Occupational exposure to antimony trioxide: a risk assessment

Area of Science:

• Toxicology
• Occupational Health
• Carcinogenesis

Background:

• The US National Toxicology Program (NTP) identified antimony trioxide as reasonably anticipated to be a human carcinogen.
• Sufficient evidence from animal studies and mechanistic data support its carcinogenic potential.

Purpose of the Study:

• To estimate the potential human cancer risk associated with occupational exposure to antimony trioxide.
• To quantify cancer risk under various workplace exposure scenarios.

Main Methods:

• Utilized data from NTP's 2-year inhalation studies in mice.
• Applied US Environmental Protection Agency (EPA) cancer dose-response models and benchmark dose methods.
• Estimated human cancer risk using typical and worst-case occupational exposure scenarios.

Main Results:

• Typical occupational exposure in flame retardant industries estimated a cancer risk of 0.025 (25 in 1000) over 40 years.
• Worst-case scenarios projected a cancer risk of 0.11 (110 in 1000) for similar workers.
• At the current Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL), the estimated cancer risk was 0.096 (96 in 1000).

Conclusions:

• Antimony trioxide exposure in certain occupational settings significantly increases cancer risk.
• Risk estimates highlight the need for stringent exposure controls in industries utilizing antimony trioxide.