I have been grappling with this question for many years. This issue has a number of technical components that make it hard to explain easily. However, here are the components.
First, most people, other than industrial hygienists, find it extremely difficult to comprehend the measurements found in Section 8 of any Safety Data Sheet (SDS – previously referred to as MSDS) where the manufacturer states the threshold limits of exposure to a solvent. I covered this topic in a previous Syntax essay. See: https://www.syntaxofcolor.com/post/solvent-safety
Briefly, solvent danger is evaluated by the amount of accumulated exposure over an 8-hour work day. Remember, safety data is designed for industrial use, not specifically for artists. Some solvents evaporate rapidly and give off volatile organic compounds (VOC) at a rate that makes them reach toxic limits quickly. Thus, low threshold limit numbers indicate the solvent reaches dangerous levels rapidly. Higher threshold numbers relate to slower evaporation rates.
Regardless, all solvents release components that should not be inhaled repeatedly. What I find disturbing is solvents that have nearly or absolutely no odor. While that feature is great for not being bothered by nasty smelling solvents while painting, no odor solvents fail to provide your senses with any indication that you are in the presence of a solvent.
My point is that I see a number of artists who regularly have an open container of solvent in their studio space. Without any smell involved, it is easy to be complacent and leave the solvent container open or to even forget it is open after a day of painting indoors.
I am pondering the idea that manufacturers should add a non-toxic scent to solvents similar to how natural gas is scented to warn people of its presence. Natural gas is very dangerous to breath or to have a concentration of it indoors and the warning smell is critical in revealing its presence.
Similarly, any scientific workspace that uses radiation has safety protocols and lockouts that prevent accidental exposure to radiation. Like odorless mineral spirits, radiation is undetectable at low levels and is most definitely cumulative.
So, why not ask art materials manufacturers to figure out how to add a harmless scent that warns the user that they have either left a container of solvent exposed to air or they have used an amount of solvent while painting or cleaning brushes that is now airborne in enough of a quantity that approaches or exceeds a harmful level.
Some art material manufactures market solvents that have an extremely low evaporation rate. Hardware stores sell odorless mineral spirits that many artists use that not only contain mineral spirits but also contain traces of other more harmful solvent distillates. Cheap solvents are cheap because they are not as highly refined as more expensive distillates.
In nearly all cases, you get what you pay for. My concern is that odorless solvents don’t give the user any feedback that a dangerous quantity of VOC have accumulated in the workspace to serve as an indicator that the artist should do what they should have in the first place and set up proper ventilation and/or purchase a more refined, safer odorless solvent. Regardless, some odor indicator would be an added safety measure that would help artists.
I have no clue as to what smell could be added.It should not be pleasant, but neither should it be obnoxious.Perhaps you as readers of this essay can weigh in on the question if you agree that solvents should have a warning scent added to them.
The Syntax of Color