Do you paint a lot of miniatures? Many miniature painters lick their brushes (see here). I’ve been guilty of doing this, too, but less so now after thinking it might be dangerous in the long-term.
But, is licking your brush really bad for you?
The internet is all over the place on this topic. I hoped to clarify with some actual evidence (hint: there isn’t much) to determine if brush licking during miniature painting is bad for you (see disclaimer at the end of the article).
(Other related reading: saliva bad or good for sable brushes?)
Summary: Accidental oral consumption of acrylic miniature paints labeled non-toxic by major company brands via brush licking may be safe.**
If you want to know more about how we reached this opinion, read on.
Let’s define toxicity….
To understand the potential danger (or non-danger) of brush licking, we should know the definition of a toxin.
A toxin is any chemical that alters the normal function of an organism.
In our case, what we really want to know is if licking our brushes with some paint on it will make us seriously ill or lead to your death.
The medical definition of toxicity is straight-forward:
“Medical Definition of Toxicity (LD50): the amount of a toxic agent (as a poison, virus, or radiation) that is sufficient to kill 50 percent of a population of animals [or humans] usually within a certain time— called also median lethal dose.” (source 1 or source 2)
Toxicity is measured as an LD50, or a lethal dose that can kill 50% of persons that are exposed to the agent. In this case, we’re talking about paint that’s on a brush in our mouth. We are concerned with toxicity through an oral route.
An important point we can make based on this legal definition of toxicity is that toxicity is dose-dependent, or how much of the chemical a person is exposed to. Dose is listed as an amount per body weight.
For example, to understand if coffee is dangerous because of the caffeine it contains, we would need to understand the toxicity of caffeine. The LD50 or lethal dose of caffeine (not the coffee itself) is ~150–200mg of caffeine per kilogram (kg) of body mass. Without going into all the mathematical steps (i.e., body weight calculations, average caffeine in a cup of coffee, etc.), this data means that you would need to drink more than 50-100 cups of regular coffee to approach a toxic level of caffeine consumption (source).
But, why are my paints labeled as “non-toxic”?
True. Many acrylic paints designed for miniature painting are labeled as non-toxic. This includes the most popular miniature paints produced and sold by Games Workshop (Citadel Paint), Privateer Press (P3 Paint) Vallejo, Scale 75, and Reaper Miniatures (Master Series Paint, MSP).
However, let’s read the legal definition of what the non-toxic label means in the United States:
Nontoxic materials are not considered to be harmful or destructive to human health. It is to be noted that at some level, every substance is toxic. Therefore, the toxicity must be evaluated in terms of quantity of material. If the quantity of a substance that causes harm is less, its toxicity is determined to be higher (source).
This basically means that acrylic paints for miniatures that have the label “non-toxic” can still be harmful. The risk for harm is based on how much you’re exposed to.
Overall, in the course of normal handling of non-toxic paint, e.g., painting a mini, where some paint might get on your skin, acrylic paints are considered legally safe.
However, the non-toxic label does not account for non-intended uses, such as oral consumption through brush licking.
What is the oral dose of paint required to kill a miniature painter?
Companies who manufacture and distribute acrylic paint products label them as non-toxic base this term on “normal-use”. It is fair to say that paint brush licking falls outside the normal-intended use defined by legal standards.
For an interesting article on historically dangerous brush-licking, visit here.
Let’s dig deeper into the painting dose required to hurt you if you actually consume paint through licking your brush.
To do this, we can look up the Safety Data Sheets (SDS) provided for acrylic paints. Note that not every company provides these to the public through online sources.
Games Workshop, Scale 75, Privateer Press, and Reaper Miniatures do not have their SDS sheets available on the internet. But, it should be possible to get these SDS documents from these companies by contacting them directly.
By law in many countries, companies must make their product safety information, e.g., MSDS or SDS, available to consumers upon request.
Any acrylic paint that contains toxic chemicals purchased in the United States (or other developed country) will have it marked on its label or box.
Games Workshop, Scale 75, and Reaper Miniatures list almost all of their paint lines as non-toxic. Games Workshop states for its line of Citadel paint that: “All of our paints are non-toxic, water-based acrylic that are designed for use on plastic, metal, and resin Citadel miniatures.”
Vallejo is the only company of the major brands that provides an easily accessed safety listing online with SDS documents of their paint lines (see safety info here).
An Opinion Based on Limited Data
To form an opinion on the topic of paint lethality, we will use the SDS LD50 safety information from one line of Vallejo paint to understand if brush licking yields any immediate lethal risk for a miniature painter.
To formulate an opinion using limited data, we must make assumptions.** For example, if all paint lines are the same formulation as Vallejo (same ingredients, such as pigments, mediums, flow improvers, etc.), then it is possible extrapolate these data and findings to the other paint brands.
