Flame retardants are chemical compounds incorporated into consumer products and materials to reduce the risk of fire and slow down the combustion. Flame retardants have received more attention when the fire accidents occur. Their use has grown by flammability regulations and standards.

Antimony trioxide (ATO, Sb2O3), one of the most economically flame retardant solution, has been known as synergist with halogenated flame retardants. The demand of ATO globally is driven by the development of innovative flame retardants due to the stringent fire safety regulations and standards. It is commonly used in building materials, electrical equipment, wire and cable, automotive parts, and household products including furniture and textiles.

Meanwhile, the carcinogenicity and health effects have become a main concern of the use of ATO. According to the United States Environmental Protection Agency (USEPA), ATO is identified as having high acute aquatic toxicity. In 1986, ATO has been included in California’s Proposition 65 list as a carcinogen. This listing requires businesses to provide the warning about significant exposure to Antimony trioxide that cause cancer.

The US National Toxicology Program (US Federal Department of Health and Human Services) published a Report on Carcinogens Monograph on Antimony Trioxide in October 2018. The 5,500 studies have been identified in this report. It can be concluded that “ATO reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity”. ATO tends to increase oxidative stress and damage, inhibit DNA damage repair, and cell differentiation.

CIERRA™ - FR has been developed as environmental and health friendly, non-halogen flame retardant to replace of ATO. The result shows that CIERRA™ - FR can substitute ATO dosage and maintain flame retardant property. CIERRA™ - FR has excellent compatibility with PVC system. This effective additive requires small loading to form denser char and decrease smoke release.

Photo: Steve Johnson on Unsplash

Washington State Department of Ecology, June 2015 “Flame Retardants A Report to the Legislature” https://fortress.wa.gov/ecy/publications/documents/1404047.pdf

US National Toxicology Program, 19 October 2018 “Report on Carcinogens Monograph on Antimony Trioxide” https://ntp.niehs.nih.gov/ntp/roc/monographs/antimony_final20181019_508.pdf

Pinfa News, 13 March 2019 “Regulatory pressure tightens on antimony (ATO)” https://www.pinfa.eu/mediaroom/regulatory-pressure-tightens-on-antimony-ato/

Keywords: ATO, Antimony trioxide, Flame Retardant, Proposition 65, Cacinogen