Personal Protective Equipment (PPE) Good Work Practices; Disposal and Storage; Hazard Summary. Hydrofluoric acid (HF) and Hydrogen Fluoride (HF) are very poisonous, highly irritating and corrosive.

Hydrofluoric acid, when exposed to the air, can create a toxic ground-hugging cloud that can move on the wind and injure or kill those in its path, causing damage to bones and tissue.

As regulators pointed out, the explosion in 2015 did not directly involve hydrofluoric acid but that debris came close to hitting tanks with the chemical inside.