- Lacquer is a water resistant and glossy wood finish, produced synthetically, or with shellac. Shellac is secreted by the lac insect, an aphid native to India and Thailand, and was widely used before synthetic lacquer was invented. Shellac is FDA approved for food and pharmaceutical coatings. 1, 2
- Synthetic lacquers contain many petroleum derivatives, including epoxy, xylene, acetone, acetone derivatives and others. 3, 4 Natural shellac has been cultivated for centuries through the controlled spreading of the lac insect to new trees and harvesting of their resinous secretion. The secretion is scraped from trees, heated and filtered, and then dried into thin flakes. 1 Canned shellac contains shellac from the insect dissolved in ethanol and isopropyl alcohol. 5
- Petroleum products contribute to global warming and climate change. Synthetic lacquer is composed of solvents that are extremely toxic to aquatic life if released into the environment. 4, 6 Cultivation of natural shellac can damage plant life and agriculture if the insects spread excessively and drain sap from plants beyond the cultivation area. 7
- Fumes from both liquid shellac and synthetic lacquer can cause respiratory irritation, eye irritation, dizziness, and nausea. Long term exposure or overexposure can cause brain damage. Skin exposure causes irritation, and allows solvents to be absorbed into the body through the skin. 3, 5 Synthetic lacquer is suspected of causing cancer, and is generally more dangerous than shellac. 3 Lacquer is considered safe after it is completely cured. 8
- The organization PRADAN works to make lac rearing and cultivation a viable source of income for poor communities in eastern India. 9
Safe Use and Exposure
- Work outdoors, or in a well ventilated area with a crossbreeze. Wear a respirator. Never work in an area where others will be exposed to the fumes. Wear gloves to avoid skin exposure, and wash hands after use. After six months to three years, shellac expires and will need to be replaced. It will also spoil if it is heated above 75 degrees, so store in a cool place for best results. 1 Shellac is extremely flammable, and shellac-soaked rags are a fire hazard. Allow rags to dry completely before disposal. Do not smoke while working with shellac.
- Lacquers are a hazardous material. 10 At Pratt, lacquer can be disposed of in a sealed and labeled container in the hazardous waste bins. New York City residents can also dispose of lacquer at SAFE Disposal Events, which are held every few months. 11 Excess shellac can be allowed to evaporate in a safe and well ventilated area, and then disposed of in the regular trash. Donate usable material to the givetake.
- Choose shellac over synthetic lacquers that contain many toxic petroleum derivatives. Avoid products with CA 65 labels, which indicate carcinogenic contents.
- “The Story of Shellac”, The Natural Handyman, http://bit.ly/2g717ds
- “SHELLAC – A TRADITIONAL FINISH STILL YIELDS SUPERB RESULTS”, antiquerestorers.com, http://bit.ly/2gzuG8d
- MINWAX Clear Brushing Lacquer MSDS, http://thd.co/2hcUarW
- PARKS KITS 3PK GLOSS SUPER GLAZE 9/14/2012 PART A MSDS, http://thd.co/2h29Tvb
- BEYE QT 4PK CLEAR SHELLAC MSDS, http://thd.co/2g5YGN3
- “Cresyl Glycidyl Ether”, PubChem, http://bit.ly/2h2mcaK
- “Uses of lac insect in industries”, Chinese Jouranl of Entomology, Special Publication No. 5, http://bit.ly/2hcWX4u
- “Q & A: Is Polyurethane Food-Safe?”, Popular Woodworking Magazine, http://bit.ly/2he1QOL
- “Lac Cultivation”, Pradan, http://bit.ly/2hec2a1
- “Managing and Disposing of Household Hazardous Waste”, New York State Department of Environmental Conservation Division of Materials Management, http://on.ny.gov/2g6Pu5W
- “SAFE Disposal Events”, NYC Department of Sanitation, http://on.nyc.gov/1QQjDm0