Mineral oil and contaminants: theory and
practical solutions for paper & board
3° Congresso Scientifico Nazionale Food Contact Expert
Desenzano del Garda 25 e 26 giungno 2014
Food
Funct. Barrier
Heiko Diehl
BASF SE
Agenda
Functional migration barrier concept
Testing of apolar migrating contaminants – BASF‘s Hexane-test method
Barrier functionality for multiple migrating contaminants
2
Migration of contaminants
- only a paper & board problem ?
Lebensmittel
Primärverpackung
MOSH <C16 MOSH > C16
Schoko Spritzgebäck PP-Tray, PP-Acrylat-Folie
<0,3
<1
Schoko Waffeln
PP-Tray, PP-Acrylat-Folie
<0,2
<0,8
Schoko Waffelröllchen PP-Tray, PP-Folie
2
2
Mandel-Nusskonfekt PP-Tray, PP-Folie
<0,2
<1
Butterkeks Vollmilch PP-Tray, PP-Folie
1
4,3
Gebäckstangen
PP-Folie
1,7
4,2
Dinkelkleie
Papier
58
43
Σ MOSH
<1,3
<1
4
<1,2
5,3
5,9
101
MOAH
<0,1
0,3
1,9
0,4
<0,1
0,5
13
DIPN
<0,05
0,1
0,1
0,1
<0,05
0,3
1,7
Quelle: Ausmaß der Migration unerwünschter Stoffe aus Verpackungsmaterialien aus Altpapier in Lebensmittel, BMELV Okt. 2012
7/1/2014
3
Annex to BfR Recommendation 36
Preconditions for the use of recycled fibers
as raw materials for the production of paper
“..[..].For dry, non-fatty foodstuffs having a large surface area (e.g. flour,
semolina, rice, breakfast cereals, breadcrumbs, sugar and salt),
migration of volatile and hydrophobic substances via the gas phase has
to be considered particularly. This could be compensated by the use
of an appropriate additional packaging.”
 An appropriate packaging should prevent migration
of harmful substances.
 What means volatile, hydrophobic?
As of 01.01.2012
4
Hansen Solubility Parameter (HSP) concept
Determination of the polar nature
of contaminants
: Enthalpy of vaporization
Energy of cohesion
R:
T:
Hildebrandt solubility parameter
Hansen solubility parameter
Gas constant
Temperature
V:
molar volume
Ecoh: energy of cohesion
d:
p:
h:
dispersive (“hydrophobicˮ)
polar
hydrogen bonding
5
Classifying gases, vapors and volatile substances
Map for Contaminants with Gas Phase
Migration Potential at 25°C
δt [MPa] 0,5
n – Alances: C5 – C24
25,0
Photoinitators:
Benzph., 4 – MBP
x
Carbondoxide
“polar”
Gases
Vapors
Volatile substances with gas phase
migration potential vapor pressure < 1hPa
20,0
Phthalates: DMP, DEP,
DBP, DOP, DEHP
x BPA
Liquids, vapor
pressure > 1hPa
Oxygen
15,0
“apolar”
10,0
0
50
100
150
200
250
300
350
400
450
Source: Hansen Solubility Parameters, A User's Handbook, CRC Press Taylor & Francis Group New York 2007, p. 430ff
500
MW [Da]
6
Functional migration barrier concept
How is Regulation for recycl. Plastics ?
Exception for
 plastics made from chemical recycling (de – polymerisation)
 Offcuts and scraps from the production of plastic food contact materials,
that has not been in contact with food or otherwise contaminated
Recycled plastic used behind a plastic functional barrier
as defined by EU 10/2011
7
Functional migration barrier concept
What is a Functional Barrier ?
“..[..]. is a layer within food contact materials or articles preventing the migration
of substances from behind that barrier into the food. Behind a functional barrier,
non-authorised substances may be used, provided they fulfil certain criteria and
their migration remains below a given detection limit.”
Source: EU 10/2011
„How much of contaminant is
within the food?“
Functional barrier requirement fulfilled if:
t b > t Shelf life food
m
D
K
mass transfer
Diffusion coefficient
Partition coefficient
tb
tb
SML
mfood
t SML
P
A
mcont
lag time
specific migration limit
mass of packed food
exposure / time period until SML in food is reaches
Permation rate of contaminant
surface area of packaging
mass contaminant
or
t SML > t Shelf life food
using
tSML =
SML • mfood
P• A
mcont.< SML; m
cont. = P • A • tSML
mfoodl
8
Functional migration barrier concept
BASF – Barrier Design for Food Packaging
e.g.: selective barrier function only to MOSH, MOAH, POSH
9
Functional migration barrier concept
Selected Barrier Materials
Barrier I
ecovio® PS 1606
Barrier II
Polyamide 6 (PA6),
Tradename Ultramid®
Barrier III
New BASF Dispersion
Epotal SP 101 D®
10
Agenda
Functional migration barrier concept
Testing of apolar migrating contaminants – BASF‘s Hexane-test method
Barrier functionality for multiple migrating contaminants
11
Testing of apolar migrating contaminants
Measuring Barrier Performance by determining
Hexane Vapor transmission Rate (HVTR)
It has been detected that n-hexane is a suitable simulant to study the barrier
properties of packaging materials against migration contaminants e.g. mineral oil
saturated hydrocarbons (MOSH) in the range of C12 up to C24.
