nontoxicprint

by Debu Barve

illustration of a typical lapis lazuli or synthetic ultramarine

molecule (chromophore); natural and synthetic variants are considered

almost identical. Lapis (Lazurite / Azurite) is considered one of the most complex minerals 

found in nature.

GUIDE: 

black ---- Si4+ / Al3+   |    yellow --- Na+  |   green --- S3-

the abundance and surplus of sulfides is clearly visible,

and this accounts for the latent potential for toxicity

Seven samples of sds sheets from different manufacturers and countries (safety data sheet) for ultramarine pigment powder. Some give adequate information about hydrogen sulfide risks; most products and their sds sheets, however, especially by US vendors, do not include what we believe to be essential information.

LEAD: Some ultramarine pigment compositions also list lead as an ingredient ; lead is a catalyst and will exacerbate the risk of poisonous emissions during paint mixing.

Ultramarine Paint and Ammonia

Considering the real and present danger posed by ultramarine pigment powders, the question arises if ready mixed waterbased paints, such as ultramarine acrylics are safe or not. The many acrylic paint manufacturers not only assure us of the safety of the ultramarine paint tubes, but also invariable place a 'nontoxic' symbol on the tube.

Looking at the basic chemistry involved when adding water to ultramarine acrylic, however gives cause for possible concern. Almost all acrylic paints contain significant amounts of ammonia, and this can often be detected by smell. Some products even contain a large amount of ammonia, as any acrylic painter will testify.

The ultramarine chromophore molecule is largely constructed from aluminum and sodium atoms that create 'cages' within which large amounts of sulfide atoms are loosely trapped.

But both aluminum and sodium atoms are known to quickly dissolve in ammonia solution, possible in a heat-generating exothermic reaction. 

Given these basic facts, it seems highly likely that at least some kinds of acrylic paint (e.g. those with high ammonia concentrations) are likely to produce poisonous hydrogen sulfide emissions during paint mixing and application by the artist.

There are also anecdotal reports of artists working with large amounts of acrylic paint who became unconscious while working, which may well be consistent with undiagnosed hydrogen sulfide poisoning.

CAUTION IS ADVISED! 

Best, always wear a mask with 

active carbon filter and always 

ensure good ventilation.

Bio-resins and acrylics: 

Fast-paced Research into sustainable plastics

Research into bio-based acrylics and resins has recently gone past the R+D stage, and 

we can expect innovative polymer paint products for artists and decorating 

to become available within the next few years.

PHA -- Polyhydroxyalkanoate -- seems to be among the most promising base ingredients for truly eco-based polymer paints. Above is a listing of some of the key characteristics by the 

Lowell Center for Sustainable Production • University of Massachusetts Lowell 

This table is an Excerpt from:

https://ec.europa.eu/environment/aarhus/pdf/35/Annex_11_report_from_Lowell_Center.pdf

(excerpt from Wikipedia): Pigments and their History:

Minerals have been used as colorants since prehistoric times. Early humans used paint for aesthetic purposes such as body decoration. Pigments and paint grinding equipment believed to be between 350,000 and 400,000 years old have been reported in a cave at Twin Rivers, near Lusaka, Zambia. Ochre, iron oxide, was the first color of paint. A favored blue pigment was derived from lapis lazuli. Pigments based on minerals and clays often bear the name of the city or region where they were originally mined. 

Raw Sienna and Burnt Sienna came from Siena, Italy, while Raw Umber and Burnt Umber came from Umbria. These pigments were among the easiest to synthesize, and chemists created modern colors based on the originals. These were more consistent than colors mined from the original ore bodies, but the place names remained. Also found in many Paleolithic and Neolithic cave paintings are Red Ochre, anhydrous Fe2O3, and the hydrated Yellow Ochre (Fe2O3.H2O). Charcoal—or carbon black—has also been used as a black pigment since prehistoric times.

Synthetic pigments were introduced as early as the third or fourth millennium BCE. The first synthetic pigment is Egyptian blue (blue frit), calcium copper silicate CaCuSi4O10, made by heating a mixture of quartz sand, lime, a flux and a copper source, such as malachite. Already invented in the Predynastic Period of Egypt, its use became widespread by the 4th Dynasty. It was the blue pigment par excellence of Roman antiquity; its art technological traces vanished in the course of the Middle Ages until its rediscovery in the context of the Egyptian campaign and the excavations in Pompeii and Herculaneum.

Later premodern synthetic pigments include white lead (basic lead carbonate, (PbCO3)2Pb(OH)2), vermilion, verdigris, and lead-tin-yellow. Vermilion, a mercury sulfide, was originally made by grinding a powder of natural cinnabar. From the 17th century on, it was also synthesized from the elements. It was favored by old masters such as Titian. Indian yellow was once produced by collecting the urine of cattle that had been fed only mango leaves. Dutch and Flemish painters of the 17th and 18th centuries favored it for its luminescent qualities, and often used it to represent sunlight.

Since mango leaves are nutritionally inadequate for cattle, the practice of harvesting Indian yellow was eventually declared to be inhumane.[16] Modern hues of Indian yellow are made from synthetic pigments. Vermillion has been partially replaced in by cadmium reds.

Because of the cost of lapis lazuli, substitutes were often used. Prussian blue, the oldest modern synthetic pigment, was discovered by accident in 1704.By the early 19th century, synthetic and metallic blue pigments included French ultramarine, a synthetic form of lapis lazuli. 

Ultramarine was manufactured by treating aluminium silicate with sulfur. Various forms of Cobalt and Cerulean blue were also introduced. In the early 20th century, Phthalo Blue, a synthetic metallo-organic pigment was prepared. At the same time, Royal Blue, another name once given to tints produced from lapis lazuli, has evolved to signify a much lighter and brighter color, and is usually mixed from Phthalo Blue and titanium dioxide, or from inexpensive synthetic blue dyes.

The discovery in 1856 of mauveine, the first aniline dye, was a forerunner for the development of hundreds of synthetic dyes and pigments like azo and diazo compounds. These dyes ushered in the flourishing of organic chemistry, including systematic designs of colorants. The development of organic chemistry diminished the dependence on inorganic pigments.

Many artists think cadmium paints are relatively safe to use, unless accidentally ingested. Yet there is anecdotal evidence that it is not uncommon for professional artists to suffer the debilitating effects of cadmium poisoning, especially through long term use. 

in a test carried out by the company most artists felt the new cadmium 

free colors equaled or exceeded cadmium colors