What action qualifies someone for a warrantless arrest for smelling a toxic vapor?

The correct answer relates to the concept of probable cause in the context of arrest laws. When a law enforcement officer detects the intentional act of someone smelling or purchasing a toxic vapor with the intent to get high, this behavior directly indicates that the individual is engaging in illegal activity related to substance abuse.

This intentionality establishes a clear basis for probable cause, which is a necessary standard for making a warrantless arrest. The act of attempting to intoxicate oneself demonstrates both awareness of the legality of their actions and a willingness to engage in illicit behavior, fulfilling the legal criteria for immediate intervention by law enforcement.

In contrast, the other scenarios do not indicate the same level of direct engagement with the illegal act. Possessing hazardous materials might not necessarily entail intent to misuse them. Similarly, merely witnessing someone else consume the substance does not provide sufficient grounds for an arrest, nor does being near a public disturbance caused by the vapor imply that an individual is directly involved in illegal activity. Therefore, the intentional act of smelling or purchasing the vapor establishes a clear link to the illegal act that justifies a warrantless arrest.