Hazardous Chemical Reactions in Art

By Michael McCann, PhD, CIH                  a thermite reaction (Wikipedia)

Many art materials are inherently hazardous, including toxic solvents and many metals, corrosive acids and alkalis, flammable solvents and combustible materials such as wood dust, and so forth.

 However, artists not only have to be concerned about the hazardous properties of their art materials, but also have to be concerned about hazardous chemical reactions that can occur.

These hazardous reactions can occur in two basic ways: first, many art processes result in the production of toxic chemicals or other hazards as by-products of the process; and, second, many art materials are incompatible with other chemicals and can create toxic chemicals if they are accidentally mixed.  In addition, some art materials are incompatible with heat, ultraviolet radiation, and other physical processes.  These decomposition products and incompatibilities should be listed in the Reactivity section of Material Safety Data Sheets.

Hazardous Art Processes

Many art processes such as acid etching, acid pickling, kiln firing, photographic developing, patina application, etc. involve chemical reactions to produce the desired effect.  However, these chemical reactions often produce other chemicals which are hazardous.  For example, nitric acid etching on zinc plates involves a chemical reaction in which the zinc metal is converted into soluble zinc ions, thus creating etched lines or areas in the parts of the plate that are not covered with acid-resistant grounds or resists. 

This same chemical reaction, however, also converts the nitric acid into nitrogen oxide gases, including nitrogen dioxide which can cause chemical pneumonia and emphysema.  Flammable hydrogen gas is also produced.  Thus there is the need for local exhaust ventilation to remove these unwanted gases.
Many art processes also create physical hazards such as noise, vibration, ultraviolet and infrared radiation.  In particular, glassblowing, metal melting, pottery and enameling kiln firing all produce infrared radiation and heat.  Arc welding, carbon arcs and neon sculptures produce ultraviolet radiation.
See Table 1 for a list of art processes and their hazardous chemical by-products.
Incompatible Art Materials

Acids, oxidizers, oxygen, heat and ultraviolet radiation are common examples of chemicals and physical agents that are often incompatible with art materials.  Acids can react with many chemicals.  Often artists take advantage of this to create a desired effect, for example, acid etching as described above. Often however, these reactions are not intended or desired and can create hazards. 

Acids,  for example, can react with ammonia and other alkalis to neutralize them.  This neutralization reaction produces large amounts of heat which can result in spattering of boiling acid and alkali.  Acids can also react with cyanides and other chemicals to produce poison gases (e.g., hydrogen cyanide).

Oxidizers are chemicals that can react with solvents, charcoal, wood dust, and other finely divided organic materials to cause a fire or explosion. Examples of strong oxidizers are concentrated nitric acid, dichromates and chromates, nitrates, and potassium chlorate.

Oxygen in the air can oxidize linseed oil (e.g. oil paints, intaglio and lithographic inks) and other organic oils and turpentine, releasing heat in the process.  If this heat can build up, for example a pile of oil-soaked rags in a corner, spontaneous combustion occurs resulting in a fire.

Heat and ultraviolet (UV) radiation are sources of energy that can react with many chemicals to decompose them.  Examples include the production of hydrogen cyanide gas from heating or exposing potassium ferricyanide (Farmer's Reducer) to ultraviolet radiation, and the production of acrolein, a strong respiratory irritant and allergic sensitizer, and other decomposition products from the overheating of wax.

Table 2 lists the incompatibilities of many common art materials.

It is important to store art materials safely so that they will not react with each other if there is an accident and they mix.  Incompatible chemicals should be stored separately to avoid this problem.  For example, oxidizers should be stored separately from other chemicals, particularly combustible ones.  Acids should be stored in a separate acid cabinet, with concentrated nitric acid stored separately from other acids.  In addition, materials such as zinc plates should be stored away from even dilute nitric acid solutions because of the risk of an unwanted chemical reaction occurring in case of spills.


Table 1.   

Chemical Reaction Hazards of  Art Processes

 Art Process       Art Materials Hazard   

Acid Etching

zinc, nitric acid Produces nitrogen dioxide and hydrogen gas. 

Dutch Mordant

Mixing hydrochloric acid and potassium chlorate produces chlorine gas.

Acid Pickling   
sulfuric acid, sodium bisulfate

Heating produces sulfur dioxide gas.

Batik wax

Overheating and ironing out wax creates acrolein and other decomposition products.

Cleanup rags, paper towels Oil, turpenting, lithotine or d-limonene soaked rags or paper towels can cause spontaneous combustion.

Fuel-fired furnaces and kilns, 
gas, wood, etc.
Produces carbon monoxide from incomplete combustion.


silver soldering : Fluorine-containing fluxes decompose to fluoride and hydrofluoric acid fumes.

Lost wax
castingwax burnout Produces acrolein and other decompostition products.

Photography  fixing bath

Decomposition of fixer

hypo and sodium bisulfate produces sulfur dioxide gas.

sulfide and sepia toning Produces hydrogen sulfide gas.

selenium toning Produces sulfur dioxide gas.

Plastics - sculpture

heating,machining plastics Produces decomposition including hydrogen cyanide from polyeurethanes, hydrogen chloride from polyvinyl chloride and methyl methacrylate from Plexiglas.


bisque firing Decomposition of impurities in clay produces carbon monoxide, sulfur dioxide, etc.
 salt firing
Decomposition of salt to hydrogen chloride resulting in hydrochloric acid.

