Not all plastics are created equal

Whilst many plastics are perfectly safe and oh so practical, there are some plastics which are potentially harmful when used in certain applications.  The following is a brief guide to common plastics, their symbols (not always included on products – in which case you are left guessing) and their properties.

  • Polyethylene (PET or PETE)
  • Common uses: water and soft drink bottles, peanut butter jars
  • Safety:  No known hazards

  • High density Polyethylene (HDPE),  the most-often recycled plastic
  • Common uses: milk, juice, water bottles, toiletries bottles
  • Safety:  No known hazards

  • Polyvinyl chloride (PVC)
  • Common uses:  juice bottles, cling film, PVC piping, garden hoses
  • Safety: phthalates may be added, refer below.

  • Low density polyethylene (LDPE)
  • Common uses: frozen food bags, squeezable bottles, cling films  
  • Safety: No known hazards

  • Polypropylene (PP)
  • Common uses: reusable microwave ware, bottle caps, yogurt containers, microwavable disposable takeaway containers
  • Safety: No known hazards

  • Polystyrene (PS)
  • Common uses: disposable cups, plates and cutlery, disposable take-away containers
  • Safety: FDA classified as safe for food packaging (despite extensive internet material suggesting potential health concerns)

  • Other plastics; This is a catch-all category that includes Polycarbonates (PC) and Acrylonitrile Butadiene Styrene (ABS)
  • Common uses: some baby bottles are made of Polycarbonate. Lego blocks and musical instruments such as recorders are made of ABS
  • Safety: Polycarbonate may contain Bisphenol A (BPA). ABS does not contain BPA.

    So what should you avoid?

    Bisphenol A (BPA) has been shown in some studies to be potentially harmful to health.  Whether these studies prove conclusive or not (health authorities in different countries currently take different views), high temperatures (e.g. microwaves) are believed to increase BPA leaching into container contents, and the harmful effects are believed to be most serious during early development, so it may be safest to avoid BPAs in items such as baby bottles. This means avoiding polycarbonate (type 7) and PVC (type 3).  However note that type 7 includes plastics other than polycarbonate, such as ABS, which does not contain BPAs.  Plastic types 1, 2, 4, 5 and 6 do not contain BPAs.  BPAs may also be present in metal cans which have a plastic lining e.g. infant formula.

    Canada has banned BPAs in baby bottles.  However the Food Standards Australia NZ article on BPA states “our dietary modelling shows that a 5 kg baby would need to drink around 80 bottles of formula a day every day for many years before it would get up to the safety limit.”  Analysis is ongoing with a further review being undertaken by the FDA, so the position is far from conclusive.  But when it’s your own baby, the Precautionary Principle always applies, right?

    Phthalates have been shown to be harmful to health in various studies as they interfere with hormones. Some PVCs, but not all, contain phthalates. Many countries restrict (see US Consumer Product Safety Improvement Act) or ban (e.g. see the European Directive) phthalates in specified goods, but not all countries.  High temperatures are believed to increase the risk of food contents being contaminated. Once again, if following the Precautionary Principle, it’s safest to avoid PVCs in certain items such as baby bottles, sippy cups, toys and teethers.


    3 responses to this post.

    1. Posted by gab on May 13, 2010 at 11:59 pm

      Hello Miss Sophie,

      Very interesting. I’m glad I don’t have to follow the Precautionary Principle that strictly these days!

      Something which may be of interest to you … either 5 or 6 (I can find out if you are interested) can be used in art, like the old Smiths Chips shrinkies. You write on them or paint them with appropriate paint, and then shrink them down in the oven. My friend Erin does it, and I must say she’s produced some quite creative stuff. Excellent entertainment for the munchkins.




    2. […] (good-looking, hard wearing, and heavy as with the possibility of a dodgy plastic liner) or a safe plastic (lightweight, recyclable, and pretty tough but are they […]


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