In the next table we can see that mineral and natural paints are preferable to synthetic paints in terms of a lesser environmental impact. Their manufacture consumes fewer resources, and they are practically free of potentially harmful substances.

Mineral paints Natural paints Synthetic paints
Environmental impact According to a study of mineral paint manufacturers, the environmental impacts (energy consumption, emissions, waste) throughout the life cycle of silicate paints is 2 to 4 times lower than synthetic paints.1 The raw materials are derived from renewable resources - plant and animal sources. The industrial wastes biodegrade quickly, and many of them are compostable. Paints are manufactured using simple processes that do not require a lot of energy.

Although they are biodegradable, vegetable oils do not dissolve in water, so they can not be disposed of down the drain.
The use of petroleum products is associated with a number of problems: wars, climate change, oil spills, resource depletion...

Some industrial wastes are classified as dangerous and must be put into toxic waste storage sites, where they remain forever.
Durability Penetrates walls and bonds chemically to them (“petrifies”), to create an unbreakable bond. For this reason, as well as their breathability, or high vapor permeability, they are the longest lasting paints. Particularly silicate paints, which can last more than 25 years on some buildings (some painted with silicate paints over a century ago are still in perfect condition). Widely used for the protection of architectural heritage.

Lime paint does not last as long in high rainfall areas, and is particularly susceptible to acid rain, or being rubbed off, particularly in the case of in interiors such as corridors and stairwells.
It penetrates into walls and incorporates itself better than synthetic paints.

Highly vapor permeable.

Are anti-static, so walls get less dirty than with synthetic paints.
Contain large molecules that do not integrate into walls but form a layer over them. So it peels and cracks easier on exterior walls. Synthetic paints can last from 5 to 10 years on the exterior of a building.

Are less breathable paints because the film of paint obstructs the pores of the wall. That is why they are more susceptible to mold and can ruin walls. Although some synthetic paints are marketed as “breathable”, they are far less vapor permeable than those in other families of paints.

Generate static electricity, so they attract more dust to the walls. When heated, they soften, and dust sticks to it. It may need to be repainted sooner than if using another paint family.
Toxicity Many of the ingredients are corrosive, so direct contact with the skin will dry it out.

Have no volatile compounds (except for water). Do not release any toxic substances either during painting or afterwards; for this reason they don't cause problems for people with allergies or asthma.

Walls painted with them don't grow fungus, insect larvae, or bacteria; that is why they have been used to prevent the spread of disease.

In the event of fire, they do not burn or emit any toxic gases.
Either water or orange peel oil or other citrus oils can be used as a solvent. Vapors of orange peel oil can cause allergic reactions.

Natural paints do not use mineral pigments that are classified as dangerous.

Skin contact causes no problems.

The label usually contains the complete list of ingredients, so that you can see if there are any ingredients to which you are allergic.
The most toxic solvents (toluene, xylene) are gradually getting replaced by less noxious alternatives such as glycols. Glycols are less volatile, so that the paint smells less, but takes longer to evaporate, so solvents may be in the air for longer after painting. Paint thinners can get absorbed through the skin. Are harmful to aquatic ecosystems.

Some synthetic pigments are classified as carcinogens.

The remaining components of synthetic paints are mostly volatile petroleum distillates, with some degree of toxicity, particularly the antibacterial and antifungal agents. Some can cause allergies.

1. Trischler & Partner: Comparison of the environmental impacts of silicate paints and synthetic emulsion paints.