Raku firing Smoke and carbon monoxide from reduction firing in sawdust, leaves, etc.

Stained glass soldering

Zinc chloride fluxes decompose to hydrochloric acid. Other fluxes also have hazardous decomposition products.
Welding arc welding Produces ozone and nitrogen dioxide.
Wood workingparticle board, plywood Machining decomposes formaldehyde-based glues to formaldehyde.


Table 2.  Incompatible Art Materials

 Art Materials   -     Uses    -    Incompatabilities   -    Hazard    

Acetic Acid   photography   
see Acids -Acids etching 

alkalais Neutralization of acid with alkali releases heat which can cause boiling.

Alkalais  cleaning
   acids   see above

Ammonium bichromate     dye mordant
 see Oxidizers -

Ammonium hydroxide patina     
  see Alkalis and Bleach,

household  -Ammonium nitrate   patina   heat; see also Oxidizers Flammable Ammonium persulfate photography see Oxidizers

Explosive Ammonium sulfide
patina   see Sulfides 

Ammonium thiocyanate    photography acids Forms hydrogen cyanide

Arsenic compounds    glassblowing
 old pigments 
acids, alkalis Forms arsine gas

Benzoyl peroxide   plastics 
see Peroxides -

Bichromates -   see Dichromates and Oxidizers

Bisulfites      photography acids Forms sulfur dioxide    

household photography
 acids  Forms chlorinegas
ammoniaForms poison gas

Chlorinated hydrocarbons  degreasers  
fabric cleaner 
heat, acids, UV Forms phosgene gas

Chromates   ceramics  
see Oxidizers -

Chromic acid cleaner   see Oxidizers -

Copper Nitrate patina     see Oxidizers -

Cyanides   photography
cleaning gold
 acids Forms hydrogen cyanide

Dichromates   lithography
  dye mordant 
see Oxidizers -

Dioxane film splicing   oxygen in air Forms explosive 
Ethers solvent oxygen in air Forms explosive peroxides

Ethylene dichloride solvent   see Chorinated hydrocarbons -

Ferric ferrocyanide     blueprinting acid, heat, UV Forms hydrogen cyanide

Ferric nitrate patina   see Oxidizers -

Hydrofluoric acid   glass etching
see Acids -

Hydrogen peroxide,   concentrated photography
see Oxidizers -

Lead chromate pigment 
  see Oxidizers -

Lye papermaking   see Alkalis -

Methyl chloroform solvent see Chlorinated hydrocarbons -

Methylene chloride paint remover   see Chlorinated hydrocarbons -

Methyl ethyl ketone    peroxide   plastic resin

see Peroxides,

explosive Nitrates patinas see Oxidizers -

Nitric acid, conc. intaglio see Oxidizers
  see Acids

Oxidizers - wood dust, solvents, organic material Flammable, explosive

Perchloroethylene   degreaser 
dry cleaning 
see Chlorinated hydrocarbons -

Periodates   cleaning
see Oxidizers -

Peroxides, organic plastic  
resin hardener 
heat Flammable, explosive
Phosphoric acid
lithography see Acids -

Potassium chlorate

hydrochloric acid
   see Oxidizers 
Produces chlorine gas

Potassium dichromate or bichromate
- see Dichromates  and Oxidizers

Potassium cyanide   gold cleaning
see Cyanides -

Potassium ferricyanide     photography
acids, heat, UV Forms hydrogen cyanide Potassium periodate - see Oxidizers -

Potassium permanganate   photography see Oxidizers -

Potassium persulfate   photography see Oxidizers -

Potassium sulfide   patina
see Sulfides -

Potassium thiocyanate   photography 
see Ammonium thiocyanate -

Selenium compounds photography  
stained glass 
 acids   Forms hydrogen selenide gas

Sepia toners    
photography acids Forms hydrogen sulfide

Sodium bisulfite     photography acids Forms sulfur dioxide

Sodium bisulfate pickling acids, heat Forms sulfur dioxide Sodium cyanide
- see Cyanides -

Sodium dichromate or bichromate
- see Oxidizers -

Sodium formaldehyde bisulfite   dyeing heat, acid Forms formaldehyde
Sodium hypochlorite
heat, acid Forms chlorine gas
 Sodium sulfide photography
see Sulfides -

  Forms hydrogen sulfide

Sodium sulfite
see Sulfites

Sulfites photography acid Form sulphur dioxide

Sulfuric acid   lithography
 see also Acids 
Forms sulfur dioxide

1, 1, 1-Trichloroethane
solvent see Chlorinated hydrocarbons -

Trichloroethylene degreaser see Chlorinated hydrocarbons -

Turpentine solvent oxygen in air Spontaneous combustion with rags

Zinc chromate pigment see Oxidizers -

Zinc sulfide pigment see Sulfides -

Art Hazard News, Volume 19, No. 4, 1996

This article was originally printed for Art Hazard News, © copyright Center for Safety in the Arts 1996. It appears on nontoxicprint courtesy of the Health in the Arts Program, University of Illinois at Chicago, who have curated a collection of these articles from their archive which are still relevant to artists today.