Binders and Diluents
Toxicity of Solvents

Toxicity of Solvents
Solvents are found in a wide variety of art materials such as varnishes, fixatives, painting mediums, brush cleaners, and lacquer thinners as well as in solutions of synthetic resins, shellac, waxes, paint removers, and varnish removers. Painters should check the labels of the products that they use to find out if they contain toxic solvents such as benzene (benzol) or methyl alcohol (methanol). Some brands of industrial products such as paint removers, rubber cement, and cleaning fluids contain unsafe solvents. It is sometimes possible to choose a safer product in which a harmful solvent has been replaced by a less toxic material. The toxicity of the individual materials used as diluents or solvents is indicated in the description of each material [separate documents] [on pages 39-43 in book] and in the summary table [see document] [page 44 in the book]. [Kay, Reed. The Painters Guide to Studio Methods and Materials. Englewood Cliffs, NJ: Prentice-Hall, Inc., 1983. p. 43]

Summary - Precautions to be Taken While Using Solvents

1. Choose less dangerous solvents to replace more hazardous ones whenever possible. Never use benzene (benzol) or employ products in which it is an ingredient.

2. Keep the studio well ventilated by opening the windows.

3. Use an exhaust fan to expel toxic vapors and to draw in fresh air from another window.

4. When necessary, use a suitable respirator mask, approved by the Bureau of Mines or by NIOSH.

5. Keep covers on containers of solvents.

6. Remove rags and papers that have been soaked in oils or solvents from the studio building promptly.

7. Minimize the use of spray cans.

8. Protect the skin from solvents by using gloves. Wash hands with cleansing creams or soap and water rather than with solvents.

9. Respect the fire hazard of solvents. Do not allow smoking or an open flame in the studio area where solvents are kept.

[p. 46.]

Solvents and Skin Damage
When most solvents come in contact with the skin, they remove the protective oil that helps to keep normal skin healthy. This causes the skin to dry out and to be prone to blistering and cracking. When this happens, materials may more easily penetrate the skin, causing allergic responses or infections. As much as possible, artists should avoid getting solvents on their skin. Whenever they can, painters should clean their hands by using soap and water or a cleansing cream, rather than by dousing the skin with turpentine or other solvents. Barrier creams, applied before the painting sessions as directed by the manufacturer, may be helpful in reducing skin exposure to solvents and paint.

Plastic or rubber gloves can protect the painter's hands if they must come in contact with substantial amounts of solvent during the painting process itself. Inexpensive disposable gloves made of plastic can be bought from dealers in laboratory supplies. [pp. 45-46.]

Inhalation of Solvents
Solvents are a greater danger to the artist's health when they are used in a room that is not well ventilated. Whenever possible, a flow of fresh air should be kept coming into the studio to dissipate the effects of solvent fumes. An exhaust fan, either set into a window opening or vented through an outside wall, is the best system to change the room air. When the operation causing the fumes can be carried out in one area--for example, at a fixed location of a work bench--an exhaust system using an exhaust hood and fan to collect the fumes and diffuse them outside the studio is desirable. A source of fresh air to replace the air being exhausted is necessary for the efficient operation of any exhaust ventilation system. Such a system should be designed by a professional who is knowledgeable as to the principles of ventilation and can apply them to the specific studio hazard. It is important to design the system so that the artist does not get between the vapor source and the exhaust fan, where the fumes would actually be intensified.

Respirator masks can give artists important protection against vapors, provided that the mask selected is the correct one for the purpose. Some respirators are designed primarily for nuisance dusts, others for toxic dust particles, and others for chemical gases and fumes. Lists indicating appropriate models and brands of respirators can be obtained from various agencies of industrial safety, such as the National Institute for Occupational Safety and Health (NIOSH). In addition to respirator masks that contain filter cartridges to screen out toxic dust or poisonous gases, there are more elaborate air line respirators that provide filtered compressed air, pumped from an air compressor through a flexible hose line into a face mask.

Aside from equipment to protect the painter, other precautions can help to reduce the risk from solvent vapors. Solvents should be kept in tightly shut containers. Rags containing solvent should be discarded quickly. The practice of keeping large quantities of solvent in open, wide-mouth containers for cleaning brushes should be discouraged. A smaller brush-washing container that can be covered when it is not in actual use will do the job as well and will not allow as much solvent to evaporate into the studio air.

Spray cans should be used only when the effect desired by the artist cannot be obtained by any other means. A varnish applied by brush contains its solvent, as does varnish packaged in a spray can, but the spray can contain an aerosol propellent which is in some cases an additional health hazard. The spray may also distribute solvents and particles of resin or pigment more widely through the studio air, increasing the risk that the artist will inhale these materials. [p. 45.]

Fire Hazards
A solvent whose flash point is listed in the Table of Solvents and Thinners [see document] as being less than 70Á F. --that is, less than normal room temperature--should be considered a serious fire hazard. It should be remembered that temperatures in studios often rise to 80ÁF. or even more in the summer or in some overheated industrial buildings. In such cases a solvent whose flash point is within that higher range becomes a fire hazard. Artists should avoid storing large quantities of solvent in the studio. Flammable solvents should be kept in safety cans. There should be no smoking or open flames in the studio near open containers of solvents. A fire extinguisher kept in the studio should be of the type that is rated by Underwriters Laboratories (UL) as effective for flammable liquids, such as oils, gasoline, and paint solvents, as well as for combustible solids, such as paper, wood, and textiles, and for electrical fires.

Among the most flammable solvents are gasoline, benzene, and acetone. Their flash points are below 12ÁF. Only slightly less flammable is the group consisting of benzine, V.M. and P. naphtha, toluene, ethyl alcohol, methanol, and methyl ethyl ketone. All of these have flash points below a room temperature of 70ÁF. Turpentine, mineral spirits, xylene, and kerosene are less flammable, with flash points between 80ÁF. and 130ÁF.

Paint rags soaked in linseed oil and paint continue to absorb oxygen after they have been discarded in the studio. This oxidation process generates heat. If the rags are confined for a time in a limited space and the heat is not dissipated, they may get hot enough to start burning by spontaneous combustion. For this reason, oil-soaked rags should be removed from the studio each day, so that they do not become a fire hazard. [p. 46.]

[Kay, Reed. The Painter's Guide to Studio Methods and Materials. Englewood Cliffs, NJ: Prentice-Hall, Inc., 1983.]