Substance
n – Pentane
n – Hexane
n – Heptane
n – Octane
n – Nonane
n – Decane
n – Hexadecane
n – Heptadecane
n – Octadecane
n – Eicosane
n – Decosane
n – Tricosane
n – Tetracosane
δd
δp
δhb
[hPa]
[MPa1/2]
[MPa1/2]
[MPa1/2]
570
160
48
14
5
1
<1
<1
<1
<1
<1
<1
<1
14,5
14,9
15,1
15,3
15,5
15,7
16,4
16,5
16,6
16,8
16,9
17,0
17,1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Molar weight Melting point Vaporpressure
[g/mol]
72
86
102
114
128
142
226
240
254
283
311
324
339
[°C]
– 130
– 94
– 79
– 57
– 53
– 30
18
22
27
35
48
47
52
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Testing of apolar migrating contaminants
BASF‘s-Hexane-test method (I)
Semi-quantitative testing method, quantity of hexane vapor that passes under
controlled conditions from an evaporation chamber through the exposed surface
of a packaging sample is determined.
Evaporation Cell
Closure with barrier
mass n – hexane [g]
Card board 300g/m2
10,000
Card board 300g/m2
+ Barrier I, 18μm
Card board 300g/m2
+ Barrier II, 15μm
1000
Card board 300g/m2
+ Barrier III, 15μm
100
10
Sealing
Barrier sample
1
0
8
16
24
t [hrs]
13
Testing of apolar migrating contaminants
“Calibrating” BASF‘s-Hexane-test
method (II)
Hexane vapor transmission rate (HVTR) at various barrier coating
weights, e.g. Barrier II
HVTR[g/m² d]
[mg/ dm²]
1
2100
2000
1900
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
Hexane-Test
MOSH C14-C24
Tenax ®-Test
0,9
MOSH C24-C35
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
6,5
8,2
9,4
12,5
17,7
19
Barrier coating
weight [g/m2]
0
6,5
8,2
9,4
12,5
17,7
19
Auftragsgewicht
[g/m²]
The use of the HVTR-method allows a quick and general classification of mineral
oil barrier materials and shows an adequate correlation to Tenax® food migration test
(DIN EN 14338)
14
Agenda
Functional migration barrier concept
Testing of apolar migrating contaminants – BASF‘s Hexane-test method
Barrier functionality for multiple migrating contaminants
15
Barrier Performance Study “Paper Sachet”
Lag time experiment
16
Barrier Performance Study “Paper Sachet”
Migration Test set up according to DIN EN 14338
Dry food simulant
Tenax®
Test exposure 50 days at 40°C,
simulating 13 months at 23°C
Paper 60gsm
SP 101-D 5gsm
LDPE 15gsm
Contaminants
MOSH/MOAH Σ 400ppm
Actual detection limit
for MOAH (C10-C24): 150ppb
17
Barrier Performance Study “Packaging Films vs. Barrier on
Cardboard ”
Permeation experiment
18
Barrier Performance Study “Packaging Films vs. Barrier on
Cardboard ”
Permeation rates of typical food contaminant
P [µg/d dm²]
HDPE 44µm
at 40°C
Barrier I 23µm
10000
OPP 43µm
1000
100
10
1
1-Methylnaphthalene
C16
DIPN
0,1
> C16
Phenanthrene
0,01
TXIB
Benzophenone
0,001
0
50
100
150
200
250
300
350
400
Mw [Da]
Method: Ewender, J., Welle, F., Franz, R., Permeation of Mineral Oil Components from Cardboard
Packaging Materials through Polymer Films, Packag. Technol. Sci. (2012).
19
Case Study: Shelf life vs. Permeation
of Contaminants, Food example Cereals
t SML > t Shelf life food
tSML =
SML
mfood
t SML
P
A
mcont
SML • mfood
P• A
specific migration limit
mass of packed food
exposure / time period until SML in food is reaches
Permation rate of contaminant
surface area of packaging
mass contaminant
mcont.< SML; m
cont. = P • A • tSML
mfoodl
mCereals = 500g; Acardboard box = 8,9 dm²; shelf life 365 days
t SML at 40°C [d]
Contaminant
Hexadecane
Octadecane
Benzophenone
Tetracosane
Molecular weight
[Da]
226
254
182
338
SML
[ppm]
12 1
4 1
0,6 2
0,6 3
OPP
[43 μm]
6
6
0,3
674
Ultramid ®
[13µm]
13219
2957
3371
3371
Ecovio®
[23µm]
13219
22472
427
3371
1) BfR 2013, 2) BfR XXXVI, 3) worst case JECFA, withdrawn 2012
20
Conclusion
Packaging industry and especially paper & cardboard packaging
industry can benefit from using functional migration barriers to overcome
undesired migration of harmful substances.
The use of the HVTR-method (Hexane Test) allows a quick and general
classification of mineral oil barrier materials and shows an adequate
correlation to Tenax® food migration test (DIN EN 14338)
For paper & cardboard packaging effective and efficient barrier solutions
are available against the migration of volatile substances that show
migration potential.
Using recycled paper board protected with functional migration barriers
is a contribution to sustainable packaging of food.
21
Contact
Heiko Diehl
Global Brand Owner Management
Center for Sustainable Paper Packaging
EP/VB, Paper Chemicals
Phone: +49 621 60-76692
Fax: +49 621 60-6676692
E-Mail: [email protected]
November
2012
22
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