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Re: [IP] plastics

Tara Dufour wrote:
> My mom is a nurse and brought up a concern she had when I told her I was
> getting the pump. She said they are currently questioning the plastics used
> in IV's and other medical soft plastics because of chemical found it soft
> plastic childrens toys.  Most of these toys using this type of plastic have
> been taken off the market until more research is done. Has anyone heard if
> the plastics used in the tubings and inserts for the pump are the same type
> of plastics used in these soft toys?

OK, Tara, I'm a plastics molding engineer (though in a whole different realm 
of plastics) and think I know what she's talking about. There is a lot of
about PVC plastics (which is Poly Vinyl Chloride, BTW). They are trying to ban
it's use in Europe, for instance.

Anyway, the pump hoses are made of 2 different plastics which are "co-extruded",
which keeps the 2 in separate layers. The outer layer is a more flexible plastic

To quote the information on MiniMed's webpage at:



It has long been known that polyolefin plastics have fewer binding sites, are
more resistant to carbon
dioxide penetration, and leach far fewer materials into solution than PVC
plastic. But polyolefin tubing
by itself is not satisfactory, since it is brittle and can kink or break easily.
By making a tubing with an
inner layer of polyolefin plastic, a middle bonding layer, and an outer layer of
PVC plastic for kink
resistance and strength, April and her team were able to combine the best
features of both plastics into
tough insulin-compatible "Polyfin" tubing. They also decided that Polyfin tubing
should not be sterilized
by gamma radiation, but by another process that does not affect compatibility. 

So, in short, the newer tubing noiw in use doesn't have this problem.

Ted Quick
email @ redacted
email @ redacted
Insulin Pumpers website http://www.insulin-pumpers.org/
for mail subscription assistance, contact: HELP@insulin-pumpers.org