TiO₂ comes in many different forms. However, only a few of these forms are considered food-grade (acceptable to be added to food). Many studies that raised concern about the safety of TiO₂, including the concern for genotoxicity, used forms of TiO₂ that are not considered acceptable for use in food and have different properties than food-grade TiO₂. Other studies did use food-grade TiO₂, but took steps to break the material down into smaller particles than what would normally be found in food.

There's also evidence that inhaling titanium dioxide particles can be dangerous. That's mainly a concern for industrial workers. In places where it's produced, or where it's used to make other products, workers can breathe it in as a dust. The Occupational Health and Safety Administration has exposure standards manufacturers must meet.

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