Many artists have questions about solvent safety. Solvents are used to thin oil paints for creating a wash if you wish to tone a canvas, for a thin underpainting or drawing layer or to break down stiff brands of paint. Solvents are also used as part of many oil painting mediums and to clean brushes used for oil or enamel painting. There are a few types to choose from, including those intended to be kinder to the environment and you. There are three main groups of solvents: white spirit (both the fast evaporating, strong smelling kind and the slow evaporating, low-odour kind), turpentine, and citrus and other plant derived solvents. Below is a description of how they differ and the variants found within each group. Our Solvent Safety Table shown below is a simple reference guide to help clarify the differences between the solvents that we sell but it always pays to employ a little common sense when working with any solvent. Outside of water, there are no totally safe solvents, though there are some that are significantly safer than others.
Some artists have a physical reaction (headache, nausea, etc) to one solvent but not another. If you are having trouble with one you might wish to try another. I get headaches from regular Mineral Spirits and even have to take care to keep my odourless mineral spirits covered. Other artists are sensitive to the smell of turpentine, but I am fine with genuine turps. I also like Oil of Spike Lavender (it is a strong solvent that only takes a small amount to paint with) and I don’t find it smells very strong but visitors to my studio vary in sensitivity to it – some say it is strong but like it, some don’t notice it much but others find it overpowering. So maybe don’t use it if you are expecting a visit from a curator. If you are bothered by all solvents you can still paint with oils without using any solvents by using Solvent-Free mediums or a drying oil and washing your brushes with first safflower oil and then soap. Or you could switch to Water-mixable oils or slow-drying acrylics which act more like oils than regular acrylics.
Here are descriptions of the major solvents used in oil painting:
White spirit is a petroleum distillate, either a light or heavy naphtha that is generally grouped into four types. It is most commonly known as mineral spirits in the US/Canada, and mineral turpentine in Australia and New Zealand. Sometimes it is also called turpentine substitute, petroleum spirits or paint thinner. If you come across a solvent that has the word ‘mineral’ in its name, it is most likely to be a petroleum distillate, as opposed to a genuine turpentine (which is a distillate from a tree resin). Artist white spirit can be used in painting mediums and to clean brushes. All forms of artist white spirit, including low-odour solvents, are more pleasant to use than the cheaper household white spirit that is found in your local DIY store. This is because they don’t smell as much and are purer, with less of a mix of hydrocarbons, and no recycled matter in their formulae. This is also important for your painting mediums too because it doesn’t contain the impurities that may be found in household white spirit, artist white spirit can thin paint without causing yellowing or the cracking of paint in years to come.
Artist white spirits are effective when thinning or cleaning synthetically derived oil painting mediums, such as alkyd resin, but are less effective for breaking down natural resins such as copal, mastic or dammar for some oil mediums – you will need gum turpentine, oil of spike lavender or in some cases a citrus solvent to do this.
White spirit is mainly classed as an irritant for short-term exposure to skin or inhalation. The real problem is exposure over many years to an average enclosed-space concentration for breathing – it can lead to chronic negative central nervous system effects. Long-term skin contact can result in severe skin irritation.
White spirits have a characteristic unpleasant kerosene-like odour. Chemical manufacturers have developed a low odour version of white spirits which contains less of the highly volatile shorter hydrocarbons. Odourless mineral spirits are white spirits that have been further refined to “remove the more toxic aromatic compounds, and are recommended for applications such as oil painting, where humans have close contact with the solvent” (according to Recochem inc). Low-odour Solvents and Odourless Mineral Spirits (OMS) such as Gamsol, Low Odour Solvent, Sansodor and Shellsol T are slow to evaporate. This makes them less hazardous in the studio and a pot of Gamsol for cleaning brushes can last a long while. But some artists find the slow evaporation a drawback when painting. The low-odour solvents can be grouped with the citrus solvents for some uses – for example neither can be used to dilute Golden MSA Varnishes, the varnish turns cloudy or thickens to a goo – but genuine turpentine or white spirit works well for a smooth dilution. This test shows that the removal of the aromatic compounds changes white spirit significantly, not just in odour. Most artists find them not strong of ‘bite’, they are a more gentle disolvant.
Turpentine is also sometimes called spirit of turpentine or oil of turpentine. It is slightly more viscous than white spirit, and is obtained through the distillation of resin obtained from a few types of pine trees. The bark of the tree is removed in order for it to secrete oleoresin onto the surface of the wound to seal the opening. The oleoresin collected can be evaporated by steam distillation in a copper still. Turpentine made from the sap of a living tree is called gum turpentine. It is the strongest and the highest quality. Only gum turpentine will dissolve resins like damar resin for making mediums and varnish. Lower grade turpentines are made from the distillation of liquids derived from forest waste, which can come from a number of different types of pine trees, stumps and sawdust. Household turpentine from a hardware store is likely to leave a gum residue that may prevent your painting from fully drying or can cause yellowing to occur over time. These can still be purified to a point where they are suitable for oil painting, but they will not be made purely from one kind of tree so will vary in behaviour, may have a less pleasant fragrance and will not dissolve resins.
