CE 435 Introduction to Polymers
IARC Re-classifies Parliament calls
First Phthalates DEHP
DEHP as non- for alternatives
Plasticizer Introduced Declared
carcinogenic to phthalates
1860 1930 1980’s 1998 2001
Timeline Science and
What are Government
(and why do we care)? Health or
What is a plasticizer?
Where are they commonly found?
A Plasticizer is a polymer additive.
Effect on polymer properties: an
important distinction from other
Increases polymer flexibility, elongation
Types of Plasticizer (I)
Internal vs. External
Internal plasticization occurs via
Copolymerization is one type of internal
External plasticization occurs via
Externalis the most common: cost, ease
Types of Plasticizer (II)
Primary vs. Secondary
Primary Plasticizer affects resin
Secondary is a “Plasticizer-
plasticizer”: used to increase the
effectiveness of the primary
Plasticizers In PVC
Cling-film for food Toys: teethers for
packaging. infants and Ernie’s
Medical devices: favorite bath-time
blood bags, IV bags, companion.
Plasticizers All Around Us
Liquid plasticizers used in coating to
protect car chassis.
• Lubricity Theory
• Gel Theory
• Free-Volume Theory
Assumes the rigidity of the resin (pure
polymer) arises from “intermolecular
Plasticizer molecules are introduced on
At room temperature, these molecules
act as lubricants for the polymer chains.
Resin-resin interactions occur at
“centers of attachment.”
Plasticizer molecules break these
interactions and masks the centers from
each other, preventing re-formation.
This theory is not sufficient to describe
interaction– should be combined with
Free volume: “internal space” available
in the polymer for the chains to move.
This volume increases sharply at the
glass transition temperature, Tg.
Plasticizer is meant to decrease the
glass transition temperature, imparting
increased flexibility to polymer at room
Choosing Your Plasticizer
How Much Plasticizer Necessary
Interaction Parameters: Our Friends Flory
Degree of Flexibility Desired
Phthalates: the #1 Choice for PVC
Yearly Plasticizer Production
Plasticizers are the largest class of polymer
Global volume of 10 billion lbs in 1999
$5 billion value with 2-3% yearly market growth.
<1% of Phthalates produced are used in
10% are used in medical applications.
What are they Chemically Speaking?
A Phthalate ester derived from phthalic
acid by an esterification reaction.
Mechanism: phthalic acid to phthalate ester
Oily liquid ( like vegetable oil)
High boiling point
Inert, and very stable over long periods
DEHP (Di(2-ethylhexyl) phthalate)
Properties of DEHP
Insoluble in H2o
Soluble in mineral oil, hexane, most organic
Easily dissolved in bodily fluids, such as saliva
Boiling point: 386.9oc
Density: 0.9732 g/L
Molecular weight: 390.5618 g/mol
Uses of DEHP:
Used in medical devices
Raincoats ( and the list goes on……..)
DINP (Diisononyl Phthalate)
Properties of DINP
Insoluble in H2O
Soluble in most organic solvents
Boiling point: not available
Density: not available
Molecular weight: 418.6 g/mol
Uses of DINP:
Replaced DEHP in toys when initially
determined to be carcinogenic.
Uses of DEHP in Medical
Phthalates (DEHP) in Medical Devices:
Blood Storage Bags
Why is DEHP used?
Uses of DEHP in Medical
Long shelf life
Withstands high pressures without leaking
Withstands both freezing and steam
Collapse when empty, therefore they do
not have to be injected with sterile air to
replace the blood or fluid being withdrawn.
Uses of DEHP in Medical
Other convincing reasons
DEHP contributes to the extended storage
of red blood cells.
Doubles shelf life compared to other
5-7 billion patient days of exposure without
any reported adverse health effects
DEHP is a Carcinogen?
Studies in the early 1980’s on the effects of DEHP
on rodents by U.S National Toxicology Program
and International Agency for Research show
Scientific papers give rise to concerns of reduced
sperm counts from phthalates, due to the
endocrine disruption theory.
The International Agency for Research on
Cancer changes reverses its position on
DEHPs Carcinogenic effects.
