Introduction
Painting uses some extremely refined and concentrated substances in its craft. Paint is a material that may be composed of high concentrations of heavy metals that would concern people whom are committed to bio-ethics (for instance by supporting organic food and reducing their consumerism and use of plastics).
If we want to care for the Earth and ourselves, it is time to work toward creating a more comprehensive profile of eco-friendly materials, and preference those in our studio practice.
Building a Profile of Ecological Art Materials
We can define three aspects to consider when considering the environmental profile of a paint or painting material
1) Biotoxicity – Acute poisoning response on exposure to a toxic material. Or chronic exposure – one of the occupational hazards to a painter or art teacher.
For example : Cadmium Red paint. Cadmiun is a known carcinogen and endocrine disruptor. Cadmium is one of six substances banned by the European Union’s Restriction on Hazardous Substances (RoHS) directive. Yet dermal exposure (uptake through the skin) is generally not regarded to be of significance (Lauwerys 1988). Still, its unregulated sale means it may well find its way into situations where people are absorbing it through chronic occupational exposure.
2) Ecotoxicity – The detrimental effect a substance has on ecosystems as an environmental pollutant.
Zinc, titanium, cadmium, cobals, and the earths, are all mined. But there are degrees of mining impact. Take for instance titanium white compared to raw umber. Manufacture of Titanium white relies on large scale mineral sand mining, refining and processing, and results in a number of waste streams, including sulphuric acid and radioactive metal sulfates, each of which carries an environmental impact.
Raw umber requires very little processing for the painter. is an ambundant, cheap material, it is essentially a refined subsoil. There are huge quantities of it in the earths crust. Sometimes it is found exposed on the surface as veins in mountainsides and cliff-faces, sometimes riverbeds. The manner in which the pigment is ‘liberated’ from the rock will influence the ecotoxicity profile of the pigment.
3) Embodied Energy/Carbon – CO2 and other greenhouse gases, and includes emissions from all the extraction, transport and manufacturing processes required before products are ready at the factory for delivery to the customer
For example : Difficult to access information on this. We can however say that metals, then plastics, have significantly higher embodied energy than earth pigments.
By considering these 3 facets – then adding context, we may decide whether a material is bio-ethical.
Example Profile : Titanium Dioxide Oil Paint
Taking the commonly used Titanium Dioxide as an example, we can apply our three considerations to build a profile
Titanium Dioxide
Biotoxicity :
– Generally Recognized as Safe (GRAS) by the U.S. Food and Drug Administration.
– Different risk profiles depending on type of exposure (dust inhalation, dermal exposure, gastrointestinal consumption) and form of Titanium Dioxide.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3423755/
– Used as food additive in milk and bread. France banning Titanium Dioxide in food from 2020.
– Precautions advised. “The overall exposure of an average individual TiO2 NPs is not known; there are still opened questions regarding toxicokinetics and specific organ toxicity of TiO2 NPs, in particular at oral and dermal exposure, and thus it is impossible to make a reliable quantitative risk assessment.”
Ecotoxicity :
– Ilmenite or heavy metal sand mining is associated with Radionuclide-enriched water from the mine tailings finding their way into watercourses. “Rio Tinto’s Ilmenite mine in Madagascar has breached a legal buffer zone, exposing local people to “unacceptably high” environmental risks, a new study by the Andrew Lees Trust has found.”
– Emissions during manufacture including (depending on process) CO2, N2O, SO2, NOx CH4 and VOCs
– Raw materials are derived from scarce resources
Embodied Energy :
– High (54 – 76 MJ/kg)
_________________________________________
The Questions of Context and Relativity
Although Titanium Dioxide appears to be relatively non-toxic, the impacts, cumulatively, of mining Ilmenite, preparing with Sulphuric acid, and the C02 footprint involved in the entire process, make Titanium Dioxide seem unethical to use. But it is an almost indispensable paint in modern art.
How then do we quantify our bioethics in standpoint to using an ecotoxic substance? We must look at things in proportion. Although titanium dioxide paint may be one of the most concentrated forms of titanium dioxide available to the public, the fine art painter is using it in quantities that are very small compared to the painting-and-decorating in architecture, or the amounts of titanium dioxide pumped into bread and milk by the food industry.
In-fact the fine art painter only has many different colors available to them, because essentially they are available as byproducts of much vaster industries, such as plastic colorants.
Conclusions
Putting it Together Practically
I surveying the 3 facets – biotoxicity, ecotoxicity, embodied energy of Cadmium Red, by using the following search strings:
- Health risk cadmium
- Occupational risk cadmium
- Chronic Exposure cadmium
- Where is cadmium from
- How is cadmium mined
- Cadmium byproduct
- Cadmium embodied energy
I reached quickly the following conclusions:
- Cadmium is a known carcinogen and endocrine disruptor.
- Cadmium and zinc mining is associated with significant watercourse pollution.
- The nearest embodied energy assessment for cadmium I could find was 17 mega-joules per kilogram. This was surprisingly fairly low – lower than that of cast iron.
Would I consider replacing cadmium in my painting repertoire? What options would I have?
I could look at a paint manufacturers range in the art shop or online to find a paint that has optical resemblance of hue to cadmium red, then explore its behavior and properties. Because obviously any replacement has to outperform not only cadmium’s environmental profile but match it or exceed it in terms of other properties – such as its usability, cost and durability or ‘archivability’ – i.e its permanence.
Upon examination of neighboring pigments to Cadmium on various pigment color wheels, I honed in on Pyrrole Red (PR254). Pyrrole red is synthesized, not mined. It is currently considered non-toxic and therefore is a perfect alternative to cadmium reds. Pyrrole has equal opacity but is superior to cadmium especially for exterior application due to better resistance against strong UV light and moisture.
This kind of assessment can be used to weigh up the creation of a painters palette and begin the work toward a painters praxis of high bio-ethical standards. I will be updating with research on this as I make progress.
