Antimony (Sb) is a metalloid chemical element found naturally in minerals at low concentrations. Antimony is used in a number of industries, including the production of batteries and other metal alloys. Antimony is used as a catalyst in the production of polyesters. Antimony trioxide is used in combination with brominated flame retardants to increase fire resistance and is thus known as a flame retardant synergist.

The Healthy Stuff lab has measured antimony by XRF in many products made of polymers. The measured concentration level gives a clue as to its source:

  • Lower levels (150-700 ppm) are consistent with residual antimony from polyester polymerization. 
  • Higher levels (2,000-6,000 ppm) are consistent with flame retardant applications.

In either case, it is possible for antimony to be released from the plastic material (ATSDR 1995, Zhu 2016).


Health Effects

Depending on the chemical form and level of exposure:

  • Antimony trioxide is classified as a carcinogen in the state of California and has been listed as a possible human carcinogen by the International Agency for Research on Cancer and the European Union.

  • In long-term studies, animals that breathed very low levels of antimony had eye irritation, hair loss, lung damage, and heart problems (ATSDR 1995).

  • Higher levels of antimony have been shown to cause fertility problems and lung cancer in animals (ATSDR 1995).

  • Limited research indicates that antimony may weakly mimic naturally-occurring estrogen. The human health implications of this discovery are unknown (Choe 2003).

  • Workers exposed to antimony trioxide exhibit changes to their DNA (El Shanaway 2017). 



ATSDR. ToxFAQs™ for Antimony. Toxic Substances Portal (1995). 

Choe, S.Y. et al. Evaluation of estrogenicity of major heavy metals. Science of the Total Environment 312, 15–21 (2003).

Zhu, L. et al. Exposure Assessment of Sb2O3 in PET Food Contact Materials. Biomedical and Environmental Sciences 29(4), 305-313 (2016).  

El Shanawany, S. et al. The potential DNA toxic changes among workers exposed to antimony trioxide. Environ Sci Pollut Res Int. 24(13), 12455 (2017).

Published on September 27, 2016

IMPORTANT NOTE: ratings do not provide a measure of health risk or chemical exposure associated with any individual product, or any individual element or related chemical.