I have neglected this blog. I really have too many blogs. But then I have too many domain names (dot com, dot net, or in this case, dot biz). So what can be done, other than to add a new post to this blog? 😉
I am here to talk about PEL, or “Permissible Exposure Limit” of oil painting solvents, or in this case, Gamsol vs. Turpenoid brand odorless mineral spirits.
Among all my artist friends, Gamblin’s Gamsol has always seemed like the best, most safe odorless mineral spirit product out there. It had a higher flashpoint than competing products, and was “safer” to ship (due to this higher flashpoint). However, it’s still a mineral spirit, and as such is harmful if swallowed.
But now we have a new product. Turpenoid is now available in a new variation, “Turpenoid Light.” (See above picture, bottle on the right.)
After doing some research on this, it appears that the difference between Turpenoid Light and Gamsol is that Turpenoid Light has a higher flashpoint (200 degrees F) compared to Gamsol’s 145 degrees F.
The other detail is that Turpenoid (both regular Turpenoid as well as this new Turpenoid Light) has a PEL (Permissible Exposure Limit) of 500. (Higher is better.) Gamsol’s PEL is apparently 300.
From my understanding (which admittedly is limited) PEL pertains to how fast the solvent evaporates, and how much of the solvent’s harmful elements are in the air to possibly cause us harm after lengthy exposure. The slower the solvent evaporates, the less exposure we get to its vapor. So, the higher the PEL (slower evaporation) the better.
I’m not an expert on the technical issues of all of this, so I’ll not pretend to speak from any authority. You can download Gamblin’s document regarding Gamsol here (direct link to PDF file) where they explain more about PEL, as well as confirm that Gamsol’s PEL is 300.
I’ve used both Gamsol and regular Turpenoid, and found them both to be acceptable and very useful in my oil painting. Neither of them stink. They both seem to thin my paints equally well. I can use either and be happy. However, I love trying out new products, so of course I’ve ordered some bottles of Turpenoid Light! It seems like it’s going to be giving Gamsol a run for its money in both its diminished harmful effects as well as higher flashpoint. This is very exciting!
Of course, it must be said that neither Turpenoid Light or Gamsol are “harmless.” They are still solvents and shouldn’t be ingested. Lengthy exposure to their vapors could eventually create problems for some people.
Which brings us to Turpenoid Natural. It’s not actually an odorless mineral spirit, but some sort of weird concoction which will thin oil paint (I am leery about this part) and clean brushes. I use it as a semi-replacement for odorless mineral spirits. I’ll swish my brushes in a jar of Turpenoid Natural clean off the paint in my brushes. Then I’ll wipe off the brushes on a paper towel before starting to paint again, because I don’t want a lot of Turpenoid Natural in my paint mixtures.
If I plan on adding solvent to a paint mixture, I will dip my brush into odorless mineral spirits (like Gamsol, Turpenoid, etc) rather than using Turp Natural. Technically you’re “supposed” to be able to mix Turp Natural in your paints (but no more than 25% Turp Natural-to-paint ratio) but I don’t trust it. How long has this been tested? What are the long-term effects on the paint film? Turpenoid Natural has not been out that long. How can anyone know for sure?
However, Turpenoid Natural is an excellent alternative when you must work in an enclosed space (like in the Winter, where you don’t want to have windows open). You don’t have to worry as much about children or animals somehow getting exposed to it. You can use it in a poorly ventilated area with no concerns. It’s non-toxic, non-flammable. Just don’t mix any substantial amount in your paint!