Tie back long hair. Refrigerate all chemicals. Label all test tubes and bottles correctly. Dispose of extinguished matches properly.
I gave my students this multiple choice question: Which of these is an important safety rule to follow when using chemicals?

Only one answer is correct among these 4 choices:
- Tie back long hair.
- Refrigerate all chemicals.
- Label all test tubes and bottles correctly.
- Dispose of extinguished matches properly.

Could you tell me which one is correct?

Label all test tubes and bottles correctly.