di‐t‐butylphenol (ng/cm2)

53

VI. CONCLUSION

Five factors affecting extraction efficiency onto both conventional ink printed

packaging and UV/EB cured packaging were evaluated. For both conventional ink

packaging extraction and UV/EB cured packaging extraction, the simulants were the

most affectable factor than others. Nevertheless, time, temperature, and solvent volume to

surface area ratio variables had also significant influence on migration. By the regression

analysis of those experiment data, the more accurate effect of each parameter would be

estimated.

Moreover, comparisons of those factors affecting water soluble and insoluble

extractables were performed. During the overall experiments, there were no significant

differences of migration patterns between water soluble and insoluble compounds of both

conventional ink printed and UV/EB cured packaging migrants. For both water soluble

and insoluble migrants, simulated solvent was the most affecting factor to extraction, as

well.

Thus, we suggest the optimized and accelerated testing protocol as on Table 13.

for determining FDA compliance of the conventional ink packaging and the UV/EB

cured packaging. Especially, with agitation, raised temperature as 60°C, simulant volume

to surface area ratio as 5-10mL/Inch², 24-hour extraction instead of 10 days can be safe

and assurable for substitution. Through our experiments, it is proven that the results of

the accelerated testing protocols are also equivalent to those of FDA recommended

protocol.

54

Table 13. Conditions for the 24-hour accelerated testing equivalent to FDA

recommendation

Food Simulant Time Temp. Ratio of Simulant Volume to Surface Area (mL/ In²)

Accelerated Conditions 10% EtOH 24 hours 60°C 5-10

95% EtOH 24 hours 40-60°C 5-10

FDA Recommendation 10% EtOH 10 days 40°C 10

95% EtOH 10 days 40°C 10

55

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