Any idea why this petroleum jelly separates at room temperature?

YoungLiaYoungLia Member
edited July 2016 in Formulating
At room temperature (20-27C or 68-80F) somewhat we noted separation (liquid part exist) on my formulation which contain 95% USP petroleum jelly and 5% solids. We presume its from the petroleum jelly as we also noted liquid phase when we tried storing the petro jelly  at 25C or 77F.  
The manuf MSDS claims that the melting point is 45-60C or 113-140F.

What does the industry do with this kind of petro jelly to ensure homogeneity at room temperature? It will be problematic for packaging later on if it separates at room temperature...

Or should we throw this petro jelly to the bin and get a better one?
The one I've used is not the cheapest - USP grade and $15/kg!

I have also requested 5 other suppliers in a quest for different USP Petroleum Jelly, but can someone share something please? 
Anything I have to do before processing petro jelly or anything I need to look out for when purchasing petro jelly? Being all the same CAS number, experience counts I suppose. Anyone?

It also appear to me putting the Petroleum jelly through three roll mill ( to make my product) also makes more liquid phase at room temperature. Any thoughts?

Thanks heaps in adv.

Young Lia


Comments

  • PerryPerry Administrator, Professional Chemist
    Did you test the melting point?
  • BobzchemistBobzchemist Member, PCF student
     I wouldn't trust the MSDS very much. Did you get a Certificate of Analysis?

    Perry's right, as usual - you need to test the melting point range yourself.

    Also, "petroleum jelly" is almost always a homogeneous material, especially at room temperature - there should be no liquid present. So, it does sound like you may have been the target of deceitful practices. True petroleum jelly can be mimicked by a gelled mixture of mineral oil and waxes. This is much, much cheaper (for the supplier) than the real material is. Unfortunately, the gel can break down and release the mineral oil, and this is made much more apparent by shear, which is what you're seeing when you roller mill.

    I would recommend finding a different supplier.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • Yes, it was stored in a 25C/77F room, it gives out liquid phase. Other petroleum jelly on the test did not. 
    Did suspect some fishy business, because the item doesn't have batch number. Complaint, and got a replacement but batch number doesn't tally with the CoA. Thanks for the input.
     
    And yes, this experience add extra measures in validating raw material coming in.
    Cant believe some people still do this in their business. 

    Any other test I should do to validate the supplied Petroleum Jelly prior use?

  • chemicalmattchemicalmatt Member, Professional Chemist
    Young, I've found in most cases that petrolatum is the better material to use over petroleum jelly.  Ask for petrolatum white USP grade, never have a problem again.  Petroleum jelly, sometimes referred to as "mineral jelly", is indeed a mixture of mineral oil, paraffins and microcrystalline waxes, all from the same white oil cut from crude petroleum. Your supplier obviously did some black-art chemical mixing to produce something close to the commercial product, then took it to market.  $15 per kg! Man, I am SOOO in the wrong business.
  • BobzchemistBobzchemist Member, PCF student
    I totally missed that - I think of petrolatum and "petroleum jelly"  as two different names for the same product.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • Yes, I also think petrolatum and petroleum jelly is the same with the same CAS number. USP petrolatum is the USP petroleum jelly. BP/Ph Eur/JP are also equivalent to USP.
    The catch is USP or non USP petroleum have the same CAS number. 
  • Chemist77Chemist77 Member, PCF student
    Revelation for me as well, all this time I was happy treating them same. 
Sign In or Register to comment.