Final answer:
The CEO, the head of security, and the laboratory supervisor must be notified in the event of a label error.
Step-by-step explanation:
In the event of a label error, the individuals who must be notified include the CEO, the head of security, and the laboratory supervisor. These individuals hold positions of authority and are responsible for ensuring the safety and wellbeing of the organization and its employees. The CEO is responsible for making critical decisions and providing overall guidance, while the head of security and the laboratory supervisor have direct oversight of safety protocols and procedures.