DOP & DEHP

[polyman2999]

Hello all

is there is difference between DOP & DEHP ? and why DEHP used in manufacturing of medical PVC , not DOP ?

which plasticizer can be used in manufacturing of medical PVC ? and why ? and what is the rule ?

polyman

[Skip]

I'm not sure of the medical "approvals" of DOP and DEHP, but they are chemically different with respect to the alcohols that are "esterified" or reacted with phthalic anhydryde. DOP uses (I think) iso-octyl alcohol (a C-7 chain and a CH3 side branch), while DEHP uses "ethyl-hexyl alcohol", a C-6 chain with a CH3CH2- side branch.
I believe both have USFDA sanction for food contact/medical use???
Another version is DNOP, using a straight chain C8 octyl alcohol.

All are efficient, safe plasticizers for PVC!

[Louis]

Not sure if there are any rles as such, but the push is towards DEHP free vinyl extrusions.

[Len]

I'm not sure of the medical "approvals" of DOP and DEHP, but they are chemically different with respect to the alcohols that are "esterified" or reacted with phthalic anhydryde. DOP uses (I think) iso-octyl alcohol (a C-7 chain and a CH3 side branch), while DEHP uses "ethyl-hexyl alcohol", a C-6 chain with a CH3CH2- side branch.
I believe both have USFDA sanction for food contact/medical use???
Another version is DNOP, using a straight chain C8 octyl alcohol.

All are efficient, safe plasticizers for PVC!

Skip and all,

Unfortunately or not... The terms DOP and DEHP are used completely interchangably.
The following are all meta-substituted phthalates.
DIOP is the isooctyl phthalate. DNOP is the di-n-octyl phthalate. Di-Octyl-Phthalate or frequently called di-2-ethylhexyl phthalate are both called DOP. By the way DOP and 2EHP have the same CAS # 117-81-7, so be careful w/ those substitutions .

There was a DOIP (iso-phthalate, meta benzene ring position) plasticizer, but I think that's gone from the industry.

I believe the OXO alcohols are the same for DOP and 2EHP in practice. Technically you are correct, the di-octyl is a six chain alcohol w/ side branching that can include ethyl, but two methyl groups on the hexyl chain is also common, and other octyl-isomers might also be used in the OXO alcohol blend that is eventually reacted w/ phthalic anhydride to make these plasticizers.

This is the world as best as I can remember it (Rich Mullens)
Len
ps- happy new year