Question

which is a precautionary measure? using a fire extinguisher to put out a flame wearing safety goggles while mixing chemicals

Explanation:

A precautionary measure is something done in advance to prevent harm. Wearing safety goggles while mixing chemicals is a precaution to prevent eye injury. Using a fire extinguisher to put out a flame is a corrective measure (done after the fire has started).

Answer:

wearing safety goggles while mixing chemicals