Description/Application

  • In painting, a retarder is a medium used to slow the drying time of acrylic paints, giving more time for blending or highlights.
  • In printmaking, a retarder is a medium used to slow the drying time of printing ink to allow the printmaker to use the same batch of ink for an extended period of time without drying.

Resources

  • Different brands use different chemical compositions for their retarder recipes. A common ingredient is ammonia, in low quantities (1% or less). Another common ingredient is Propylene Glycol, a synthetic liquid substance that is petroleum based.

Environment

  • Environmental impact varies between each manufacturer and commonly include materials being “practically non-toxic to aquatic organisms”. 1
  • When retarder containing propylene glycol is allowed into the air, it requires one or two days for half of what is released to break down. When propylene glycol is mixed with water or soil, it requires a few days to a week to break down. 1

Human Health

  • Hazardous exposure to retarder depends on the brand used. Golden Acrylic’s Retarder MSDS  claims to have no impact on human health if used properly2, while Lascaux’s Retarder MSDS suggests that it can be damaging to health, due to more chemicals being present in their retarder formula. 3 Inhalation is the main route of exposure and can be problematic to painters and printmakers due to the close proximity of the artist to their work. 5 

Safe Use and Exposure

  • Wash areas exposed to retarder thoroughly after handling. Avoid eye and skin contact by wearing gloves and goggles. Inhaling fumes can be dangerous and a respirator may be used. Keep container closed when in use and upright to prevent leakage. Store in a cool, dry, place. 6

Proper disposal

  • To properly dispose, wipe up any excess or spilled retarder with a rag or towel and place in dry trash. Do not wash down drain. Solvents are not necessary for cleaning, soap and water should remove unwanted retarder from work area. 7 Contain a large spill with sand or other inert material and transfer to trash.

Safe Alternatives

  • Homemade retarder can be achieved made by mixing water and glycerol into paints. 8

Sources

  1. AKUA LIQUID PIGMENT – RETARDER MSDS, http://bit.ly/2gznyJb
  2. “Propylene Glycol”, ASTDR, http://bit.ly/2g6EmWQ
  3. Golden Paints MSDS, http://bit.ly/2gZ6RaD
  4. Lascaux Artist Acrylic Retarder MSDS, http://bit.ly/2gZ6XPx
  5. “Waterbased Silkscreen Printing”, Nontoxicprint, http://bit.ly/2ggY6KV
  6. Lascaux Artist Acrylic without Cadmium MSDS, http://bit.ly/2gzpeT9
  7. “Making acrylics dry slow. Any help, please?”, Wetcanvas.com, http://bit.ly/2gNddwa
  8. Golden Paints MSDS, http://bit.ly/2gZ6RaD