Turpentine that has undergone the greatest purification treatments will have greater solvency, and will dry fully without yellowing. For that reason it is best to use artist quality turpentine that states that it has been triple distilled (that is the meaning of ‘English Distilled’). The more distilled the turpentine the faster it will dry. The highest quality turpentine (such as our English Distilled Turpentine) will have what many find to be a pleasant pine fragrance.
Turpentine is the fastest drying of the solvents so many artists prefer it as it gives a nice brush drag (instead of it being too slippery) and their underpainting will dry quickly. This speed of drying comes from its fast evaporation, so it is important to have good ventilation and to cover your container quickly. Artists who prefer genuine turps also report that turps ‘bites’ the paint better than OMS, it doesn’t take much to break a stiff paint down to a fluid paint. (Be aware that resin from the larch tree is sold as Larch Venice Turpentine, but in spite of the name it is not a solvent, it is used as the resin component in some oil mediums.) Turpentine is flammable and emits vapours that can irritate the skin and eyes and damage the lungs.
Citrus and other plant based solvents
There are now a number of citrus-scented turpentines available, such as Zest-It, Seville Citrus Turpentine and Studio Safe citrus solvent. Most are closer to turpentine than petroleum distillate in their uses, and can dilute natural resins such as copal, mastic and dammar. They reduce residue and are a great solvent to use both in cleaning up and for thinning oil paints and mediums. These have a low flash point so are many times considered safe for plane travel, but check with your airline first. As always, remember that when something is labelled as ‘non-toxic’ that only covers it’s expected normal use, so it is not non-toxic to ingest for example. Zest-it make two versions of their oil paint solvents – the original dilutent and the citrus-free solvent. I am not sure which group the Zest-it Solvent (Citrus Free) belongs in – it has a much stronger bite than OMS but it is not a citrus solvent.
Oil of Spike Lavender is another popular solvent — it is slower drying than turpentine and has a very strong bite so a little goes a long way. I find that Oil of Spike is strong smelling but the smell is not bothersome to me, but other people think it is an overpowering smell, so you will need to see how it works in your studio. The green label Turpenoid is a good brush cleaner but is not suitable as a paint thinner, most artists report that the paint never dries. The blue label Turpenoid works well to thin oil paints.
Ten Point Oil Paint Solvent Safety Guide
- Always read the warning label on any product you use.
- Always store your solvent in its original container. There’s no guarantee that anything else won’t be broken down by the solvent! Never pour your solvent into an empty drinks bottle, for obvious reasons.
- Always make sure your container of solvent is clearly labelled.
- Always keep oil solvents out of reach of children and animals, and never leave them out and unattended.
- Always keep solvents away from food.
- Always keep solvents away from cookers, heaters and fires. Most are combustible!
- Always work in a well ventilated room to avoid dizziness, lightheadedness and headaches, as well as respiratory issues. Low odour solvents evaporate more slowly so there should be less in the air. Also close your container as soon as you can to minimise its evaporation into the air.
- Wear gloves when possible. Allowing solvents to remove the natural oils on your skin (letting it dry your skin out) leaves your skin without the natural sealant of a layer of oil. Without that barrier it is then vulnerable to absorbing toxins. So gloves or a barrier cream are a must to keep solvent from contacting your skin. Also wear safety goggles or other protective clothing if you’re splashing it around!
- Wash your skin with warm soapy water soon after exposure to solvents to avoid any irritation.
- Dispose of solvents properly. Contact your local authority waste management office for advice and never pour them down the sink!
Solvent Safety Table
Here is a PDF version to print for your studio:
Jackson’s Solvent Safety Table
Solvents available on the Jackson’s Art website
Artist White Spirit
Winsor & Newton White Spirit
Low Odour and Odourless Solvent
Jackson’s Shellsol T Odourless Solvent
Wallace Seymour Shellsol T – Low-odour Mineral Solvent
Gamsol Odourless Mineral Spirit
Daler-Rowney Low Odour Thinner
Sansodor Low Odour Solvent
Jackson’s Low Odour Solvent
Jackson’s Pure Turpentine
Jackson’s English Distilled Turpentine
Winsor & Newton English Distilled Turpentine
Roberson Rectified Turpentine
Rustin’s Pure Turpentine
Citrus Solvent and Oil of Spike Lavender
Zest-It Oil Paint Dilutant (Their original solvent.)
Zest-it Solvent (Citrus Free) (Their strong odourless solvent. It is not citrus but it is a much stronger solvent than the low-odour/odourless solvents so I put it in this group.)
Wallace Seymour Seville Citrus Turpentine
Roberson Studio Safe Orange Solvent
Lefranc and Bourgeois Oil of Spike Lavender.
Chelsea Classical Studio Oil Of Spike Lavender Solvent
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