Phthalate Plasticizers

1
Phthalate Plasticizers
CE 435 Introduction to Polymers Brian Amato Sarah
Karl Carla Ng
2
Timeline (history)
European Parliament calls for alternatives to
phthalates
IARC Re-classifies DEHP as non-carcinogenic
FirstPlasticizer
DEHP Declared Carcinogenic
Phthalates Introduced
1860
1930
1980s
2001
1998
3
Outline

• Health Concerns
• Science and Industry Response
• Government Positions
• Health or Hype?
• Conclusions.

• Introduction
• A Plasticizer Timeline
• Theory
• What are Phthalate Plasticizers(and why do we
  care)?
• The Plasticizer Market

4
Introduction

• What is a plasticizer?
• Where are they commonly found?

5
General Definition

• A Plasticizer is a polymer additive.
• Effect on polymer properties an important
  distinction from other additives.
• Increases polymer flexibility, elongation or
  workability.

6
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.
• External is the most common cost, ease of
  processing.

7
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.

8
Plasticizers In PVC

• Cling-film for food packaging.
• Medical devices blood bags, IV bags, tubing.
• Vinyl floors.
• Synthetic leather.
• Electrical Cables.

• Toys teethers for infants and Ernies favorite
  bath-time companion.

9
Plasticizers All Around Us

• Non-PVC Uses
• Liquid plasticizers used in coating to protect
  car chassis.
• Paints.
• Printing Inks.
• Adhesives.

10
Plasticizer Theory

• Three Mechanisms
• Lubricity Theory
• Gel Theory
• Free-Volume Theory

11
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.

12
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.

13
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.

14
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

15
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.
• lt1 of Phthalates produced are used in childrens
  toys.
• 10 are used in medical applications.

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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
17
Phthalate Plasiticizers

• Properties
• Colorless
• Oily liquid ( like vegetable oil)
• Ester odor
• High boiling point
• Inert, and very stable over long periods

18
Phthalate Plasiticizers

• Types
• DEHP (Di(2-ethylhexyl) phthalate)
• Structure

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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

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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..)

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Phthalate Plasiticizers

• DINP (Diisononyl Phthalate)
• Structure

22
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

23
Phthalate Plasiticizers

• Uses of DINP
• Replaced DEHP in toys when initially determined
  to be carcinogenic.

24
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

25
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.

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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

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Health Concerns

• DEHP is a Carcinogen?
• Studies in the early 1980s 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.

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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.

29
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?

30
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?

31
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

32
Other Health Concerns Aside From Medical

• Plasticizers and Infants
• Toys and Teethers
• Plasticizers in Food
• Packaging Film

33
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
  Manufacturers 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.

34
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.

35
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.

36
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.

37
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

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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.

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References

•  
• 1.http//www.fda.gov/cher/minutes/plast1010899.htm
  l
• 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
•  

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• 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
•  

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• 8.Christensen, Jackie Hunt. Toxic Toy Story.
  Mothering. Sept. 1998 p38 (1)9.OMara, 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 p16511.Ullmans Encyclopedia of Industrial
  Chemistry, Vol A20 pp439-451, VCH Publishers,
  Inc, 1992

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• 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

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• 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