Re: Southern California Ruling on Cleaning Solvents

From: MICHELLE P WYATT 328-8537 (
Date: Thu May 28 1998 - 00:07:28 EEST


Please don't panic yet! As I have discussed previously, DuPont highly
recommends the use of propylene carbonate in cleaning the Somos(R) 7100 family
of resins. After reading your message, I called Huntsmen Chemicals, one of the
only manufacturers of propylene carbonate, and relayed your message and

They have tested the VOC using ASTM method D-2369 which is using the material in
an oven heated to ~110 C with air current moving at a specific rate over it.
The VOC in this instance was approximately 350 g/L. HOWEVER, they are calling
the board to ask what method needs to be used to test the VOC as a cleaning
solvent. No one in the stereolithography business is using propylene carbonate
to clean parts at 110 C. They are hoping that a different method can be used.
If a different one is not allowed, they are going to try for an exemption ruling
on propylene carbonate. Huntsmen Chemicals sells a lot of propylene carbonate
to California users for purposes other then stereolithography, and they have a
huge interest in making sure that propylene carbonate is approved for use under
this new ruling.

If they cannot get propylene carbonate approved, DuPont Somos(R) will exert a
lot of effort to find an alternative solvent. I have a huge advantage in
working with one of the largest chemical manufacturers in the world....

I will keep you posted....

Michelle Wyatt
Technical Marketing Engineer
DuPont Somos(R)
Two Penn's Way, Suite 401
New Castle, DE 19720
Tel: 302-328-8537
Fax: 302-328-5693

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