Can Coatings Primer and Safety Assessment: Communicating Evidence of Absence
Conflict of Interest Statement
Mark Maier is currently a paid consultant and former employee of the Valspar Corporation. This educational presentation is made solely by and on behalf of Sheperian Toxicology, LLC who is responsible for its content. Mark Maier received no compensation from Valspar Corporation for this work.
Fair Use Notice Graphics in this presentation are/were publicly available and are used solely for educational purposes and may not be used otherwise. Source credit is given for graphics in this presentation when available.
Different Cans, Different Coatings
Food & Beverage Ends‒Coil Coating
National Coil Coating Assn
Valspar Corp.
Food Can Manufacturing Two Piece
Side Seam Three Piece
Beverage Can Multi-Step Engineering Marvel
“Engineer Guy” Bill Hammack, Univ. Illinois The Ingenious Design of the Aluminum Beverage Can
YouTube: https://www.youtube.com/watch?v=hUhisi2FBuw
Demands Placed on Coatings
“Engineer Guy” Bill Hammack, Univ. Illinois The Ingenious Design of the Aluminum Beverage Can
Beverage Can Manufacturing
Crown Beverage Packaging, Inc.
Visy Industries Holdings Pty Ltd
Beverage Can Ends
Han, J. et al. Appl. Erg 2008. 39: 150
Pressco Technology , Inc.
Pressco Technology Inc.
End Punched
from Coated
Coil
Tooling and Riveting
Coating must maintain seal after tooling and riveting
Migration from Film
INCDTIM Romania
Migration Chromatogram
Innovations in Food Safety, Shelf Life and Food Safety
If BPA is Replaced, What Choices are Available?
Acrylic Vinyl Oleo PE 1 PE II
Beverage End
Beverage Body 3PC Food Food D&I Food
DRD Food End Food EZO Closure
BPA BASED EPOXY
Wish List for BPA Replacement Coating
1. Epoxy Performance–must be epoxy chemistry
2. No estrogenic monomers
3. Total Migration–< 50 ppm (0.5 mg/in2); < 1,000 Da.
4. Specific Migrations–< 0.5 ppb (TTC-based)
5. Industrial Scale Raw Materials
6. Acceptable cost
Step 1 Find New Materials
Valspar Corp
Valspar Corp
Most New Coatings were Made Using Pre-Authorized Materials Listed “in the Box”
Epoxy Monomers in the Box were Estrogenic
New Molecules Were Needed
Performance vs. Hazard
Chemical Reactivity
No Biological Hazard
Molecules were Needed that React with Each Other
…but physiologically, do…
…And
What Can be Learned from BPA Epoxy?
C. 4,4'-methylenediphenol functionality found in BPA is essential
A. Bisphenol A is estrogenic in vitro 1
2
B. There are two sources of BPA in the polymer synthesis
A. Is There a Non-Estrogenic Bisphenol?
Bisphenols are the only commercially viable source for 4,4'-methylenediphenol functionality.
BPA
B. Could the Bisphenol be Taken Out of the Last Step?
C. V70 Route of Synthesis
4,4'-methylenediphenol functionality
Why Should People Believe these Molecules are Safe?
Just because I said so?
Prescriptive Approaches were Tried
defa
ult
Force Fit
Green Screen TI
PED
co
ntra
dict
misunderstand
Excessive
Keeping in Mind Reactants ≠ Products
≠
≠
Sodium
Chlorine
GreenScreen®
Designing endocrine disruption out of the next generation of chemicals. Schug et al. Green Chem., 2013,15, 181-198
“While in silico and in vitro assays offer less costly starting points, in vivo assays are necessary to conclude that a
chemical is unlikely to have EDC activity.” http://www.tipedinfo.com/tiped_tier/guiding-principles/
?
Tiered Protocol for Endocrine Disruption (TiPED)
defa
ult
Force Fit
Green Screen
TIPE
D
cont
radi
ct
misunderstand
Excessive
Do Your Own Science First Table III. Summary of analysis and assay results for ER (read-across target) and read-across sources TMBPFDGE, BADGE, NOGE and oligo-BFDGE.
Green = Negative experimental result, Red = Positive experimental result RA = Read-across (only applies to “target” substance, ER) ND = no data available Numbers indicate relative potency in the standard Ames assay (Table IV)
ER TMBPFDGE BADGE NOGE oligo-
BFDGE In vitro
MLA -S9 culture ND MLA +S9 culture ND
TA-98 -S9 plate TA-100 -S9 plate
TA-1535 -S9 plate TA-1537 -S9 plate
TA-98 +S9 plate TA-100 +S9 plate 3.9 4.7 25.0
TA-1535 +S9 plate 33.6 35.5 117.8 TA-1537 +S9 plate
Mutagenicity CAESAR Model Model Model Model Model Model TA-98 -S9 mpf RA ND ND ND
TA-100 -S9 mpf RA ND ND ND TA-1535 -S9 mpf RA ND ND ND TA-1537 -S9 mpf RA ND ND ND
TA-98 +S9 mpf RA ND ND ND TA-100 +S9 mpf RA ND ND ND
TA-1535 +S9 mpf RA ND ND ND TA-1537 +S9 mpf RA ND ND ND
GS GADD45 -S9 culture RA ND ND ND GS GADD45 +S9 culture RA ND ND ND
In vivo
Micronucleus Oral Oral Oral ND Oral Comet Assay or other DNA damage Oral Oral Oral Oral Oral
Chromosomal aberration RA ND Oral Oral Oral
Transgenic Mouse RA ND ND Oral
Carcinogenicity RA ND ND Dermal
Carcinogenicity Model Model Model Model Model Carcinogenicity QSAR QSAR QSAR QSAR QSAR
Repeated Oral Dose (mg/kg-bw/d)
28-56Day NOAEL = 100 LOAEL = 300 Repro/Dev
NOAEL = 300
ND
Chronic NOAEL = 15
Subchronic NOAEL = 50; LOAEL = 250
ND
90-Day NOAEL = 250 (limit dose)
14-day NOAEL =
300; LOAEL = 1000
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(Listing does not necessarily imply endorsement, approval, or further discussion)
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Regulatory
Ask for Help
Then… Let Your Best Critics Review Your Work, do Their Own, and Try to Prove You are Wrong.
Go Beyond …
Female mammary glands (right side) were whole-mounted for three-dimensional inspection
Terminal end buds, branching, budding and ductal extension were examined; lymph node was used as point of reference
Qualitative analysis – Absence – Minimal – Slight – Moderate – Marked – Abundant
Go Beyond …
Extract
Concentration
References
“Engineer Guy” Bill Hammack, Univ. Illinois. The Ingenious Design of the Aluminum Beverage Can. https://www.youtube.com/watch?v=hUhisi2FBuw
Soto AM, Schaeberle C, Maier MS, Sonnenschein C, Maffini MV. Evidence of
Absence: Estrogenicity Assessment of a New Food-Contact Coating and the Bisphenol Used in Its Synthesis. Environ Sci Technol. 2017 Feb 7; 51(3):1718-1726.
Acknowledgements
Tom Mallen, Ronnie Weaver, and everyone at Valspar
Maricel Maffini–Independent Consultant Ana Soto Lab–Tufts University Food and Beverage Brand Owners Can Makers …and
…Talented Scientists & Engineers from these Organizations (Listing does not necessarily imply endorsement or approval)
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