Which class is associated with toxic and infectious substances?

The correct answer relates to Class 6, which is specifically designated for toxic and infectious substances. This classification system is part of the United Nations' recommendations for the transport of dangerous goods.

Class 6 includes substances that can cause significant harm to living organisms or the environment upon exposure. This includes materials such as poisons or infectious agents that can cause diseases in humans or animals. The regulations surrounding this class are stringent because these substances pose serious health risks during transport and require careful handling and labeling.

Understanding the classifications of dangerous goods is essential in ensuring safety in transportation and handling. Therefore, distinguishing Class 6 as the category for toxic and infectious substances is crucial for compliance with safety protocols in shipping and handling materials that may endanger public health or safety.