Endocrine disruption theory in regards to
Research with laboratory rats suggests
sexual developmental issues by
reducing fetal testosterone levels
Testosterone levels were reduced to
How does this relate to Humans? Or
Tests were performed on Monkeys who
are primates like humans
DEHP & DINP were both used and
yielded no noticeable biological or
physical responses to treatment
Should this give manufacturers of Phthalates
a clear conscience? Not Necessarily
Researchers in Puerto Rico claim that
premature breast development of young girls,
thelarche, may be the result of Phthalate
8 out of every 1000 girls suffer from this
Other Health Concerns Aside
Plasticizers and Infants:
Toys and Teethers
Plasticizers in Food:
In response to concerns about the safety of
plasticizers, industry and science worked
together to study the effects and disseminate
Toy manufacturers voluntarily replaced phthalates
and, in some cases, PVC.
European Chemical Industry Council (CEFIC)
forms EMSG, ECPI.
ECPI conducts joint research with Chemical
Manufacturer’s Association (CMA) in the U.S.
The EPA, the Vinyl Institute and NIH provide
information to consumers about their rights and
the safety of phthalate-containing products.
Several European nations banned the use of
phthalates in toys.
International Agency for Research on Cancer
classifies DEHP as carcinogenic, then reverses
their decision in February of 2000.
As late as April of this year, the European
Parliament calls for the use of substitution
products. Seek to eliminate environmental effects
The EPA regulates the amount of DEHP and DINP
in the environment. They are listed as toxic
chemicals subject to reporting requirements under
the Pollution Prevention Act (PPA).
The FDA has issued no warnings on phthalate
plasticizers, and does not consider them to be
carcinogenic. No action has been taken by the US
government in issues outside of the environmental
aspect of phthalates. Any consumer product
industry response has been voluntary.
Health or Hype?
Evaluating the Positions of the Major Players
Have come out against the Vinyl industry in
general, due to their belief in the toxicity of
The Vinyl Institute
Seeks to disseminate information about the
importance of vinyl products in our life and the
evidence that they are not harmful to humans.
Alternatives to Plasicizers
EPZ (Edible Plasticizer)
TXIB Plasticizer (hard oil)
DEHP is still used in medical devices although
alternatives are being explored
Michael Fumento of the Hudson Institute:
“If your child eats toys, phthalates are the
least of your worries!”
Conflicting evidence about the effects of
phthalates in humans and the environment.
Possible consequences for the food chain.
In the end, it is up to consumers to educate
themselves and make informed decisions.
3.Abbott, Barbara D. (2000). “The Plasticizer
Diethylhexyl Phthalate Induces
Malformations by Decreasing Fetal
Testosterone Synthesis during Sexual
Differentiation in the Male Rat.”
Toxicological Sciences 58, 339-349
4.Ackley, David C. (2000). “Effects of Di-isononyl
Phthalate, and Clofibrate in Cynomologus
Monkeys.” Toxicological Sciences 56,
5.Carraher, Charles E. Polymer Chemistry: an
Introduction 4th Ed. (1996) Marcel Dekker, Inc. NY,
New York 424-426
6.Durodie, Bill “Poisonous Propaganda, Global Echoes
of an Anti-Vinyl Agenda.” Competitive Enterprise
Institute, July 2000
8.Christensen, Jackie Hunt. Toxic Toy Story.
Mothering. Sept. 1998 p38 (1)
9.O’Mara, Peggy. Winning the Fight Against
PVC. Mothering. March 1999 p35 (1)
10.Raloff, J. Girls May Face Risks from
Phthalates. Science News. Sept 9, 2000 v158
11.Ullman’s Encyclopedia of Industrial
Chemistry, Vol A20 pp439-451, VCH
Publishers, Inc, 1992
12.Woodyatt, K.G. Lambe, K.A. Myers, J.D.
Tugwood and R.A. Roberts, “The Peroxisome
Proliferator (PP) response element upstream
of the human CoA oxidase gene is inactive
among a sample human population:
significance for species differences in
response to PPs.” Carcinogenesis, vol.20 no.3
13.Zacharewski, T.R., M.D. Meek, J.H.
Clemons, Z.F. Wu, M.R. Fielden and J.B.
Matthews, “Examination of the in vitro
and in vivo estrogenic activities of eight
commercial phthalate esters.”
Toxicological Sciences, Vol. 46, pp.282-