Naturally Occurring DEHP in PVC Tubing - Statements about tubing being DEHP-Free

chris1price

Trusted Information Resource
#1
Hi

I have been told that DEHP can occur naturally in PVC; making it difficult to make statements about tubing being DEHP-Free.

I think this very unlikely and can find no reference to it. Has anyone heard of this, and what level of DEHP might be present?

Chris
 
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somashekar

Staff member
Super Moderator
#2
Re: Naturally Occurring DEHP in PVC Tubing

Hi

I have been told that DEHP can occur naturally in PVC; making it difficult to make statements about tubing being DEHP-Free.

I think this very unlikely and can find no reference to it. Has anyone heard of this, and what level of DEHP might be present?

Chris
Have you had a chance to get the chemical analysis done of the raw PVC moulding granules from a third party lab ?
Anywhere between 5 to 45% of DEHP is an additive to make flexible PVC parts.
When someone says naturally occuring, do they mean that the additive is not from their process but PVC supplied blended for moulding the tubing, which obviously I guess is flexible ?
 

chris1price

Trusted Information Resource
#3
Re: Naturally Occurring DEHP in PVC Tubing

Hi
They are saying that the DEHP is not being added to the PVC at any stage, but it can be there as part of the original PVC chemical manufacturing process.

I actually think this is an excuse to avoid looking for genuinely DEHP-free tubing which is used by everyone else!

Chris
 

somashekar

Staff member
Super Moderator
#4
Re: Naturally Occurring DEHP in PVC Tubing

Hi
They are saying that the DEHP is not being added to the PVC at any stage, but it can be there as part of the original PVC chemical manufacturing process.

I actually think this is an excuse to avoid looking for genuinely DEHP-free tubing which is used by everyone else!

Chris
PVC raw material manufacturers offer both rigid PVC compounds and flexible PVC compounds in their range of materials. One must consult the compounder's TDS that is used in the tube making or check with the manufacturer about the specific tubing raw material in question to find if DEHP is an additive in it, and if so how much w/w %.
 

harry

Super Moderator
#5
Re: Naturally Occurring DEHP in PVC Tubing

Hi

I have been told that DEHP can occur naturally in PVC...................
I've read that it can occur under certain situations and in the presence of certain 'media' - but with no details quoted to back-up the claim. Assuming it is correct, it happens under very rare situations and the claim that it can happen in everyday used tubing sounds far fetch.
 
M

MIREGMGR

#6
There's no possibility of any phthalate synthesizing itself as part of the vinyl chloride polymerization process. Can't happen.

Certainly PVC resin could be contaminated during compounding or subsequent compound processing (extrusion, etc.) if run on machines that were not cleaned from the previous batch, which was phthalate plasticized. My understanding is that the industry norm, except for specialty makers, is not to clean such machinery between batches.

I'm told that for compounded, shape-processed flexible PVC to be phthalate free, it has to be run on lines that only process phthalate free materials.
 

Kales Veggie

People: The Vital Few
#7
Hi

I have been told that DEHP can occur naturally in PVC; making it difficult to make statements about tubing being DEHP-Free.

I think this very unlikely and can find no reference to it. Has anyone heard of this, and what level of DEHP might be present?

Chris
I am not sure if I understand this correctly. PVC is not a natural material, but man made. DEHP is not a natural material, it is man made.

Who told you this? Do you have a reference?
 
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