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Phthalate Plasticizers

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					Phthalate Plasticizers




               CE 435 Introduction to Polymers
                                  Brian Amato
                                    Sarah Karl
                                     Carla Ng
  Timeline (history)

                                                         European
                                      IARC Re-classifies Parliament calls
First       Phthalates   DEHP
                                        DEHP as non-     for alternatives
Plasticizer Introduced   Declared
                                        carcinogenic     to phthalates
                         Carcinogenic



  1860      1930         1980’s               1998             2001
Outline
  Introduction              Health
                             Concerns
  A Plasticizer
   Timeline                  Science and
                             Industry
  Theory
                             Response
  What are                  Government
   Phthalate                 Positions
   Plasticizers
     (and why do we care)?   Health or
                             Hype?
    The Plasticizer
     Market                  Conclusions.
Introduction
  What is a plasticizer?
  Where are they commonly found?
General Definition

  A Plasticizer is a polymer additive.
  Effect on polymer properties: an
   important distinction from other
   additives.
  Increases polymer flexibility, elongation
   or workability.
Types of Plasticizer (I)
  Internal    vs. External
      Internal plasticization occurs via
       chemical interactions.
         Copolymerization   is one type of internal
         plasticization.
      External plasticization occurs via
       physical interactions.
         Externalis the most common: cost, ease
         of processing.
Types of Plasticizer (II)
  Primary   vs. Secondary
    Primary  Plasticizer affects resin
     properties.
    Secondary is a “Plasticizer-
     plasticizer”: used to increase the
     effectiveness of the primary
     plasticizer.
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.
     tubing.
    Vinyl floors.
    Synthetic leather.
    Electrical Cables.
Plasticizers All Around Us
  Non-PVC    Uses
    Liquid plasticizers used in coating to
     protect car chassis.
    Paints.

    Printing Inks.

    Adhesives.
Plasticizer Theory
 Three Mechanisms:

 •   Lubricity Theory
 •   Gel Theory
 •   Free-Volume Theory
Lubricity Theory
   Assumes the rigidity of the resin (pure
    polymer) arises from “intermolecular
    friction.”
   Plasticizer molecules are introduced on
    heating.
   At room temperature, these molecules
    act as lubricants for the polymer chains.
Gel Theory
  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
   Lubricity Theory.
Free-Volume Theory
  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
   temperature.
Choosing Your Plasticizer
  Effectiveness Considerations
    How Much Plasticizer Necessary
    Interaction Parameters: Our Friends Flory
     and Huggins.
  Application Considerations:
    Temperature Range
    Degree of Flexibility Desired

  Phthalates:   the #1 Choice for PVC
Plasticizer Market
    Yearly Plasticizer Production
        Plasticizers are the largest class of polymer
         additives produced.
        Global volume of 10 billion lbs in 1999
        $5 billion value with 2-3% yearly market growth.
  <1% of Phthalates produced are used in
   children’s toys.
  10% are used in medical applications.
Phthalate Plasiticizers
    What are they Chemically Speaking?
      A Phthalate ester derived from phthalic
       acid by an esterification reaction.
      Mechanism: phthalic acid to phthalate ester



                          H
Phthalate Plasiticizers
    Properties
      Colorless
      Oily liquid ( like vegetable oil)

      Ester odor

      High boiling point

      Inert, and very stable over long periods
Phthalate Plasiticizers
      Types:
      DEHP (Di(2-ethylhexyl) phthalate)
         Structure
Phthalate Plasiticizers
      Properties of DEHP
         Insoluble in H2o
         Soluble in mineral oil, hexane, most organic
          solvents
         Easily dissolved in bodily fluids, such as saliva
          and plasma.
         Boiling point: 386.9oc

         Density: 0.9732 g/L

         Molecular weight: 390.5618 g/mol
Phthalate Plasiticizers
      Uses of DEHP:
        Used in medical devices
        Toys

        Pacifiers

        Vinyl Upholstery

        Food containers

        Table cloths

        Shower curtains

        Raincoats ( and the list goes on……..)
Phthalate Plasiticizers
      DINP (Diisononyl Phthalate)
         Structure
Phthalate Plasiticizers
      Properties of DINP
         Insoluble in H2O
         Soluble in most organic solvents

         Boiling point: not available

         Density: not available

         Molecular weight: 418.6 g/mol
Phthalate Plasiticizers
      Uses of DINP:
           Replaced DEHP in toys when initially
            determined to be carcinogenic.
Uses of DEHP in Medical
Devices
    Phthalates (DEHP) in Medical Devices:
        Blood Storage Bags
        IV Bags
        Catheters
        Dialysis tubing
  Benefits:
        Why is DEHP used?
             Cost efficiency
             Safety
             Resists kinking
Uses of DEHP in Medical
Devices
    Long shelf life
    Transparent

    Withstands high pressures without leaking

    Withstands both freezing and steam
     sterilization
    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
Devices
    Other convincing reasons
      DEHP contributes to the extended storage
       of red blood cells.
      Doubles shelf life compared to other
       plasitcizers.
      5-7 billion patient days of exposure without
       any reported adverse health effects
Health Concerns
    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
         carcinogenic effect.
        Scientific papers give rise to concerns of reduced
         sperm counts from phthalates, due to the
         endocrine disruption theory.
Health Concerns
    Concerns Abated:

      The International Agency for Research on
       Cancer changes reverses its position on
       DEHPs Carcinogenic effects.
      Endocrine disruption theory in regards to
       DEHP disproved.
Health Concerns
  Research with laboratory rats suggests
   sexual developmental issues by
   reducing fetal testosterone levels
  Testosterone levels were reduced to
   female levels
  How does this relate to Humans? Or
   does it?
Health Concerns
  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
  Species specificity?
Health Concerns
  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
   exposure
  8 out of every 1000 girls suffer from this
   condition
Other Health Concerns Aside
From Medical
    Plasticizers and Infants:
        Toys and Teethers
    Plasticizers in Food:
        Packaging Film
Industry/Science Response
    In response to concerns about the safety of
     plasticizers, industry and science worked
     together to study the effects and disseminate
     information.
        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.
Government Decisions
    Europe
        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
         of phthalates.
Government Decisions
    United States
        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

     Greenpeace
         Have come out against the Vinyl industry in
          general, due to their belief in the toxicity of
          chlorine.
     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
  Benzoates
  Citrates
  DINA
  EPZ (Edible Plasticizer)
  TXIB Plasticizer (hard oil)
  168 Plasticizer
  DEHP is still used in medical devices although
   alternatives are being explored
Conclusion
  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.
References

 1.http://www.fda.gov/cher/minutes/plast10108
     99.html
 2.http://www.pirg.org/masspirg/enviro/sw/pvc
 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, Di-2-ethylhexyl
    Phthalate, and Clofibrate in Cynomologus
     Monkeys.” Toxicological Sciences 56,
    181-188
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
7.http://www.cei.org
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
ill p165
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
  pp.369-371, 1999
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-
  293, 1998

				
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