Saftey of plasticizers in PVC tubing (DEHP)

[jermanimal]

I have been reading a little about DEHP that is a common plasticizer in PVC. PVC is normally rigid, adding a plasticizer like DEHP makes it flexible like in braided clear tubing you can get at hardware store.

DEHP isn't very good for you, FDA has banned it in medical devices because of over exposure from IV and other tubing, especially persons with kidney problems that need frequent transfusions.

Anyway there are alternative ways to make flexible PVC as the medical community has adopted as a standard and wondered if the FDA has outlawed the use in all flexible PVC that is for food use.

The temperature ratings for braided PVC are low, 70 degrees, but it physically works to pump around 170 degree water. I am curious if I am going to ingest a lot of DEHP.

I can only assume heating up the PVC causes it to leach more chemicals. Is the temp rating because it leaches more chemicals, or gets soft?

 

[BrewNinja1]

Temp ratings are for a temp and pressure. So it will be (im making this up) 170* @ 30 psi. So usually you can go higher psi at lower temps, or lower psi at higher temps. Has nothing to do with chemical leaching. Since its not food safe, they really dont have to care about that part of it.

 

[Walker]

I can only assume heating up the PVC causes it to leach more chemicals. Is the temp rating because it leaches more chemicals, or gets soft?

The temp rating is probably more of a physical issue with it getting soft, but I am not sure.

At any rate, it's a given that you do NOT want to use PVC for hot liquids that you indend to consume. For cold liquids, it's fine, but not for hot.

You never mentioned, but what exactly are you using the braided PVC for?

I've used braided pvc line for keg tap lines before, so that was at a temp of about 40-45*F. For anything hot, I use only silicone tubing, which is NFS rated and handles very high temps.

 

[jermanimal]

I was testing out a herms layout just moving water around, checking temps and seeing how much hi-temp stuff I should get. Our local shop has norprene tubing...fda approved for food up to 275 degrees. Was going to ultimatly use that, but need to justify the price.