From:
Monona Rossol <0000030664c37427-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject:
Re: [DCHAS-L] heavy metals in art studio paints
Date:
Feb 21, 2020 20:24 UTC
Reply-To:
ACS Division of Chemical Health and Safety
In-Reply-To:
Re: [DCHAS-L] heavy metals in art studio paints
Gamsol is still a solvent. When you do the calculations from the molecular weight of the Gamsol hydrocarbons also the nasty new Appendix Hydrocarbon mixtures, the TLV is 100 ppm. So they still need exhaust ventilation. It is just that it needs less than if they use other solvents. And hopefully you don't let them have turpentine with a TLV of 20 ppm. n that case, they need to work in a wind tunnel.
Monona
-----Original Message-----
From: James Saccardo <James.Saccardo**At_Symbol_Here**CSI.CUNY.EDU>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Sent: Fri, Feb 21, 2020 2:47 pm
Subject: Re: [DCHAS-L] heavy metals in art studio paints
Just to follow up with you, yes, they know they can work without thinners and they argue amongst themselves about it - Believe it or not, the one member who wants
to abstain from using thinners, however insists on the cadmium - you can't make this stuff up.
Of course the students will adapt as you so keenly point out, it the dinosaurs that will not and we are waiting for them to become extinct.
Either way, I will look into the Gamsol and Isopar X products as I am curious. Congrats on your ACGIH Committee appointment and thanks for your passion I this
subject matter. Have a great weekend,
James
From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
On Behalf Of Monona Rossol
Sent: Thursday, February 20, 2020 10:09 PM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] heavy metals in art studio paints
There are some techniques of painting with oils without using solvents. I think it is mentioned in the chapters I just sent you. They use very thin oils, and clean
brushes with soap and water or with the soap-like professional bush-cleaning products sold by art material manufacturers.
But all the major art material manufacturers now make lines of water-washable oil paints. They have modified linseed oil with -OH groups to make them easy to clean
up with water. Professors of art usually HATE these products because they actually have to modify their techniques a bit. But when you introduce them to students early, those students usually quickly learn to make them sing and once they do, they don't want
to switch to the smelly solvent processes.
They should be used because it is only a few school, mostly ones I did the specs for, that are set up with the displacement ventilation sufficient to safety oil paint
traditionally.
If they insist on using a thinner and slapping them down repeatedly doesn't deter them, then get them to switch to Gamsol or Isopar X solvents. This particular
petroleum distillate with a small amount of higher molecular weight hydrocarbon in it to slow the evaporation rate, makes it possible to use the lowest dilution ventilation rate. I'll run the number for you if you need to prove it. I usually show a powerpoint
to the faculty with the actual formula from the ACGIH manual of recommended practice when we are in the planning stages of a new or renovated building. The most important thing to show them is that the TLV is in the denominator and the Evaporation Rate is
in the numerator for the formula that generates the required cfm/pint.
But I use this ppt and its slides of good and bad ventilation systems to convince them they really need to change their ways in the new facility. And while we can
design ventilation to deal with ANYTHING, the cost of the ventilation systems, the energy lost in running them, and the immorality of teaching students to use unnecessarily dangerous and environmentally disastrous products is proven graphically in a way that
often gets a turn around among people famous for their recalcitrance.
Oh, that reminds me. On February 17, I was notified that I have been accepted as a Consultant to the ACGIH Industrial Ventilation Committee. I'm so looking forward
to this work.