Vallejo lists their safety information conveniently on their website (here). They have a listing of all their paint lines, including Vallejo Model Color, Game Color, Metallic Color, and many others.
If we pull the Model Color, Game Color, and Metallic Color SDS sheets and look at the toxicology information, this is what we get:
- Model Color = LD50 oral > 5000 mg/kg (rat)
- Game Color = LD50 oral > 2000 mg/kg (rat)
- Metallic Color = “toxicological properties…is not available.”
Model Color Paint is “less toxic” than Game Color for brush licking, because you need to consume more Model Color paint to reach its LD50. Now, when we say less toxic, we mean it has a higher dose threshold for risk (5000 versus 2000 mg/kg). Of course, the toxicology data is based on studies in rats of oral consumption, but we might expect this to be same for humans (source).
Vallejo Metallic Color paints have no toxicology information. This is kind of a warning sign that metallic paints, in general, may have hidden risks that we can’t speculate about because we don’t have enough data.
As we stated earlier, all of this data means that if you lick your brushes you’re likely not going to die in a single sitting. You can’t consume enough paint to reach the dose threshold for acutely lethal effects on your body.**
Okay, so how much paint can I lick (lethal dose in a single sitting)?
Let’s take Vallejo Game Color, which has an oral LD50 of 2000mg/kg (in rat or human). An average adult rat has a body mass of about 350 grams (or close to 0.35 kg). An average adult human male or female has a body mass of 70kg (154 lbs) (source). If we do the calculations (not all shown here), a human would need to consume about 140 grams of Vallejo Game Color paint.
A typical bottle of Vallejo Game Color paint is about 17 ml liquid volume (or 26.5 grams of paint, if we calculate using the density of Vallejo Black Game Color paint – see SDS).
So, for you to have a 50% risk of dying from Vallejo Black Game Color Paint, you would need to consume via brush licking more than ~5 bottles in less than 24 hours (e.g., acute toxicity).
And, this is if you weighed 70 kilograms. If you weigh more, you could reasonably consume more than this estimate before getting to lethal levels of paint consumption.
If you are concerned with safety, please do the research and form your own opinion.
This article only discusses the question of brush licking or paint consumption through an oral route in the acute setting.
In addition to using the LD50 values from the product SDS documents, there are other potential hazardous implications. But, I have not detailed these here for lack of available safety information.
Importantly, the chemicals you need to avoid consuming that could be in acrylic paint brands include chromium, cadmium, cobalt, manganese, and lead. Note that cadmium and cobalt are also parts of the names of paint colors, e.g., cobalt blue. Acrylic paints should not contain these chemicals if they carry a non-toxic label. In addition, there are other volatile substances in paint that may pose a serious hazard (check for yourself here and here).
The lack of dangerous health implication data suggests that you should speculate on safety with caution.
To the question whether brush-licking in typical miniature acrylic painting is dangerous, the answer is scientifically “unclear”.
The article is an opinion of safety risk associated with brush licking. There are many other risky behaviors and chemicals we would be more concerned with in the miniature painting hobby (e.g., airbrushing in an enclosed space, paint thinners, aerosol primers, enamel varnishes), which carry explicit warnings. Ultimately, whether or not to engage in a particular hobby activity is a personal choice.
Non-toxic labeled acrylic paints formulated for miniature painting are likely safe if you accidentally consume paint from brush licking.
Lick your brushes at your own risk.
This article is an opinion-piece based on Vallejo paint SDS LD50 information that is available on the internet. The author extrapolated data to other paint brands on assumption that non-toxic labeled paints carry similar lethal toxic risk. This assumption excludes the possibility that other brands of acrylic paint may have different acute lethal toxicology risks, e.g., LD50 levels.
The article also forms an opinion specifically regarding the question of toxicity issues related to brush licking and accidental acrylic paint consumption through an oral route and only in the acute setting (e.g., total concentration consumed in no more than 24 hours).
There is no data available to assess the potential chronic toxicity or cumulative hazards associated with long-term brush-licking. Additionally, this article does not account for purposeful misuse of paint outside its intended-use, prolonged exposure to acrylic paint on any external or internal part of the body, or the actual oral consumption of acrylic paint labeled “non-toxic”.
There is also not enough scientific evidence to conclude a rigorous safety determination of brush licking due to a lack of evidence across several other dangerous health implications associated with acrylic paint exposure: These include: 1) ingestion, 2) inhalation, 3) contact with skin or eyes, 4) CMR (i.e., carcinogenicity, mutagenicity, and reproductive toxic effects), 5) sensitizing effects, 6) specific target organ toxicity (STOT) due to acute or chronic exposure, and 7) aspiration hazard.
If you have any questions or would like to leave feedback about the content of this article, please leave me a comment below or send a message.