Before starting working within the new responsibilities
Explanation:
Training for new responsibilities are always provided before starting working within the new responsibilities so that we can perform the work efficiently without any mistake.
In a manufacturing site also if someone is transferred to a new site so, training regarding chemical hazards should beprovided before starting working within the new responsibilities so that the person can take all the safety measures before performing any work with chemicals otherwise it can be dangerous.
Hence, the correct answer is Èefore starting working within the new responsibilities
.