Toxicity of Watercolor Paints

Color chart showing a variety of colors from winsor and newton's cotman series watercolor.

Are you worried about toxins in watercolor paints? Terms like “cadmium” are not very reassuring to say the least. I decided to do some research to figure out how dangerous watercolor paints can be.


Pigments containing metals such as cadmium, mercury, and lead are toxic. However, you must consider how much is needed to actually kill you. If you mention any of these metals to a lay individual, you’ll get an emotive response – “That’s poisonous! You’ll die from touching that!”

dosis facit venenum

-Theophrastus Bombastus von Hohenheim

“The dose makes the poison.” This is a quote I clearly remember from my fourth year toxicology course.

Cadmium sulphide (CdS) is found in cadmium yellow. Its LD50 is 7080mg/kg (rat, oral) or 1166mg/kg (mouse, oral). The LD50 of a substance is the dose needed to kill half of the test population, indicating a substance’s acute toxicity. Hence, the higher the LD50, the less toxic it is. We don’t have the LD50 for humans because it would be unethical to test on humans of course. Doing some quick math (assuming an average human weighs 62kg)…You would need 438.96g or 72.292g (depending on which LD50 you use) of CdS to kill someone. That is A LOT of paint you would need to eat to kill yourself. That’s like eating 70+ tubes of paint.

Furthermore, CdS is an inorganic compound so it is in a state that is not bioaccessible. Getting a little bit of it on your hand is not too worrying. It would be a different story if you were to consume it as it would react with your stomach acid, but why would you want to eat paint anyway?

However, there’s still a lingering paranoia remaining anytime we deal with anything that even contains that word “toxic”. Is there still a possibility that they can still accumulate within your body in the long-term, and as a result cause harmful effects? I wouldn’t negate the possibility, but I also don’t want to stop painting anytime soon. Instead, let’s take some steps to keep the risks low. Or as I remember it from my first-year chemistry labs… MSDS and PPE – Material Safety Data Sheets and Personal Protective Equipment!




  • Don’t eat the paint (it’s not tasty or nutritious)
  • Don’t lick any of your brushes
  • Wash your hands after painting


  • Keep containers and tools specifically for painting
  • Don’t use things you eat or drink out of to hold your paints or paint water (Don’t make that mistake of drinking out of your paint mug!!)


  • Wear gloves and an apron if you don’t want the paint to contact your skin
  • Cover any cuts or open wounds
  • Proper ventilation and masks if anything is aerosolized/sprayed

Research (our most important step)

  • Each brand’s paints will vary in ingredients
  • Visit their websites’ healthy and safety section
  • Know what you’re working with and what pigments are in your paints (ask if you don’t know)
  • Check out our review of Mijello’s Mission Gold Watercolor Paints that tout their non-toxicity

Do your own due diligence and check the toxicity of your favorite colors. This material has been prepared for informational purposes only, and assume no liability for any inaccurate, delayed or incomplete information, nor for any actions taken in reliance thereon.

Please like and follow us!

Leave a Reply

Your email address will not be published. Required fields are marked *