Most inhalants are ordinary products you could pick up at a hardware store or supermarket. These include paint thinner, propane, gasoline, whipped cream cans, and bottles of glue. All of these products have strong chemical fumes that can be inhaled for the purpose of experiencing a strong feeling of euphoria.
Because they are so readily available, they are also easy to abuse. Inhalant abuse is especially common among teens and young adults. They likely already have these substances in their homes and want to know what it would be like to inhale the fumes.