You must carry a mask with you when transporting which of the following?

When transporting chlorine, it is essential to carry a mask due to the hazardous nature of this chemical. Chlorine is a toxic gas that can cause serious health effects when inhaled, even at relatively low concentrations. The use of a mask provides a necessary level of respiratory protection for the individual handling or transporting the substance.

Chlorine can be released during transportation, either through a leak or accident, creating an immediate risk to not only the driver but also to those nearby. In such situations, having a mask readily available allows for prompt protective action. This is crucial to ensure safety and compliance with regulations surrounding the transportation of hazardous materials.

While the other substances listed—gasoline, paint, and poisonous solids—also pose risks, the specific requirement for a mask during the transport of chlorine is tied to its status as a gas that can pose acute inhalation hazards. This emphasizes the need for proper personal protective equipment when dealing with highly dangerous chemicals like chlorine.